Berberine as a multi-target therapeutic agent for obesity: from pharmacological mechanisms to clinical evidence

Abstract

Obesity, clinically defined by pathological adipose tissue accumulation disrupting metabolic homeostasis, has reached pandemic proportions. The World Obesity Atlas 2024 reports over 1.5 billion projected cases by 2035, highlighting its growing threat among pediatric and adult populations globally. While newly approved pharmacotherapies such as glucagon-like peptide-1 receptor agonists (GLP-1 RAs) show efficacy, their clinical utility remains constrained by dose-dependent gastrointestinal complications, underscoring the urgent need for safer alternatives. This therapeutic gap has revitalized interest in natural bioactive compounds, particularly berberine (BBR)—a benzodioxoloquinolizine alkaloid derived from Coptis chinensis and related medicinal plants. Preclinical and clinical studies demonstrate BBR’s multimodal anti-obesity mechanisms: (i) adenosine monophosphate-activated protein kinase (AMPK) activation enhancing lipolysis and β-oxidation, (ii) peroxisome proliferator-activated receptor γ (PPAR-γ) suppression inhibiting adipogenesis, (iii) gut microbiota modulation improving metabolic endotoxemia, and (iv) uncoupling protein 1 (UCP1) upregulation promoting adipose browning. Notably, BBR metabolites demonstrate pharmacological activity comparable to or exceeding that of the parent compound. However, BBR’s translational applications face biopharmaceutical challenges, including poor intestinal absorption (< 1% bioavailability) due to P-glycoprotein efflux and first-pass metabolism. This comprehensive review critically evaluates recent advances in BBR’s anti-obesity pharmacology through three lenses: (1) preclinical and clinical evidence from randomized controlled trials, (2) molecular mechanisms underlying metabolic regulation, and (3) innovative strategies for pharmacokinetic optimization. Given its multi-target efficacy and botanical safety profile, BBR represents a cost-effective adjuvant for obesity management, particularly in resource-limited settings. Future research should prioritize standardized clinical protocols and pharmacogenomic studies to optimize therapeutic outcomes.

Introduction

Global epidemiological data reveal that over 2 billion individuals exceed healthy weight thresholds (body mass index (BMI) ≥ 25 kg/m²), including 600 million clinically classified as obese (BMI ≥ 30 kg/m²) [1]. Under the World Health Organization (WHO) Asia–Pacific criteria (overweight: BMI ≥ 23 kg/m²; obesity: BMI ≥ 25 kg/m²), diagnostic prevalence would rise significantly, with geospatial analyses identifying concentrated obesity clusters in BRICS nations and rapidly industrializing regions of Asia, Africa, and Latin America [2]. Projections from the World Obesity Atlas 2024 forecast a 96% increase in global obesity prevalence, from 800 million cases in 2020 to 1.5 billion by 2035, cementing its status as a pandemic requiring urgent multinational action [3].

Obesity arises from polygenic dysregulation of energy homeostasis and metabolic adaptation, mediated by interconnected molecular networks underlying pathogenesis:

(i) UCP1-mediated thermogenesis pathway governing energy expenditure; (ii) leptin-dependent pro-opiomelanocortin/neuropeptide Y (POMC/NPY) neuroendocrine modulation in appetite regulation; (iii) insulin-sensitive phosphatidylinositol 3-kinase-protein kinase B (PI3K/AKT) metabolic signaling cascade; (iv) AMPK/sirtuin 1-p53 (AMPK-SIRT1-p53) mitochondrial homeostasis axis; (v) GLP-1-cAMP-protein kinase A (GLP-1-PKA)-dependent nutrient-sensing mechanism; (vi) nuclear factor-κB (NF-κB)-driven inflammatory response network activated by endoplasmic reticulum (ER) stress; (vii) short-chain fatty acids-carbohydrate-responsive element-binding protein/sterol regulatory element-binding protein 1 (SCFAs-CHREBP/SREBP1) lipid metabolic circuitry modulated by gut microbial metabolites. This multidimensional framework contributes to heterogeneous clinical manifestations, complicating therapeutic outcomes while exacerbating obesity-associated comorbidities such as cardiovascular diseases (CVD), type 2 diabetes mellitus (T2DM), non-alcoholic fatty liver disease (NAFLD), obesity-related nephropathy (ORN) [4–8].

Current therapies—lifestyle interventions [9], pharmacotherapy (e.g., GLP-1 RAs) [10], and bariatric surgery (e.g., Roux-en-Y bypass) [11, 12]—exhibit limitations: non-pharmacological approaches suffer from suboptimal adherence rates, inadequate protocol personalization, unreasonable intervention measures, transient weight reduction effects, and substantial rebound risks [13–15], while drugs (e.g., phentermine, orlistat, liraglutide/semaglutide, naltrexone-bupropion, phentermine-topiramate) pose cardiovascular, gastrointestinal, pancreatitis, medullary thyroid carcinoma, and kidney metabolic risks [16–25]. Surgical options, though effective, incur procedural morbidity (e.g., postoperative pain, dumping syndrome, hypostatic pneumonia, stress ulcers, metabolic sequelae, and thromboembolic risks) and are restricted to severe cases (BMI ≥ 40 kg/m² or ≥ 35 kg/m² with comorbidities) or failed medical treatment [25–37].

These challenges drive interest in natural compounds such as Coptis chinensis rhizome-derived BBR, a low-cost botanical with multi-target anti-obesity effects. The anti-adipogenic effects of BBR include modulation of lipid metabolism, adipocyte browning, gut microbiota regulation, and anti-inflammatory pathways [38–41]. Despite proven efficacy in metabolic disorders, its clinical utility is hindered by poor oral bioavailability (< 1%) in rodent models pharmacokinetic studies due to intestinal efflux, hepatic metabolism, and physicochemical instability [42–44].

On February 1, 2025, we conducted a comprehensive literature search across PubMed, Web of Science, CNKI, and other databases. The search strategy employed the following keyword combinations related to BBR and obesity: ("berberine"[Mesh] OR"alkaloids"[Title/Abstract] OR"Coptis chinensis"[Title/Abstract] OR"natural products"[Title/Abstract]) AND ("obesity"[Mesh] OR"overweight"[Title/Abstract] OR"metabolic syndrome"[Title/Abstract] OR"adipose tissue"[Title/Abstract] OR"adipocyte differentiation"[Title/Abstract] OR"lipid"[Title/Abstract] OR"gastrointestinal microbiota"[Title/Abstract] OR"adipose tissue macrophages"[Title/Abstract] OR"inflammations"[Title/Abstract]). This review synthesizes evidence on BBR’s anti-obesity pharmacology, focusing on: (i) Clinical translatability of therapeutic effects; (ii) Molecular mechanisms underlying metabolic regulation; (iii) Innovative strategies for bioavailability enhancement.

Berberine pharmacokinetics and safety profile in obesity therapeutics

Berberine pharmacokinetics

Coptidis Rhizoma (the dried rhizome of Coptis chinensis), a botanical renowned for its isoquinoline alkaloid content, holds ethnopharmacological significance across East Asian medical traditions: Huang Lian in traditional Chinese medicine, Ouren in Japanese Kampo, and Hwang-Ryun in Korean herbalism [38]. Phytochemical analysis of its methanolic extract identifies n-butanol-soluble bioactive constituents, with BBR (chemical structure: 2,3-methylenedioxy-9,10-dimethoxyprotoberberine chloride) as the predominant component, alongside epiberberine, coptisine, palmatine, and magnoflorine [45]. This benzylisoquinoline alkaloid exhibits broad taxonomic distribution, naturally occurring in Berberis species such as B. aristata, B. petiolaris, B. aquifolium, B. thunbergii, and B. vulgaris [46].

Tissue distribution studies in rats demonstrate preferential hepatic accumulation of BBR following oral administration, with presystemic elimination in the small intestine and subsequent distribution to renal, muscular, cardiac, and pancreatic tissues [47]. Orally administered BBR in rats undergoes extensive phase I and II biotransformation (Fig. 1), primarily mediated by hepatic cytochrome P450 (CYP) isoforms CYP2D6 and CYP1A2. Phase I metabolism generates demethylated, demethylenated, and hydroxylated intermediates, while Phase II conjugation via uridine diphosphate-glucuronosyltransferases (UGT2B1 and UGT1A1) produces glucuronidated or sulfated metabolites for excretion [48, 49]. Notably, intravenous administration shifts metabolic dominance toward demethyleneberberine glucuronidation [47]. Intestinal microbiota in humans and rats further metabolize BBR through nitroreductase-mediated demethoxylation and hydrogenation, producing absorbable dihydroberberine (dhBBR), which reoxidizes post-absorption to restore BBR bioactivity [50]. Pharmacokinetic studies in rats and humans confirm BBR biotransformation into four primary metabolic metabolites: berberrubine (M1), thalifendine (M2), demethyleneberberine (M3), and jatrorrhizine (M4) [46, 47, 51]^.

Fig. 1.

