桑枝多糖对糖尿病肾病大鼠肾脏组织抗氧化作用的影响

目的：研究桑枝多糖对链脲佐菌素（STZ）诱导糖尿病大鼠的血糖和抗氧化作用的影响。方法：STZ（120 mg·kg^-1）腹腔注射诱导糖尿病大鼠模型，并随机分为5个组（n=10）：模型对照组，二甲双胍对照组（320 mg·kg^-1），桑枝多糖低、中、高剂量组（0.3，0.6，1.2 g·kg^-1），另设10只大鼠作为空白对照组。大鼠灌胃给药60 d，并测定大鼠空腹血糖（FBG）。终点法测24 h尿微量白蛋白含量。给药60 d后处死大鼠，对大鼠肾脏HE染，光镜下观察肾脏病理学的变化；试剂盒测定大鼠肾脏中锰超氧化物歧化酶（Mn-SOD）、谷胱甘肽过氧化物酶（GSH-Px）的活性和丙二醛（MDA）含量；比色法检测肾组织中线粒体呼吸链复合物Ⅰ、Ⅲ活性。结果：与模型组比较，糖尿病大鼠经桑枝多糖治疗后血糖有所下降并显著降低尿微量白蛋白含量（P<0.05）。模型组大鼠肾脏中Mn-SOD、GSH-Px活性以及肾组织线粒体呼吸链复合物Ⅰ、Ⅲ活性显著降低，而MDA含量则升高。桑枝多糖给药后Mn-SOD、GSH-Px、线粒体呼吸链复合物Ⅰ、Ⅲ活性有所升高，MDA含量下降（P<0.05）。结论：桑枝多糖能显著降低糖尿病大鼠的血糖，其作用机制可能与提高糖尿病大鼠的抗氧化作用有关。

Anti-oxidative effects of Ramulus mori polysaccharides on diabetic nephropathy rats

OBJECTIVE To investigate influence of Ramulus mori polysaccharides (RMP) on blood glucose and anti-oxidative effects in streptozotocin-induced diabetic rats.METHODS Diabetic rats were induced by intraperitoneal injection of 120 mg·kg^-1 streptozotocin (STZ) and were randomly divided into the following 5 groups with 10 animal per group:model control group, metformin control group, low-, medium-, high-dose (0.25, 0.50, 1.00 g·kg^-1) of RMP groups. Other 10 normal rats were treated as normal control. Rats were administered orally for 60 days, FBG was measured at 0, 7, 14 days. After the last administration, Mn-SOD, GSH-Px and MDA were determined in renal tissues. Pathological changes of renal tissues were observed through HE staining. Mitochondrial respiratory chain complex Ⅰ and Ⅲ activities were determined in renal tissues.RESULTS Compared with normal group, FBG of other groups was significantly increased (P<0.01). Compared with model group, blood glucose of RMP groups was decreased (P<0.05). Compared with normal group, Mn-SOD and GSH-Px activities of model group were reduced, while MDA level was increased. After RMP administration, Mn-SOD, GSH-Px, complex Ⅰ and Ⅲ activities were up-regulated, but serum MDA level was decreased (P<0.05).CONCLUSION Hypoglycemic mechanism of RMP on STZ-induced diabetic rats may relate to improvement of anti-oxidative capability.