茶多酚对动物脑组织受自由基损伤的保护作用研究

Protective Effect of Tea Polyphenols on Brain Injury by Free Radicals

目的研究茶多酚(Tea polyphenols,TPs)对动物脑组织受自由基损伤的保护作用。方法采用Fenton反应诱导大鼠脑组织匀浆的脂质过氧化模型和结扎小鼠大脑中动脉(MCAO)致脑梗塞模型;分别测定了茶多酚在这两种体内外脑组织模型中的抗氧化作用。结果在体外,茶多酚可剂量依赖性地抑制Fenton反应导致的脑组织匀浆中过氧化脂质(LPO)的生成,其IC50为1.7×10-4mol·L-1。在体内,腹腔注射20mg·kg-1的茶多酚可有效改善MCAO小鼠的运动功能障碍(P<0.01),缩小脑梗死范围(抑制率为24%,P<0.01),减少脑组织中LPO的生成(P<0.01)及提高SOD和GSH-PX的活性(P<0.05)。结论茶多酚对体内外的脑组织有一定程度的抗氧化作用。

OBJECTIVE To evaluate the antioxidant effects of tea polyphenols （ TPs ） on brain tis-sue.METHODS In vitro and in vivo models were applied , ie.Fenton reaction induced lipid peroxidation in rat brain homogenates,and the middle cerebral artery occlusion （MCAO） in mice.Then the antioxidant effects of TPs on brain tissue were assayed.RESULTS In vitro,the IC50 of TPs of inhibiting the production of lipid peroxides （LPO） in rat brain homogenate was 1.7 ×10^-4mol· L^-1.TPs exert the effect in an dose-dependant manner.In vivo, ip.20mg· kg^-1 TPs ameliorate the motor dysfunction of MCAO mice effectively （P〈0.01）,reduce the cerebral infarcted size （ inhibitory rate is 16%） , decrease the LPO production （ 9.45 ±0.21 nmol ·mg^-1 pro.vs 9.87 ± 0.19nmol×10^-4 mg^-1 pro.in model group,P〈0.01） ,increase the activity of SOD （19.7 ±1.1 U·mg^-1 pro.vs 18.3 ±1.3 U·mg^-1 pro.in model group,P〈0.05 ） and GSH-PX （23.8 ±1.9 U· mg^-1 pro.vs 21.4 ±2.0 U·mg^-1 pro.in model group ,P〈0.05 ） in brain tissue.CONCLUSION TPs possess antioxidant effect on brain tissue both in vitro and in vivo.