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. 2025 Nov 9;63(1):800–818. doi: 10.1080/13880209.2025.2583832

From Vision to Reality: Five Years of the Botanical Safety Consortium

Constance A Mitchell a,, Amy L Roe b, Scott Auerbach c, Cécile Bascoul d, Michelle Embry a, Stephen Ferguson c, Stefan Gafner e, Matthias Gossmann f, Bill J Gurley g, Holly Johnson h, Olaf Kelber i, Julie Krzykwa a, Jacob Larson j, Yitong Liu k, Catherine Mahony l, Andre Monteiro da Rocha m, Stefan Pfuhler l, Vincent Sica l, Suramya Waidyanatha c, Remco H S Westerink n, Kristine Witt o, Hellen Oketch-Rabah p, Cynthia Rider c
PMCID: PMC12604121  PMID: 41208233

Abstract

Context

Botanicals, including products derived from plants, fungi, and algae, are increasingly consumed worldwide. Their complex compositions and variable phytochemical profiles present significant challenges for safety assessment. Traditional toxicology methods are time and resource intensive, and the variability of botanicals makes it difficult to test one lot as representative.

Objective

The Botanical Safety Consortium (BSC), launched in 2019, was established to advance fit-for-purpose toxicity testing strategies for botanicals. This manuscript summarizes the progress of the BSC, with emphasis on the activities of its Working Groups.

Methods

The BSC Working Groups evaluate established new approach methodologies (NAMs), including in vitro assays, in silico models, and non-protected whole organisms such as C. elegans, for their applicability to botanical hazard assessment. Case studies of botanicals were selected based on known toxicity profiles to test assay performance and determine whether botanicals behave differently from single chemicals in these systems.

Results

The evaluations address toxicological endpoints such as hepatotoxicity, genotoxicity, developmental and reproductive toxicity, neurotoxicity, cardiotoxicity, and dermal toxicity. Early findings have identified fit-for-purpose screening tools that can generally be applied to botanical testing, with some nuances and considerations.

Conclusion

Future work will focus on refining and enhancing the tool-kit through assay refinement, filling endpoint gaps with additional assays, and incorporating ADME data and in silico modeling approaches. This collaborative, science-driven framework aims to modernize botanical safety evaluation, address regulatory needs, and ultimately protect public health while supporting the global demand for botanical-based dietary supplements, cosmetics, and other products.

Keywords: Botanical, safety, NAMs, toxicology, natural products, dietary supplements

Introduction

Botanicals present unique challenges for safety assessment (Mitchell et al. 2022). We define botanicals primarily as products made from plants but also including algae and fungi. Botanicals consist of dozens to hundreds of individual phytochemical constituents (Saud and Salamatullah 2021), with chemical profiles (both qualitative and quantitative) varying due to factors such as climate, growing conditions, harvesting practices, and processing methods. Even within the same plant species, geographical and environmental differences can lead to distinct chemical compositions. Compounding the natural complexity of botanicals, there is the potential for adulteration and contamination of individual ingredients, and finished products often combine multiple botanicals, making chemical characterization and safety evaluations even more challenging.

The global herbal supplement market has grown significantly this millennium, with sales increasing from approximately $4 billion in 2000 to over $12.55 billion in 2023 (Smith et al. 2024). While not common, there are known adverse effects from botanicals, such as dietary supplements or other products. For example, Garcinia cambogia, a tropical fruit extract promoted for weight loss, has been implicated in cases of hepatotoxicity. A widely publicized case involved the product Hydroxycut, which contained Garcinia cambogia as one of its ingredients. Multiple reports linked its use to acute liver injury, prompting the U.S. Food and Drug Administration to issue a warning and leading to a voluntary recall of several Hydroxycut products in 2009 (LiverTox 2012; Lunsford et al. 2016). The rising consumer demand and instances of toxicity highlights the critical need to ensure the safety of these products.

Currently safety assessments, especially in the US, presume safety for botanicals as dietary supplements (Dietary Supplement Health and Education Act of 1994 1994; Mitchell et al. 2022). Evaluations are typically based on ‘history of safe use’ (e.g., Asian ginseng having long standing evidence of safety). Evidence of harm is often needed for regulatory action and is typically identified through collecting, monitoring, and assessing adverse event reports associated with use of products that are available to consumers (i.e., pharmacovigilance) (Shaw et al. 2012; Paik et al. 2020). History of use may be sufficient for preparations that mimic traditional preparations, but often botanical supplements are a highly concentrated form of the plant or combined in a product with other botanicals. Additionally, history of use data does not usually cover delayed effects (e.g., cancer, developmental, and/or reproductive effects) and it does not account for susceptible populations (e.g., people with chronic liver disease) (Galli et al. 2019).

There is strong consumer demand for botanical products, yet their safety assessments often fall short compared to the rigorous toxicity profiles required for pharmaceuticals and pesticides. This gap, combined with the inherent variability of botanical products, presents unique challenges. To address these, the Botanical Safety Consortium (BSC) was established as a global collaborative initiative bringing together experts from academia, industry, and government agencies (Roe et al. 2019; Mitchell et al. 2022). The BSC aims to advance the evaluation of botanical safety by identifying and evaluating fit-for-purpose toxicity assays for botanicals as complex mixtures. These tools can then be used by others to screen for toxicity. These assays encompass key toxicity endpoints, including hepatotoxicity, genotoxicity, developmental and reproductive toxicity, dermal toxicity, neurotoxicity, and cardiotoxicity (Figure 1).

Figure 1.

Figure 1.

Working Groups and areas of focus of the Botanical Safety Consortium as of 2025.

The BSC is supported by experts in toxicology, pharmacognosy, chemical analysis, data interpretation, ADME (absorption, distribution, metabolism, and excretion), and in vitro to in vivo extrapolation. Its work is coordinated by a Steering Committee and executed through expert Working Groups. Officially launched in October 2019, the BSC was formalized through a Memorandum of Understanding (MOU) between the U.S. Food and Drug Administration (FDA), the National Institute of Environmental Health Sciences (NIEHS), and the Health and Environmental Sciences Institute (HESI Global) (FDA 2019).

The goal of the BSC is to identify and substantiate a suite of assays that researchers and manufacturers can use to evaluate complex botanical mixtures with a focus on human-relevant NAMs that reduce the use of in vivo models and are in line with the 3Rs of animal research – Reduction, Refinement, and Replacement. At this stage, the consortium is intentionally evaluating a broad suite of assays to determine which tools are most informative and reproducible for complex botanical mixtures; ultimately, the specific tools and number of assays applied will depend on their demonstrated performance, the context of use, and potential regulatory expectations. We envision that data from these assays could be useful in multiple contexts, including prioritizing botanicals for more in-depth toxicity studies, comparing related botanical products, and filling data gaps for data poor botanical ingredients. This manuscript offers an overview of the BSC’s progress since its inception in late 2019, highlighting key milestones achieved by its working groups and outlining future directions to advance botanical safety evaluation.

Progress since 2019

Since its inception, the BSC worked to identify assays and botanicals to use as case studies. Botanicals selected as case studies (Table 1) for the assays (Table 2) were identified based on a combination of available human data (e.g., adverse event reports, clinical trials, etc.), animal data (e.g., National Toxicology Program 2-year rodent cancer bioassays) and mechanistic information (e.g., in vitro genetic toxicology studies). Many of the selected botanicals are not dietary supplements but make good case studies as they have known toxic effects (e.g., aconite is a known poison and is a useful case study for cardiotoxicity and neurotoxicity assays).

Table 1.

Botanical case studies for the BSC as of June 2025.

Standardized common name Scientific name Plant part(s)
Aconite Aconitum napellus L. Mixed parts
Aristolochia  Aristolochia fangchi Y.C. Wu ex L.D. Chou & S.M. Hwang Root
Ashwagandha Withania somnifera (L.) Dunal Root
Asian ginseng Panax ginseng C.A. Mey. Root
Blue cohosh Caulophyllum thalictroides (L.) Michx. Root and Rhizome
Comfrey Symphytum officinale L. Root or leaf
Ephedra Ephedra sinica Stapf Aerial parts
Green Tea Camellia sinensis (L.) Kuntze Leaf
Goldenseal Hydrastis canadensis L. Root and Rhizome
Kava Piper methysticum G. Forst. Root and Rhizome
Kratom Mitragyna speciosa Korth. Leaf
Milk thistle Silybum marianum (L.) Gaertn. Seed
Oleander Nerium oleander L.  Aerial parts
Usnea lichen Usnea spp. Whole Plant
Tripterygium Tripterygium wilfordii Hook. f. Root
Yohimbe Pausinystalia johimbe (K. Schum.) Pierre ex Beille Bark

Table 2.

