Metformin-phytochemical combination therapy in metabolic dysfunction-associated steatotic liver disease: mechanistic insights and therapeutic potential

The liver disease known as MASLD (metabolic dysfunction-associated steatotic liver disease) involves fat build-up, inflammation, and scarring of the liver, and is driven by multiple overlapping biological pathways — making it hard to treat with a single drug. Metformin, the widely used diabetes medication, helps the liver burn fat more efficiently by activating a cellular energy sensor called AMPK, but it does relatively little against inflammation and oxidative damage. This review asks whether pairing metformin with plant-derived compounds (phytochemicals) can cover those additional pathways. The authors searched four major databases and compiled preclinical animal studies that tested metformin alongside a specific isolated phytochemical in MASLD models. Across all eligible studies, the combinations consistently outperformed either drug alone — reducing liver fat, lowering inflammation markers, and curbing fibrotic (scarring) signals. Certain pairings, notably with berberine, silymarin, chlorogenic acid, and genistein, also enhanced autophagy pathways (the cell's self-cleaning machinery) and improved gut-liver communication. The authors conclude that this multi-pathway strategy looks promising but needs well-designed human trials to confirm safety, optimal dosing, and pharmacokinetic compatibility.

• Metformin–phytochemical combinations consistently outperformed monotherapy across all eligible preclinical in vivo studies in reducing hepatic steatosis, oxidative stress, and inflammatory mediators — no studies reported inferior efficacy for the combination.
• Combinations involving berberine, chlorogenic acid, genistein, malvidin, morin, silymarin, and p-coumaric acid were specifically associated with improved fatty acid β-oxidation and suppression of de novo lipogenesis and fibrotic signaling pathways.
• Enhancement of autophagy-related pathways was reported as an additional benefit across multiple phytochemical classes, alongside favorable modulation of adipose tissue metabolism and gut-liver axis signaling, though the magnitude and specific autophagy markers varied by compound and experimental model.
• Metformin's known limitation — restricted impact on inflammatory and redox pathways — was mitigated by phytochemical co-administration, suggesting complementary rather than merely additive mechanistic coverage.
• The review identified a gap in pharmacokinetic compatibility data: no included preclinical study systematically assessed drug–phytochemical interactions at the absorption, distribution, metabolism, or excretion level.

This is a comprehensive narrative/systematic preclinical review. The authors searched PubMed, Scopus, Web of Science, and Google Scholar for original in vivo animal studies testing metformin combined with an isolated phytochemical compound in MASLD (or equivalent steatohepatitis) models. Only studies using intact animal models (not cell lines) were included, and data were extracted on compound identity, dosing regimens, animal model type, and outcomes spanning metabolic, inflammatory, fibrotic, and signaling endpoints. No meta-analytic pooling of effect sizes is reported; the synthesis is qualitative.

Because all included evidence is preclinical (animal models), direct extrapolation to human MASLD is premature — species differences in hepatic metabolism, gut microbiota composition, and drug bioavailability may not translate. The qualitative rather than quantitative synthesis means it is impossible to rank combinations by effect size or establish optimal dose ratios. Pharmacokinetic interactions between metformin and phytochemicals (e.g., transporter competition, cytochrome P450 modulation) were not systematically addressed in the source studies and remain a critical unknown. The next logical experiments would be dose-finding pharmacokinetic studies in large-animal models followed by Phase I/II clinical trials in MASLD patients with standardised histological endpoints.

This review extends [§90], which examines AMPK activation and autophagy flux in the context of type-2 diabetes pathogenesis and metabolic correction via intermittent fasting — both articles converge on AMPK as a nodal regulator linking energy sensing to autophagic clearance, though they differ in intervention modality (dietary vs. pharmacological-phytochemical). It parallels [§66], where a LIPE-PNPLA2-AMPK-mTOR axis is shown to govern lipophagy flux, reinforcing the mechanistic plausibility that AMPK-activating combinations like metformin-berberine could modulate hepatic lipophagy in MASLD. The work also parallels [§38], which maps mammalian lysophagy mechanisms and their pathophysiological implications — the autophagy-enhancement findings reported for several phytochemical pairings in the present review likely engage the same lysosomal degradation machinery reviewed there. Finally, the multi-pathway combinatorics framework discussed here contextualises findings from [§91] and [§92], which explore mTOR-pathway inhibition strategies in other disease contexts, underscoring that rational combination design targeting AMPK/mTOR nodes is a cross-disease translational priority.

• 2-TIP QANDLI DIABET PATOGENEZIDA AUTOFAGIYA JARAYONINING ROLI VA INTERVAL OCHLIKNING BIOKIMYOVIY KORREKSIYASI
  Both articles centre on AMPK activation and autophagy modulation in metabolic disease, but [id=90] uses intermittent fasting rather than pharmacological-phytochemical combinations, allowing readers to compare dietary vs. drug-based AMPK engagement in overlapping metabolic contexts.
• PRRSV NSP2 hijacks host lipophagy via a LIPE-PNPLA2-AMPK-MTOR axis to promote viral replication
  Directly relevant mechanistic parallel: [id=66] demonstrates that a LIPE-PNPLA2-AMPK-mTOR axis controls lipophagy during viral infection, providing molecular detail on how AMPK-activating agents like metformin may also modulate hepatic lipophagy in MASLD.
• Mammalian Lysophagy: mechanisms and pathophysiological implications
  The autophagy-enhancement benefits attributed to several metformin-phytochemical combinations in this review likely involve lysosomal pathways comprehensively mapped in [id=38], making it essential reading for understanding the downstream cellular machinery being modulated.
• Phase 3 Trial of eRapa in Patients With Familial Adenomatous Polyposis
  Offers a clinical-stage contrast: [id=91] reports a Phase 3 trial of rapamycin (mTOR inhibitor) in a human disease context, illustrating what bench-to-bedside translation of AMPK/mTOR-targeting combination strategies looks like and what endpoints are needed — directly relevant to the translational gap this review identifies.