The combination of paeoniflorin and metformin synergistically inhibits the progression of liver fibrosis in mice

Liver fibrosis is a pathological process that endangers human health, for which effective treatments remain elusive to date. Paeoniflorin (PAE), a pineane-type monoter penoid compound from the traditional Chinese medicine PaeoniaeRubra Radix, and metformin (MET), an oral biguanide hypoglycemic agent, both demonstrate anti-inflammatory and hepatoprotective effects. In current work, we first discovered that the combined treatment of PAE and MET synergistically inhibited the progression of liver fibrosis in two different animal models: therapeutic and preventive. This therapeutic effect is evidenced by a reduction in the expression levels of liver fibrosis markers and an improvement in histopathological characteristics. Mechanistic exploration further revealed that this combination therapy downregulated the expression of TGF-β1 and p-Smad2, while upregulating Smad7 expression in both models. Importantly, we also found that this combinatorial approach significantly reduced hepatotoxicity and nephrotoxicity in both models. Our findings suggest an effective combination therapy for liver fibrosis and provide the possibility of therapeutic improvement for patients with liver fibrosis.