Abstract
Background
The growing resistance of malaria parasites, particularly Plasmodium falciparum, to most antimalarial drugs underscores the urgent need for novel therapeutic strategies. Green-synthesized magnesium oxide nanoparticles (MgO NPs), prepared using Matricaria chamomilla, have shown promise in biomedical applications. This study presents the first evaluation of green-synthesized MgO NPs derived from M. chamomilla for their antiplasmodial effects against P. falciparum 3D7 and K1 strains.
Methods
M.chamomilla extract was used for the biosynthesis of MgO NPs, which were characterized by ultraviolet-visible (UV-Vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), dynamic light scattering (DLS), and MTT assays. The antiplasmodial activity of MgO NPs synthesized with varying solvent ratios (30:70, 50:50, and 70:30 mL of distilled water to ethanol) was evaluated in vitro.
Results
FESEM images revealed quasi-spherical MgO NPs with particle sizes ranging from 30 to 80 nm. DLS analysis showed hydrodynamic sizes of 183 nm, 161 nm, and 606 nm for the 30:70, 50:50, and 70:30 solvent ratios, respectively. The half-maximal inhibitory concentration (IC₅₀) values against the P. falciparum 3D7 strain were 0.19, 0.21, and 0.22 mg/mL for the 30:70, 50:50, and 70:30 ratios, respectively; against the K1 strain, the corresponding IC₅₀ values were 0.41, 0.45, and 0.42 mg/mL.
Conclusion
The green-synthesized MgO NPs exhibited in vitro antiplasmodial activity against both chloroquine-sensitive and chloroquine-resistant P. falciparum strains. These findings support further investigation into their potential applications as antimalarial agents in preclinical models.
Supplementary Information
The online version contains supplementary material available at 10.1186/s12906-025-05081-9.
Keywords: Malaria, Plasmodium falciparum, Matricaria Chamomilla, Magnesium oxide nanoparticles, Antiplasmodial activity
Introduction
Malaria continues to pose a major global public health challenge, accounting for substantial morbidity and mortality worldwide despite significant advances in prevention and treatment strategies. The disease is caused by Plasmodium parasites, transmitted to humans through the bite of infected female Anopheles mosquitoes. Among the five Plasmodium species capable of infecting humans, Plasmodium falciparum is responsible for the most severe clinical manifestations, frequently leading to complications such as metabolic acidosis, multi-organ failure, and death [1–4].
The development of continuous in vitro culture systems for P. falciparum, pioneered by Trager and Jensen in 1976, has been instrumental in advancing malaria research, particularly in the fields of parasite biology, immunology, and antimalarial drug discovery [5, 6]. Nevertheless, the emergence and widespread distribution of drug-resistant Plasmodium strains have severely undermined the effectiveness of existing therapeutic regimens [7], necessitating the identification of novel antimalarial agents with alternative mechanisms of action.
Historically, medicinal plants have served as a rich source of bioactive compounds for the treatment of infectious diseases and continue to offer valuable leads for the development of new therapeutic agents [8]. Matricaria chamomilla (commonly known as German chamomile), widely distributed across temperate regions including southern and western Iran, possesses well-documented antibacterial, anti-inflammatory, and antiparasitic properties. Its efficacy has been demonstrated against various protozoan parasites, including Toxoplasma gondii and Leishmania species [9–15].
The convergence of nanotechnology and phytotherapy has introduced innovative strategies for enhancing the therapeutic potential and bioavailability of plant-derived compounds. In particular, the green synthesis of metallic nanoparticles using plant extracts has attracted considerable attention as an environmentally sustainable, biocompatible, and cost-effective approach, capable of producing nanoparticles with improved stability and enhanced biological activity compared to crude plant extracts [16]. Among various nanomaterials, magnesium oxide (MgO) nanoparticles have emerged as promising candidates due to their low toxicity, ease of synthesis, affordability, and broad-spectrum antimicrobial and antiparasitic properties [17].
