Integrating metabonomics and metagenomics sequencing to study the anti-liver fibrosis effects of palmatine in Corydalis saxicola Bunting

Ethnopharmacological relevance: Corydalis saxicola Bunting (CS), a traditional Chinese folk medicine, has been effectively used for treating liver disease in Zhuang nationality in South China. However, the main anti-liver fibrosis ingredients in CS are incompletely understood.Aim of the study: To elucidate the main anti-liver fibrosis ingredients in CS and its underlying mechanism.Material and methods: Firstly, spectrum-effect relationship (SER) strategy was applied to identify the major ingredients against liver fibrosis in CS. Subsequently, 1H NMR metabonomics and metagenomics sequencing techniques were used to clarify the intervention of palmatine (PAL) on liver fibrosis. Furthermore, the expression of tight junction proteins and the levels of liver inflammation factors were examined, the effect of PAL on microbiota was verified by FMT. Results: The SER model revealed that PAL was the most important active ingredient in CS. 1H NMR fecal metabonomics showed that PAL could reserve the abnormal levels of gut microbial-mediated metabolites of liver fibrosis, such as isoleucine, taurine, butyrate, propionate, lactate, glucose, which mainly involved in amino acid metabolism, intestinal flora metabolism and energy metabolism. Metagenomics sequencing found that PAL could callback the abundance of s__Lactobacillus_murinus, s__Lactobacillus_reuteri, s__Lactobacillus_johnsonii, s__Lactobacillus_acidophilus and s__Faecalibaculum_rodentium to varying degree. Furthermore, the intestinal barrier function and the levels of hepatic inflammation factors were significantly ameliorated by PAL. FMT demonstrated that the therapeutic efficiency of PAL was closely associated with gut microbiota. Conclusion: The effects of CS on liver fibrosis were attributed in part to PAL by alleviating metabolic disorders and rebalancing gut microbiota. The SER strategy may be a useful method for the discovery of active constituents in natural plants.