芍药苷对高脂饲养大鼠胰岛素抵抗和脂肪组织TNFα、GLUT4表达的影响

目的观察芍药苷对高脂饲养大鼠胰岛素敏感性和血脂谱的影响，并研究其作用机制。方法将雄性SD大鼠按随机数字表法分为正常组、高脂饲养组、芍药苷低剂量组和芍药苷高剂量组，除正常组喂食普通饲料外，其余各组喂食高脂饲料，芍药苷干预组另分别给予低、高剂量芍药苷腹腔注射，第6周末各组大鼠禁食12h后处死，采血测定血清甘油三酯（TG）、总胆固醇（TC）、游离脂肪酸（FFA）、空腹血糖（FBG）及胰岛素（Ins）并计算胰岛素敏感指数（IsI），剪取附睾脂肪，定量PCR方法检测附睾脂肪组织肿瘤坏死因子α（TNFα）、葡萄糖转运子4（Glut4）表达。结果芍药苷高剂量组大鼠与高脂组相比，附睾脂肪重量减少，FBG、Ins、FFA水平降低（P〈0．05），ISI明显改善（-5．84±0．24VS-6．44±0．25，P〈0．05），芍药苷低剂量组亦有类似趋势。高脂组大鼠脂肪组织内TNFctmRNA表达上调，Glut4mRNA表达下调，两用药干预组TNFctmRNA水平较高脂组有明显降低（P〈0．05），芍药苷高剂量组Glut4mRNA表达显著高于高脂组（P〈0．05）。结论芍药苷能够减少高脂饲养大鼠内脏脂肪含量，抑制脂肪组织TNFotmRNA的表达、上调Glut4mRNA水平，从而降低血糖，改善胰岛素抵抗。

Effects of paeoniflorin on insulin resistance and adipose tissue TNFcmnd GLUT4 expressions in obeserats fed with high-fat food

Objective To observe the effect of paeoniflorin on insulin resistance in rats fed with high-fat diet and to investigate the possible mechanisms. Methods Male Sprague Dawley （SD） rats were randomized into 4 groups： normal control, high-fat diet, high-dosage paeoniflorin （ HDP group）, and low- dosage paeoniflorin （LDP group）. The control group was fed with ordinary diet, while the others with high- fat diet, paeoniflorin intervention groups were given low- or high-dosage paeoniflorin by intraperitoneal injec- tion. After 6 weeks, fasting serum triacylglycerol （ TG）, total cholesterol （ TC）, free fatty acids （ FFA）, fasting blood glucose （FBG）, and insulin were determined. Insulin sensitivity index （ISI） were calculated and then the animals were sacrificed to acquire epididymal fat mass. The tumor necrosis factor alpha （TNFot） and glucose transporter 4 （Glut4） expressions in adipose tissue were detected by quantitative real- time polymerase chain reaction（PCR）. Results Compared with high-fat fed group, HDP group had lower epididymal fat pad weight, reduced level of FBG, insulin and FFA （ P 〈0. 05） and improved ISI（ -5.84 3= 0. 24 vs - 6. 44 3= 0. 25, P 〈 0. 05 ）. LDP group had similar trends. In adipose tissue, the TNFot expres- sion in LDP and HDP group was lower, Glnt4 expression in HDP group was higher than that of high-fat fed group （ P 〈 O. 05）. Conclusion Paeoniflorin can reduce visceral adipose content, inhibit TNFot express-ion and increase Glut4 expression in adipose tissue, eventually lower glucose, and improve insulin resist- ance caused by high-fat diet.