Metabolic pathways of oral Berberine. Orally administered BBR undergoes extensive hepatic metabolism via CYP2D6/CYP1A2-mediated phase I reactions (demethylation, demethylenation, hydroxylation), followed by UGT2B1/UGT1A1-mediated phase II glucuronidation/sulfation to form excretable metabolites. Gut microbiota convert BBR into absorbable dhBBR via nitroreductase, which reoxidizes post-absorption. Key metabolites include berberrubine, thalifendine, demethyleneberberine, and jatrorrhizine. Tissue distribution favors liver accumulation, with presystemic elimination in the intestine, kidney, muscle, heart, and pancreas. Figure was created with BioGDP.com. References: [47]. CY cytochrome, UGT Uridine diphosphate-glucuronosyltransferase, dhBBR dihydroberberine. Graphical annotations: Red plus symbols (+) denote activation/stimulation of biological processes or pathway; Red prohibition icons (⊘) represent biological processes or pathway inhibition or suppression; Blue plus symbols (+) indicate combinatorial modulation of multiple substances. Text-associated markers: Black downward arrows (↓): Reduction or downregulation; Red upward arrows (↑): Enhancement or activation

Safety profile in obesity therapeutics

Having served as an over-the-counter gastrointestinal agent in Chinese pharmacopeia for seven decades, BBR demonstrates exceptional tolerability in clinical applications, particularly for diarrhea management [38]. Accumulated pharmacological evidence positions BBR as a safe and effective botanical alternative to synthetic anti-obesity drugs, attributable to its plant origin and favorable risk–benefit ratio. A randomized double-blind trial evaluating BBR Phytosome^™ (550 mg/tablet, twice daily) in patients with impaired fasting glucose (IFG) demonstrated unremarkable adverse event profiles comparable to placebo, confirming its short-term tolerability [52].

Nevertheless, gastrointestinal disturbances—including nausea (20%), constipation (16%), and hemorrhoidal complications (28%)—were observed in Bandala’s longitudinal studies, though these symptoms typically subsided during the initial treatment phase [53]. Notably, co-administration strategies have emerged to mitigate these effects. Cui et al. identified quercetin (QR), a bioactive constituent of Amomum villosum Lour. (AVL), as an effective adjuvant for alleviating BBR-induced constipation through synergistic pharmacological interactions [54]. Although the existing evidence supports BBR’s overall safety profile, multicenter randomized controlled trials remains imperative to establish standardized clinical protocols.

Evidence for Berberine’s antiadiposity effects

Emerging translational research has progressively elucidated the therapeutic potential of BBR in metabolic disorder management, with particular emphasis on its anti-obesity properties across experimental models and human trials.

Berberine’s antiobesity efficacy assessment

Preclinical pharmacological evidence

Numerous experimental investigations employing animal models have demonstrated BBR’s dose-dependent anti-obesity effects (Table 1).

Table 1.

Summary of preclinical studies on Berberine’s metabolic effects

Model	Intervention	Key findings	Molecular targets	Refs.
Obese mice	Oral BBR (150 mg/kg/day) for 6 weeks	•Attenuated HFD-induced weight gain as compared to placebo (658.58 ± 54.04 vs 715.59 ± 46.70 g) •No caloric intake alteration	Reduces mRNA levels of IL-1β, PAI-1, STAMP-2, NADPHox, MCP-1 and F4/80, restores expression of claudin-1 and ZO-1	[55]
Obese mice	Intraperitoneal BBR (10 mg/kg) for 3 weeks	•Reduced food consumption •Lowered body weight and adiposity •Improved leptin (compared to placebo: 30.8 ± 13 ng/ml vs 39.8 ± 4.5 ng/ml) and glucose homeostasis	Suppresses NPY expression	[56]
Obese mice	Oral BBR (200 mg/kg) for 2 weeks	•Restored mesenteric arteriole tone •Normalized PVAT NO/NA balance •Improved vascular dysfunction	Suppresses eNOS expression	[57]
Hyperlipidemic mice	Oral BBR (200 mg/kg) for 56 days	•Reduced hepatic lipid accumulation •Enhanced Blautia producta abundance •Upregulated LDLR-mediated clearance	Activates butyric acid-producing key enzymes: Buk	[58]
Obese mice	Oral BBR (100/200 mg/kg/day, 5 times/week)	•Mitigated HFD-induced obesity (U73122 partially inhibited) •Activated pleiotropic metabolic pathways •Up-regulated the level of GLP-1 and IL-25	Activates TAS2R-IL-25 signaling pathway	[59]
Obese mice	Oral BBR (150/300 mg/kg/day) for 4 weeks	•Dose-independent weight reduction •Appetite-independent efficacy •Improved glycemic and lipidemia parameters	Activates RhoA/ROCK signaling pathway	[60]
Obese mice	Oral BBR (100 mg/kg)	•Ameliorated insulin resistance •Reduced total body mass and AT ratio •Normalized serum lipidemia biomarkers •Attenuated diet-induced adipogenesis	Downregulates miR-27a	[61]
Diabetic mice	Oral BBR (100/200/500 mg/kg) for 30 days	•Dose-responsive improvement of lipodystrophy •Improved glycemic parameters	Suppresses gluconeogenic enzymes: PEPCK, G6Pase, and FBPase	[44]
Obese mice	Oral BBR (100 mg/kg) for 8 weeks	•Enhanced muscle strength/function •Reduced ectopic lipid deposition •Inhibited myocyte apoptosis	Activates FUNDC1-mediated skeletal muscle mitophagy	[62]
Obese mice	Daily by gavage BBR (150/300 mg/kg) for 4 weeks	•Reduced lipid droplet •Attenuate hepatic steatosis	Regulates BSCL2 and PPARα-mediated CIDEA/PLIN4/PLIN2 signaling pathway	[63]
Overweight PCOS mice	Intragastric administration of BBR (4.5 mg/kg/d) for 28 day	•Improve the sex hormone levels •Improve ovarian function •Improve glucose and lipid metabolism levels •Reduces levels of Ghrelin while enhancing levels of CCK, PYY, and GLP-1	Activates PI3K/AKT signaling pathway	[64]
Transgenic mouse model (Alb-Luc-UTR)	Oral BBR (200 mg/kg/day) for 14 days	•Lowered the liver abundance of mRNA destabilizing protein hnRNP D	Reduces hnRNP D abundance	[147]

BBR Berberine, HFD high-fat diet, PVAT perivascular adipose tissue, NO/NA nitric oxide/noradrenaline, LDLR low-density lipoprotein receptor, GLP-1 Glucagon-like peptide-1, IL-25 interleukin-25, AT adipose tissue, IL-1β interleukin-1β, PAI-1 plasminogen activator inhibitor-1, STAMP-2 six transmembrane protein of prostate-2, NADPHox nicotinamide-adenine dinucleotide phosphate oxidase, MCP-1 monocyte chemoattractant protein-1, F4/80 EGF-like module-containing mucin-like hormone receptor-like 1, ZO-1 zonula occludens-1, NPY neuropeptide Y, eNOS Endothelial nitric oxide synthase, Buk butyrate kinase, TAS2R bitter-taste receptors, RhoA Ras homolog gene family member A, ROCK Rho-associated kinase, miR-27a miRNA-27a, PEPCK Phosphoenol pyruvate carboxykinase, G6Pase glucose-6-phosphatase, FBPase Fructose-1,6-bisphosphatase, FUNDC1 FUN14 domain containing 1, BSCL2 Berardinelli‐Seip congenital lipodystrophy 2, PPARα peroxisome proliferator‐activated receptor α, CIDEA cell death‐inducing DNA fragmentation factor alpha‐like effector A, PLIN perilipin, PCOS polycystic ovary syndrome, CCK cholecystokinin, PYY Peptide YY, PI3K/AKT phosphatidylinositol 3-kinase-protein kinase B, Alb albumin, Luc luciferase, UTR untranslated region, hnRNP D heterogeneous nuclear ribonucleoprotein D