Assays being explored and evaluated by the Working Groups.

Working Group Assay Status
Cardiotoxicity Seahorse (O2 assay) Data analysis
Microelectrode arrays In progress
Voltage-sensitive dyes Data analysis
Transient Calcium measures Data analysis
Contractile Force Data analysis
Safety Pharmacology Screen Data analysis
Dermal Toxicitya    
Developmental and Reproductive Toxicity Transcriptomics in cell lines Data analysis
Zebrafish embryo mortality and development Data analysis
C. elegans Data analysis
devTox quickPredict assay Complete
Reprotracker Planning
Safety Pharmacology Screen Data analysis
Genotoxicity Ames Test Complete
In vitro micronucleus Data analysis
ToxTracker Complete
Neurotoxicity Zebrafish embryos mortality and behavioral assays Data analysis
C. elegans Data analysis
Microelectrode array Data analysis
Hepatotoxicity Transcriptomics in hepatic cells Data analysis
LDH release Data analysis
Albumin Planning
Cell Painting Data analysis
Cytotoxic reactive metabolites Data analysis
Cyp3A4 induction and inhibition Data analysis
a

Dermal Toxicity Working Group formed in late 2023 and has not finalized their assay selection yet.

Assays (including in vitro assays, in silico models, and non-protected whole organism systems) were selected by each of the toxicity Working Groups based on expert opinion, availability of the assays, and endpoints covered. Preference was given to assays with some level of validation (e.g., OECD Test Guidelines). For the botanicals, a summary of expected test results is provided in Table 3. Botanicals selected as case studies were tested in the assays to assess the suitability of the assay for evaluating complex mixtures.

Table 3.

Expected effects for each botanical in each toxicity Working Group as of 2025.

Standardized common name Expected effects for hepatotoxicity Expected effects for botanical-drug interaction Expected effects for neurotoxicity Expected effects for genotoxicity Expected effects for cardiotoxicity Expected effects for DART
Aristolochia fangchi Unknown Unknown Unknown Positive Unknown  Unknown
Ashwagandha Unknown Unknown Negative Unknown Unknown  Unknown
Asian ginseng Negative Positive Negative Negative Negative Negative
Blue cohosh Unknown Unknown Unknown Unknown Unknown  Positive
Comfrey Positive Unknown Unknown Positive Unknown  Unknown
Ephedra Positive Unknown Positive Unknown Positive  Unknown 
Goldenseal Positive Positive Unknown Negative Negative Positive
Green tea Positive Positive Negative Mixed evidence Unknown  Unknown
Kava Positive Unknown Negative Negative Unknown  Unknown 
Kratom Positive Positive Positive Unknown Positive  Unknown
Milk thistle Negative Positive Negative Mixed evidence Negative Unknown
Usnea lichen Positive Unknown Negative Mixed evidence Unknown  Mixed evidence
Yohimbe Mixed evidence Unknown Positive Unknown Positive Unknown
Tripterygium Unknown Unknown Positive Unknown Positive Unknown
Aconite Unknown Unknown Positive Unknown Positive Unknown
Oleander Unknown Unknown Positive Unknown Positive Unknown

Note, more details including literature are published in each Working Group’s strategy paper [hepatotoxicity and botanical-drug interactions (Roe et al. 2025); neurotoxicity (Kanungo et al. 2024); genotoxicity (Witt et al. 2025); cardiotoxicity (krzkywa et al. 2025); DART (Mahoney et al. Under Review)]. green indicates positive, blue indicated negative, salmon indicates mixed evidence, gray is unknown. Additionally, some Working Groups are considering additional botanicals to better understand their assays (e.g., DART and dermal).

Additional foundational work was done to source and provide authentication evidence for the botanicals selected, to ensure that responses in assays were due to expected constituents not adulterants or mistaken identity (Waidyanatha et al. 2024). Work was also done to collect existing literature on the botanical case studies, resulting in a best practices guidance and template for conducting literature reviews on botanicals (Patel et al. 2023). Additional work is underway to incorporate ADME information to help aid in the interpretation of results from NAMs. Finally, progress on the data analysis process is described to evaluate the assays and what further work needs to occur.

Each section below describes the progress and planned next steps for each Working Group. Every team has shared their strategy and preliminary results at scientific conferences for feedback, including meetings like the Society of Toxicology, the International Conference on the Science of Botanicals, or meetings relevant to their focus (e.g., Safety Pharmacology Society Annual Meeting for Cardiotoxicity).

Chemical Analysis

The Chemical Analysis Working Group has been crucial to the success of the BSC, providing evidence for the authenticity of botanical materials tested in the bioassays (Waidyanatha et al. 2024). Additionally, by identifying and quantifying key constituents, this enabled in silico modeling for toxicity endpoints and ADME.

Botanicals were selected by the toxicity Working Groups based on existing data (positive and negative) from toxicity studies. Most botanicals were sourced in large quantities (1–2 kg) to provide sufficient test sample of the same material in each assay. Sources were selected based on expertise in the Working Group and often came with certificates of authentication. No commercial ‘off-the-shelf’ products were used in this phase (e.g., capsules from a wellness store). For the BSC, the majority of extracts were prepared at the National Center for Natural Products Research (NCNPR), University of Mississippi (Gurley et al. 2025). Extraction methods reflected profiles reported in the literature, with 95% ethanol used to capture key constituents. Solubility testing was done in ethanol and DMSO, and most extracts were equally or more soluble in DMSO. Since DMSO is commonly used in in vitro assays, it was selected as a vehicle control in the assays and used to prepare the dose formulations for the assays.

Analytical methods, including liquid chromatography and mass spectrometry, were used to identify and quantify constituents. While one lot of each botanical was used in the bioassays, multiple lots were analyzed by the Chemical Analysis Working Group for green tea and ashwagandha as pilot studies to compare constituent quantities (Sica et al. 2025). For example, 3 lots of green tea extracts were screened to select one lot which was characterized using commercial standards, identifying major compounds totaling approximately 81% of extract weight (Waidyanatha et al. 2024). Other methods like high performance thin layer chromatography (HPTLC) were used as orthogonal results to support authentication of the botanicals. Additionally, contaminant analyses were performed in select cases to support that effects induced in the assays are due to the botanical itself, not a heavy metal or microbial contamination. Data are publicly accessible via the National Toxicology Program (NTP) website [https://cebs-ext.niehs.nih.gov/cebs/paper/15717] (NTP 2024). Additionally a manuscript is published describing the strategy of the Working Group with more details (Waidyanatha et al. 2024). There is also work to publish methods on the constituent quantification, including milk thistle (Muchiri and van Breemen 2024) and kratom (in progress) chemical standardizations and another on ashwagandha incorporating a semi-universal detector (Sica et al. 2025).

Future work for this team will include publishing additional methods papers, supporting assay data analysis, and expanding the botanical library as needed (e.g., for the Dermal Working Group or adding more botanicals to other Working Groups).

Literature review process

Toward the mission of the BSC, current assay results will be benchmarked with existing literature on botanicals. Therefore, to ensure information was collected in a systematic way, a literature review process was created, including the development of a template that other researchers doing botanical toxicity research can use and was published in an open-access publication (Patel et al. 2023). Sections in the template include pre-clinical and clinical data, accepted nomenclature, traditional use, commercial use, and known constituents. By fostering collaboration between toxicologists, pharmaconogists, and botanists, this review process supports the collection and generation of high-quality research, which can help advance the safety evaluation of botanical products.

The literature review process was developed as a structured framework for consolidating data, resources, and best practices to inform botanical safety studies efficiently and comprehensively. Once the process was completed, toxicity Working Groups used the template to collect information on the selected botanicals to later benchmark assay results to existing literature.

Data Analysis

The Data Analysis team plays a central role in standardizing and interpreting the large amount of data generated by the various Working Groups. The team developed a standard data template to collect information from disparate labs and formats in one form, enabling easier comparison of data across assays and botanicals.

A uniform data analysis pipeline was developed as a first pass of analysis so that working groups could get a sense of results and how the assays compare to existing literature on specific botanical ingredients. Benchmark Dose Modeling (BMD) was used to determine whether a botanical was ‘active’ in an assay across the tested concentrations. Data analysis will be an iterative process with the involvement of data analysts and Working Group members to understand the typical analysis methods and statistical tests associated with the assays. For example, any statistically significant increase in cytotoxicity may be worth noting for ‘activity’ but in order to determine specific toxicity to a given system, additional biological changes could be required.

