Finger Citron Extract Ameliorates Glycolipid Metabolism and Inflammation by Regulating GLP-1 Secretion via TGR5 Receptors in Obese Rats

Abstract

Finger citron (FC) is one of many traditional Chinese herbs that have been used to treat obesity. The aim of this study was to elucidate the pharmacological effects and mechanisms of FC on obese rats. Rats were fed with a high-fat diet as a model of obesity and treated with FC at three different dosages for 6 weeks. Pathology in liver tissue was observed. Glucose levels, lipids levels, and inflammatory indicators in serum were evaluated by enzyme‐linked immunosorbent assay. Furthermore, the expression of G protein-coupled receptor 5 (TGR5) pathway genes in rat colon tissue was detected by reverse transcription-polymerase chain reaction analysis (RT-PCR). Our result revealed that FC alleviates obesity by reducing body weight (BW) and waist circumference, managing inflammation and improving glycolipid metabolism, liver function, and liver lipid peroxidation in vivo. In addition, the mechanism of FC on obesity is possibly the stimulation of glucagon-like peptide-1 (GLP-1) secretion by activating the TGR5 pathway in intestinal endocrine cells. Our studies highlight the obesity reduction effects of FC and one of the mechanisms may be the activation of the TGR5 pathway in intestinal endocrine cells.

Mechanism of action of the bile acid receptor TGR5 in obesity

“…An experiment showed that TGR5 is expressed on intestinal L cells, and TGR5 receptor agonists can effectively promote the induction of GLP-1 release 149 . The increase in GLP-1 secretion can effectively regulate glucose levels, lipometabolism and inflammation 150 and plays an essential role in maintaining glucose homeostasis and improving insulin resistance 151 , 152 .…”

Characteristic aroma analysis of finger citron in four different regions based on GC–MS‐HS‐SPME and ROAV

“…Their skin is bright yellow, wrinkled and shiny. It is also an excellent herbal medicine and has been reported to be beneficial for the liver, stomach and pancreas, as well as reduce the occurrence of hypertension and respiratory infections (Gao et al, 2020; Kim et al, 2013; Luo et al, 2020; Yang et al, 2021; Zhang, 2015). Finger citron is mainly grown in Zhejiang, Guangzhou, Sichuan and Yunan province of China.…”