【摘要】 目的:观察番石榴叶提取物对肥胖KKay小鼠脂肪组织肿瘤坏死因子(TNF-α)、过氧化物酶体增殖物激活受体-γ(PPAR-γ)基因表达的影响,探讨其调控肝脏糖代谢AKT信号通路的机制。方法:6周龄雄性肥胖KKay小鼠16只,适应性喂养2周后,随机分为对照组和番石榴叶水提物组,所有动物给予高脂饲料喂养,番石榴叶水提物组按0.11g/kg灌胃(相当于生药材2g/kg),对照组给予同体积蒸馏水灌胃,疗程为4周。每周监测进食量、饮水量、体质量;入组时、第2周、第4周时分别进行2h口服葡萄糖耐量实验(OGTT),第29天空腹眼眶取血处死小鼠,分别检测血浆胰岛素、甘油三酯(TG)、胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、游离脂肪酸(FFA)水平,计算HOMA-IR指数,留取肝脏组织、附睾上脂肪-80℃备用,RT-PCR法检测脂肪组织TNF-α、PPAR-γ基因表达,Western Blot法检测肝脏组织AKT蛋白表达。结果:与对照组比较,治疗4周后,番石榴叶提取物显著降低KKay小鼠胰岛素水平、改善糖耐量及HOMA-IR指数(P<0.05),下调脂肪组织TNF-α基因表达(P<0.05),上调脂肪组织PPAR-γ基因表达(P<0.05),上调肝脏AKT蛋白表达(P<0.05),对小鼠体质量、血清TG、TC、LDL-C及FFA无显著影响。结论:番石榴叶提取物通过对脂肪组织TNF-α、PPAR-γ基因表达的调节,影响肝脏糖代谢AKT蛋白表达,改善糖耐量和胰岛素抵抗。更多还原

【Abstract】 Objective: To observe the insulin resistance ef ects of Guava leaf(GL) extracts on adipose tissue TNF-α and PPAR-γ gene expression in KKay mice. Methods: 16 male obese KKay mice, 6 weeks old, were randomly divided into control group and Guava leaf water extracts group(0.11g/kg) after being fed for 2 weeks. All mice were given high fat diet and 4-week treatment. Body weight and food intake were measured every week. OGTT and fasting insulin level were tested on day 0, day 14 and day 28. The insulin resistance index was calculated by HOMA-IR. The concentrations of plasma insulin and FFA were assayed using specific ELISA kits. The concentrations of plasma triglycerides and cholesterol were determined by regular biochemistry assays using specific kits. The adipose tissues were collected from individual rats and subjected to lysis. TNF-α and PPAR-γ total RNA was extracted from the adipose tissues using Sepasol-RNA I Super G and reversely transcribed into cDNA using the Rever Tra Ace qPCR RT Kit, according to the manufacturers’ instructions. Hepatic tissue AKT protein was tested by Western Blot. The relative levels of each target protein to control β-actin were determined by densitometry analysis using the Image J 6.0. Results:Treatment with GL water extracts significantly reduced the levels of plasma glucose at 120 min post glucose challenge(P<0.05), the fasting insulin, and the values of HOMA-IR(P<0.05). Furthermore, treatment with GL water extracts decreased TNF-α gene expression, increased the PPAR-γ gene expression in adipose tissues and increased hepatic tissue AKT protein expression(P<0.05). Conclusion: GL water extracts may improve the hepatic tissue glucose metabolism by regulate TNF-α and PPAR-γ gene expression in adipose tissues.更多还原