贵州凤冈富锌富硒绿茶对衰老模型小鼠Trx含量及肝脏超微结构的影响

Influences of Green Tea with Rich Zn and Se from Fenggang County,Guizhou Province on Trx Content and Liver Ultrastructure of Aging Model Mice

目的:研究贵州凤冈富锌富硒绿茶对衰老模型小鼠硫氧还原蛋白(Trx)含量及肝脏超微结构的影响,探讨富锌富硒绿茶保肝抗衰老的机制。方法:昆明雄性小鼠70只均分为正常对照组、衰老模型组、阳性对照组、富锌富硒绿茶高、中、低剂量组和普通绿茶组,除正常对照组给予腹腔注射生理盐水外,其余6组均给予腹腔注射0.2 mg/(g·d)D-半乳糖制备衰老模型;造模第3周正常对照组和衰老模型组均给予蒸馏水灌胃,其余5组分别给予维生素C,高、中、低3种浓度富锌富硒绿茶及普通绿茶灌胃,1次/d,连续4周;最后1次灌胃后2 h取小鼠眼眶血,酶联免疫法(ELISA)检测小鼠血清Trx的含量,电镜下观察小鼠肝脏组织的超微结构。结果:与正常对照组相比,衰老模型组Trx含量明显降低(P<0.01),说明造模成功;与衰老模型组相比,富锌富硒绿茶组及普通绿茶组Trx含量升高(P<0.01,P<0.05);与普通绿茶组相比,富锌富硒绿茶组Trx含量升高(P<0.05),说明富锌富锌绿茶抗氧化作用强于普通绿茶;富锌富硒绿茶高剂量组Trx含量高于中、低剂量组,中剂量组高于低剂量组,但差异无统计学意义(P>0.05);电镜结果示衰老模型组肝细胞体积缩小,细胞核和细胞器损伤严重;富锌富硒绿茶组肝细胞体积正常,细胞核和细胞器接近正常;普通绿茶组肝细胞胞质内部分线粒体肿胀,内质网轻度扩张;阳性对照组胞质内线粒体及内质网结构接近正常,胞浆轻微肿胀疏松,肝细胞核形态基本接近正常细胞核。结论:贵州凤冈富锌富硒绿茶能明显增加衰老模型小鼠血清Trx含量,具有延缓衰老的作用。

Objective： To study the effect of Fenggang tea with rich Zn and Se on thioredoxin （Trx） content and liver ultrastructure of D-galactose-induced aging mice and to explore the mechanism of pro- tecting liver and anti-aging of the tea. Methods： Seventy Kunming male mice （15 - 18 g） were random- ly divided into control group, positive control group （Vitamin C）, high, middle and low dose groups of zinc-rich and selenium-rich green tea （RZS tea groups）, ordinary green tea group, and aging model group. Except control group, mice in all groups received intraperitoneal injection of 0.2 mg/（g · d） D-galactose to become aging mice model. In 3 weeks after model construction, RZS tea groups re- ceived intragastric administration of preset high, middle and low doses of zinc-rich and selenium-rich green tea. While positive control group, and ordinary green tea group received intragastric administra- tion of Vitamin C and ordinary green tea respectively, and control group and aging model group re- ceived the same amount of saline. All intragastric administrations lasted four consecutive weeks, once per day. In 2 hours after the last administration, the orbital blood was taken for detection of Trx con- tent by ELISA, and liver ultrastructure of mice was examined by electron microscope. Results： Com- pared with the control group, serum Trx content of aging model obviously decreased （P 〈 0.01 ） , which indicated the model was built successfully. Serum Tl-x contents in RZS tea groups were obviously higher than those of aging model group （ P 〈 0. 01, P 〈 0.05 ）. Compared with ordinary green tea group, Trx content increased in RZS tea groups, showing the anti-oxidation effect of RZS tea was high- er than that of ordinary tea. Among RZS tea groups Trx content in high dose group was higher than that in middle and low dose groups, but the differences were not significant （ P 〉 0.05 ）. In aging model group, the volume of liver cells decreased. The cell nucleus and organelle of liver cell was seriously in- juried. On the contrary, in RZS tea groups, the volume of liver cells was normal. The shape of cell nucleus and organelle of liver cell were close to that of normal control group. In ordinary green tea group, part of mitochondria in liver cytoplasm swelled and the endoplasmic reticulu expanded slightly. In positive control group, the structure of mitochondria and endoplasmic reticulu of liver cells was close to normal, and cytoplasm swelled and loosen slightly. The shape of liver cell nuclei was close to that of normal liver cell. Conclusions： Zinc-rich and selenium-rich green tea from Fenggang can increase ser- um Trx content in aging mice model and has some effects of anti-aging.