The Data Analysis team’s primary role is to provide a standardized framework for data interpretation, rather than making definitive determinations about activity or inactivity for the botanicals. This iterative process relies on close collaboration with assay developers, ADME specialists, and other experts to align analytical methods with the biological relevance of the models. Looking ahead, the team is focused on analyzing increasingly complex datasets, such as multi-dimensional data from zebrafish embryo behavioral studies. Additionally, the team aims to publish its pipeline, compare BMD modeling with pairwise comparisons of the datasets, and make data publicly available to promote transparency.

Hepatotoxicity

The Hepatotoxicity Working Group is developing screening strategies to identify botanicals with potential hepatotoxic effects, both directly and due to botanical-drug interactions. This team is exploring the use of in silico tools and in vitro assays, using botanicals as case studies to evaluate the utility of the tools. A full description of the assays and botanicals selected can be found in the 2024 publication of the Working Group (Roe et al. 2025).

Botanicals were selected as case studies for hepatotoxicity based on evidence from clinical studies and animal studies. These include comfrey, goldenseal, decaffeinated concentrated green tea, kava, and kratom, all of which have demonstrated varying degrees of liver-related injuries. For example, comfrey is linked to sinusoidal obstruction syndrome due to pyrrolizidine alkaloid metabolism and endothelial cell damage (Mei et al. 2010), while goldenseal has been associated with liver tumors and cholestatic hepatitis in animals (NTP 2010). Green tea extracts, particularly when catechins are concentrated, have been implicated in hepatotoxicity under fasting conditions in animal studies (Oketch-Rabah et al. 2020).

The group has explored various in vitro assays to screen for hepatotoxicity and botanical drug interactions. For cell types, primary human hepatocytes were selected for initial work, both as two-dimensional human hepatocyte cultures and hepatocyte spheroids, though other cell types (e.g., HepG2 or HepaRGs) were initially discussed. Various assays were selected including ‘traditional’ in vitro endpoints for liver like LDH leakage, albumin measurements, and CYP 3A4 induction and inhibition. Additionally, more ‘omics based approaches like Cell Painting and transcriptomics were utilized to provide both mechanistic information and cell-population level effects.

Preliminary results have been promising when comparing assay results to existing data. For example, hepatocyte models have demonstrated LDH leakage and decreased albumin production for botanicals like kratom, while Cell Painting data have revealed patterns indicative of cellular stress for goldenseal. Additionally, a session organized by this team at the 2024 Society of Toxicology meeting was published as a workshop report, highlighting liver induced toxicity via in vitro studies, clinical trials, and adverse event reports (Koturbash et al. 2024).

Future efforts have been discussed to include expanding the assay battery to include phase 2 enzyme induction and inhibition assays, oxidative stress assays, and deeper analyses of omics data. The group also is considering the evaluation of multiple lots of specific botanicals, studies of individual phytochemical constituents, and the incorporation of gut models to better understand botanical interactions. Preliminary results are also guiding potential follow-up work. For example, kava constituents showed substantial induction of CYP3A4 in vitro, which to our knowledge has not been previously reported. To see if this effect is true or an in vitro over prediction, the group is considering measuring internal doses using other models to better approximate how this extract would be processed in the human gastrointestinal systems.

Genotoxicity

The Genotoxicity Working Group is developing a screening strategy to identify botanicals with genotoxic potential. Similar to the Hepatotoxicity Working Group, existing assays for genotoxicity were selected for testing with data-rich botanicals. A full description of the team’s strategy was published in early 2025 (Witt et al. 2025).

Botanicals selected by this group have a range of genotoxic and non-genotoxic activity. For instance, Aristolochia was selected as a prime candidate for assay evaluation because of its well-documented genotoxicity attributed to its major constituents- aristolochic acids e.g., (Bhalli et al. 2013). Comfrey was also selected as a case study expected to yield positive results in genotoxicity assays, as it contains pyrrolizidine alkaloids which are documented genotoxicants (EFSA 2011). Additional botanicals such as goldenseal root, kava root, and milk thistle provide a spectrum of genotoxicity and carcinogenicity profiles that are expected to help in refining testing approaches.

The Working Group was able to select from many well-established in vitro assays for evaluating genotoxicity. The initial strategy is based on using the bacterial reverse mutation (Ames) test (OECD 2020) and two in vitro micronucleus assays (OECD 2023), each in a different mammalian cell type, to evaluate 13 of the botanical case studies. These two types of assays cover gene mutations and chromosomal damage, respectively. Additionally, the ToxTracker® assay (Hendriks et al. 2016; 2024) is being used to identify induction of DNA damage and certain types of cellular stress. In addition to the in vitro assays, in silico genotoxicity predictive modeling of identified constituents of the 13 botanicals has been conducted.

Initial test results are promising. Expected positives were identified by the combination of assays and expected negatives were confirmed. For example, Aristolochia induced positive responses in all four assays as expected. In contrast, comfrey, another known positive, induced a less potent response in the Ames test than expected, possibly due to the concentration of pyrrolizidine alkaloids in the extract. To clarify the results with comfrey, efforts are underway to benchmark the genotoxicity of the individual pyrrolizidine alkaloids against the results from the whole-extract. Constituent versus whole-extract comparison of genotoxicity will be extended to include all 13 botanicals. Testing with the ToxTracker assay has provided complementary data to the Ames and micronucleus assays, enhancing insights into the mechanistic pathways of genotoxicity of the 13 botanicals.

Future efforts will include follow-up testing to extend our knowledge about the performance of the testing battery and about the relevance of findings in the context of extracts with previously unknown genotoxicity potential. In select cases, to further contextualize results, advanced methods like error-corrected sequencing for mutagenicity assessments may be utilized. The group also aims to refine data interpretation by integrating in silico toxicity predictions with experimental data. Collaborations with the ADME team will explore how metabolic pathways influence genotoxicity, improving the interpretation of in silico and in vitro findings. Additional data analysis will include benchmark dose modeling for in vitro micronucleus data and leveraging the Tgx-DDI transcriptomic biomarker (Li et al., 2019) to gain further insights into DNA damage pathways.

In addition to the strategy paper (Witt et al. 2025), discussions on study design for the Ames test resulted in a publication exploring whether repeat tests are necessary, which is a benefit to the entire field of genotoxicity testing (Zeiger et al. 2024).

Developmental and Reproductive Toxicity (DART)

The Developmental and Reproductive Toxicity (DART) Working Group is developing a strategy to screen botanicals for DART potential. By employing a combination of in vitro, and non-protected animal models, together with characterization data and in silico tools, the group is evaluating whether these methods can reliably assess the DART potential of botanicals. A more in-depth description is available via Mahoney et al. (under review).

Similar to other Working Groups, botanicals for DART assays were selected based on existing data, including animal studies and mechanistic information. Blue cohosh, traditionally used to induce labor, has been associated with fetal cardiac defects, craniofacial abnormalities, and mitochondrial impairment (Rader and Pawar 2013). Asian ginseng was chosen as a negative control due to its evidence of a lack of reproductive or developmental toxicity (CIR 2012). Other botanicals have disparate evidence on DART.

The group is exploring the combination of various tools to screen for DART, including human pluripotent stem cell biomarker studies, zebrafish embryo assays for mortality and malformations, C. elegans reproduction and development assays, safety pharmacology assays related to DART targets, and transcriptomics in both zebrafish embryos and human cell lines for Connectivity Map (CMap) analysis and mechanistic insights. Preliminary results indicate a higher activity for blue cohosh versus Asian ginseng in the DevTox quick predict model, with evidence also of malformations in zebrafish embryos and fecundity in C. elegans respectively. Connections were observed in CMap analysis of the blue cohosh transcriptomics data to substances of known teratogenic and developmental risk and in the safety pharmacology panel, there was evidence of interactions with a number of targets that associate with more potent developmental toxicants.

Next steps will include a deeper analysis of current data collected for the botanical case studies, including integration of biomarker, functional and mechanistic data and considerations of the limitations of the various assays. Concentration responses and aspecific effects of high doses has been identified as an area where more evaluation is needed. The group is also exploring characterization data and QSAR tools such as the DART Decision Tree.

It was difficult to find plants related to dietary supplements with reported or suspected DART effects, and so following these initial case studies, the group plans to expand the case studies to include additional botanicals, particularly those known to be associated with issues in livestock (e.g., Veratrum californicum; Welch et al. 2011). Notably, even though the goal eventually is to be able to screen across the entire reproductive lifecycle, such botanicals are generally more associated with adverse effects on embryo development and given this is of paramount importance, these will be prioritized.