While M. chamomilla has been previously utilized for the green synthesis of metallic nanoparticles, prior investigations have predominantly focused on their antibacterial, antioxidant, and cytotoxic properties [18–22]. To date, the antiplasmodial potential of M. chamomilla-mediated MgO nanoparticles has not been explored. The present study aims to address this knowledge gap by synthesizing MgO nanoparticles using M. chamomilla extract and evaluating their in vitro antiplasmodial efficacy against both chloroquine-sensitive (3D7) and chloroquine-resistant (K1) strains of P. falciparum.
Materials and methods
Preparation of Matricaria chamomilla hydroethanolic extract
M.chamomilla was purchased from a certified medicinal herb supplier in Tehran, Iran. The plant material was authenticated by a botanist at the Department of Pharmacognosy, Tehran University of Medical Sciences. Only the dried flower parts were used for extract preparation in the biosynthesis of MgO nanoparticles. For the extraction process, 2 g of the powdered plant material was mixed with 50 mL of distilled water and 50 mL of 96% ethanol in a round-bottom flask. The mixture was refluxed on a magnetic stirrer (Alfa D500, Iran) at 65 °C and 300 rpm for 2.5 h.Following extraction, the solution was filtered through Whatman No. 1 filter paper, and the filtrate was collected. This procedure was subsequently repeated using two additional solvent ratios: 30 mL of distilled water with 70 mL of ethanol, and 70 mL of distilled water with 30 mL of ethanol, following the same reflux and filtration conditions. All prepared extracts were stored at 4 °C in airtight containers until further use.
Synthesis of MgO nanoparticles
Magnesium chloride anhydrous (Sigma-Aldrich, Germany) was used for the synthesis of magnesium oxide (MgO) nanoparticles, following the method described by Verma et al. [23], with slight modifications. 5 mL of each of the three prepared M. chamomilla extracts was mixed with 15 mL of distilled water in separate beakers. The mixtures were placed on a magnetic stirrer set to 60 °C with continuous stirring at an appropriate speed. Subsequently, 0.1 g of anhydrous magnesium chloride was carefully added to each beaker. The temperature was then increased to 80 °C, and the beakers were covered with aluminum foil to minimize evaporation. Stirring was maintained under these conditions for 4 h. Upon completion, the resulting nanoparticle suspensions were allowed to cool and stored at 4 °C for further characterization and analysis.
Characterization of MgO nanoparticles
The optical properties of the synthesized magnesium oxide nanoparticles (MgO-NPs) were assessed using a UV–visible spectrophotometer (PerkinElmer Lambda 25, USA) across a wavelength range of 200–800 nm. Fourier transform infrared (FTIR) spectroscopy was performed using a Tensor 27 spectrometer (Bruker, Germany) to identify functional groups associated with nanoparticle formation, recording spectra over a range of 500–4000 cm⁻¹. The average hydrodynamic diameter of the MgO-NPs was determined by dynamic light scattering (DLS) using a HORIBA SZ-100 instrument (Japan). The morphological characteristics of the nanoparticles were examined by field emission scanning electron microscopy (FE-SEM) employing a TESCAN MIRA3 system (Czech Republic). Additionally, the surface charge and colloidal stability of the MgO-NPs were evaluated by measuring the zeta potential using the same HORIBA SZ-100 analyzer.
Hemolysis assay
The hemolytic activity of three hydroethanolic extracts of M. chamomilla (50 D.W/50 ETH, 70 D.W/30 ETH, and 30 D.W/70 ETH) and their corresponding green-synthesized magnesium oxide (MgO) nanoparticles was assessed following the methodology described by [24] with minor modifications.
Human heparinized blood (blood group O⁺) was obtained anonymously as leukocyte-reduced blood products from the Blood Transfusion Organization’s blood bank without any personal identifiers. The study protocol was approved by the Ethics Committee of Tehran University of Medical Sciences (Ethics ID: IR.TUMS.MEDICINE.REC.1402.652). Due to the anonymous nature of the samples and in accordance with national regulations, the requirement for informed consent was waived by the Ethics Committee.
