Gut microbes combined with metabolomics reveal the protective effects of Qijia Rougan decoction against CCl4-induced hepatic fibrosis

Background: The occurrence and development of Hepatic fibrosis (HF) are closely related to the gut microbial composition and alterations in host metabolism. Qijia Rougan decoction (QJ) is a traditional Chinese medicine compound utilized clinically for the treatment of HF with remarkable clinical efficacy. However, its effect on the gut microbiota and metabolite alterations is unknown. Therefore, our objective was to examine the impact of QJ on the gut microbiota and metabolism in Carbon tetrachloride (CCl4)-induced HF. Methods: 40% CCl4 was used to induce HF, followed by QJ administration for 6 weeks. Serum biochemical analyses, histopathology, immunohistochemistry, RT-PCR, 16S rRNA gene sequencing, and non-targeted metabolomics techniques were employed in this study to investigate the interventional effects of QJ on a CCl4-induced HF model in rats. Results: This study demonstrated that QJ could effectively ameliorate CCl4-induced hepatic inflammation and fibrosis. Moreover, QJ upregulated the expression of intestinal tight junction proteins (TJPs) and notably altered the abundance of some gut microbes, for example, 10 genera closely associated with HF-related indicators and TJPs. In addition, metabolomics found 37 key metabolites responded to QJ treatment and strongly associated with HF-related indices and TJPs. Furthermore, a tight relation between 10 genera and 37 metabolites was found post correlation analysis. Among them, Turicibacter, Faecalibaculum, Prevotellaceae UCG 001, and unclassified Peptococcaceae may serve as the core gut microbes of QJ that inhibit HF. Conclusion: These results suggest that QJ ameliorates hepatic inflammation and fibrosis, which may be achieved by improving intestinal tight junctions and modulating gut microbiota composition as well as modulating host metabolism.

TMT-based proteomics analysis identifies the interventional mechanisms of Qijia Rougan decoction in improving hepatic fibrosis

ETHNOPHARMACOLOGICAL RELEVANCE

Qijia Rougan decoction (QJ), consisting of eight herbs and two animal drugs, is an effective traditional Chinese medicine with hepatoprotective and antifibrotic effects. However, its underlying action mechanism remains unclear.

AIM OF THE STUDY

To explore the mechanism underlying the treatment of liver fibrosis in rats by QJ.

MATERIALS AND METHODS

Rats with fibrosis were constructed using carbon tetrachloride (CCl4). The QJ was orally administered to fibrotic rats. Hepatic pathological changes were evaluated using hematoxylin and eosin and Masson's trichrome staining. The differentially expressed proteins (DEPs) in QJ were analyzed using quantitative proteomics. Subsequently, the underlying mechanisms in liver fibrosis after QJ treatment were validated using Western blotting.

RESULTS

The QJ markedly improved liver function and attenuated fibrotic progression. Based on the tandem mass-tag based (TMT) proteomics, we identified 818 common DEPs between QJ vs Model and Model vs Control, including 296 upregulated and 522 downregulated DEPs, which mostly participate in metabolic pathways, oxidation-reduction reactions, and collagen biosynthetic processes. In addition, we found that QJ reduced hepatocellular death by inhibiting the expression of caspase proteins, repressing pro-apoptotic proteins, and promoting anti-apoptotic proteins. We further demonstrated that QJ suppressed the Akt/mTOR pathway.

CONCLUSION

QJ exerted hepatoprotective effects in CCl4-induced rats through multi-pathway regulation. This study provides protein information on liver fibrosis treated with QJ.