Finally, exposure considerations (e.g., placental transfer, fetal exposure, breast milk exposure) and evaluation of NAMs that were not available at the start of the program have been identified for further exploration.

Cardiotoxicity

The Cardiotoxicity Working Group is focused on evaluating in vitro tools to screen for the cardiotoxicity of botanicals. The group has conducted studies on 16 botanicals, including aconite, ephedra, and oleander, which were selected based on their known cardiotoxicity. Aconite, for instance, has been linked to clinical disorders such as tachycardia (Majumder et al. 2023), making it a compelling case study for cardiotoxic evaluation. A full description of the assays and botanicals selected by this team can be found in Krzykwa et al. (2025).

The group employed human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) for the selected assays, given their established use in cardiotoxicity testing. Assays included microelectrode arrays (MEAs) (Sala et al. 2017), optical mapping for calcium and voltage changes (da Rocha et al. 2020), and methods to measure mitochondrial function (Holt et al. 2023) and contractile force (Goßmann et al. 2020). These techniques assessed parameters such as action potential characteristics, contractile behavior, and rhythm irregularities.

Preliminary results demonstrated that yohimbe exposure resulted in prolonged calcium cycling, implicating its effects on the sarcoplasmic reticulum calcium pump. Green tea exhibited dose-dependent reductions in contractile activity and a complete loss of network synchronization at high concentrations. In contrast, ginseng showed minimal effects under the same conditions, suggesting a low cardiotoxic potential. Some notable challenges with these assays were solubility issues and determining appropriate concentration ranges for testing so that many botanical extracts produced effects only at high concentrations.

Future efforts will focus on refining concentration ranges, comparing findings across other cell types, and integrating in silico predictions with experimental data. The group also plans to collaborate with external teams working on safety pharmacology and advanced 3D cardiac models to enhance the translational relevance of their findings. Moving forward, an aim is to incorporate more demographically diverse cell lines to evaluate differences in botanical-induced cardiotoxicity across sexes and ethnicities. By exploring donor pools from diverse populations, the group hopes to better understand variability in cardiotoxic responses and improve the applicability of their findings to real-world scenarios (Paik et al. 2020).

Neurotoxicity

The Neurotoxicity Working Group is evaluating NAMs as potential screening tools for neurotoxic endpoints in botanicals. Botanicals were identified based on their suspected neurotoxicity, with a focus on known mechanisms of action, in vivo studies, human clinical data, and activation of neuronal pathways. Examples include aconite and oleander, both of which are known to impact neuronal function (Farkhondeh et al. 2020; Li et al. 2022). A full description of the strategy for this Working Group has been published (Kanungo et al. 2024)

The group is exploring multiple assays and endpoints to evaluate neurotoxicity. MEAs were used to measure electrical activity in cortical neurons, capturing parameters such as spikes, burst activity, and network synchronization (van Kleef et al. 2024). Zebrafish embryo behavioral assays provided insights into sensory-motor responses, while C. elegans locomotion assays assessed movement and response to stimuli. These complementary methods enabled the group to evaluate the impact of botanical compounds on various aspects of neuronal function, ranging from electrical activity to organism-level behaviors.

Preliminary findings demonstrated dose-dependent decreases in neuronal activity for botanicals such as ephedra. Aconite exhibited a distinct phenotype characterized by intense but diminished bursts of neuronal activity, likely linked to its modulation of sodium channels. Ginseng, in contrast, showed minimal effects, suggesting low neurotoxicity. Despite these promising results, challenges remain in interpreting assay results and correlating in vitro effects with in vivo relevance. Discrepancies between predicted and observed activities highlight the need for further exploration of dose levels, metabolism, and the ability of compounds to cross the blood-brain barrier.

Future efforts will focus on enhancing data analysis, including the application of benchmark dose modeling across multiple endpoints to better characterize neurotoxic effects. The group is exploring the addition of acetylcholinesterase activity assays to capture critical pathways not currently addressed in their battery of tests. Assays targeting developmental neurotoxicity are also under consideration, as they may provide a more comprehensive understanding of the impact of botanicals on neuronal development and function. The group has noted the potential for alignment between cardiotoxicity and neurotoxicity assays, given the shared characteristics of excitable cells in these systems. This overlap may present opportunities to streamline testing for both endpoints, improving efficiency while maintaining scientific rigor. Additionally, zebrafish embryos and C. elegans were utilized by this team and by the DART Working Group, another opportunity to compare endpoints. By integrating results from complementary tools and addressing gaps in their current assay battery, the Neurotoxicity Working Group aims to enhance the evaluation of botanical neurotoxicity and contribute to the broader understanding of botanical safety.

In addition to the strategy paper, this team has published results from the MEA studies (van Kleef et al. 2024; Van Kleef et al., 2025).

Absorption, distribution, metabolism, excretion (ADME)

To enhance the interpretation of in vitro toxicity study results, ADME modeling is being piloted in the BSC for the individual constituents quantified by the Chemical Analysis team. Using tools originally developed for pharmaceuticals, these methods assess the physicochemical properties, metabolism, and toxicity potential of botanicals, providing critical context for bridging in vitro findings to broader toxicological evaluations.

The team analyzed 103 phytochemical constituents from 13 botanicals to predict properties like solubility, permeability, absorption and clearance pathways. Commercially available tools like ADMET Predictor® classify these compounds using frameworks such as the Biopharmaceutical Classification System (BCS) and Extended Clearance Classification System (ECCS). The BCS groups compounds by solubility and gut permeability, helping to interpret bioavailability data. For instance, glycosides from ashwagandha and Asian ginseng show low permeability (BCS class III or IV), leading to poor absorption and bioavailability (Liu et al. 2024). The ECCS categorizes clearance pathways, revealing that many phytochemical constituents, including those found in ashwagandha, blue cohosh, ephedra, goldenseal, green tea, kava, kratom, and yohimbe are classified under ECCS class 2, whose clearance is primarily mediated by liver metabolism and exhibit high interaction potentials with cytochromes P450 enzymes (CYPs). (Liu et al. 2025). This work further highlights the interest in pursuing gut models to evaluate the disposition and botanical-drug interaction potential of phytochemical constituents.

In silico modeling can also predict metabolites, essential for understanding NAM results as many in vitro systems do not have the same level of metabolic capability as humans. Analyses showed variability across commercially available prediction tools, with some compounds, like aristolochic acid, yielding consistent results, while others diverged, highlighting the need for further refinement. Physiologically based pharmacokinetic (PBPK) modeling using GastroPlus has also been employed to predict internal exposure, such as plasma and tissue concentrations, identifying high-exposure compounds to inform safety assessment.

In silico toxicity modeling was performed by most of the toxicity Working Groups. However, due to the number of models and the lack of ADME information in the tools, there were many flags for toxicity. By integrating ADME and in silico toxicity predictions, the team performed a pilot study to try to prioritize or deprioritize constituents based pairing in silico toxicity results with absorption information. Compounds with low absorption (<30%) are flagged as less relevant toxicologically as they are less likely to reach the target site, while those with high absorption (>30%) and predicted genotoxicity or hepatotoxicity are prioritized.

Future efforts can include looking at in vitro ADME tools, better predicting internal exposure, refining absorption and clearance evaluations, and expanding modeling capabilities.

Dermal Toxicity

The Dermal Working Group is the most recently launched team of the BSC, starting in late 2023. It is focused on developing a screening strategy to evaluate potential dermal toxicity of botanicals, including skin irritation, skin sensitization and phototoxicity. By evaluating existing approaches for botanicals, the group aims to identify reliable tools for assessing dermal safety of these mixtures.

With the recent interest in botanicals used in cosmetics, the BSC has added additional botanicals that would be used in products not administered orally and thus needed to select new botanical case studies for this endpoint. The list included known sensitizing agents like poison ivy and essential oils known to be phototoxic (e.g., oil of bergamot).

Similar to genotoxicity, there are many mature in vitro assays that can be used for dermal toxicity, many of which include OECD Test Guidelines. For example, the group is exploring the use of the OECD 442 series (C-E) for skin sensitization and OECD 439 skin irritation assay.

Future efforts will focus on evaluating the proposed assays for testing using botanicals, with particular attention to skin irritation, sensitization, and UV-induced phototoxicity. As testing progresses, the group will refine its strategies. A strategy paper is in progress describing the selected assays and the list of botanicals relevant for dermal toxicity.

