萝卜硫素对高脂饲粮诱导的肥胖小鼠肠道抗氧化能力和肠道微生物的影响

Effects of Sulforaphane on Intestinal Antioxidant Capacity and Intestinal Microbiota of High Fat Diet Induced Obese Mouse

本试验旨在研究萝卜硫素(SFN)对高脂饲粮诱导的肥胖小鼠肠道抗氧化能力和对肠道微生物的调节作用及机制。选取60只6周龄雄性无特定病原体(SPF)级C57BL/6J小鼠,普通饲粮适应性喂养2周后,随机分为6组,每组10只。2组为正常小鼠:正常对照组(NC组)、正常+SFN组(NC+SFN组),饲喂正常饲粮,SFN以10 mg/(kg BW·d)的剂量每周注射5次;另外4组小鼠,饲喂高脂饲粮,构建肥胖小鼠模型,12周建模成功后分组:肥胖对照组(HFD组)、肥胖+SFN组(HFD+SFN组)、肥胖+抗生素组(HFD+ABX组)、肥胖+SFN+抗生素组(HFD+SFN+ABX组),饲喂高脂饲粮,SFN以10 mg/(kg BW·d)的剂量每周注射5次,抗生素饮水干预。试验期28 d。结果表明:1)与HFD组比,HFD+SFN组小鼠的体重显著降低(P<0.05)。2)SFN可显著升高正常小鼠和肥胖小鼠肠道中核因子E2相关因子2(Nrf2)、超氧化物歧化酶1(SOD1)和谷胱甘肽过氧化酶4(GPX4)的mRNA相对表达量(P<0.05),且HFD+SFN组的SOD2和GPX4的mRNA相对表达量显著高于HFD+ABX组和HFD+SFN+ABX组(P<0.05),HFD+SFN+ABX组的Nrf2、SOD1和GPX4的mRNA相对表达量显著高于HFD+ABX组(P<0.05)。3)SFN对正常和肥胖小鼠肠道菌群Alpha多样性均无显著影响(P>0.05),ABX处理则显著降低肥胖小鼠肠道菌群的多样性(P<0.05)。与HFD组比,HFD+SFN组小鼠肠道的厚壁菌门/拟杆菌门(F/B)值显著降低(P<0.05),并接近NC组(P>0.05),肠道拟杆菌属相对丰度减少,嗜黏蛋白阿克曼氏菌和异杆菌属等与抗肥胖有关的微生物的相对丰度增加。且SFN干预后能显著升高ABX肥胖小鼠的F/B值(P<0.05),使其接近NC组(P>0.05)。综上所述,SFN可能通过参与激活Nrf2信号通路增加肠道抗氧化酶活性,进而缓解肥胖诱导的氧化应激,并通过调节抗肥胖菌群来改善肥胖和抗生素治疗诱导的肠道菌群紊乱,从而达到抗肥胖作用。

The aim of this study was to investigate the effects and mechanism of sulforaphane(SFN)on the intestinal antioxidant capacity and the regulation of intestinal microbiota in high fat diet fed obese mouse.Sixty 6-week-old male SPF-grade C57BL/6J mice were selected,after 2 weeks of acclimatization feeding with normal diet,were randomly divided into 6 groups with 10 mice in each group.The two groups of normal mice:the blank control group(NC group)and the normal+SFN group(NC+SFN group),which were both fed a basal diet and SFN was administered 5 times a week at 10 mg/(kg BW·d);the other 4 groups of mice were fed a high fat diet,the obese mouse model was constructed,and the groups were divided after 12 weeks of successful modeling:obesity control group(HFD group),obesity+SFN group(HFD+SFN group),obesity+antibiotics group(HFD+ABX group),obesity+SFN+antibiotics group(HFD+SFN+ABX group),which were fed a high fat diet,the intervention was performed with 10 mg/(kg BW·d)doses of SFN(injected 5 times a week)and antibiotics water.The experiment lasted for 28 days.The results showed as follows:1)the body weight of mice in the HFD+SFN group was significantly lower compared with the HFD group(P>0.05).2)SFN significantly increased the mRNA relative expression levels of nuclear factor E2 related factor 2(Nrf2),superoxide dismutase 1(SOD1)and glutathione peroxidase 4(GPX4)in the intestinal tract of the normal and obese mice(P<0.05),and the mRNA relative expression levels of superoxide dismutase 2(SOD2)and GPX4 in the HFD+SFN group was significantly higher than that in the HFD+ABX group and the HFD+SFAB group(P<0.05).Moreover,the mRNA relative expression levels of Nrf2,SOD1 and GPX4 in the HFD+SFAB group was significantly higher than that in the HFD+ABX group(P<0.05).3)SFN had no significant effect on intestinal flora alpha diversity in normal and obese mice(P>0.05),while ABX treatment significantly decreased the diversity of intestinal flora in obese mice(P<0.05).Compared with the HFD group,the ratio of Firmicutes/Bacteroidetes(F/B)in the intestines of mice in the HFD+SFN group was significantly lower(P<0.05)and to a level similar to that in the NC group(P>0.05),with a decrease in the relative abundance of Bacteroide,and an increase in the relative abundance of anti-obesity-related microorganisms,such as Akkermansia muciniphila and Allobaculum.And SFN intervention significantly increased the F/B value of obese mice given ABX(P>0.05),to a ratio close to that of the NC group(P>0.05).In summary,SFN may alleviate obesity-induced oxidative stress by participating in the activation of Nrf2 signaling pathway to increase intestinal antioxidant enzyme activities,and improve the disturbance of intestinal flora induced by obesity and antibiotic treatment by regulating anti-obesity flora,so as to achieve anti-obesity effects.