Protective Effects of Clinacanthus nutans (Burm.f.) Lindau Aqueous Extract on HBV Mouse Model by Modulating Gut Microbiota and Liver Metabolomics

Abstract

Background. Clinacanthus nutans (Burm.f.) Lindau (C. nutans) has been used in the therapy of hepatitis B (HB) and is effective; however, the mechanism of action has not been elucidated. Objective. To investigate the protective effects of C. nutans aqueous extract on the hepatitis B virus (HBV) mouse model based on correlation analysis between gut microbiota and liver metabolomics. Materials and Methods. We firstly constructed the animal model by high-pressure injection of pcDNA3.1(+)/HBV plasmid into the tail vein and treated it with C. nutans. The biomarkers and inflammatory cytokines of HB were detected by enzyme-linked immunosorbent assay and quantitative PCR; the Illumina-MiSeq platform was used for investigating gut microbiota; the LC-MS/MS method was utilized on screening liver tissue metabolites; multiomics joint analysis was performed using the R program. Results. Compared with the modeling group, C. nutans significantly decreased the expression levels of HBsAg, IL-1β, TNF-α $\left(P<0.05\right)$ in the serum, and cccDNA $\left(P<0.05\right)$ in the liver tissues of mice. C. nutans dramatically reduced the ratio of Firmicutes and Bacteroidetes $\left(P<0.05\right)$ and significantly declined the proportion of Lactobacillaceae and Lactobacillus $\left(P<0.05\right)$ , dramatically increasing the relative abundance of Bacteroidales_S24-7_group, Rikenellaceae, and Alistipes $\left(P<0.05\right)$ ; LC-MS/MS analysis results showed that C. nutans dramatically upregulate hippuric acid, L-histidine, trehalose, D-threitol, and stachyose and downregulate uridine 5′-diphosphate, cholic acid, trimethylamine N-oxide, CDP-ethanolamine, and phosphorylcholine $\left(P<0.05\right)$ . The correlation analysis revealed that C. nutans affects the related metabolite levels of hippuric acid and cholic acid through the modulation of crucial bacteria (Alistipes) $\left(P<0.01\right)$ , exerting specific anti-inflammatory effects. Conclusion. These results suggest that C. nutans exerts protective effects in HBV model mice, showing the therapeutic potential for anti-HBV infection.