Next steps and conclusions

Next steps for the BSC are to focus on evaluating the initial assays now that data are available, publishing results, and as resourcing allows, tackling the described next steps. Table 4 summarizes the progress and proposed next steps for each team. New areas, such as dermal toxicity, are being incorporated to broaden the applicability of the consortium’s work, while ongoing studies aim to refine assay batteries to improve sensitivity and specificity.

Table 4.

Summary of the progress of BSC Working Groups, potential Next steps, and publications.

Working Group Highlights of Progress Potential Next Steps Publications
Chemical Analysis
  • Sourced 16 botanicals

  • Prepared extracts

  • Supported the authentication of botanicals

  • identified key constituents

  • Published a strategy paper and a method manuscript on milk thistle

  • Publish additional method papers

  • Expand botanical library

  • Support data analysis for assays

  • Waidyanatha et al. 2024

  • Muchiri and van Breemen 2024

  • Sica et al. 2025

Literature Review
  • Developed a systematic review template

  • Utilize the template for additional botanical case studies

Data Analysis
  • Standardized data templates

  • Developed Benchmark Dose Modeling pipeline

  • Continue BMD modeling and pairwise data analysis

  • Analyze complex datasets

  • Publish data pipelines

  • Make data publicly available

 
Hepatotoxicity
  • Selected botanical case studies

  • Selected assays

  • Generated data in the select assays using the botanical case studies

  • Created a strategy manuscript

  • Presented at scientific meetings

  • Published a workshop report

  • Launched a comparison of botanical extracts and individual constituents for LDH release, MTT, and Cell Painting

  • Analyze assays data

  • Benchmark assay to existing literature

  • Publish results

  • Collaborate with ADME, Data Analysis, and Chemical Analysis Working Groups to refine toolkit of assays

  • Expand assay battery

  • Incorporate gut models for ADME studies.

  • Roe et al. 2025

  • Koturbash et al. 2024

Genotoxicity
  • Published an analysis of historical Ames Data

  • Add mammalian gene mutation assays

  • Explore in silico models

  • integrate ADME data

  • Compare studies on individual constituents (e.g., aristolochic acids and aristolochia extract) to benchmark responses

DART
  • Selected additional botanicals relevant to DART

  • Expand botanical case studies

  • Explore additional assays

  • Mahoney et al. 2025 (under review)

Cardiotoxicity  
  • Test the botanicals in diverse cell lines

  • Align with the Neurotoxicity Working Group to compare assays

  • Krzykwa et al. 2025

Neurotoxicity
  • Published a methods paper on the MEA assay with botanical

  • Launched a comparison of botanical extracts and individual constituents for MEAs

  • Align with the Cardiotoxicity Working Group to compare assays.

  • Kanungo et al. 2024

  • van Kleef et al. 2024

  • Van Kleef et al. 2025 (under review)

ADME
  • Performed PBPK modeling

  • Launched case studies on
    • Absorption
    • Clearance
    • Metabolism
  • Refine tools for internal exposure predictions

  • Publish case studies on in silico modeling

  • Incorporate in vitro data with in silico predictions for ADME

Dermal Toxicity
  • Launched new group

  • Selected botanicals relevant to toxicities

  • Selected assays for skin irritation/sensitization and phototoxicity

  • Source and authenticate botanicals

  • Evaluate assays using botanical case studies

  • Publish strategy paper and results

Strategy paper in preparation

Future directions will emphasize cross-disciplinary collaboration to address gaps and improve the translational relevance of current assays. Efforts to integrate ADME data, chemical characterization, and toxicological modeling will enhance the interpretation of in vitro results and provide a better understanding of dose-response relationships. Benchmarking results against existing literature and advancing computational tools to account for complex interactions in botanical mixtures will be critical for ensuring that findings are robust and accurate. Additionally, targeted outreach and publications will help disseminate progress and engage with broader scientific and regulatory communities.

The BSC has also participated in global outreach. In addition to sharing the results at many international conferences (Figure 2 e.g., Society of Toxicology, International Congress on Natural Products Research), the Steering Committee put together a training course entitled ‘Cultivating Safety: Toxicology 101 of Botanicals and Natural Products’ which is aimed at scientists in natural product research that want to learn and adopt the basics of toxicology. This course debuted at the 2024 ICNPR meeting in Krakow, Poland and will be presented at other scientific meetings in the future.

Figure 2.

Figure 2.

BSC events as of September 2025. A ‘living’ list can be found here.

Additionally, we have partnered with groups around the world. After the COVID anti-viral treatments entered the market, we published a review paper on botanicals that may induce botanical-drug interactions (Smith et al. 2023). We also have an ongoing survey of botanicals taken by patients attending a diabetes and hypertension clinic in Blantyre, Malawi, led by investigators at the Kamuzu University of Health Sciences (Nyirenda et al. in press). An off shoot of this review is the quantification of aristolochia acid content of Aristolochia species found in the region as it was one of the species used by patients at the clinic. Both of these studies will be published in collaboration with the BSC network.

In conclusion, the BSC has made significant progress toward developing a cohesive strategy for botanical safety assessment that accounts for the complexity of botanical products. By leveraging advances in NAMs, chemical analysis, and data interpretation, the consortium is building a foundation for tools that researchers will be able to use for botanical safety. These efforts aim to support regulatory frameworks, improve consumer safety, and enable innovation in the development of safe botanical products.

Acknowledgements

We acknowledge the consortium members for their support and helpful feedback of this document. We thank Chad Blan and Dori for their careful review of the manuscript. We acknowledge the committee members for their support and helpful feedback of this document.

Biographies

Constance A. Mitchell is a Senior Scientific Program Manager at HESI. Prior to joining HESI in early 2020, she was an ORISE Fellow at the US Environmental Protection Agency working on chemical prioritization under the Toxic Substances Control Act. She completed her graduate studies in Environmental Toxicology at the University of California Riverside. There she investigated flame retardant-induced developmental toxicity. As a Senior Scientific Program Manager, she provides scientific, strategic, and management support to collaborative scientific committees involving academic, government, nonprofit, and private sector scientists. She manages the Emerging Systems Toxicology for Assessment of Risk (eSTAR) Committee and the Botanical Safety Consortium (BSC).

Amy L. Roe is a board-certified toxicologist with over 33 years of professional experience in both the pharmaceutical and consumer product industries. Her expertise includes general, descriptive, and regulatory toxicology, as well as special expertise in drug/xenobiotic metabolism and pharmacokinetics. She is a Director Principal Toxicologist at Procter & Gamble and currently serves on the BSC Steering Team and Co-chairs the BSC Hepatotoxicity Working Group.

Scott Auerbach is a Molecular Toxicologist that leads the Toxicoinformatics Group within the Predictive Toxicology Branch of the Division of Translational Toxicology at NIEHS. In addition to his role as Toxicoinformatics Group Leader, he leads efforts related to the analysis and interpretation of multivariate data sets (i.e., microarray, RNA-seq, High-throughput screening) for purposes of informing toxicological assessment.

Cécile Bascoul is Director of Product Safety at doTERRA. Her research is focused on safety and toxicology of essential oils, specific constituents, potential contaminants and natural complex substance ingredients for cosmetic and nutritional use. Cécile has about 20 years of experience in clinical and pre-clinical research, from academia, as well as the pharmaceutical, cosmetic and nutraceutical industries.

Michelle Embry received her PhD in Toxicology in 2004 and her BS in Biology and Environmental Science and Policy in 1998 from Duke University. She is currently the Deputy Director of Environmental Science at HESI, where she provides leadership, technical direction, and guidance to varied, multi-stakeholder, collaborative committees on topics related to risk assessment and environmental protection worldwide. Prior to joining HESI in 2006, she worked as an Ecological Risk Assessor at the US EPA’s Office of Pesticide Programs. She has expertise in both human health and ecotoxicology, with an emphasis on integrated approaches and alternative methods. Her current project portfolio includes the Animal Alternatives in Environmental Risk Assessment Committee and the Development of Methods for a Tiered Approach to Assess Bioaccumulation of Chemicals Committee, two of HESI’s projects aimed at improving ecological risk assessment. Her work also includes the Risk Assessment in the 21st Century (RISK21) Committee, which developed a scientific, transparent, and efficient approach for human health risk assessment, including a web-based tool that has led to outreach and training activities on risk assessment approaches worldwide. In addition, she works with HESI staff and partners on project development related to chemical risk assessment issues.

