芡实醇提物对糖尿病肾病大鼠肾功能的影响及其体外抗氧化能力测定

摘要

目的：探讨芡实醇提物对糖尿病肾病大鼠肾功能的影响，并测定芡实醇提物、水提物上清和沉淀的体外抗氧化能力。方法80%乙醇提取芡实种仁，浓缩冻干后得干燥粉末，药渣采用水提醇沉法，经抽滤旋蒸制备上清和沉淀。雄性SD大鼠腹腔注射链脲佐菌素60 mg/kg诱导糖尿病肾病模型，灌胃给予芡实醇提物（75、150、300、600 mg/kg）12周后，检测大鼠尿蛋白、尿微量白蛋白、血肌酐（Cr）和尿素氮（BUN）含量，并观察肾组织病理学变化。通过对Fe3+还原力、1，1-二硝基-2-三硝基苯肼（DPPH）、O2－和OH－自由基清除率的比较，测定3种提取物的抗氧化能力。结果与糖尿病肾病模型组比较，各剂量芡实给药组均能降低大鼠24 h尿蛋白和尿微量白蛋白含量，芡实150和600 mg/kg组尿蛋白显著降低（P＜0.05）；与模型组比较，各剂量芡实给药组大鼠血中BUN均有不同程度降低，芡实300 mg/kg组降低更为显著（P＜0.01）。12周末肾组织病理学观察结果表明，芡实醇提物300和600 mg/kg能够明显减轻肾组织损伤。芡实醇提物在浓度为0.6、0.8和1.0 mg/ml时，显示有一定的抗氧化能力，表现为对Fe3+的还原，对DPPH、O2－和OH－的清除。结论芡实醇提物具有降低糖尿病肾病大鼠尿蛋白的作用，该作用可能与其抗氧化能力有关。%Objective To investigate the effect of Euryale ferox seeds ethanol extract on renal funtion of diabetic nephropathy (DN) induced by strepotozotocin (STZ) in rats and the antioxidant ability of ethanol extract,water extract supernatant and precipitation. Methods Ethanol extract of Euryale ferox seeds were prepared by ethanol extraction and followed by evaporation and freeze-dry. The seeds residue was further extracted with water and precipitated with ethanol to obtain water extract supernatant and precipitation. Sprague Dawley male rats were given intraperitoneal injection of STZ at a dose of 60 mg/kg to induce DN. STZ-induced DN rats were administrated by gavage with different dose of Euryale ferox seeds ethanol extract(75, 150, 300 and 600 mg/kg body weight) once daily for 12 weeks. 24 h urine was collected for examining urinary protein and microalbumin every four weeks. Blood serum was also collected for examining of serum creatinine (Cr) and blood urea nitrogen (BUN) level after rats sacrificed at the end of 12 weeks after administration, and the pathological changes of kidney were observed. Antioxidant capacity of the three extracts were determined by Fe3+ reduction, and radical scavenging rate to 1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazl(DPPH), O2-and OH-free radicals. Results Compared with model group, the content of 24 h urine protein and urine microalbumin of DN rats were reduced in all Euryale ferox seeds ethanol extract administration groups, and 24 h proteinuria were significantly reduced in the group of 150 and 600 mg/kg administration(P<0.05);BUN level was also reduced in all dose of Euayale ferox seeds ethanol extract administration, and more remarkably reduced in the group of 300mg/kg (P<0.01). 12 weeks after administration, kidney damage amelioration was observed in pathological sections of rats in Euryale ferox seeds ethanol extracts 300 and 600 mg/kg groups. Meanwhile, Euryale ferox seeds ethanol extract showed a certain antioxidant abilities in reducing of Fe3+ and scavenging DPPH, O2- and OH- at the concentrations of 0.6, 0.8 and 1.0 mg/ml. Conclusion Euryale ferox seeds ethanol extract could decrease proteinuria of STZ-induced DN rats,this may be associated with its antioxidant capacity.