Abstract:The effects of quercetin on colonic inflammation in a mouse model of high-fat diet-induced obesity were investigated in this study. Thirty male C57BL/6J mice were randomly divided into three groups, including low-fat diet group (LF), high-fat diet group (HF), and high-fat diet feeding with quercetin group (50 mg/kg·BW, HF+Q). Quercetin was administered orally once a day for 20 weeks. The morphology of colon was observed by hematoxylin-eosin staining. The concentration of LPS was detected by ELISA. The levels of cytokines, including IL-6、IL-1β and TNF-α were measured by Real-time PCR and western blotting. The activation of the TLR4/NF-kβ signaling pathway was determined by western blotting. The HFD-induced body weight gain was significantly reduced by quercetin in obese mice (p<0.05). Besides, the colonic morphological damage was ameliorated, and the concentration of LPS was reduced to 5.04 ng/mL (compared with HF group: 7.01 ng/mL, p<0.05) by quercetin. Compared with the HF group, the protein expressions of TNF-α (39.04%), IL-1β (17.73%) and IL-6 (25.47%) were inhibited by quercetin, and the activation of TLR4/NF-kβ signaling pathway was inhibited by quercetin. In conclusion, tissue inflammation in colon of obese mice can be improved and the expression of inflammatory factors can be reduced by quercetin. The mechanism may be associated with the reducing the activation of TLR4/NF-kβ signaling pathway.