Stephen Ferguson leads the Predictive Toxicology & Screening Group within the Division of Translational Toxicology (DTT) at the National Institute of Environmental Health Sciences (NIEHS) advancing multiple research initiatives to model tissues and predict human responses to chemical exposures. His primary focus seeks to advance the development, qualification, and application of microphysiological systems (MPS) to model and understand human hepatic and renal responses to xenobiotic exposures (i.e., adaptive, pathophysiological, interindividual). Steve’s research applies a range of imaging, cell-based assays, and ‘omics technologies to model and predict human responses to a range of exposures that include per- and poly-fluorinated alkyl substances (PFAS), botanicals mixtures, herbicides, and human drug therapeutics). Prior to joining the DTT, Steve served as Associate Director of R&D (ADME-Tox) for Life Technologies (now Thermo-Fisher), received his BS and PhD degrees in chemistry (bioinorganic, biotechnology) from North Carolina State University in 2000, and currently serves as adjunct faculty to the Curriculum in Toxicology at the University of North Carolina at Chapel Hill.

Stefan Gafner holds a BSc in pharmacy and a PhD in phytochemistry. He is currently the Chief Science Officer of the American Botanical Council (ABC) and also Director of the ABC-AHP-NCNPR Botanical Adulterants Prevention Program (BAPP). Stefan has been with ABC since 2013. Prior to his role at ABC, he served as Director of Analytical Chemistry at Tom’s of Maine.

Matthias Gossmann holds a biotechnology degree and a doctorate in chemistry. Since 2008 he has been co-developing the CellDrum technology, a precursor to the FLEXcyte technology, primarily dedicated to academic exploration. During his doctoral thesis, Matthias further elevated CellDrum into an industrial demonstrator with human iPSC-derived cardiomyocytes, laying the foundation for today’s FLEXcyte 96 instrument. His tenure as a senior scientist at Axiogenesis AG marked a pivotal phase where he employed a broad range of different cell-based assay technologies on human cell models, marking a substantial stride toward replacing animal cells in research.

Bill J. Gurley is a Principal Scientist at the National Center for Natural Products Research at the University of Mississippi, Oxford. His research interests include mechanisms of herb-drug interactions, toxicity of multiple-component herbal dietary supplements, phytochemical modulation of human drug-metabolizing enzymes and drug transport proteins, pharmacokinetics of phytochemicals in humans and botanical supplement use in special populations. Gurley has been conducting pre-clinical and clinical research on botanical dietary supplements for more than 20 years.

Holly Johnson is Chief Science Officer, American Herbal Products Association. Holly has over 20 years experience in botanicals research as a pharmacognosist with a specialization in medical ethnobotany. She is the chief science officer for the American Herbal Products Association, an alliance of over 350 companies doing business in the natural products industry.

Olaf Kelber is Senior Science Fellow, R&D Phytomedicines, Bayer Phytomedicines Supply and Development Center. Olaf is working as a scientist in R&D of phytomedicines and natural products. Biologist by training, with a specialization in toxicology, he has long standing experience also in pharmacology and clinical research on phytomedicines and is active in scientific societies in the field of natural products, and is the secretary of the leading global society for natural product research, GA, and member of the scientific EWG of Kooperation Phytopharmaka.

Julie Krzykwa is a Scientific Program Manager at the Health and Environmental Science Institute (HESI). Prior to joining HESI in 2023, she was a study director for aquatic toxicity tests at Smithers Environmental Risk Sciences contract research laboratory. Julie holds a PhD in Biology from Texas Christian University, where her dissertation research on fish embryo acute toxicity test (OECD 236) was awarded a SETAC/Procter & Gamble Fellowship for Doctoral Research in Environmental Science. She also had post-baccalaureate experience as a contractor to the US EPA, working on aquatic toxicity testing methods. In her role, Dr. Krzykwa provides scientific, strategic, and management support for HESI’s Next Generation EcoRisk Project, UVCB Committee, and Botanical Safety Consortium.

Jacob Larson currently holds the position of Senior Research Scientist, Toxicology at Herbalife. He received his Master’s degree in Public Health, Toxicology from the University of Michigan and worked for 15 years as a toxicologist at NSF International in the drinking water chemical and dietary supplement certification areas before joining Herbalife in 2020. He is a board-certified toxicologist, a member of the Society of Toxicology, and a member of the Johns Hopkins Center for Alternatives to Animal Testing (CAAT) Advisory Board. Jacob is also a member of the BSC DART working group.

Yitong Liu is a board-certified toxicologist in the Human Foods Program at the U.S. Food and Drug Administration. She has 15 years of research experience in using in silico (e.g., QSAR and PBPK modeling) and in vitro (e.g., hepatic cell models, enzyme assays) methods to identify chemical hazards associated with food substances. She is also involved in the pre-market regulatory review of food ingredients, such as herbal dietary supplements. Yitong actively publishes in toxicological and pharmacokinetic fields, serves in working groups and task forces for botanical safety, reviews journal articles and research proposals, and is frequently invited to speak on botanical related topics in meetings and conferences.

Catherine Mahony is a Research Fellow for Procter & Gamble, UK with more than 25 years of Product Safety experience in the consumer product industry. Within that role, she has worked across multiple business units providing scientific leadership for assessments aimed at characterizing the safety of ingredients. Nowadays she strives for the use of New Approach Methodologies to address safety and has been instrumental in developing and implementing NAM practices in sectors such as Cosmetics, Herbal Medicines and Food. She is also deeply involved in multiple global initiatives aimed at developing and applying Next Generation Risk Assessment (NGRA) to utilize and integrate NAMs.

Andre Monteiro da Rocha is a Research Assistant Professor in the Department of Internal Medicine—Cardiology at the University of Michigan Medical School, and a member of both the Samuel and Jean Frankel Cardiovascular Center and the Cell Regeneration Core. He earned his DVM (1999), MS (2001), and PhD (2005) from the University of São Paulo, Brazil. From 2011 to 2015, he conducted postdoctoral research at the University of Michigan in Obstetrics and Gynecology, focusing on pluripotent stem cell biology. His research centers on the development, characterization, and differentiation of human pluripotent stem cell–derived cardiomyocytes, including modeling genetic diseases such as cardiomyopathy and exploring maturation via extracellular matrix technologies.

Stefan Pfuhler received his Ph.D. in Biology from the department of Pharmacology and Toxicology of The University of Ulm in 1997. He joined Procter and Gamble in 2000 and currently serves as a R&D Senior Director Research Fellow in its Global Product Stewardship division. Dr. Pfuhler’s research focuses on alternatives to animal testing and in-vitro-only testing strategies, including the validation of 3-dimensional human skin-based genotoxicity assays. He currently serves as chair of the Genotoxicity Work Group of the International Collaboration on Cosmetic Safety (ICCS), co-chair of HESI’s Botanicals Consortium Genotoxicity and Mechanism-based Risk Assessment Working Groups, as well as on HESI’s Board of Trustees.

Vincent Sica is a Senior Scientist at The Procter & Gamble Company. Since joining in 2016, he has played an instrumental role in the characterization of botanicals for use in various dietary supplements and consumer goods. His analytical expertise combines mass spectrometry with orthogonal techniques to provide a comprehensive analysis of complex mixtures. His interest in leveraging advanced analytical techniques to understand botanicals and natural products began during his time at the University of North Carolina at Greensboro, where he earned his Ph.D. in Medicinal Biochemistry.

Suramya Waidyanatha is a supervisory biochemist and leads the chemistry and ADME (absorption, distribution, metabolism and excretion) Resources Group (CARG) in the Division of Translational Toxicology (DTT). She designs the research needs in analytical chemistry, ADME and toxicokinetics and facilitates the use of corresponding data in the design, conduct, interpretation, and reporting of toxicology research data in peer reviewed manuscripts and government reports. Waidyanatha also administers and monitors contracts conducting ADME studies, toxicokinetics studies, and analytical chemistry activities in support of toxicology research at DTT. Waidyanatha received her B.S. (Honors) in Chemistry from University of Colombo, Sri Lanka and her M.S in Biochemistry from University of Illinois, Chicago. She received her Ph.D. in Analytical Chemistry from University of Maine prior to joining the School of Public Health at the University of North Carolina at Chapel Hill as a Postdoctoral Fellow. She continued her career at the University of North Carolina as a Laboratory Director and a Senior Scientist where she investigated biomarkers of exposure and effect to xenobiotics. Waidyanatha joined DTT in 2008 as a chemist. She is listed as an author in over 100 peer-reviewed manuscripts and government reports.

