楤木总皂苷对2型糖尿病模型小鼠肾组织Toll样受体的影响

Study on the affection of TLR of aralia in renal tissue of diabetic mice

目的 观察楤木总皂苷对2型糖尿病模型小鼠肾损伤的保护作用，探讨其作用机制。方法 将50只小鼠按随机数字表法分为正常组，模型组，楤木总皂苷低、中、高剂量组，每组10只。除正常组外，其余各组于高脂高糖饮食8周后一次性注射STZ溶液45 mg/kg，诱导2型糖尿病小鼠模型。造模成功后，楤木总皂苷低、中、高剂量组分别灌胃楤木总皂苷30、60、120 mg/kg，正常组和模型组灌胃等体积生理盐水，1次/d，连续给药8周。分别于给药后4、8周，检测各组小鼠24 h尿蛋白含量。末次给药后，检测各组小鼠血糖、胰岛素及血清TNF-a、IL-1β和NF-κB水平，采用免疫组化染色、Western blot法、实时定量PCR检验肾组织中Toll样受体（Toll-like-receptors, TLR）-2、TLR4蛋白和mRNA表达。结果 与模型组比较，楤木总皂苷低、中、高剂量组小鼠24 h尿蛋白含量、血糖、胰岛素抵抗指数降低（P＜0.05），胰岛素含量增加（P＜0.05），血清TNF-α[（16.66±0.20）ng/L、（14.49±0.27）ng/L、（13.52±0.22）ng/L比（20.33±0.56）ng/L]、IL-1β[（0.46±0.04）ng/L、（0.44±0.04）ng/L、（0.37±0.04）ng/L比（0.55±0.05）ng/L]、NF-κB[（28.71±6.14）ng/L、（26.26±5.48）ng/L、（25.69±5.61）ng/L比（36.55±8.90）ng/L]含量降低（P＜0.05），肾组织TLR2 mRNA [（1.92±0.18）、（1.46±0.23）、（1.28±0.21）比（2.69±0.22）]、TLR4 mRNA[（2.20±0.19）、（2.08±0.27）、（1.57±0.22）比（2.78±0.23）]、TLR2蛋白[（0.82±0.11）、（0.52±0.06）、（0.44±0.07）比（0.77±0.13）]、TLR4蛋白[（0.52±0.04）、（0.42±0.09）、（0.26±0.06）比（0.86±0.12）]表达降低（P＜0.05）。结论 楤木总皂苷可明显降低2型糖尿病模型小鼠血糖、胰岛素抵抗指数和24 h尿蛋白，升高胰岛素，其作用机制可能与抑制肾组织TLR2和TLR4蛋白表达，降低炎症反应有关。

Objective To investigate the protective effect of aralia total saponins on renal injury induced by streptozotocin （STZ） in type 2 diabetic rats, meanwhile to explore its protective mechanism. Methods Fifty male Kunming mice were randomly divided into the normal group, the model group and the aralia total saponins low, middle and high does groups. All the rats were given high fat diet 8 weeks and then received STZ 45mg/kg to built type 2 diabetic rats model, except the noraml group. After the models establishment,the aralia total saponins low, middle and high does groups were given the aralia total saponins 30, 60, 120 mg/kg treatment, andthe normal group and the model group were given the equal normal saline, once each day. After 4th and 8th week administration, the urinary protein levels of 24 h in each group were detected. After the last treatment, all the mice were sacrificed to detected the changes of blood glucose, insulin and inflammatory related factors. Immunohistochemistry, Western blotting and real-time quantitative PCR were used to observe the expression of TLR2 and TLR2 in the kidney tissue. Results Compared with the model group, the low, middle and high does groups in 24-hour proteinuria, blood glucose, insulin resistance index decreased （P〈0.05）, the insulin increased（P〈0.05）. The serum TNF-α （16.66 ± 0.20 ng/L, 14.49 ± 0.27 ng/L, 13.52 ± 0.22 ng/L vs. 20.33 ± 0.56 ng/L）, IL-1β （0.46 ± 0.04 ng/L, 0.44 ± 0.04 ng/L, 0.37 ± 0.04 ng/L vs. 0.55 ± 0.05 ng/L）, NF-κB （28.71 ± 6.14 ng/L, 26.26 ± 5.48 ng/L, 25.69 ± 5.61 ng/L vs. 36.55 ± 8.90 ng/L） significantly decreased （P〈0.05）. The kidney TLR2 mRNA （1.92 ± 0.18, 1.46 ± 0.23, 1.28 ± 0.21 vs. 2.69 ± 0.22）, TLR4 mRNA（2.20 ± 0.19, 2.08 ± 0.27, 1.57 ± 0.22 vs. 2.78 ± 0.23）, TLR2 porteins （0.82 ± 0.11, 0.52 ± 0.06, 0.44 ± 0.07 vs. 0.77 ± 0.13）, TLR4 proteins （0.52 ± 0.04, 0.42 ± 0.09, 0.26 ± 0.06 vs. 0.86 ± 0.12） significantly decreased （P〈0.05）. Conclusions The aralia total saponins can significantly reduce the blood glucose, insulin resistance index and 24-hour urinary protein in type 2 diabetic nephropathy of rats, increase the insulin, and analyzing its mechanism may be total saponins can inhibit the expression of TLR2 and TLR2 protein in the kidney, and further reduce the inflammatory response.