Abstract:The purpose of this study was to investigated the ameliorating effect of quercetin on liver steatosis and its influence on tryptophan metabolites in obese mice induced by a high-fat diet. The obese mouse model was established using a high-fat diet. Male C57BL/6J mice were randomly divided into a control group (NC), a model group (HFD) and a quercetin intervention group (HFD+Q), with 10 mice in each group. The mice in the HFD+Q group were given 50 mg/kg.BW quercetin by gavage for 16 weeks. The body weights and liver weights of mice were measured. Fat deposition in the liver was detected tissue sections and oil red O staining. The ALT, AST, TC and TG levels were determined by ELISA. The relative expression levels of inflammatory cytokines, IL-1β, TNF-α and IL-6, and lipid metabolism-related genes, FAS, SREBP-1c and ABCA1, in the liver were determined by qPCR. The contents of serum tryptophan metabolites, indole-3-acetic acid (IAA) and indole-3-propionic acid (IPA), were determined by LC-MS targeted analysis. Quercetin intervention significantly (P<0.05) decreased the HFD-induced body weight gain, liver steatosis, and the levels of IL-6 (50.88%), IL-1β (42.52%), TNF-α (62.96%), FAS (80.36%) and SREBP-1c (23.54%), whilst increasing the mRNA expression level of ABCA1 (5.21 times) and the contents of tryptophan metabolites, indole-3-acetic acid (1.71 times) and indole-3-propionic acid (1.12 times). In conclusion, quercetin can reduce liver fat deposition, decrease the expression of inflammatory factors in the liver, ameliorate HFD-induced hepatic steatosis in obese mice, while increasing the contents of serum tryptophan metabolites such as indole-3-acetic acid and 3-indolepropionic acid.