Remco HS Westerink is an Associate Professor at the Institute for Risk Assessment Sciences (IRAS) and head of the Neurotoxicology Research Group at Utrecht University. He earned his MSc in Biology in 1997 and his PhD in Neurotoxicology in 2002, both from Utrecht University. His research focuses on how toxic substances (such as environmental pollutants, pesticides, pharmaceuticals, and natural toxins) affect the development, function, and degeneration of the nervous system, using advanced in vitro models. His group employs sophisticated cell-culture systems, including hiPSC-derived neuronal networks and multi-electrode arrays (MEAs), to assess chemical impacts on neuronal activity, calcium signaling, and neurotransmission, while also reducing reliance on animal testing. He leads and contributes to several European research initiatives, including TUBE (in vitro neurotoxicity of ultrafine air pollutants) and ENDpoiNTs (developmental neurotoxicity of endocrine disruptors). Additionally, he has served as President of the International Neurotoxicology Association (2017–2019) and is currently Editor-in-Chief of the journal NeuroToxicology.

Kristine Witt recently retired. She previously served as the Genetic Toxicology Group Leader, Division of the National Toxicology Program/NIEHS, in Research Triangle Park, NC. Her duties included serving as the NTP co-chair for the Assay Evaluation and Screening Working Group within the Toxicology in the 21st Century (Tox21) consortium (the multi-agency high throughput screening initiative), as well as directing the acquisition, interpretation, and presentation of genetic toxicity test data in support of the NTP mission through the NTP’s genetic toxicology testing contract. She led a Tox21 project that compared data from high throughput screening (HTS) assays that measured specific types of DNA damage/repair to data acquired from traditional genetic toxicity tests to clarify the role for HTS in identifying potential genotoxicants among the thousands of compounds for which inadequate data exist. In addition to her Tox21 and contract management duties, she provided reviews, evaluations, and interpretations of genotoxicity test data for inclusion in over 250 NTP Technical Reports, several of which were focused on commonly used botanical extracts such as black cohosh, ginseng, ginkgo biloba, milk thistle, and kava kava.

Hellen Oketch-Rabah joined the Office of Dietary Supplements Programs (ODSP), in the Human Foods Program (formerly CFSAN) at the U.S. FDA in June 2023. Prior to joining ODSP she was at the United States Pharmacopeia (USP) from 2011 in different roles in the Dietary Supplements and Herbal Medicines Department, developing dietary supplements quality monographs. Before that, she was the Principal Scientist at Herb Pharm Inc., a dietary supplement manufacturing facility in Oregon. Dr. Oketch-Rabah did her Post-Doc at the Lawrence Berkeley National Laboratory in California on breast cancer biology and phytochemicals for treatment of postmenopausal symptoms. Earlier in her career, she was an assistant Professor of Pharmacognosy at the School of Pharmacy, University of Nairobi, Kenya. Dr. Oketch-Rabah earned her Ph.D. in Pharmacognosy/Medicinal Chemistry from the Royal Danish School of Pharmacy (University of Copenhagen) working on Kenyan Medicinal Plants with antimalarial and antileishmanial properties.

Cynthia Rider is a Toxicologist in the Division of Translational Toxicology at the National Institute of Environmental Health Sciences (NIEHS). Cynthia serves as a project leader for testing programs including botanical dietary supplements. Her research focuses on evaluating and refining methods to predict mixture toxicity based on data from components or whole reference mixtures.

Funding Statement

This work was supported in part by the Health and Environmental Sciences Institute’s (HESI Global) Botanical Safety Consortium. It is recognized via a Memorandum of Understanding between the US FDA, NIEHS, and HESI [MOU 225-19-032] that outlines joint commitments to a multisector and multidisciplinary Botanical Safety Consortium. Portions of this manuscript, including drafting and language refinement, were supported by OpenAI’s ChatGPT (GPT-4o, May 2024 version). The AI tool was used under human supervision to assist with improving clarity and flow based on author-provided content. All content was reviewed and validated by the authors for accuracy and appropriateness. No interpretation or decision-making was delegated to the AI system. This research was supported in part by the Intramural Research Program of the NIH, National Institute of Environmental Health Sciences (ZIA ES103373). This scientific initiative is primarily supported by in-kind contributions (from public and private sector participants) of time, expertise, and experimental effort. These contributions are supplemented by direct funding (that largely supports program infrastructure and management) that was provided by HESI’s corporate sponsors. A list of supporting organizations is available at https://botanicalsafetyconsortium.org/

Disclosure statement

No potential conflict of interest was reported by the author(s). The initials AR, CB, MG, OK, JL, CM, SP, VS are employed by a personal care company, biotech company, or trade industry association.

Data availability statement

Data sharing is not applicable to this article as no new data were created or analyzed in this study