The blood was centrifuged at 2500 rpm for 10 min with normal saline. This washing step was repeated three times to thoroughly remove plasma and the buffy coat. The packed erythrocytes were then resuspended in normal saline to prepare a 1% red blood cell (RBC) suspension. For preparation of stock solutions, 660 µL of each extract or nanoparticle suspension was transferred into 1 mL microtubes, and the volume was adjusted to 1 mL with 340 µL of normal saline. Serial dilutions were subsequently prepared to obtain final concentrations of 1, 0.5, 0.25, and 0.125 mg/mL.
Then, 200 µL of the 1% RBC suspension was added to each of the 24 microtubes containing different extract or nanoparticle concentrations. The samples were incubated at 37 °C for 1 h. Positive control was prepared by mixing 200 µL of RBC suspension with 200 µL of distilled water, and negative control by mixing 200 µL of RBC suspension with 200 µL of normal saline. After incubation, microtubes were centrifuged at 1500 rpm for 5 min. Supernatants were carefully collected, and the released hemoglobin was quantified spectrophotometrically at 541 nm using a CECIL 1010 spectrophotometer (UK). Hemolysis percentage was calculated using the formula described by [25].
 |
MTT assay
The cytotoxicity of the synthesized MgO nanoparticles was evaluated using the MTT (3-[4,5-dimethylthiazol-2-yl]−2,5-diphenyl tetrazolium bromide) assay, a colorimetric method based on the reduction of tetrazolium salt to insoluble formazan crystals by metabolically active cells [26]. Human dermal fibroblast (HDF) cells were cultured in high-glucose Dulbecco’s Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS) and 1% penicillin-streptomycin. A total of 6,000 HDF cells in 100 µL of complete medium were seeded into each well of a 96-well microplate and incubated at 37 °C with 5% CO₂ for 24 h to allow cell attachment.
Following incubation, 100 µL of MgO nanoparticle suspensions at concentrations of 1.5, 1.0, and 0.5 mg/mL, prepared from two synthesis ratios (30 D.W/70 ETH and 50 D.W/50 ETH), were added to the respective wells. The plates were then incubated for an additional 48 h under the same conditions. Subsequently, 10 µL of MTT solution (5 mg/mL; Sigma-Aldrich, USA) was added to each well, followed by a 3-hour incubation period to allow for formazan formation. The supernatant was then carefully discarded, and 100 µL of dimethyl sulfoxide (DMSO; Bioldea, Iran) was added to solubilize the formazan crystals. The plate was gently shaken for 1–2 min, and the optical density (OD) was measured at 570 nm using a microplate reader (BioTek, USA).
Each concentration was tested in triplicate, and cell viability was calculated as a percentage relative to untreated control wells using the following formula:
 |
P. falciparum cultivation
The P. falciparum strains 3D7 (chloroquine-sensitive) and K1 (chloroquine-resistant) were cultured in vitro using the method established by Trager and Jensen [27], with minor modifications. The complete culture medium (CCM) was prepared using RPMI 1640 medium supplemented with 25 mM HEPES, 2 g/L glucose (Gibco, USA), 10% heat-inactivated human serum, 50 mg/L hypoxanthine, and 50 mg/L gentamicin (Sigma-Aldrich, Germany).For parasite cultivation, 4.5 mL of CCM was mixed with two drops of infected erythrocyte suspension. Fresh, non-infected erythrocytes were then added following centrifugation at 5000 rpm for 5 min to achieve a final hematocrit of 10%. The culture plates were incubated at 37 °C in a candle jar. Parasites were sub-cultured every 48 h, and cultures were maintained until a parasitemia level of 2–3% was achieved, at which point they were used for subsequent antiplasmodial assays.