In a pivotal study by Xu et al. 6-week administration of BBR (150 mg/kg/day) effectively attenuated body weight gain in high-fat diet (HFD)-induced obese rats without affecting caloric intake [55]. Complementary research by Park et al. demonstrated that parenteral BBR administration (10 mg/kg daily for 3 weeks) in HFD-fed murine models significantly reduced in food intake, body weight, adiposity indices, leptin concentrations, and glycemic parameters when compared with untreated controls [56]. Notably, vascular pathophysiology investigations by Wang et al. identified novel mechanisms involving mesenteric microvascular dysregulation in obese rats, characterized by abnormal nitric oxide (NO) overproduction and diminished noradrenaline (NA) synthesis in perivascular AT (PVAT). These pathological alterations were normalized through BBR intervention (200 mg/kg), demonstrating its vascular modulatory capacity [57]. Concurrently, Yang et al. documented BBR’s lipid-lowering efficacy (200 mg/kg oral dose) in hyperlipidemic mice through gut microbiota modulation, specifically enhancing Blautia producta populations, which subsequently upregulated hepatic low-density lipoprotein (LDL) receptor expression and promoted cholesterol clearance in HepG2 cells [58]. Dose–response analyses across studies confirm BBR’s anti-adipogenic potential. Sun et al. established that oral supplementation (100–200 mg/kg/day) mitigated HFD-induced weight gain through pleiotropic mechanisms [59]. Wang et al. further showed that both low-dose (150 mg/kg/day) and high-dose (300 mg/kg/day) regimens over 4 weeks achieved comparable weight reduction in obese mice, independent of appetite modulation [60]. In corroborative studies by Du et al. oral BBR administration (100 mg/kg/day) demonstrated marked therapeutic efficacy in HFD-induced murine models, manifesting as (a) mitigation of insulin sensitivity impairment, (b) reduction in both total body mass and adipose tissue proportion, and (c) normalization of serum metabolic markers, collectively contributing to substantial attenuation of diet-induced adiposity pathogenesis [61]. Gupta et al. systematically quantified BBR’s dose-dependent amelioration (100, 200, and 500 mg/kg) of glucocorticoid-induced lipodystrophy, confirming its metabolic regulatory capacity across diverse etiological models [44]. Wu et al. demonstrated that chronic oral BBR administration (100 mg/kg in saline) over 8 week significantly enhanced muscular strength and neuromuscular performance in rodent models. Notably, this regimen not only mitigated body mass accumulation and ectopic lipid deposition but also alleviated obesity-associated dyslipidemia, concurrently counteracting myofiber degeneration and apoptosis in skeletal tissue [62]. Wang’s et al. found that 4-week gavage administration of BBR significantly alleviated hepatic lipid accumulation by modulating perilipin family protein expression involved in lipid droplet (LD) metabolism, thereby reducing LD diameter in hepatocytes [63]. Zhang et al. established that combined therapy with berberine and Jianpi Yishen Huazhuo formulation (JPYSHZF) in obese PCOS rats ameliorated PCOS through PI3K/AKT pathway activation, addressing endocrine dysfunction, lipid-glucose dysmetabolism, and gut hormone imbalance [64].

Clinical pharmacological evidence

Similarly, emerging clinical evidence from human trials has substantiated the dose-dependent anti-adiposity effects of BBR across diverse metabolic parameters (Table 2).

Table 2.

Summary of clinical trials on Berberine’s antiobesity effects

Type of study	Number of participants	Intervention	Key findings	Adverse effects	Refs.
Non-RCT	10 eligible patients	Oral BBR (500 mg thrice daily) for 12 weeks	•An average weight loss (approximately 2.3 kg) •12.2% decrease in TC and 23% reduction in TG •Improved serum lipid profiles	Abdominal pain	[65]
Randomized study	50 eligible patients	Oral BBR (500 mg thrice daily) lasted 3 months	•Significant BMI reduction •Decreased visceral fat proportion •Reduced adipocyte volume	Nausea, constipation, hemorrhoidal bleeding	[53]
Randomized study	60 eligible patients	Oral BBR (1.5 g/day) over 12 weeks	•Clinically relevant waist circumference reduction •BMI improvement in obesity and prediabetic populations		[67]
Randomized study	70 eligible patients	Oral BBR (1500 mg/day) for 3 months	•Decreased trunk fat •Attenuated hepatic lipid accumulation •Ameliorated steatosis •Reduced liver fibrosis	Flatulence, a bitter aftertaste	[68]
Meta-analysis (6 RCTs)	501 eligible patients	Oral BBR (1000 mg/day) for 12 weeks	•Improved lipid metabolism •Enhanced insulin sensitivity •Reduced hepatic steatosis progression	Not explicitly mentioned	[69]

BBR Berberine, TC total cholesterol, TG triglyceride, BMI body mass index, RCTs randomised controlled trials

In a pivotal 12-week intervention study by Hu et al. daily supplementation with 1.5 g BBR elicited marked reductions in serum lipid profiles among obese participants, achieving 23% and 12.2% decreases in triglyceride (TG) and total cholesterol (TC) concentrations, respectively [65]. Bandala et al. corroborated these findings through a 3-month randomized trial in which thrice-daily preprandially administration of 500 mg BBR tablets resulted in statistically significant reductions in adiposity indices, including BMI, visceral fat proportion, and overall adipocyte volume [53]. Population-specific benefits were identified by Chen et al. in cohorts with obesity and prediabetes, where 12-week BBR interventions (1.5 g/day) produced clinically relevant decreases in waist circumference and BMI [66, 67]. Mechanistic insights from a double-blind placebo-controlled trial by Koperska et al. demonstrated that 1500 mg/day BBR administration over 3 months attenuated trunk fat mass and hepatic lipid accumulation, liver fibrosis and steatosis severity [68]. In addition, a comprehensive meta-analysis by Wei et al. encompassing six randomized clinical trials (RCTs; n = 501) quantitatively confirmed BBR’s therapeutic potential, establishing 1000 mg/day as an effective dosage for improving lipid parameters, insulin sensitivity, hepatic function markers, and steatosis progression [69, 70].

Synthesizing preclinical and clinical evidence, these findings validate BBR’s anti-adipogenic efficacy and highlight its translational potential for obesity management. Complementary bibliometric analysis by Gasmi et al. systematically evaluated four decades of research (1982–2022), concluding that BBR exhibits sufficient therapeutic validity to warrant clinical implementation in adiposity-related disorders [71]. Collectively, these results position BBR as a multimodal therapeutic agent capable of addressing adiposity, metabolic dysregulation, and obesity-related comorbidities.

Mechanistic basis of Berberine’s antiadipogenic effects

Berberine-mediated suppression of adipocyte differentiation

Adipogenesis involves the phenotypic conversion of preadipocytes into lipid-laden mature adipocytes (Fig. 2). This process is characterized by sequential activation of adipogenic transcriptional regulators and adipocyte-specific genetic programs [38]. Pharmacological interventions targeting these molecular mediators represent a strategic approach to inhibit excessive AT expansion.

Fig. 2.

Berberine inhibits adipocyte differentiation. In 3T3-L1 preadipocytes, BBR downregulates PPAR-γ and C/EBP-α (core adipogenic drivers) while upregulating PPAR-δ, which antagonizes lipid accumulation. It suppresses CREB phosphorylation, disrupting cAMP/PKA signaling and subsequent activation of C/EBP-β and PPAR-γ. BBR also inhibits Gal-3, a mediator of PPAR-γ nuclear translocation and ectopic adipogenesis, via transcriptional repression and miRNA-mediated mRNA destabilization. In addition, BBR enhances antioxidant defenses via Nrf2 activation and improves insulin sensitivity through AMPK/TLR4 pathways, collectively modulating adipokine networks to counteract obesity-related metabolic dysfunction. Figure was created with BioGDP.com. References: [4, 38, 72]. C/EBP-β CCAAT/enhancer-binding protein-β, C/EBP-δ CCAAT/enhancer-binding protein-δ, PPAR-γ peroxisome proliferator-activated receptor γ, C/EBP-α CCAAT/enhancer-binding protein-α, PPAR-δ peroxisome proliferator-activated receptor δ, Ho-1 heme oxygenase-1, CREB cAMP-response element-binding protein, IBMX 3-isobutyl-1-methylxanthine, Gal-3 Galectin-3, NOX1 NADPH Oxidase I, IMAT intermuscular adipose tissue, Nrf2 nuclear factor erythroid 2-related factor 2, SOD superoxide dismutase, GPX glutathione peroxidase, GSH glutathione. For graphical annotations and text associated markers given within the image, please refer Fig. 1 caption

Modulation of CCAAT/enhancer-binding protein-α, peroxisome proliferator-activated receptor γ, and peroxisome proliferator-activated receptor δ activities in 3T3-L1 adipocytes by Berberine

Adipogenic differentiation in mice follows a continuous transcriptional cascade (Fig. 2): The process initiates with hormonal induction of transient early regulators CCAAT/enhancer-binding protein-β (C/EBP-β, Fig. 2) and CCAAT/enhancer-binding protein-δ (C/EBP-δ, Fig. 2), which subsequently activate master transcriptional drivers peroxisome proliferator-activated receptor γ (PPAR-γ, Fig. 2) and CCAAT/enhancer-binding protein-α (C/EBP-α, Fig. 2). These core factors coordinate the expression of terminal differentiation markers (e.g., AP2) that establish adipocyte identity [72]. During terminal differentiation, PPAR-γ and C/EBP-α reciprocally sustain their expression through positive feedback loops, maintaining elevated levels essential for lipid droplet formation and metabolic programming [72].

The 3T3-L1 preadipocyte model serves as a gold-standard experimental platform for investigating molecular determinants of adipogenic commitment and transcriptional regulation during adipocyte maturation [38]. Temporal expression profiling in this system reveals C/EBP-α transcriptional activation during differentiation initiation, confirming its regulatory role in sustaining PPAR-γ expression [73]. Analyses demonstrate C/EBP-α’s constitutive presence in both white and brown adipocyte lineages in mice, where overexpression accelerates differentiation kinetics, while endogenous concentrations progressively increase during terminal maturation [74]. Crucially, experiments utilizing non-adipogenic fibroblasts establish that C/EBP-α-mediated adipogenesis requires PPAR-γ co-activation, underscoring the interdependence of these transcriptional regulators [75].

