绿茶对高糖环境下乳鼠海马神经细胞的保护作用

Protective effect of green tea on hippocampal neurons in rats under high glucose

目的探讨绿茶对高糖环境下乳鼠海马神经细胞的保护作用。方法取SD雄鼠6只,分别用绿茶浓缩液、生理盐水灌胃,按血清药理学方法制备绿茶浸出液血清和空白血清。取出生24 h内SD乳鼠的海马组织,采用酶消化法分离培养海马神经细胞,分为8组,对照组培养基葡萄糖浓度为25 mmol/L;高糖组葡萄糖浓度为45mmol/L;空白血清低、中、高浓度组葡萄糖浓度为45 mmol/L,并分别加入25%、50%、100%浓度的空白血清;绿茶低、中、高浓度组葡萄糖浓度为45 mmol/L,并分别加入25%、50%、100%浓度的绿茶浸出液血清。干预后48 h,采用倒置显微镜和透射电镜观察各组神经细胞形态及超微结构改变;干预后第7天,采用乳酸脱氢酶(LDH)试验及CCK-8法检测神经细胞活性和损伤程度。结果与对照组相比,高糖组海马神经细胞出现损伤现象,如胞体不规则、突触减少等;绿茶低、中、高浓度组较高糖组均有不同程度改善。高糖组LDH水平高于对照组(P<0.01);绿茶低、中、高浓度组LDH水平均低于高糖组,且高浓度组低于低浓度组(P均<0.01);绿茶各浓度组LDH水平均低于相应空白血清对照组(P均<0.05)。高糖组CCK-8低于对照组(P<0.01);绿茶低、中、高浓度组CCK-8均高于高糖组,且高浓度组高于低浓度组(P均<0.05);绿茶各浓度组CCK-8均高于相应空白血清对照组(P均<0.05)。结论高糖能够引起海马神经细胞的损伤,绿茶能够有效改善海马神经细胞形态和结构,升高细胞活性,降低其损伤程度,具有一定的神经保护作用。

Objective To investigate the protective effect of green tea on hippocampal neurons after high glucose injury in neonatal rats. Methods Six SD male rats were treated with green tea concentrated solution and normal saline by gavage. Blank serum and green tea extract serum were prepared according to serum pharmacology. The hippocampus tissues of SD neonatal rats born within 24 h were isolated and cultured by enzymatic digestion. The cells were then divided into 8 groups. The glucose concentration in the control group was 25 mmol/L; the glucose concentration in the high glucose group was 45 mmol/L; the glucose concentration in the low,medium,and high concentration groups（ blank serum control groups） were 45 mmol/L,and 25%,50%,and 100% concentrations of blank serum were added; the glucose concentration in the low-dose,medium-dose,and high-dose green tea groups was 45 mmol/L,and 25%,50%,and 100% concentrations of green tea extract serum were added,respectively. Using the inverted microscope and transmission electron microscope to observe morphological and ultrastructural changes of nerve cells,CCK-8 and lactate dehydrogenase（ LDH） test for detection of nerve cell activity and the degree of injury. Results Compared with the control group,the hippocampal neurons in the high glucose group showed damage,such as irregular cell bodies and decreased synapses. Compared with the high glucose group,the morphology and ultrastructure of hippocampal neurons in the low-dose,medium-dose,and highdose green tea groups improved to different extents. The level of LDH in the high glucose group was higher than that in the control group（ P〈0. 01）. The LDH levels in the low-dose,medium-dose,and high-dose green tea groups were lower than those in the high glucose group,and the high concentration group was lower than the low concentration group（ all P〈0. 01）. The LDH levels in different doses of green tea groups were lower than those in the corresponding blank serum control groups（ P〈0. 05）. The CCK-8 in the high glucose group was lower than that in the control group（ P〈0. 01）. The CCK-8 in the low-dose,medium-dose,and high-dose green tea groups was higher than that in the high glucose group,and the high concentration group was higher than the low concentration group（ P〈0. 05）. The CCK-8 in the different doses of green tea groups was higher than that of the blank serum control groups（ P〈0. 05）. Conclusion The high glucose can cause damage to the morphology and structure of hippocampal neurons,while green tea can effectively improve the morphology and structure of hippocampal neurons,increase the cell activity,reduce their degree of injury,and have a certain neuroprotective effect.