In vitro anti-plasmodial assay
An in vitro assay was conducted to evaluate the antiplasmodial activity of the green-synthesized MgO nanoparticles against both 3D7 and K1 strains of P. falciparum. Briefly, stock solutions of the synthesized MgO nanoparticles were prepared in RPMI 1640 medium at final concentrations of 0.125, 0.25, 0.5, and 1 mg/mL. Chloroquine diphosphate (Sigma-Aldrich, Germany) was used as a reference drug and prepared at concentrations of 1, 5, 25, and 50 µg/mL. Additional MgO nanoparticle solutions at the same concentrations were prepared in parallel to assess their independent effects on erythrocytes.
For the assay, 100 µL of each test solution was dispensed into designated wells of a sterile 96-well microplate, along with appropriate controls. The positive control consisted of RPMI medium containing infected erythrocytes, while the negative control contained RPMI with uninfected erythrocytes. All experiments were performed in triplicate. Subsequently, 20 µL of P. falciparum-infected erythrocytes (adjusted to 2–3% parasitemia) were added to each well.
The plates were incubated at 37 °C for 24 h in a candle jar to maintain a low-oxygen environment. Following incubation, thin blood smears were prepared from each well, fixed with methanol, and stained with 10% Giemsa solution. Parasitemia was determined by counting the number of infected erythrocytes per 10,000 red blood cells under a light microscope. The percentage inhibition of parasite growth was calculated in comparison to the positive control.
 |
Statistical analysis
Statistical analyses were performed using GraphPad Prism software (GraphPad Software, USA). Data were expressed as mean ± standard deviation (SD) of at least three independent experiments. Comparisons between groups were conducted using two-way analysis of variance (ANOVA) followed by Tukey’s post hoc test, and independent samples t-tests where appropriate. Statistical significance was indicated as follows: P < 0.05 (*),P < 0.01 (**),P < 0.001 (***), and P < 0.0001 (****).
Results
Spectroscopic analysis
UV-visible (UV-Vis) spectroscopy is a widely employed technique to assess the optical absorption properties of various materials and solutions [28]. In the present study, UV-Vis spectra were recorded for all three ratios of green-synthesized MgO nanoparticles over the wavelength range of 200–800 nm (Figure 1). Distinct absorption maxima were observed at approximately 250 nm for the 30 D.W/70 ETH formulation, and at 264 nm for both the 50 D.W/50 ETH and 70 D.W/30 ETH formulations. These characteristic peaks correspond to the electronic transitions associated with MgO nanoparticles and confirm their successful synthesis.
Fig. 1.
UV–visible absorption spectra of green-synthesized magnesium oxide nanoparticles (MgO NPs) prepared with different extract-to-solvent ratios: (a) 30 D.W/70 ETH, (b) 50 D.W/50 ETH, and (c) 70 D.W/30 ETH. Distinct absorption peaks at approximately 250 nm and 264 nm correspond to characteristic electronic transitions of MgO nanoparticles
According to Fig. 2, FTIR spectroscopy of the MgO nanoparticles synthesized using M.chamomilla extract revealed characteristic functional groups responsible for reduction and stabilization. Broad absorption bands around 3348 and 3289 cm⁻¹ correspond to O–H stretching vibrations from phenolic and alcoholic groups, indicating the presence of flavonoids involved in the reduction process. Peaks near 2979 and 2976 cm⁻¹ are attributed to C–H stretching vibrations, while bands at 1643–1652 cm⁻¹ reflect C = O and C = C stretches from aromatic compounds. Signals at 1414 and 1382 cm⁻¹ correspond to C–H bending and O–H deformations, supporting the presence of phenolic and tertiary alcohol groups. Bands between 1084 and 1044 cm⁻¹ indicate C–O and C–O–C stretching vibrations typical of plant-derived organic molecules. Aromatic C–H bending vibrations appear at 877–878 cm⁻¹. Importantly, absorption peaks at 680–651 cm⁻¹ confirm the formation of MgO nanoparticles [29, 30].
Fig. 2.