PPAR-γ, a nuclear receptor superfamily member, serves as the principal adipogenic switch governing white and brown adipocyte differentiation [76, 77]. It regulates lipid metabolism through transcriptional control of fatty acid-processing enzymes and adipokine secretion [78]. Mechanistically, PPAR-γ sequentially upregulates C/EBP-β and C/EBP-δ during differentiation initiation before stabilizing C/EBP-α expression in mature adipocytes, as demonstrated in 3T3-L1 cells [79]. In contrast, PPAR-δ (Fig. 2) demonstrates counterregulatory properties [80].

Experimental evidence reveals BBR’s multimodal interference with this transcriptional network. Choi et al. demonstrated BBR’s concentration-dependent suppression of PPAR-γ and C/EBP-α in 3T3-L1 models, exhibiting superior anti-adipogenic potency compared with other alkaloids [38]. Yang et al. demonstrated that BBR suppresses lipid deposition in porcine adipocytes in a concentration- and time-dependent manner through heightening AMPK alpha (AMPKα) phosphorylation, which downregulates key adipogenic regulatory genes including PPAR-γ2, C/EBP-α, acetyl-CoA carboxylase-1 (Acc-1), fatty acid synthase (Fas), fatty acid binding protein 4 (Fabp4), and stearoyl-CoA desaturase 1 (Scd1) [81]. Mechanistic studies [80] by Shou et al. elucidated BBR’s capacity to activate PPAR-δ in both in vitro (3T3-L1 adipocytes) and in vivo (HFD-fed murine models). Transcriptomic analyses revealed enhanced PPAR-δ binding to cognate promoters following BBR treatment. This ligand-receptor interaction upregulated key downstream targets such as mitochondrial uncoupling protein 2 (Ucp2) and pyruvate dehydrogenase kinase 4 (Pdk4), demonstrating BBR-mediated activation of PPAR-δ transcriptional networks. Activated PPAR-δ exhibited bidirectional modulation: suppressing C/EBP-α and PPAR-γ promoter activities while enhancing heme-oxygenase-1 (Ho-1) transcription. This dual regulatory mechanism underlies BBR’s metabolic reprogramming effects.

Suppression of cAMP-response element-binding protein, CCAAT/enhancer-binding protein-β, and galectin-3 activities by Berberine

Activation of cAMP-response element-binding protein (CREB, Fig. 2) serves as a critical initiator of adipogenic commitment, orchestrating early-phase transcriptional activation of C/EBP-β during adipocyte lineage differentiation. This signaling cascade in mouse embryonic fibroblasts (MEFs) and 3T3-L1 preadipocytes ultimately drives the expression of terminal differentiation regulators PPAR-γ and C/EBP-α [82]. Pharmacological agents such as 3-isobutyl-1-methylxanthine (IBMX) and cAMP mimetics enhance adipogenic progression through CREB pathway potentiation [83].

Galectin-3 (Gal-3, Fig. 2), a β-galactoside-binding lectin, demonstrates dual regulatory roles in adipogenesis [84]. Immunophenotyping reveals its predominant Gal-3 expression in preadipocytes of humans and HFD-fed mice, when compared with negligible levels in mature adipocytes, with temporal upregulation correlating with adipocyte proliferation and obesity pathogenesis [85, 86]. Functional analyses indicate that Gal-3 mediates preadipocyte mitogenesis via carbohydrate-dependent interactions, whereas genetic ablation studies demonstrate impaired terminal adipogenic differentiation without overt adipocyte apoptosis or altered fat distribution [85, 87]. Florido et al. evaluated 8687 participants and found elevated Gal-3 levels associated with increased BMI [88]. Clinical observations further implicated its role in obesity-related oxidative stress through NADPH Oxidase I (NOX1)-dependent superoxide generation in microvascular endothelia [89–93]. Complementary studies in HFD-fed mice reveal Gal-3’s upstream regulatory role in PPAR-γ activation [94].

Obesity-associated intermuscular adipose tissue (IMAT, Fig. 2) is proposed to originate from PDGFRα⁺ mesenchymal progenitors [95]. Takada et al. suggested that obesity-induced Gal-3 secretion from immune cells in obese mice hijacks PDGFRα⁺ progenitor differentiation toward ectopic adipogenesis via PPAR-γ nuclear translocation [96, 97]. Moreover, genetic ablation of Gal-3 in murine models attenuates intermuscular adipose deposition during tissue repair by downregulating adipogenic master regulators such as PPAR-γ and C/EBP-α [97].

Mechanistic investigations by Zhang et al. elucidated BBR’s capacity to attenuate IBMX/forskolin-induced CREB phosphorylation, thereby disrupting C/EBP-β promoter binding and subsequent PPAR-γ and C/EBP-α induction during 3T3-L1 differentiation. This inhibition of the cAMP/PKA pathway constitutes a pivotal anti-adipogenic mechanism [98]. Wang et al. demonstrated that BBR exerts dual suppression via transcriptional repression (Gal-3 promoter inhibition) and post-transcriptional modulation (Gal-3 mRNA destabilization and miRNA let-7d upregulation) in obese mice [94].

Berberine-mediated modulation of metabolic adipokine expression

Emerging evidence delineates BBR’s capacity to orchestrate redox homeostasis through mitochondrial respiratory chain modulation (Fig. 2). Utami et al. revealed that BBR-induced suppression of Complex I electron transport triggers nuclear translocation of nuclear factor erythroid 2–related factor 2 (Nrf2), subsequently upregulating antioxidant defense systems in diabetic rat via transcriptional activation of superoxide dismutase (SOD), glutathione peroxidase (GPX), and glutathione (GSH) biosynthesis pathways [99]. This redox-regulatory mechanism (Fig. 2) synergizes with BBR’s metabolic effects, notably through AMPK-dependent and Toll-like receptor 4 (TLR4) -mediated enhancement of insulin responsiveness and cellular glucose utilization, collectively establishing its multimodal regulatory potential over adipokine networks [4, 100, 101]. Such coordinated molecular interactions provide the pathophysiological basis for BBR’s therapeutic efficacy in metabolic dysregulation. Ye et al. further substantiated its translational value across 18 included randomized trials, positioning BBR as a frontier candidate for mitigating obesity-associated metabolic syndrome and cardiovascular risks through systemic adipokine modulation [102].

Berberine-mediated adipose tissue browning and thermogenic regulation

Adipose depots are functionally stratified into energy-storing white adipose tissue (WAT, Fig. 3) and thermogenic brown adipose tissue (BAT, Fig. 3), with beige adipose tissue (BeAT, Fig. 3) representing a transitional phenotype capable of BAT-like thermogenesis. WAT primarily stores energy as triglycerides within unilocular lipid droplets, mobilizing free fatty acids (FFA) during metabolic demand [103]. In contrast, BAT facilitates energy dissipation via uncoupling protein 1 (UCP1)-dependent mitochondrial uncoupling, bypassing ATP synthesis to generate heat [104, 105]. Beige adipocytes, arising either from Myf5-negative precursors or transdifferentiated mature WAT (termed WAT browning), exhibit spatial distribution patterns distinct from classical BAT depots [106–110].

Fig. 3.

Berberine-mediated white adipose tissue browning and thermogenic regulation. BBR augments thermogenic capacity within adipose depots by two principal strategies exist: (1) inducing phenotypic conversion of WAT into beige adipocytes, and (2) potentiating the pre-existing BAT activity. Figure was created with BioGDP.com. Reference: [103]. WAT white adipose tissue, BAT brown adipose tissue, BeAT beige adipose tissue, FFA free fatty acids, UCP1 uncoupling protein 1, β-HB β-hydroxybutyrate, EDN3/EDNRB endothelin 3/endothelin receptor B, FNDC5 Fibronectin type III domain-containing protein 5, β3ARs β3-adrenergic receptors, NR2F6 nuclear receptor subfamily 2 group F member 6, NRF1 nuclear respiratory factor 1, GDF15 growth differentiation factor 15, ISR integrated stress response. For graphical annotations and text associated markers given within the image, please refer Fig. 1 caption

The thermogenic potential of BAT and WAT browning has garnered significant attention as a therapeutic strategy against obesity, owing to their capacity to enhance energy expenditure through non-shivering thermogenesis [104, 111, 112]. Two principal strategies exist for augmenting thermogenic capacity (Fig. 3): inducing phenotypic conversion of WAT into beige adipocytes, and potentiating the pre-existing BAT activity. Subcutaneous adipocytes exhibit greater browning propensity as compared to visceral counterparts, attributable to enhanced differentiation plasticity [113].

