桑葚浓缩汁对D-半乳糖诱导氧化损伤大鼠肾脏的保护作用

Protective Effect of Mulberry Juice Concentrate on D-Galactose-Induced Oxidative Stress in Kidney of Rats

研究桑葚浓缩汁对氧化损伤大鼠肾脏的保护作用。采用D-半乳糖(D-galactose,D-Gal)建立衰老模型,将实验大鼠随机分为6组:空白对照组、阴性对照组(D-Gal模型)、阳性对照组(D-Gal+VE)、桑葚浓缩汁低、中、高剂量组。通过检测大鼠肾脏组织匀浆中超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)和谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)活力、丙二醛(malondialdehyde,MDA)含量,测定大鼠血清一氧化氮(nitric oxide,NO)、血尿素氮(blood urea nitrogen,BUN)和血清肌酐(serum creatinine,Scr)浓度、总抗氧化能力(total antioxidant capacity,T-AOC)及B淋巴细胞瘤-2相关X蛋白(B-cell lymphoma-2-associated X protein,Bax)基因的表达,并通过病理组织学切片评价桑葚浓缩汁对氧化损伤蛋白的影响。结果表明:与阴性对照组相比,桑葚浓缩汁中、高剂量组可以显著提高肾组织SOD、GSH-Px、CAT活力和T-Ao C(P<0.05);降低MDA、BUN及Scr浓度;抑制NO浓度升高(P<0.05),并成一定量效依赖关系;Bax表达降低;其中桑葚浓缩汁高剂量效果最好,GSH-Px活力为150.33 U、Scr浓度为34.54μmol/L、BUN浓度为8.96 mmol/L,均达到了阳性对照组水平(P>0.05);NO浓度为29.78μmol/L,达到空白对照组水平(P>0.05)。病理学组织切片显示,与阴性对照组相比,桑葚处理组症状明显减轻,尤其中、高剂量组,极少量肾小管上皮细胞胞浆疏松、淡染,无明显的充血、出血。综上所述,桑葚浓缩汁对D-Gal诱导氧化损伤大鼠肾脏有较好的保护作用。

To study the protective effect of mulberry juice concentrate on oxidative injury in the kidney of rats, an aging rat model was established by injection of D-galactose （D-Gal） and the experimental rats were divided into six groups, including normal control, negative control, positive control group （D-Gal ＋ VE）, D-Gal ＋ mulberry juice concentrate low-, middle- and high-dose groups. Superoxide dismutase （SOD）, catalase （CAT） and glutathione peroxidase （GSH-Px） activities and malondialdehyde （MDA） content in liver homogenate, nitric oxide （NO）, urea nitrogen （BUN）, creatinine （Scr） and total antioxidant capacity （T-AOC） in serum, and the expression of B-cell lymphoma-2-associated X protein （Bax） gene in kidney were measured. Besides, hematoxylin-eosin stained kidney sections were histopathologically examined. The results showed that compared with the negative control group, mulberry juice concentrate at middle and high doses could significantly increase the activities of SOD, GSH-Px, CAT and T-AOC in renal tissue （P 〈 0.05）, decrease MDA level in renal tissue, serum BUN and Scr levels and repress the increase in serum NO （P 〈 0.05） in a dose-dependent manner. In addition, the expression of Bax was significantly reduced （P 〈 0.05）, and the best result was observed at high dose, where GSH-Px activity was 150.33 U and serum Scr and BUN were 34.54 μmol/L and 8.96 mmol/L, respectively, which were close to the levels of the positive control group （P 〉 0.05）, and serum NO was 29.78 μmol/L, which was similar to that of the blank control group （P 〉 0.05）. Histopathological examination showed that compared with the model group, the symptoms of kidney injury in the treatment groups were obviously alleviated, especially in the middle- and high-dose groups, where few renal tubular epithelial cells were loose and pale, without obvious congestion or bleeding. In summary, mulberry juice concentrate has a good protective effect on D-Gal-induced oxidative stress in the kidney of rats.