Fourier transform infrared (FTIR) spectra of Matricaria chamomilla extract and green-synthesized magnesium oxide nanoparticles (MgO NPs). The spectra display characteristic absorption bands across wavenumbers (cm⁻¹), indicating the presence of functional groups involved in nanoparticle formation and stabilization
This concise spectrum analysis confirms that phytochemicals in M. chamomilla extract play a key role in the green synthesis, acting as reducing and capping agents to stabilize MgO nanoparticles.
DLS analysis
The particle size distribution of MgO NPs synthesized with extract-to-solvent ratios of 30 D.W/70 ETH, 50 D.W/50 ETH, and 70 D.W/30 ETH was measured using dynamic light scattering (DLS), yielding average hydrodynamic diameters of 183 nm, 161 nm, and 606 nm, respectively. Complementary morphological analysis was performed using field emission scanning electron microscopy (FE-SEM), providing detailed insights into the shape and surface characteristics of the nanoparticles.
Microscopic analysis
As shown in Fig. 3, field emission scanning electron microscopy (FE-SEM) images of the green-synthesized magnesium oxide nanoparticles (MgO NPs) revealed quasi-spherical morphologies with particle sizes ranging from approximately 30 to 80 nm, as determined by ImageJ software analysis.
Fig. 3.
Field emission scanning electron microscopy (FE-SEM) images of green-synthesized magnesium oxide nanoparticles (MgO NPs) at two magnifications. Scale bars represent (a) 1 μm and (b) 500 nm, illustrating the morphology and size distribution of the nanoparticles.
Zeta potential
Zeta potential analysis was performed to evaluate the colloidal stability of MgO NPs. The measured zeta potentials for the MgO NPs synthesized using extract-to-solvent ratios of 30 D.W/70 ETH, 50 D.W/50 ETH, and 70 D.W/30 ETH were + 3.9 mV, − 6.2 mV, and − 3.9 mV, respectively. Although these values fall within a relatively low range, they suggest moderate colloidal stability, as particles with zeta potentials beyond ± 30 mV are generally considered highly stable in suspension. The observed values indicate a tendency for limited aggregation under physiological conditions, consistent with other reports on plant-mediated nanoparticle synthesis.
Hemolysis assay
As illustrated in Fig. 4, hemolysis assays revealed a concentration-dependent hemolytic effect for both Matricaria chamomilla extracts and their corresponding green-synthesized MgO nanoparticles (MgO-NPs). At the highest tested concentration (1 mg/mL), the 70 D.W/30 ETH extract induced the greatest hemolysis (87.5%), which was significantly higher than all other groups (P < 0.001). The 50 D.W/50 ETH and 30 D.W/70 ETH extracts also exhibited substantial hemolytic activity at this concentration, causing 48.13% and 33.20% hemolysis, respectively. In contrast, their corresponding MgO-NPs demonstrated markedly reduced hemolytic effects at 1 mg/mL, with values of 26.60% and 24.00%, respectively (P < 0.01 compared to their crude extracts).
Fig. 4.
Comparative hemolysis rates of Matricaria chamomilla hydroethanolic extracts and their corresponding green-synthesized magnesium oxide nanoparticles (MgO NPs) at different concentrations. Data represent the mean hemolysis percentages of each formulation, demonstrating concentration-dependent effects and reduced hemolytic activity in MgO NPs compared to crude extracts
At lower concentrations (0.5, 0.25, and 0.125 mg/mL), all MgO-NP formulations consistently induced hemolysis levels below 15%, with no statistically significant difference from the negative control group (P > 0.05), indicating improved biocompatibility of the nanoparticle formulations relative to the crude extracts.
MTT assay
As shown in Fig. 5, HDF cell viability decreased in a concentration-dependent manner following exposure to both green-synthesized MgO nanoparticle formulations. Notably, MgO NPs synthesized with a 50 D.W/50 ETH ratio exhibited significantly lower cytotoxicity compared to those prepared with a 30 D.W/70 ETH ratio at equivalent concentrations. The corresponding CC₅₀ values for each formulation are presented in Table 1.
Fig. 5.