Adipose browning encompasses the transdifferentiation of lipid-storing WAT into UCP1-expressing beige adipocytes, a process modulated by external stimuli including β-adrenergic activation, cold acclimation, and physical exertion [114, 115]. In rodents, this phenotypic shift is governed by a transcriptional network involving master regulators (PRDM16, PPAR-γ, PGC-1α, C/EBP-β) and metabolic mediators (FGF21, BMP7, adiponectin), mitochondrial dynamics modulators (ATGL, irisin) and epigenetic factors (zinc finger protein) [116–120]. The recent mechanistic breakthroughs elucidate novel pathways driving WAT browning (Fig. 3):

Ketone Body Signaling: β-hydroxybutyrate (β-HB) enhances mitochondrial biogenesis and lipolytic flux while upregulating thermogenic gene clusters in 3T3-L1 cells and rat models [121].

Neuropeptide crosstalk: EDN3/EDNRB signaling promotes white adipocyte progenitor differentiation via intracellular cAMP and EPAC1-ERK-mediated pathway activation in obese mice [122].

Mitochondrial remodeling: Fibronectin type III domain-containing protein 5 (FNDC5)/irisin orchestrates mitochondrial fusion-fission balance through upregulation of TFAM, MFN1, MFN2, and OPA1, and downregulation of DNM1L and FIS1 in patients with obesity (n = 125) and HFD-fed rats (n = 29), while suppressing mitophagy during cold adaptation [123].

Adrenergic-metabolic axis: β3-adrenergic receptors (β3ARs) stimulation activates mTOR-lipin1 signaling to potentiate adipose browning in RIIβ-KO (RIIβ-/-) mice [124].

Nuclear receptor regulation: Nuclear receptor subfamily 2 group F member 6 (NR2F6) emerges as a transcriptional activator of PPAR-γ, coordinating BAT adipogenesis and systemic energy homeostasis in male wild-type (WT) and Pdgfra-Cre-mediated Nr2f6 knockout (NR2F6-PKO) HFD-fed mice [125].

Systematic characterization of UCP1-activating stimuli provides critical insights into BAT-mediated thermogenic regulation. Gong et al. categorized UCP1 modulators into three classes (Fig. 3): (i) physical/environmental stimuli (cold exposure, exercise), (ii) traditional medicine interventions (acupuncture, herbal formulations), and (iii) pharmacological/dietary modulators (gut microbiota metabolites, nutraceuticals) [126]. Experimental studies demonstrate BBR’s coordinated upregulation of thermogenic markers in AT. Mechanistically (Fig. 3), pharmacological induction with BBR in db/db mice and wild-type mice activates BAT-specific genes (UCP1, PGC-1α), mitochondrial biogenesis components (COXIV, ATP synthase and cytochrome C), and transcription factors (PPAR-α, nuclear respiratory factor 1 (NRF1) and mtTFA) in WAT models [127]. BBR chloride exhibits dual topoisomerase inhibition while orchestrating metabolic reprogramming through UCP1 upregulation and ATP synthesis suppression, redirecting energy expenditure toward thermogenesis [128]. The AMPK/PGC-1α axis constitutes a pivotal mediator of BBR’s thermogenic effects [127]. Yao et al. demonstrated AMPK/PGC-1α-dependent mitigation of ectopic lipid deposition via enhanced mitochondrial β-oxidation and biogenesis by BBR in murine skeletal muscle [129]. Ling et al. further delineated BBR’s epigenetic regulation through the AMPK-α-ketoglutarate (α-KG)-PRDM16 axis in mice and humans, where α-KG stabilizes PRDM16 transcription by inhibiting promoter methylation dynamics [130]. Sun et al. established a BBR’s multimodal anti-obesity mechanism in mice involving NAD⁺-dependent SIRT1-mediated deacetylation, autophagy protein 5 (APG5)-dependent autophagy, and FGF21 endocrine signaling that synergistically promote WAT browning [131].

Emerging evidence implicates growth differentiation factor 15 (GDF15, Fig. 3) as a key endocrine mediator. This cytokine suppresses appetite while reducing AT mass and stimulating lipolysis and thermogenesis [132]. Although adipocyte-derived GDF15 secretion is typically low, BBR elevates circulating GDF15 levels via BAT-secreted integrated stress response (ISR) activation in diet-induced obese (DIO) mice, contributing to weight loss [132, 133].

Collectively, these findings position BBR as a master regulator of adipose plasticity, bridging mitochondrial reprogramming, transcriptional control, and interorgan crosstalk to combat metabolic dysfunction.

Lipid-modulatory properties of Berberine

Obesity-associated dyslipidemia, characterized by elevated triglycerides, low-density lipoprotein cholesterol (LDL-C), and total cholesterol, predisposes individuals to atherogenesis through endothelial dysfunction and oxidative stress amplification [134–136]. Clinical investigations in hypercholesterolemic patients validate BBR’s lipid-lowering efficacy, including reductions in triglycerides (22–35%), total cholesterol (16–29%), and LDL-C (20–25%) [137, 138]. BBR counteracts atherosclerotic progression via multimodal mechanisms (Fig. 4):

1. Foam cell inhibition: By activating the AMPK/SIRT1/PPAR-γ signaling axis, BBR suppresses lectin-like oxidized LDL receptor 1 (LOX-1)-mediated oxidized LDL uptake, attenuating macrophage-derived foam cell formation—the seminal event in atherogenesis—in THP-1-derived foam cells [139]. Foam cell accumulation leads to fibrous plaque development, which evolves into atherosclerotic lesions [140].

2. Plaque stabilization: Through nuclear factor erythroid 2-related factor 2 (NRF2)/solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) pathway activation and Acyl-CoA synthetase long chain family member 4 (ACSL4) inhibition, BBR mitigates endothelial ferroptosis while reducing necrotic core formation and enhancing plaque stability in ApoE-/- HFD-fed mice [141, 142].

Fig. 4.

Lipid-modulatory properties of Berberine. BBR activates AMPK/SIRT1/PPAR-γ signaling to suppress oxidized LDL uptake, inhibiting macrophage foam cell formation and stabilizing atherosclerotic plaques via NRF2/SLC7A11/GPX4 activation. BBR enhances hepatic LDLR expression through AMPK-ERK pathways and miR-27a inhibition, improving cholesterol clearance. It upregulates PPAR-α/CPT-1 to boost β-oxidation and accelerates bile acid synthesis via CYP7A1/SREBP2. In addition, BBR restricts intestinal lipid absorption by inhibiting RhoA/ROCK1 signaling, promoting lacteal endothelial barrier integrity. These multimodal actions reduce triglycerides, LDL-C, and cholesterol while restoring adipose endocrine homeostasis. Figure was created with BioGDP.com. Reference: [60, 134]. TG triglycerides, LDL-C low-density lipoprotein cholesterol, TC total cholesterol, LOX-1 lectin-like oxidized LDL receptor 1, NRF2 nuclear factor erythroid 2-related factor 2, SLC7A11 recombinant solute carrier family 7 member 11, GPX4 glutathione peroxidase 4, ACSL4 Acyl-CoA Synthetase Long Chain Family Member 4, Vis visfatin, Res resistin, Ap apelin, Ome omentin, ERK extracellular signal-regulated kinase, hnRNP D heterogeneous nuclear ribonucleoprotein D, JNK c-Jun N-terminal kinase, CPT-1 carnitine palmitoyltransferase 1, LECs lymphatic endothelial cells, RhoA Ras homolog gene family member A, ROCK1 Rho-associated kinase 1. For graphical annotations and text associated markers given within the image, please refer Fig. 1 caption

Meanwhile, AT expansion and adipocyte hypertrophy in obesity drive pathogenic adipocytokine secretion [e.g., visfatin (Vis), resistin (Res), apelin (Ap)] while suppressing protective factors [e.g., omentin (Ome)] (Fig. 4) [143, 144]. Bandala et al. demonstrated that BBR restores adipose endocrine homeostasis in obese patients via enhancing FA oxidation, suppressing PPAR-γ-mediated lipogenic pathways, and reducing adipokine-mediated inflammation [53]. Du et al. further certified that BBR inhibits miR-27a levels, improving IR in obese mice [61]. Mechanistically, BBR enhances LDLR expression through AMPK-dependent Raf-1 and extracellular signal-regulated kinase (ERK) signaling activation in hyperlipidemic rat models, while destabilizing heterogeneous nuclear ribonucleoprotein D (hnRNP D)-mediated mRNA decay in Alb-Luc-UTR transgenic mice, thereby improving hepatic cholesterol clearance [145–147]. Investigations into BBR’s lipid-modulatory effects reveal dependency on the c-Jun N-terminal kinase (JNK) pathway. Lee et al. demonstrated that pharmacological JNK blockade abrogates BBR-mediated LDLR upregulation, establishing JNK activation as a prerequisite for its lipid-lowering activity [148].

