桑葚浓缩汁对D-半乳糖诱导氧化损伤大鼠脾脏的保护作用

Protective Effect of Mulberry Juice Concentrate on D-Galactose-Induced Oxidative Damage in Spleen of Rats

研究桑葚浓缩汁对D-半乳糖(D-galactose,D-Gal)诱导氧化损伤大鼠脾脏的保护作用。采用D-Gal建立衰老模型,将Wistar大鼠随机分为正常对照组、D-Gal模型阴性对照组、D-Gal+VE阳性对照组、D-Gal+桑葚浓缩汁(低、中、高)剂量组6组。检测脾脏总超氧化物歧化酶(total superoxide dismutase,T-SOD)、谷胱甘肽过氧化物酶(glutathione peroxidase,GSH-Px)、过氧化氢酶(catalase,CAT)的活力及丙二醛(malondialdehyde,MDA)含量,血清中肿瘤坏死因子-α(tumour necrosis factor-α,TNF-α)、白细胞介素6(interleukin-6,IL-6)的质量浓度,并对脾脏指数、半胱氨酸天冬氨酸蛋白酶(Caspase-9、Caspase-3)的表达水平进行测定,结合组织形态学评价桑葚浓缩汁对氧化损伤大鼠脾脏的影响。结果显示,与阴性对照组相比,桑葚浓缩汁中、高剂量组均可提高脾脏组织T-SOD、GSH-Px、CAT的活力(P<0.05),各剂量处理组均可降低MDA含量(P<0.05)及TNF-α、IL-6的表达,提高脾脏指数。其中高剂量处理组的T-SOD、GSH-Px、CAT活力分别达到了113.22、90.17、7.67 U/mg pro,作用效果明显;MDA含量降至13.59 nmol/mg,脾脏指数升至4.12 mg/g,均达到了正常对照组和阳性对照组水平(P>0.05);TNF-α、IL-6水平下降至56.95、76.83 pg/m L。免疫组化结果显示,桑葚浓缩汁处理组Caspase-9、Caspase-3的表达均有减轻,其中高剂量组效果最好。苏木素-伊红染色结果也证实,桑甚浓缩汁可保护脾脏结构,有效增加淋巴细胞数量,改善充血现象。可见,桑葚浓缩汁对氧化损伤大鼠脾脏有一定的保护作用,并呈一定的量效关系。

The intention of this study was to explore the protective effect of mulberry juice concentrate （MJC） on D-galactose-induced damage in the rat spleen. A rat model of aging was induced by D-galactose. Wistar rats were randomly divided into 6 groups： normal control, model, positive control （VE）, and low-, medium- and high-dose MJC treatment groups. The activities of total superoxide dismutase （T-SOD）, glutathione peroxidase （GSH-Px） and catalase （CAT）, and malondialdehyde （MDA） level of spleen homogenate were measured by using test kit. The levels of tumour necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in serum were determined; the spleen index and the expression levels of caspase-9 and caspase-3 were measured as well. Moreover, histomorphological examination was performed to evaluate the effect of MJC on oxidative damage in the rat spleen. The results showed that compared to the model group, the medium- and high-dose MJC groups could improve the activity of T-SOD, GSH-Px and CAT in spleen tissue （P 〈 0.05）. MJC at all three doses decreased MDA level （P 〈 0.05） and TNF-α and IL-6 expression levels, and increased spleen index. High-dose MJC could signifcantly increased T-SOD, GSH-Px and CAT activity to 113.22, 90.17 and 7.67 U/mg protein, decreased MDA level to 13.59 nmol/mg, and enhanced spleen index to 4.12 mg/g compared to the model group, all of which reached the levels of the normal control group and positive control group （P 〉 0.05）. In addition, the expression levels of TNF-α and IL-6 in the high-dose group were decreased to 56.95 and 76.83 pg/mL. The results of immunohistochemistry showed that the expression of caspase-9 and caspase-3 was attenuated by MJC at all doses, and the best effect was found at high dose. Hematoxylin and eosin staining also indicated that MJC could protect spleen structure, increase the number of lymphocytes and improve hyperemia. These results showed that mulberry juice concentrate has a signifcant protective effect on oxidative damage in the spleen of rats.