[Effect of nuciferine on gut microbiota and inflammatory response in obese model mice]

Abstract

The aim of this study was to elucidate the mechanism of nuciferine on alleviating obesity based on modulating gut microbiota, ameliorating chronic inflammation, and improving gut permeability. In this study, the obese model mice were induced by high-fat diet and then randomly divided into model group, and nuciferine group; some other mice of the same week age were fed with normal diet as normal group. In the modeling process, the mice were administered intragastrically(ig) for 12 weeks. In the course of both modeling and treatment, the body weight and food intake of mice in each group were measured weekly. After modeling and treatment, the Lee's index, weight percentage of inguinal subcutaneous fat, and the level of blood lipid in each group were measured. The pathological changes of adipocytes were observed by HE staining to evaluate the efficacy of nuciferine treatment in obese model mice. 16 S rRNA sequencing analysis was conducted to study the changes in diversity and abundance of gut microbiota after nuciferine treatment. Enzyme-linked immunosorbent assay(ELISA) and quantitative Real-time polymerase chain reaction(qPCR) were used to detect the levels of inflammatory factors interleukin-6(IL-6), interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α) and the expression of related genes in adipose tissue of mice in each group, so as to evaluate the effect of nuciferine on chronic inflammation of mice in obese model group. qPCR was used to detect the expression of occludin and tight junction protein 1(ZO-1)gene in colon tissure, so as to evaluate the effect of nuciferine on intestinal permeability of mice in obese group. Nuciferine decreased the body weight of obese mice, Lee's index, weight percentage of inguinal subcutaneous fat(P<0.05), and reduced the volume of adipocytes, decreased the level of total cholesterol(TC), triglyceride(TG), and low density lipoprotein cholesterol(LDL-C)(P<0.05) in serum, improved dysbacteriosis, increased the relative abundance of Alloprevotella, Turicibacter, and Lactobacillus, lowered the relative abundance of Helicobac-ter, decreased the expression of inflammatory cytokines IL-6, IL-1β, and TNF-α genes in adipose tissue(P<0.01), decreased the levels of inflammatory cytokines IL-6, IL-1β, and TNF-α in serum(P<0.05), and increased the expression of occludin and ZO-1 genes related to tight junction in colon tissue(P<0.01). Nuciferine could treat obesity through modulating gut microbiota, decreasing gut permeability and ameliorating inflammation.

Keywords: gut microbiota; gut permeability; inflammation; nuciferine; obesity.