Complementary evidence from piscine models indicates that oral BBR administration (50–100 mg/kg) enhances hepatic PPAR-α and carnitine palmitoyltransferase 1 (CPT-1) expression in Nile tilapia (Oreochromis niloticus), augmenting β-oxidation and reducing systemic lipid burden [149]. In addition, BBR modulates cholesterol homeostasis in HFD-fed mice by accelerating bile acid synthesis via upregulation of CYP7A1 (the rate-limiting enzyme for cholesterol-to-bile acid conversion) and and SREBP2 (a key transcriptional regulator) [150–152].

Structural analyses of intestinal lipid transport further elucidate BBR’s hypolipidemic action. Physiological studies confirm that lacteals mediate chylomicron translocation through discontinuous lymphatic endothelial cells (LECs) junctions, with obesity exacerbating lipid uptake via “button-like” junctional permeability (Fig. 4) [153]. Zhang et al. pioneered therapeutic modulation of this process in mutant mice lacking neuropilin1 (Nrp1) and vascular endothelial growth factor receptor 1 (Vegfr1) receptors), demonstrating that “zipper-like” LEC junction remodeling restricts chylomicron entry into lymphatic circulation [154]. Building on this, Wang et al. identified BBR-induced inhibition of the Ras homolog gene family member A (RhoA)/Rho-associated kinase 1 (ROCK1) pathway as a novel mechanism promoting mature LEC junction formation in human dermal lymphatic endothelial cells (HDLECs) and DIO mice, thereby suppressing lipid absorption through lacteal barrier fortification [60].

Berberine-mediated gastrointestinal microbiota modulation

As a pleiotropic antimicrobial agent, BBR disrupts microbial proliferation through dual inhibition of bacterial protein biosynthesis and nucleic acid replication, effectively suppressing pathogenic colonization in Streptococcus haemolyticus, Staphylococcus aureus, Neisseria gonorrhoeae, and Shigella species while enhancing leukocyte phagocytic activity [155–158]. Its microbiota-modulating capacity also extends to structural reorganization of enteric communities (Fig. 5):

1. Pathogen suppression: Reduces lipopolysaccharide (LPS)-producing Proteobacteria (e.g., Desulfovibrio, Enterobacter) abundance, attenuating metabolic endotoxemia via downregulation of LPS-binding protein (LBP) in HFD-fed rats [159].

2. Ecological balance: Restores dysbiotic Firmicutes/Bacteroidetes ratios in obesity models. Six-week administration of 200 mg/kg BBR in HFD-fed C57BL/6 J mice systematically upregulated fasting-induced adipose factor expression in visceral adipose [160, 161].

3. Metabolite regulation: Enriches butyrate-producing microbiota (e.g., Blautia producta), stimulating acetyl-CoA-butyrate conversion to improve lipid/glucose homeostasis in hyperlipidemic patients. Baseline Alistipes/Blautia ratios predict therapeutic efficacy against hypercholesterolemia [159, 162].

Fig. 5.

Berberine-Mediated Gastrointestinal Microbiota Modulation. BBR suppresses pathogenic bacteria (e.g., Proteobacteria) while restoring Firmicutes/Bacteroidetes ratios, enriching butyrate-producing Blautia and reducing LPS-producing, enhancing lipid/glucose metabolism. BBR activates GLP-1 secretion via gut-brain crosstalk and SCFA production, improving insulin sensitivity. It strengthens intestinal barrier integrity by upregulating tight junction proteins, reducing ER stress-induced goblet cell apoptosis, and boosting Akkermansia muciniphila abundance. Additionally, BBR inhibits α-glucosidase to limit carbohydrate absorption and microbial division, synergistically alleviating metabolic inflammation and dysbiosis. Figure was created with BioGDP.com. Reference: [155]. LPS Lipopolysaccharide, LBP Lipopolysaccharide binding protein, SCFA short-chain fatty acid, TAS2Rs bitter-taste receptors, A.muciniphila Akkermansia muciniphila. For graphical annotations and text associated markers given within the image, please refer Fig. 1 caption

Furthermore, mechanistic studies delineate BBR’s enteroendocrine interactions (Fig. 5):

1. Glucagon-like peptide-1 Axis Activation: Upregulates Bacteroidetes/Firmicutes ratios and short-chain fatty acid (SCFA) producers via gut-brain crosstalk, potentiating intestinal L-cell GLP-1 secretion through alleviating cell death, mitochondrial dysfunction, oxidative stress and Akt pathway restoration in HFD-fed rats [163, 164].

2. Bitter Receptor Signaling: Binds TAS2R bitter-taste receptors on intestinal tuft cells, enhancing Gα-gustducin/Gβ1γ 13 signaling and interleukin-25 (IL-25) levels to reinforce epithelial barrier integrity in HFD-fed C57BL/6 mice [59].

In addition, BBR further fortifies intestinal barrier function through:

1. Mucosal protection: Ameliorates endoplasmic reticulum (ER) stress-induced goblet cell apoptosis by restraining mucin-2 expression, upregulating Akkermansia muciniphila (A. muciniphila) abundance to stabilize tight junctions in obese and diabetic mice [165–167].

2. Metabolic reprogramming: Promotes beneficial microbiota proliferation in glucolipid metabolism disorders hamsters, and alleviates barrier dysfunction via tryptophan metabolite modulation and tight junction protein regulation [168].

Notably, BBR exhibits α-glucosidase inhibitory activity, limiting carbohydrate hydrolysis and absorption, while inhibiting FtsZ-mediated bacterial division in germ-free db/db mice, conferring dual glycemic control and antimicrobial effects [169].

Berberine-mediated modulation of adipose tissue macrophage dynamics

Macrophage polarization spans a continuum from quiescent M0 states (phagocytizing cell debris) to proinflammatory M1 (phagocytic/immunostimulatory) and anti-inflammatory M2 (tissue-remodeling) phenotypes. Adipose tissue macrophage (ATM) infiltration escalates from 10% in lean states to > 50% in obesity across murine and human models [170–173]. This phenotypic shift is mechanistically linked to meta-inflammation, adipocyte dysfunction, and IR progression [174].

BBR exerts immunometabolic reprogramming effects on ATMs (Fig. 6):

1. Infiltration suppression: a. Attenuates body mass gain, adipocyte size, and hepatic steatosis in HFD-fed C57BL/6 mice via chemotaxis inhibition, reducing ATM recruitment while increasing CD206⁺ M2 polarization [175]. b. Downregulates monocyte chemoattractant protein-1 (MCP-1) expression in nephropathy mice models, curtailing monocyte trafficking and M1 prevalence [176].

2. Phenotypic conversion: a. M2 membrane-camouflaged BBR nanoparticles (NPs) synergize with mannan to repolarize M1 macrophages toward M2 states, mitigating local inflammation and enhancing aortic collagen deposition and plaque stability in atherosclerosis models [177]. b. Promotes WAT-specific UCP1 expression and glucose tolerance while suppressing proinflammatory cytokines secretion in obese mice [178].

3. Inflammasome regulation: a. Inhibits NF-κB signaling via p65 lysine 310 deacetylation, blocking p300/ac-p65 Lys310 signaling nuclear translocation in obese mice’s macrophages [179]. b. Suppresses Nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation and IL-1β release through AMPK-dependent autophagy in a HFD-induced IR mice model, countering palmitate-induced inflammation [180].

4. Synergistic therapy: Combined treatment with isoliquiritigenin (ISL) enhances IRS1-PI3K-Akt signaling, mitigating the accumulation and infiltration of M1-ATMs and ATMs crosstalk with adipocytes while enhancing glucose uptake in DIO mice [181].

Fig. 6.

Berberine-Mediated Modulation of Adipose Tissue Macrophages Dynamics. BBR suppresses M1 macrophage infiltration via chemotaxis inhibition (e.g., downregulating MCP-1) and promotes M2 polarization using bioengineered nanoparticles, enhancing anti-inflammatory responses. BBR inhibits NLRP3 inflammasome activation and NF-κB signaling through AMPK-dependent autophagy and p65 deacetylation, reducing IL-1β release. In addition, BBR synergizes with ISL to enhance insulin signaling (IRS1-PI3K-Akt) and glucose uptake while curbing M1-ATM crosstalk with adipocytes. These actions collectively reduce adipocyte inflammation, improve metabolic homeostasis, and stabilize atherosclerotic plaques. Figure was created with BioGDP.com. Reference: [170]. ATMS adipose tissue macrophages, MCP-1 monocyte chemoattractant protein-1, NPs nanoparticles, NLRP3 Nod-like receptor family pyrin domain containing 3, ISL isoliquiritigenin. For graphical annotations and text associated markers given within the image, please refer Fig. 1 caption

These findings establish ATM modulation as a strategic therapeutic axis in BBR’s anti-obesity pharmacology [182].

Berberine’s anti-inflammatory mechanisms in adipose tissue

Chronic low-grade inflammation serves as a pathophysiological nexus linking obesity to metabolic comorbidities, including IR, T2DM, and CVD [181, 183, 184]. AT expansion in obesity triggers immune cell infiltration and cytokine dysregulation, establishing a proinflammatory microenvironment that perpetuates metabolic dysfunction [185].