MTT assay results showing the viability of HDF cells after 48 h of exposure to different concentrations (0.5, 1, and 1.5 mg/mL) of green-synthesized MgO NPs. M1: MgO NPs 30 D.W/70 ETH; M2: MgO NPs 50 D.W/50 ETH. Cell viability decreased in a concentration-dependent manner, with M2 demonstrating significantly lower cytotoxicity compared to M1 at equivalent concentrations. Statistical analysis was performed using Tukey’s multiple comparisons test; significance was denoted as ****P < 0.0001
Table 1.
CC₅₀ values (mg/mL) of green-synthesized MgO nanoparticles against HDF cells after 48 h of exposure
| Formulation | CC₅₀ (mg/mL) |
|---|---|
| 50 D.W/50 ETH | 1.30 |
| 30 D.W/70 ETH | 1.24 |
Anti-plasmodial impact of green synthesized MgO nanoparticles
According to Table 2; Figs. 6 and 7, the growth inhibition of P. falciparum 3D7 and K1 strains increased in a concentration-dependent manner following treatment with green-synthesized MgO nanoparticles. Notably, as demonstrated in Fig. 6, MgO NPs synthesized with a 30 D.W/70 ETH ratio exhibited the highest percentage of parasite growth inhibition at all tested concentrations.
Table 2.
IC₅₀ values of various green-synthesized MgO nanoparticle formulations and chloroquine against Plasmodium falciparum 3D7 and K1 strains
| Formulation | IC₅₀ of MgO NPs on P. falciparum 3D7 | IC₅₀ of MgO NPs on P. falciparum K1 | IC₅₀ of chloroquine on P. falciparum 3D7 | IC₅₀ of chloroquine on P. falciparum K1 |
|---|---|---|---|---|
| 50 D.W/50 ETH | 0.21(mg/ml) | 0.45(mg/ml) | 0.017(µg/ml) | 7.35(µg/ml) |
| 70 D.W/30 ETH | 0.22(mg/ml) | 0.42(mg/ml) | ||
| 30 D.W/70 ETH | 0.19(mg/ml) | 0.41(mg/ml) |
Fig. 6.
In vitro growth inhibition of Plasmodium falciparum 3D7 strain following treatment with green-synthesized MgO nanoparticles at 0.125, 0.25, 0.5, and 1 mg/mL. Two-way ANOVA indicated no significant differences between nanoparticle formulations at each concentration
Fig. 7.
In vitro growth inhibition of Plasmodium falciparum K1 strain treated with green-synthesized MgO nanoparticles and MgCl₂ at concentrations of 0.125, 0.25, 0.5, and 1 mg/mL. Two-way ANOVA indicated no significant differences between nanoparticle formulations at each concentration
Discussion
Malaria remains one of the most significant parasitic diseases globally, with the emergence of Plasmodium falciparum strains resistant to antimalarial drugs posing substantial challenges, particularly in developing countries. Although artesunate is highly effective against Plasmodium spp., its potential to cause irreversible adverse effects underscores the urgent need for safer, alternative therapies with improved toxicity profiles [31]. In this context, nanotechnology offers promising avenues, particularly through the environmentally friendly synthesis of metal-based nanoparticles with demonstrated antiplasmodial properties, enhanced efficacy, and reduced toxicity [32–34]. Among these, green synthesis methods utilizing plant extracts have gained considerable attention due to their biocompatibility, eco-friendliness, and cost-effectiveness. Numerous biological species have been investigated worldwide for their capacity to mediate the biosynthesis of antiplasmodial nanoparticles [35–37].
Ogunyemi et al. [17] previously reported the antibacterial properties of magnesium oxide nanoparticles (MgO NPs) synthesized using Matricaria chamomilla L. extract; however, their antiplasmodial activity remained unexplored until the present study. Characterization of the synthesized MgO NPs using UV-Vis spectroscopy, FTIR, DLS, FE-SEM, and zeta potential analysis confirmed successful nanoparticle formation, with characteristic absorption peaks around 250 nm in accordance with earlier reports [38, 39]. FTIR spectra identified functional groups associated with sesquiterpenes, flavonoids, coumarins, polyacetylenes, and phenolic compounds derived from M. chamomilla, which serve as both reducing and stabilizing agents during nanoparticle synthesis [17, 22]. The role of MgCl₂ as a reducing agent, alongside phytochemicals from the plant extract, proved essential for the reduction and stabilization of MgO NPs [23].
