大豆异黄酮干预肥胖大鼠肝氧化应激及炎症反应

本研究旨在探究不同剂量大豆异黄酮(soy isoflavones,SIF)干预肥胖大鼠后肝的氧化应激及炎症反应情况。准备80只SD大鼠,普通饲料喂养16只SD大鼠做空白对照;高脂饲料喂养64只SD大鼠9周建立肥胖大鼠模型,将64只模型大鼠随机分成4组,每组16只,大豆异黄酮(0、150、300、450 mg·kg^-1)灌喂,每周定期测量体重,连续干预4周。取肝脏组织,苏木素-伊红(Hematoxylin-Eosin,HE)染色观察肝脏组织形态学结构;检测肝脏组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性;荧光定量PCR方法检测肝脏组织中促炎因子白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)和肿瘤坏死因子-α(TNF-α)的表达。组织病理学发现,肥胖大鼠出现典型的肝细胞脂肪变性伴肝组织炎性损伤,肝SOD、CAT和GSH-Px水平降低,IL-6、IL-1β和TNF-α mRNA表达水平升高。大豆异黄酮干预后,各剂量组肝组织病理损伤得到改善,抗氧化因子活性显著提高并呈剂量效应,促炎因子表达水平显著下调。大豆异黄酮可逆转肥胖致肝组织病理损伤和提高肝脏抗氧化活性,下调肥胖相关促炎因子基因的表达,上述结果可为大豆异黄酮的应用开发提供参考。

Effects of soy isoflavones on oxidative stress and inflammatory response in liver of rats with food borne obesity

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.