Key inflammatory mediators and BBR Interventions are summarized as follows (Fig. 7):

1. Macrophage-driven inflammation: a. Suppresses M1-ATMs recruitment into epididymal WAT (eWAT) in diet-induced obese mice, attenuating cytokines (e.g., IL-6, tumor necrosis factor-α (TNF-α)) and chemokines (e.g., macrophage inflammatory protein-1α (MIP-1α) and MCP-1)-mediated inflammatory cascades [174, 185]. b. Inhibits NLRP3 inflammasome activation in ATMs through AMPK-dependent autophagy, reducing M1 polarization in C57BL/6 J mice [186].

2. Oxidative stress modulation: Upregulates the nuclear factor erythroid 2-related factor 2 (NRF-2), heme oxygenase 1 (HO-1), and glutathione-S-transferase-α (GST-α) antioxidant axis while downregulating toll-like receptor-2 (TLR-2), myeloid differentiation protein-88 (MYD-88) levels, thereby reducing IL-1β, TNF-α, and IL-8 expression in HFD-fed tilapia (Oreochromis niloticus) [144].

3. Epigenetic regulation: a. Activates mitochondrial SIRT3 deacetylase to inhibit MAPK and NF-κB pathways, countering TNF-α-induced adipocyte inflammation in HFD-fed mice [185, 187]. b. Targets immunity-related GTPase M1 (IRGM1) to suppress PI3K/AKT/mTOR signaling, as evidenced by SILAC-based proteomic profiling in ulcerative colitis mice [188].

4. Metabolite synergy: BBR metabolites (berberrubine (BBB), palmatine (PMT)) reverse obesity-associated Akt pathway inhibition, ameliorating cell death, oxidative stress and mitochondrial dysfunction in HFD-fed mice [164].

Fig. 7.

Berberine’s anti-inflammatory mechanisms in obesity. BBR suppresses M1 macrophage infiltration and NLRP3 inflammasome activation in AT via AMPK-dependent autophagy, reducing proinflammatory cytokines (IL-6, TNF-α, IL-1β). BBR enhances antioxidant defenses by upregulating NRF-2/HO-1/GST-α and downregulating TLR-2/MYD-88 signaling. Epigenetically, it activates SIRT3 to inhibit NF-κB/MAPK pathways and blocks PI3K/AKT/mTOR signaling via IRGM1 modulation. BBR metabolites (BBB, PMT) reverse Akt pathway inhibition, mitigating oxidative stress and mitochondrial dysfunction. In PCOS models, BBR downregulates TLR4/LYN/NF-κB axis, attenuating ovarian inflammation and cytokine storms. Figure was created with BioGDP.com. Reference: [183]. T2DM Type 2 Diabetes Mellitus, CVD Cardiovascular Disease, HLP hyperlipidaemia, NAFLD Non-Alcoholic Fatty Liver Disease, OSA obstructive sleep apnea, ORN Obesity-related Nephropathy, VD vitamin D, AT adipose tissue, ATMs Adipose Tissue Macrophages, TNF-α tumor necrosis factor-α, MCP-1 monocyte chemoattractant protein-1, MIP-1α macrophage inflammatory protein-1α, NRF-2 Nuclear factor erythroid 2-related factor 2, HO-1 heme oxygenase 1, GST-α glutathione-S-transferase-α, TLR-2 Toll-like receptor-2, MYD-88 myeloid differentiation protein-88, IL-1β interleukin-1β, IL-8 interleukin-8, IRGM1 immunity-related GTPase M1, BBB berberrubine, PMT palmatine, TLR4 Toll-like receptor 4, LYN lyn tyrosine kinase, PCOS Polycystic Ovary Syndrome, IR insulin resistance. For graphical annotations and text associated markers given within the image, please refer Fig. 1 caption

Polycystic ovary syndrome (PCOS, Fig. 7) is characterized by concurrent obesity and IR, with AT inflammation and apoptotic dysregulation as core features [189, 190]. BBR ameliorates ovarian inflammatory responses in PCOS rat models through downregulating TLR4/lyn tyrosine kinase (LYN)/NF-κB signaling and suppressing pro-inflammatory mediators (TNF-α, IL-1β, IL-6) via PI3K/Akt/NF-κB pathway regulation, thereby suppressing immune cell infiltration and cytokine storm cascades [191].

Formulation innovations for enhanced anti-obesity efficacy of Berberine

Despite BBR demonstrates favorable therapeutic outcomes and an established safety profile, its clinical translation is hindered by suboptimal bioavailability due to limited gastrointestinal permeability. Advanced formulation strategies are imperative to enhance its competitiveness against GLP-1RAs in obesity management (Fig. 8).

Fig. 8.

Strategies of enhancing Berberine’s bioavailability and efficacy. BBR bioavailability is improved via synergistic phytochemical combinations (e.g., with cinnamaldehyde, curcumin) and cocrystal engineering (e.g., BBR-ibuprofen cocrystal). Advanced delivery systems like biomimetic nanosystems (M2 macrophage-membrane NPs) and nanoemulsions boost absorption and targeting. Structural derivatives (THBru, OBB, 9-N-Alkyltetrahydroberberine, SHE-196exhibit superior pharmacokinetics and bioactivity. Optimized analogs (dhBBR, C9-O-arylated BBR, Di-Me) enhance solubility and efficacy. These innovations amplify BBR’s anti-obesity effects via improved solubility, metabolic stability, and tissue-specific delivery. Figure was created with BioGDP.com. Reference: [192]. F2 Cinnamaldehyde-curcumin-BBR formulations, APS Astragalus polysaccharides, ISL isoliquiritigenin, WHR waist hip rate, APIs active pharmaceutical ingredients, CCF co-crystal former, BJ BBR-ibuprofen cocrystal, TBK1 TANK-binding kinase 1, IKKε IκB kinase ε, NPs nanoparticles, NEs Nanoemulsions, THBru Tetrahydroberberrubine, OBB Oxyberberine, MCP-1 Monocyte chemotactic protein-1, Dos2 Nitric Oxide Synthase 2, akt protein kinase B, GSK-3β glycogen synthase kinase 3, SHE-196 9-(hexylamino)−2,3-methylenedioxy-10-methoxyprotoberberine chloride, dhBBR Dihydroberberine, Di-Me 8,8-Dimethyldihydroberberine. For graphical annotations and text associated markers given within the image, please refer Fig. 1 caption

Synergistic phytochemical combinations

To circumvent BBR’s inherent pharmacokinetic limitations, integration with botanical compounds enables therapeutic potentiation at reduced dosages. Key approaches include (Fig. 8):

1. Insulin-sensitizing synergy: Cinnamaldehyde and curcumin are insulin-sensitizing phytonutrients. Cinnamaldehyde-curcumin-BBR formulations (F2) enhance Akt2 phosphorylation (T450, Y475, and S474), improving insulin sensitivity without adipogenic effects in diet-induced obese mice [192, 193].

2. Gut microbiota modulation: Astragalus polysaccharides (APS) synergize with BBR to amplify anti-adipogenic effects via microbial remodeling in HFD-fed obese mice [194].

3. Multitargeted therapy: BBR-isoliquiritigenin (ISL) dual therapy attenuates adipose inflammation and dyslipidemia via IRS1-PI3K-Akt pathway activation in DIO mouse, while BBR-catechin-capsaicin polypharmacology outperforms monotherapies in 3T3-L1 adipocytes [181, 195].

4. Clinical combinations: BBR-silymarin co-administration significantly improves glycemic control (fasting glucose, HOMA-IR) and lipid profiles (TG, LDL) in diabetic patients, and decreases BMI, and the WHR in obesity patients versus BBR monotherapy [196].

5. Bitter taste inhibition: Macrocyclic encapsulation technology utilizing tetraanionic hosts enhances BBR solubility and masks bitterness via parallel-arranged aromatic compound inclusion [197].

Pharmaceutical cocrystal engineering

Drug cocrystallization—the strategic assembly of active pharmaceutical ingredients (APIs) with co-crystal former (CCF) via non-covalent interactions—optimizes physicochemical properties and bioavailability [198, 199]. The BBR-ibuprofen cocrystal (BJ, 1:1) exemplifies this (Fig. 8):

1. Pharmacokinetic enhancement: threefold higher bioavailability than BBR chloride (BCl·2H2O) in db/db mice [200].

2. Mechanistic superiority: Dual inhibition of TBK1 and IKKε in eWAT restores AMPKα-Thr172 phosphorylation, enhancing mitochondrial biogenesis (via UCP1 upregulation), catecholamine sensitivity (via cAMP upregulation and cAMP-mediated β-adrenergic signal transduction) [201, 202]. Thus, BJ leads to heighten the process of lipolysis and thermogenesis.