Dynamic light scattering (DLS) analysis revealed hydrodynamic particle sizes exceeding 100 nm, consistent with prior findings such as those by Alrashoudi et al., who reported MgO NPs averaging 126 nm [40], corroborating other literature values [39, 41]. In contrast, FE-SEM imaging displayed quasi-spherical particles ranging from 30 to 80 nm [42]. This discrepancy is attributable to the inherent differences between DLS and SEM measurements, as DLS assesses the hydrodynamic diameter - encompassing the core particle, surface coatings, and any associated solvent layers - whereas SEM measures the physical core size alone [43].
The measured zeta potential values were relatively low, indicating a tendency toward nanoparticle aggregation, which may adversely impact colloidal stability and biological interactions. Typically, zeta potentials below ± 20 mV are associated with poor colloidal stability, a finding consistent with recent nanomaterials research advocating for synthesis optimization to enhance nanoparticle stability and therapeutic performance [44]. Conversely, other studies have documented higher zeta potentials for similar green-synthesized MgO NPs, ranging from − 20.5 to −39 mV and even up to 86.79 mV, reflecting variability based on synthesis parameters [22, 39, 40]. Hemolysis assays revealed size- and dose-dependent erythrocyte lysis, with smaller MgO NPs (50 D.W/50 ETH) at 1 mg/ml inducing the highest hemolysis [16]. Interestingly, plant extracts alone exhibited significantly greater hemolytic activity compared to their nanoparticle-conjugated forms, implying that nanoparticle encapsulation mitigates the cytotoxic effects of certain phytochemicals. This protective effect is likely attributable to controlled release kinetics and modified bioavailability of active constituents when incorporated into nanoparticles, thereby reducing direct membrane interactions. Several studies have similarly reported enhanced biocompatibility and reduced cytotoxicity of green-synthesized nanoparticles compared to crude plant extracts [45–47]. According to ISO 10993-5:2009 guidelines for in vitro cytotoxicity assays, a material is considered cytotoxic if cell viability decreases below 70% relative to untreated controls [43]. In this study, MgO NPs synthesized with 50 D.W/50 ETH at 0.5 and 1 mg/ml, as well as those with 30 D.W/70 ETH at 0.5 mg/ml, maintained acceptable cytocompatibility profiles. Notably, higher cytotoxicity observed for MgO NPs synthesized with 30 D.W/70 ETH may be attributed to increased ethanol content, as Khor et al. [48] demonstrated that ethanol enhances the extraction of cytotoxic phytochemicals, including phenolic and flavonoid compounds, from plant matrices.
The antiparasitic potential of green-synthesized nanoparticles has been extensively explored for silver nanoparticles (Ag-NPs) against Leishmania spp., Giardia, and Acanthamoeba [49–53]. Previous reports also demonstrated MgO NPs’ inhibitory effects against Leishmania donovani [54]. Furthermore, a growing body of research has evaluated the antiplasmodial efficacy of nanoparticles derived from diverse biological sources. For example, Ag-NPs synthesized from Andrographis paniculata and Catharanthus roseus achieved inhibition rates of 20–83%, with IC₅₀ values between 50 and 63.64 µg/ml, while Ag-NPs produced from Ulva lactuca, Pteridium aquilinum, C. tomentosum, Azadirachta indica, and Ocimum sanctum demonstrated IC₅₀ values ranging from 0.313 to 88.34 µg/ml against P. falciparum strains [37]. In the present study, the green-synthesized MgO nanoparticles exhibited promising antiplasmodial activity, with IC₅₀ values ranging from 0.19 to 0.22 mg/ml for the chloroquine-sensitive 3D7 strain and from 0.41 to 0.45 mg/ml for the chloroquine-resistant [55]K1 strain across different extract ratios.
