罗汉果甜苷V对持续光照小鼠脂肪积累的缓解作用

【目的】探究罗汉果甜苷V(MV)缓解持续光照导致小鼠脂肪积累的作用,为罗汉果在畜禽健康养殖中的应用提供参考依据。【方法】以15周龄雄性C57BL/6小鼠为研究对象,随机分为对照组(12 h光照∶12 h黑暗)、持续光照组(24 h光照)及持续光照添加MV处理组(每日灌胃100 mg/kg的MV),试验周期为5周。试验期间监测小鼠体质量和采食量,并检测其体脂率和能量代谢水平;试验结束后处死小鼠,采集腹股沟白色脂肪(iWAT)和附睾白色脂肪(e WAT)进行称重,通过苏木精—伊红(H-E)染色观察脂肪细胞形态学特征,并以实时荧光定量PCR检测脂肪组织中脂肪代谢及能量代谢相关基因的表达情况。【结果】在整个试验过程中,各处理组小鼠的体质量与采食量均无显著差异(P>0.05),但持续光照能导致小鼠体脂率极显著升高(P<0.01,下同),而氧气消耗量、二氧化碳排出量及产热量等基础代谢参数均极显著降低,iWAT和eWAT的百分比及细胞直径均极显著增大;iWAT和eWAT中的脂肪合成相关基因(Fabp4、Pparg2和Zfp423)相对表达量极显著上调,脂肪分解相关基因Lpl相对表达量极显著下调,能量代谢基因(Sirt1和Ppargc1a)相对表达量显著(P<0.05)或极显著下调,炎症反应相关基因Nfkb1相对表达量极显著上调。经MV处理后能使持续光照小鼠上述变化指标均恢复至正常水平,即MV能有效改善持续光照导致的小鼠能量代谢紊乱、缓解脂肪累积,以及缓解脂肪代谢、能量代谢及炎症反应相关基因的异常表达。【结论】持续光照会在不改变能量摄入的情况下导致机体脂肪积累,影响机体的正常代谢和健康。MV通过调控Sirt1、Ppargc1a等重要代谢相关基因表达,改善机体代谢紊乱,并通过促进脂肪分解和抑制脂肪合成相关基因表达,有效缓解持续光照导致的小鼠脂肪积累。

Mogroside V attenuated constant light exposure-induced accumulation of body fat mass in mice

【Objective】To investigate the effect of mogroside V(MV)on alleviating fat accumulation in mice under continuous illumination,and to provide reference for the application of Siraitia grosvenori in healthy breeding of livestock and poultry.【Method】15-week-old male C57BL/6 mice were randomly divided into control group(light:darkness=12 h∶12 h),continuous illumination group(24 h continuous light exposure),and continuous illumination with MV treatment group[100 mg/(kg·d)]. During the five weeks treatment,the body weight and food intake of the mice were monitored.And the body fat content and energy metabolism of the mice were detected. After the treatment,the mice were sacrificed,and iWAT and eWAT of the mice were weighed and stained with hematoxylin-eosin(H-E)to observe the morphology of the adipose tissue. Besides,the expression level of lipometabolism and metabolizing-related genes in the adipose tissues was detected by real-time quantitative PCR.【Result】During the five weeks treatment,there were no significant differences in the body weight and food intake among three groups mice(P>0.05). But continuous illumination could extremely significantly increase the body fat content(P<0.01,the same blow). The basic metabolic parameters such as oxygen consumption,carbon dioxide emission and heat production were extremely significantly decreased,while the percentage of iWAT and eWAT and cell diameter were extremely significantly increased. In iWAT and eWAT of continuous illumination group,the relative expression levels of fat synthesis related genes(Fabp4、Pparg2 and Zfp423)and inflammatory response related genes Nfkb1 were extremely significantly up-regulated,and the relative expression levels of lipolysis related genes Lpl were extremely significantly down-regulated,and energy metabolism genes(Sirt1 and Ppargc1a)were significantly(P<0.05)or extremely significantly down-regulated. However,MV treatment could restore the above indexes changes to the level of control group. These results indicated that MV could effectively improve the energy metabolism disorder,fat accumulation,and the abnormal expression of fat metabolism,energy metabolism and inflammatory response related genes caused by continuous light exposure.【Conclusion】Continuous light exposure can induce the body fat accumulation without changing the energy intake,affecting the body metabolism and health. MV can effectively alleviate metabolic disorders by regulating the expression of metabolism-related genes Sirt1and Ppargc1a. Besides,MV can effectively alleviate fat accumulation induced by continuous light exposure in mice through promoting lipolysis and inhibiting the expression of adipose synthesis-related genes.