<i>Polygonatum sibiricum</i> polysaccharide alleviates liver fibrosis through the TGF‑β/Smad signaling pathway and reduces collagen

Liver fibrosis (LF) is a liver condition that represents a serious health risk to humans, and effective therapeutic options are limited. <i>Polygonatum sibiricum</i> polysaccharide (PSP), derived from the roots of <i>P. sibiricum</i> Red, has been demonstrated to exert anti‑inflammatory, antioxidant and antibacterial effects. However, its potential therapeutic impact on LF remains unexplored. In the present study, LF model rats were established through subcutaneous injection of carbon tetrachloride combined with a high‑fat diet and alcohol administration. Following the induction of fibrosis, rats in the PSP and Biejia ruangan (BJRG) treatment groups received daily intragastric doses of PSP and BJRG, respectively, for a duration of 4 weeks. The control and model groups were administered an equivalent volume of water. Liver function was evaluated through biochemical analyses, whereas hepatopathological alterations were assessed using hematoxylin and eosin and Masson's trichrome staining. Levels of inflammatory and oxidative stress markers were quantified using ELISA. Hepatic collagen synthesis and degradation were examined using ELISA and immunohistochemistry. Furthermore, the expression of genes and proteins associated with the TGF‑β/Smad signaling pathway were analyzed by reverse transcription‑quantitative PCR and western blotting. The results indicated that PSP exerts anti‑fibrotic effects, primarily through anti‑inflammatory and antioxidant mechanisms. Moreover, PSP appeared to promote the degradation and inhibit the synthesis of hepatic collagen fibers, potentially through modulation of the TGF‑β/Smad signaling pathway.