Systematic pharmacology-guided analysis of the therapeutic mechanism of Sedum sarmentosum against chronic liver injury

Abstract

Objective

To study the molecular mechanism of active compounds in Sedum sarmentosum Bunge. (SS) for treating chronic liver injury (CLI) induced by d-galactosamine (DalN) combined with Lipopolysaccharide (LPS).

Methods

The common targets of drugs and diseases were screened through the database, the interaction network was constructed using network pharmacology, the core targets were screened through topological analysis, and the protein-protein interaction (PPI) network was constructed. The gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis were used to find the signal pathways related to the treatment of CLI by active compounds from SS. The libdock-score of components was calculated through molecular docking and the core targets were obtained. C57BL/6J mice were treated with LPS + DalN to established CLI models. C57BL/6J mice were randomly divided into 6 groups, each group received intraperitoneal injection of 30 mg/mL D-Galn +2 μg/mL LPS for continuous 8 weeks except control group, once for 2 days. The administration method for mice is as following: Control group (con, intragastric, ig. equal amount of physiological saline water), LPS + D-Galn group (mod, intraperitoneal, ip. 30 mg/mL D-Galn+2 μg/mL LPS + ig. equal amount of physiological saline water), low dose group (low dose, ip. 30 mg/mL D-Galn+2 μg/mL LPS + ig. 20 mg/kg quercetin+20 mg/kg isorhamnetin), middle dose group (middle dose, ip. 30 mg/mL D-Galn+2 μg/mL LPS + ig. 30 mg/kg quercetin+30 mg/kg isorhamnetin), high dose group (high dose, ip. 30 mg/mL D-Galn+2 μg/mL LPS + ig. 40 mg/kg quercetin+40 mg/kg isorhamnetin). The contents of aspartate aminotransferase (AST) and glutamate aminotransferase (ALT) in serum and malondialdehyde (MDA), superoxide dismutase (SOD), reactive oxygen species (ROS) and catalase (CAT) in liver tissue were detected. The feces were collected and the gut microbiota of mice in each group was analyzed by 16s rDNA high-throughput sequencing technology. Liver tissues were collected from mice in each groups, and Western blot was performed to quantify the relative expression levels of the target core proteins.

Result

125 potential targets for CLI and 94 signaling pathways were identified, and the key gene targets for anti-CLI potential of SS were AKT1, TP53, VEGFA, CASP3, IL-6, JUN respectively. The active compounds of SS that exhibits the properties of anti-CLI may be quercetin and isorhamnetin. In addition, quercetin and isorhamnetin may significantly improve the CLI which induced by DalN + LPS via reducing the levels of AST, ALT, LDH, MDA and ROS, and increasing the levels of SOD and CAT. Significant differences in microbial communities between model group and other groups were found. Compared to model group, Phascolarctobacterium, Bacteroides, Lactobacillus were significantly reduced, while Aeromonas, Helicobacter pylori, Clostridium were significantly increased in other groups. Western blot results showed that different concentrations of quercetin and isorhamnetin could reduce the protein expression levels of AKT1, TP53, VEGFA, CASP3, IL-6, and JUN respectively.

Conclusion

It preliminarily confirms that quercetin and isorhamnetin are the main active components of SS which may interact with potential targets, revealing that SS has a “multi target-multi pathway” mechanism of action in treating CLI. They may achieve therapeutic effects through oxidative stress pathways, reducing liver function indexes, adjusting microbial communities, and regulating the expression of core proteins, which laying a foundation for further verification of its molecular mechanism.