References

  1. Bhalli JA, et al. 2013. Evaluating the weak in vivo micronucleus response of a genotoxic carcinogen, aristolochic acids. Mutat Res. 753(2):82–92. 10.1016/j.mrgentox.2013.03.002 [DOI] [PubMed] [Google Scholar]
  2. CIR . 2012. Safety assessment of Panax spp. root-derived ingredients as used in cosmetics. https://www.cir-safety.org/ingredients
  3. da Rocha AM, Creech J, Thonn E, Mironov S, Herron TJ.. 2020. Detection of drug-induced torsades de pointes arrhythmia mechanisms using hiPSC-CM syncytial monolayers in a high-throughput screening voltage sensitive dye assay. Toxicol Sci. 173(2):402–415. 10.1093/toxsci/kfz235 [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Dietary Supplement Health and Education Act of 1994 . 1994. https://uscode.house.gov/statutes/pl/103/417.pdf
  5. EFSA . 2011. Scientific opinion on pyrrolizidine alkaloids in food and feed. EFSA J. 9(11):2406. [Google Scholar]
  6. Farkhondeh T, Kianmehr M, Kazemi T, Samarghandian S, Khazdair MR.. 2020. Toxicity effects of Nerium oleander, basic and clinical evidence: a comprehensive review. Hum Exp Toxicol. 39(6):773–784. 10.1177/0960327120901571 [DOI] [PubMed] [Google Scholar]
  7. FDA . 2019. MOU 225-19-032. In Memorandum of understanding between the U.S. Food and Drug Administration and the National Institute of Environmental Health Sciences. FDA. [Google Scholar]
  8. Galli CL, et al. 2019. Development of a consensus approach for botanical safety evaluation – A roundtable report. Toxicol Lett. 314:10–17. 10.1016/j.toxlet.2019.05.008 [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Goßmann M, et al. 2020. Integration of mechanical conditioning into a high throughput contractility assay for cardiac safety assessment. J Pharmacol Toxicol Methods. 105:106892. 10.1016/j.vascn.2020.106892 [DOI] [PubMed] [Google Scholar]
  10. Gurley BJ, et al. 2025. The National Center for Natural Products Research (NCNPR) at 30: a legacy of pioneering research in natural products and dietary supplements. J Diet Suppl. 22(1):193–218. 10.1080/19390211.2024.2410758 [DOI] [PubMed] [Google Scholar]
  11. Hendriks G, et al. 2024. Interlaboratory validation of the ToxTracker assay: an in vitro reporter assay for mechanistic genotoxicity assessment. Environ Mol Mutagen. 65(1-2):4–24. 10.1002/em.22592 [DOI] [Google Scholar]
  12. Hendriks G, et al. 2016. The extended ToxTracker assay discriminates between induction of DNA damage, oxidative stress, and protein misfolding. Toxicol Sci. 150(1):190–203. 10.1093/toxsci/kfv323 [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Holt AK, et al. 2023. Aspirin reprogrammes colorectal cancer cell metabolism and sensitises to glutaminase inhibition. Cancer Metab. 11(1):18. 10.1186/s40170-023-00318-y [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Kanungo J, et al. 2024. Screening tools to evaluate the neurotoxic potential of botanicals: building a strategy to assess safety. Expert Opin Drug Metab Toxicol. 20(7):629–646. 10.1080/17425255.2024.2378895 [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Koturbash I, et al. 2024. Botanical-induced toxicity: liver injury and botanical-drug interactions. A report on a society of toxicology annual meeting symposium. regulatory toxicology and pharmacology. Regul Toxicol Pharmacol. 153, p. 105708. 10.1016/j.yrtph.2024.105708 [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Krzykwa J, et al. 2025. Developing an approach for evaluating the cardiotoxic potential of botanicals. Front Toxicol. 7. 10.3389/ftox.2025.1646044 [DOI] [Google Scholar]
  17. Kumbukani K. Nyirenda, John Mponda, Ibrahim Chikowe, Esther Kawonga, Nellie Twatasha Gomani Phiri, Mervis Msukwa, Chimota Phiri, Amy L. Roe, Mary F. Paine, Bill Gurley, Hellen Oketch-Rabah, Stefan Gafner, Julie Krzykwa, Constance A. Mitchell, Michelle R. Embry, Syril Pettit, Dallas J. Smith . (In Press). An Exploratory Evaluation of the Interaction Risk Between Herbal Products and Pharmaceutical Medicines Used Concurrently for Disease Management in Blantyre, Malawi. Pharmaceutical Biology. [Google Scholar]
  18. Li H-Het al. . 2019. TGx-DDI, a Transcriptomic Biomarker for Genotoxicity Hazard Assessment of Pharmaceuticals and Environmental Chemicals. Front Big Data. 2:36 10.3389/fdata.2019.00036. PMC: 33693359 [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Li S, et al. 2022. An insight into current advances on pharmacology, pharmacokinetics, toxicity and detoxification of aconitine. Biomed Pharmacother. 151:113115. 10.1016/j.biopha.2022.113115 [DOI] [PubMed] [Google Scholar]
  20. Liu Y, et al. 2024. Prediction of physicochemical and pharmacokinetic properties of botanical constituents by computational models. J Appl Toxicol. 44(8):1236–1245. 10.1002/jat.4617 [DOI] [PubMed] [Google Scholar]
  21. Liu Y, Lawless M, Roe AL, Ferguson SS.. 2025. Integration of computational models to predict botanical phytochemical constituent clearance routes by the Extended Clearance Classification System (ECCS). Toxicol Appl Pharmacol. 500:117385. 10.1016/j.taap.2025.117385 [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. LiverTox . 2012. Hydroxycut. LiverTox: clinical and research information on drug-induced liver injury [Internet]. https://www.ncbi.nlm.nih.gov/books/NBK548251/
  23. Lunsford KE, Bodzin AS, Reino DC, Wang HL, Busuttil RW.. 2016. Dangerous dietary supplements: garcinia cambogia-associated hepatic failure requiring transplantation. World J Gastroenterol. 22(45):10071–10076. 10.3748/wjg.v22.i45.10071 [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Majumder MI, Mahadi AR, Rahman OU, Roy BK, Shihab HM.. 2023. Accidental poisoning with aconite overdose: a case report and resuscitative emergency management in a tertiary level hospital of Bangladesh. Clin Case Rep. 11(9):e7845. 10.1002/ccr3.7845 [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Mei N, et al. 2010. Metabolism, genotoxicity, annd carcinogenicity of comfrey. J Toxicol Environ Health B Crit Rev. 13(7-8):509–526. 10.1080/10937404.2010.509013 [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Mitchell CA, et al. 2022. The botanical safety consortium: a public-private partnership to enhance the botanical safety toolkit. Regul Toxicol Pharmacol. 128:105090. 10.1016/j.yrtph.2021.105090 [DOI] [PubMed] [Google Scholar]
  27. Muchiri RN, van Breemen RB.. 2024. Chemical standardization of Milk Thistle (Silybum marianum L.) extract using UHPLC-MS/MS and the method of standard addition. J Am Soc Mass Spectrom. 35(8):1726–1732. 10.1021/jasms.4c00125 [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. NTP . 2010. Toxicology and carcinogenesis studies of goldenseal root powder (Hydrastis Canadensis) in F344/N rats and B6C3F1 mice (feed studies). Natl Toxicol Program Tech Rep Ser. TR-562(562):1–188. [Google Scholar]
  29. NTP . 2024. Botanical safety consortium – chemical analysis. https://cebs-ext.niehs.nih.gov/cebs/paper/15717
  30. OECD . 2020. Test No. 471: bacterial reverse mutation test. OECD Publishing. 10.1787/9789264071247-en [DOI] [Google Scholar]
  31. OECD . 2023. Test No. 487: in Vitro mammalian cell micronucleus test. OECD Publishing. 10.1787/9789264264861-en [DOI] [Google Scholar]
  32. Oketch-Rabah HA, et al. 2020. United States Pharmacopeia (USP) comprehensive review of the hepatotoxicity of green tea extracts. Toxicol Rep. 7:386–402. 10.1016/j.toxrep.2020.02.008 [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Paik DT, Chandy M, Wu JC.. 2020. Patient and disease-specific induced pluripotent stem cells for discovery of personalized cardiovascular drugs and therapeutics. Pharmacol Rev. 72(1):320–342. 10.1124/pr.116.013003 [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Patel D, et al. 2023. Improving the rigor and utility of botanical toxicity studies: recommended resources. Regul Toxicol Pharmacol. 144:105471. 10.1016/j.yrtph.2023.105471 [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Rader JI, Pawar RS.. 2013. Primary constituents of blue cohosh: quantification in dietary supplements and potential for toxicity. Anal Bioanal Chem. 405(13):4409–4417. 10.1007/s00216-013-6783-7 [DOI] [PubMed] [Google Scholar]
  36. Roe AL, et al. 2019. The botanical safety consortium. Appl In Vitro Toxicol. 5(1):4–9. 10.1089/aivt.2018.29018.rtl [DOI] [Google Scholar]
  37. Roe AL, et al. 2025. Developing a screening strategy to identify hepatotoxicity and drug interaction potential of botanicals. J Diet Suppl. 22(1):162–192. 10.1080/19390211.2024.2417679 [DOI] [PubMed] [Google Scholar]
  38. Sala L, Bellin M, Mummery CL.. 2017. Integrating cardiomyocytes from human pluripotent stem cells in safety pharmacology: has the time come? Br J Pharmacol. 174(21):3749–3765. 10.1111/bph.13577 [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Saud S, Salamatullah AM.. 2021. Relationship between the chemical composition and the biological functions of coffee. Molecules. 26(24):7634. https://www.mdpi.com/1420-3049/26/24/7634. 10.3390/molecules26247634 [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Shaw D, Graeme L, Pierre D, Elizabeth W, Kelvin C.. 2012. Pharmacovigilance of herbal medicine. J Ethnopharmacol. 140(3):513–518. 10.1016/j.jep.2012.01.051 [DOI] [PubMed] [Google Scholar]
  41. Sica VP, Mitchell CA, Krzykwa J, Baker TR, Waidyanatha S.. 2025. A multi-detector analytical approach for characterizing complex botanical extracts: a case study on ashwagandha. Anal Bioanal Chem. 417(21):4895–4906. 10.1007/s00216-025-06006-8 [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Smith DJ, et al. 2023. Potential pharmacokinetic interactions with concurrent use of herbal medicines and a ritonavir-boosted COVID-19 protease inhibitor in low and middle-income countries [Review]. Front Pharmacol. 14:1210579. 10.3389/fphar.2023.1210579 [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Smith T, Lang C, Craft E.. 2024. US sales of herbal supplements increase 4.4% in 2023. HerbalGram. 141:54–68. https://www.herbalgram.org [Google Scholar]
  44. Van Kleef. et al. 2025. Dose-response assessment of neuroactivebotanical extracts and their bioactive constituents using microelectrode array(MEA) recordings in rat primary cortical cultures. Pharm. Biol. 10.1080/13880209.2025.2583834. [DOI] [Google Scholar]
  45. van Kleef RGDM, Embry MR, Mitchell CA, Westerink RHS.. 2024. Neuroactivity screening of botanical extracts using microelectrode array (MEA) recordings. Food Chem Toxicol. 184:114438. 10.1016/j.fct.2024.114438 [DOI] [PubMed] [Google Scholar]
  46. Waidyanatha S, et al. 2024. Advancing botanical safety: a strategy for selecting, sourcing, and characterizing botanicals for developing toxicological tools. Food Chem Toxicol. 186:114537. 10.1016/j.fct.2024.114537 [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Welch K, et al. 2011. Dose-response evaluation of veratrum californicum in sheep. In: Poisoning by plants, mycotoxins and related toxins. CABI Wallingford UK. p. 243–250. [Google Scholar]
  48. Witt KL, et al. 2025. A proposed screening strategy for evaluating the genotoxicity potential of botanicals and botanical extracts. Food Chem Toxicol. 197:115277. 10.1016/j.fct.2025.115277 [DOI] [PubMed] [Google Scholar]
  49. Zeiger E, Mitchell CA, Pfuhler S, Liao Y, Witt KL.. 2024. Within-laboratory reproducibility of Ames test results: are repeat tests necessary? Environ Mol Mutagen. 65(3-4):116–120. 10.1002/em.22597 [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

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Data Availability Statement

Data sharing is not applicable to this article as no new data were created or analyzed in this study


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