Limitations of this study include the absence of in vivo[56] efficacy data, insufficient evaluation of long-term nanoparticle stability, and a lack of cytotoxicity benchmarking against clinically established safety thresholds. Future investigations should address these aspects through comprehensive in vivo studies, stability profiling under physiological conditions, and comparative analyses with standard antimalarial agents to facilitate the translational potential of green-synthesized MgO NPs as viable antimalarial therapeutics.
Conclusion
Green synthesis of MgO nanoparticles using Matricaria chamomilla was successfully achieved, and these MgO-NPs showed promising antiplasmodial activity against Plasmodium parasites in vitro. While these preliminary results suggest potential antimalarial applications, further investigation is needed to confirm efficacy and safety. Specifically, in vivo studies and well-designed clinical trials are essential to validate therapeutic benefits and evaluate possible toxicities. Comprehensive histopathological analyses should also be conducted to assess the impact of MgO-NPs on vital organs. Additionally, exploring the activity of these nanoparticles against other pathogens could provide insights into their broader applicability. Overall, these findings warrant cautious optimism and highlight the need for extensive future research before clinical translation.
Supplementary Information
Acknowledgements
We would like to express our sincere gratitude to all those who contributed to the successful completion of this study. Special thanks are extended to Ms. Niloofar Khamsepour for her valuable technical assistance and support throughout the experimental procedures.
Abbreviations
- D.W
Distilled Water
- ETH
Ethanol
- MgO
Magnesium Oxide
- MgO-NPs
Magnesium Oxide Nanoparticles
- UV–Vis
Ultraviolet–Visible Spectroscopy
- FTIR
Fourier Transform Infrared Spectroscopy
- DLS
Dynamic Light Scattering
- FE-SEM
Field Emission Scanning Electron Microscopy
- OD
Optical Density
- RBC
Red Blood Cell
- MTT
3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide
- HDF
Human Dermal Fibroblast
- DMEM
Dulbecco’s Modified Eagle Medium
- FBS
Fetal Bovine Serum
- CCM
Complete Culture Medium
- RPMI
Roswell Park Memorial Institute Medium
- HEPES
4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid
- IC₅₀
Half-maximal Inhibitory Concentration
- CC₅₀
Half-maximal Cytotoxic Concentration
- Ag-NPs
Silver Nanoparticles
- ANOVA
Analysis of Variance
- SD
Standard Deviation
Authors’ contributions
Z.F : Technical procedures H.H: Parasitological consultant, Article editing, Plasmodium falciparum culturingM.N: Supervisor Gh.H : Co-supervisorA.R: Technical advisorM.Sh and SA.D: Nano technology Advisors L.F and A.K: Laboratory effortsS.Sh : Statistical consultant.
Funding
This study was funded by Tehran University of Medical Sciences, (Grant Number: 1402-4-211-6 9736).
Data availability
The data that support the findings of this study are available from the corresponding authors, Mehdi Nateghpour and Gholamreza Hasanpour, upon reasonable request.
Declarations
Ethics approval and consent to participate
This study did not involve direct experimentation on human subjects. It was conducted in accordance with the ethical principles outlined in the Declaration of Helsinki. All blood samples were anonymized leukocyte-reduced products obtained from the Blood Transfusion Organization’s blood bank. The study protocol was approved by the Ethics Committee of Tehran University of Medical Sciences (Ethics ID: IR.TUMS.MEDICINE.REC.1402.652), which also waived the need for informed consent.
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Contributor Information
Mehdi Nateghpour, Email: nateghpourm@sina.tums.ac.ir.
Gholamreza Hasanpour, Email: hassanpour@tums.ac.ir.
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This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data Availability Statement
The data that support the findings of this study are available from the corresponding authors, Mehdi Nateghpour and Gholamreza Hasanpour, upon reasonable request.