Advanced delivery platforms

Biomimetic nanosystems

Emerging evidence highlights the therapeutic potential of biomimetic nanoplatforms engineered through fusion of natural cellular membranes with synthetic nanoparticles (NPs) (Fig. 8) [203]. This innovative strategy leverages cell membrane-derived surface properties to confer immune-evasive capabilities, prolong bloodstream retention, and enable tissue-specific cellular internalization, thereby addressing critical limitations in conventional nanodrug delivery systems [204–208]. Based on this, Biomimetic Nanosystems are used to enhance the bioavailability of BBR: a. M2 macrophage-membrane camouflaged BBR NPs@Mannose enhance targeting and immune evasion while prolonging circulation half-life in an atherosclerosis mouse model [177]. b. Nanoemulsions (NEs) boost oral BBR bioavailability by 212% via CYP2D6 and 3A4 metabolic shielding in HFD-fed rats [209].

Diversified nanocarriers

Polymeric, lipid, dendrimer, magnetic mesoporous silica, silver and gold-based systems optimize BBR loading and tissue distribution (Fig. 8) [210]. Erythrocyte-mediated delivery for BBR achieves macrophage-specific targeting, biocompatibility increasing, inflammation combating and improved hypolipidemic efficacy [211–213].

Structural optimization of Berberine derivatives

Thermogenic modulators

Tetrahydroberberrubine (THBru, Fig. 8): Activates PGC1α-mediated mitochondrial thermogenesis, outperforming BBR in reducing adiposity indices (Lee’s index, eWAT or BAT mass) and alleviating dyslipidemia in HFD-fed obese mice at equimolar doses [214].

Oxyberberine (OBB, Fig. 8): an oxidative biotransformation product of BBR generated through gut microbial metabolite, dose-responses attenuation of hepatic steatosis and obesity-related pathophysiological markers in HFD-induced NAFLD rodent models, surpassing BBR at equivalent dosing (100 mg/kg). Mechanistic investigations revealed OBB’s dual regulatory capacity: (i) AMPK hyperphosphorylation-mediated bioenergetic enhancement through UCP1 upregulation, and (ii) inflammation resolution via inhibiting aberrant phosphorylation of IRS-1 coupled with coordinated modulation of immunometabolic signaling—suppressing proinflammatory mediators (MCP-1, CD68, Nos2, CD11c) while activating the downstream protein expression and phosphorylation (PI3K, p-Akt/Akt and p-GSK-3β/GSK-3β) [215].

Insulin sensitizers

9-N-Alkyltetrahydroberberine (Fig. 8): Restores insulin sensitivity and reduces adipose mass in obese mice (15 mg/kg, 4 weeks) [216].

9-(hexylamino)−2,3-methylenedioxy-10-methoxyprotoberberine chloride (SHE-196, Fig. 8): Novel protoberberine analog decreasing body weight and interscapular fat mass while activating interscapular BAT activities in obese with T2DM mice [217].

Bioavailability-optimized analogs

Dihydroberberine (dhBBR, Fig. 8): a reduced derivative, 200 mg dose of dhBBR exhibits 9.4-fold higher plasma exposure in a randomized, double-blind, crossover fashion with five males (BBR AUC: D200: 929 vs B500: 42.3 ng/mL × 120 min) with dose-linear pharmacokinetics in humans comparing with 500 mg dose of BBR (BBR level: B500: 0.4 ± 0.17 ng/mL, D100: 3.76 ± 1.4 ng/mL, D200: 12.0 ± 10.1 ng/mL) [218, 219].

C9-O-Arylated Berberine (Fig. 8): Copper-catalyzed CAr–O coupling enables lipophilic modifications, enhancing membrane permeability while preserving synthetic feasibility [220].

8,8-Dimethyldihydroberberine (Di-Me, Fig. 8): Superior glycemic control (fasting glucose, HOMA-IR) and triglyceride reduction vs dhBBR at 50 mg/kg in db/db mice [221].

Conclusions and future perspectives

BBR, as a bioactive isoquinoline alkaloid with a quaternary ammonium structure, has emerged as a multifaceted therapeutic candidate for obesity management. Mechanistic studies summarized in this review reveals that it delineates its anti-obesity efficacy through five core pathways:

1. Transcriptional Regulation: Suppression of adipocyte differentiation genes and modulation of metabolic adipokine networks.

2. Thermogenic Activation: Promotion of BAT activity and WAT browning via mitochondrial uncoupling mechanisms.

3. Lipid Homeostasis: Modulation of plaque metabolism through LOX-1 downregulation and LDLR/SREBP2/CYP7A1 axis activation.

4. Gut-Microbiota Crosstalk: Remodeling of enteric microbial composition and reinforcement of intestinal barrier integrity.

5. Immunometabolic Reprogramming: Polarization of ATMs toward M2 phenotypes with concurrent suppression of NF-κB/STAT3 inflammatory cascades.

Meanwhile, emerging evidence highlights BBR’s novel molecular targets for anti-obesity:

1. AMPK/PGC-1α axis activation and SIRT1-mediated deacetylation.

2. FGF21 secretion via autophagy-dependent mechanisms.

3. GDF15 elevation through BAT-secreted integrated stress responses.

4. PRDM16 epigenetic regulation via AMPK-α-KG signaling.

5. RhoA/ROCK1 inhibition enhancing lacteal junction maturation.

In addition, pharmacological innovations address BBR’s low oral bioavailability through four core methods:

1. Botanical synergists (e.g., silymarin, isoliquiritigenin) amplifying therapeutic effects.

2. Ibuprofen cocrystals tripling systemic exposure.

3. Biomimetic nanocarriers enabling adipose-specific delivery.

4. Derivatives optimizing lipophilicity and absorption.

Although the anti-obesity mechanisms of BBR have been well-characterized in preclinical models with demonstrated efficacy, critical limitations persist in current research paradigms. Three principal challenges warrant emphasis:

1. Translational disconnect: the existing mechanistic insights predominantly derive from rodent models, which exhibit fundamental species-specific disparities in adipose distribution compared to humans. Clinical studies employing human-centric approaches remain insufficient to validate these preclinical findings.

2. Clinical design deficiencies: most human trials utilize berberine chloride formulations not optimized for obesity-specific indications, coupled with inadequate endpoint selection targeting adiposity pathophysiology.

3. Organ-centric reductionism: the current investigations predominantly focus on isolated organ systems, neglecting BBR’s pleiotropic effects within inter-organ communication networks critical to systemic metabolic regulation.

4. Single route of administration: the current preclinical animal studies and clinical human trials predominantly employ oral administration as the primary intervention method for BBR, with a notable lack of research on alternative delivery approaches such as transdermal absorption.

To address the aforementioned limitations in current BBR-based obesity therapeutics, six strategic research priorities emerge:

1. Clinical Trial Optimization: a. Conduct multicenter, double-blind RCTs establishing BMI-stratified dose-response relationships and optimal dosing regimens. b. Implement ≥ 24-month safety surveillance programs quantifying long-term adverse event incidence.

2. Precision Medicine Advancement: a. Develop personalized treatment algorithms incorporating novel BBR-responsive biomarkers. b. Explore combinatorial therapies with weight-modulating antidiabetics (GLP-1 RAs or dual GLP/GIP RAs, SGLT2 inhibitors, metformin) in obese diabetics.

3. Drug Delivery Innovation: a. Advance Phase III trials for obesity-optimized formulations (C9-O-aryl derivatives, erythrocyte-based carriers). b. There is an urgent need to develop novel topical formulations of berberine and conduct preclinical or clinical studies to evaluate the efficacy of transdermal delivery systems for weight management.

Addressing these gaps will solidify BBR’s position as a first-line phytotherapeutic for metabolic syndrome management.

BBR demonstrates robust anti-obesity effects in both preclinical and clinical settings [4, 47, 175, 222, 223]. The present review differentiates itself from prior studies through three principal innovations: (1) It provides a critical appraisal of current anti-obesity therapeutic strategies, identifying their pharmacological limitations and clinical shortcomings. (2) The work systematically elucidates BBR’s anti-obesity mechanisms through five distinct molecular dimensions, with particular emphasis on recently identified molecular targets supported by emerging evidence. (3) This synthesis advances the field by proposing novel bioavailability enhancement strategies through pharmaceutical engineering approaches, while critically addressing current research gaps in BBR’s pharmacokinetic profile and therapeutic efficacy. The review concludes with evidence-based recommendations for future investigations, prioritizing target validation studies, standardized clinical trial protocols, and personalized treatment paradigms. This synthesis provides a roadmap for advancing BBR from bench to bedside in metabolic disorder management.

Author contributions

Y.K. and H.K.Y. were responsible for manuscript writing. R.N.was responsible for searching literature. X.X.Z. and H.T.Z. provided manuscript writing guidance for the review. X.N. provided financial support. All authors have read and approved the final manuscript.

Funding

This work was supported by Funding of the"famous doctors"project of the support plan for the talents of Xingdian (RLMY20220005), The scientific and technological innovation team of Kunming Medical University (CXTD202209), Clinical Collaboration Project of Traditional Chinese and Western Medicine for Major Difficult Diseases of Yunnan Province (300073).

Availability of data and materials

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

The review in this paper have not been published previously in whole or part, all authors unanimously consent for publication.

Competing interests

The authors declare no competing interests.