Abstract:

To investigate the effects of different doses of soy isoflavones (SIF) on oxidative stress and inflammatory response of liver in food-induced obese rats, 80 SD rats were prepared and 16 SD rats fed with ordinary feed were set as blank control. SD rats were fed with high-fat diet for 9 weeks to establish obesity rat model. Then 64 obese rats were randomly divided into 4 groups, 16 rats per group. The rats were given by gavage different does of soy isoflavone (0,150,300,450 mg·kg^-1) for 4 weeks, weighed and recorded every week. Four weeks later, the rats were killed, and the liver tissue was separated. The pathological changes of liver were detected by Hematoxylin-Eosin (HE) staining. Liver superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities were detected by chemical colorimetry. Liver tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β)、interleukin-6 (IL-6) and tumor necrosis factor-α(TNF-α) were measured by qRT-PCR. It was found by histopathology that typical fatty degeneration of hepatocytes with inflammatory injury of liver tissue occurred in obese rats. The activities of SOD, CAT and GSH-Px in liver tissue were decreased, and the expression levels of IL-6、IL-1β and TNF-α were increased (P<0.05). After the intervention of soybean isoflavones, the pathological damage of liver tissue in each dose group was improved, the activity of antioxidant factors was significantly increased and showed a dose effect. Besides, the expression of pro-inflammatory factors was significantly down-regulated. Soy isoflavones can reverse obesity-induced liver tissue pathological damage and increase liver antioxidant activity, and down-regulate the expression of obesity-related pro-inflammatory factors. These results provide a reference for the application and development of soy isoflavones.

Key words: soy isoflavone, oxidative stress, inflammation, obesity, liver, rat