大黄对内毒素血症模型大鼠氧化应激损伤的保护作用初探

目的:观察大黄水提物对内毒素血症模型大鼠体内血清中超氧化物歧化酶(SOD),过氧化氢酶(CAT)活力及丙二醛(MDA),过氧化氢(H2O2)含量的影响,初步探讨大黄水提物对内毒素血症模型大鼠氧化应激的保护作用。方法:将50只SD大鼠随机分为正常组,模型组,地塞米松阳性药组(7.5×10-4g·kg-1),大黄高、低剂量组(3.0,1.5 g·kg-1)。每天早晚各给药1次,连续给药7次,末次给药0.5 h后尾静脉注射内毒素(LPS)(5 mg·kg-1)复制模型,然后每间隔0.5 h测定一次动物肛温,于造模后4 h麻醉动物,剖取脾脏、胸腺、肾上腺等组织称取各脏器质量计算其脏器系数,股动脉取血制备血清,采用比色法试剂盒测定血清中SOD,CAT活力及MDA,H2O2的含量。结果:与模型组比较,大黄水提物1.5 g·kg-1能显著降低模型大鼠的体温变化指数(TRI4)(P0.05),明显降低血清中MDA,H2O2的含量(P0.05),显著升高SOD,CAT的活力(P0.05)。结论:氧化应激是LPS诱发内毒素血症的重要环节,大黄可以通过上调SOD及CAT的活性,清除体内过度累积的自由基,干预模型大鼠体内氧化应激损伤的信号传导,起到一定的保护作用。

Preliminary Study on Protective Effect of Rhei Radix et Rhizoma Against Oxidative Stress Injury in Endotoxemia Rats Model

Objective: To observe the effect of the aqueous extract of Rhei Radix et Rhizoma on superoxide dismutase (SOD) activity, catalase (CAT) activity, the contents of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) in rats of endotoxemia, and to preliminarily explore its protective effect on oxidative stress in endotoxemia rats. Method: Totally 50 SD rats were randomly divided into the control group, the model group, the dexamethasone group (7.5×10^-4 g·kg^-1), the high and low-dose Rhei Radix et Rhizoma groups (3.0, 1.5 g·kg^-1).All animals were administered continuously twice daily for 7 times, once in the morning and the other in the evening.Then 0.5 h after the last administration, rats were received an intravenous injection of 5 mg·kg^-1 lipopdysaccharide(LPS) to replicate the endotoxemia model.The rectal temperature of rats was tested once every 0.5 h.After 4 h, the animals were anesthetized, and the blood was collected from the femoral artery, then spleen, thymus, adrenal gland and other tissues were removed.The organ coefficient was calculated.The activities of SOD, CAT and the content of MDA, H₂O₂ in serum were measured by using a colorimetric indicator. Result: Compared with the model group, the aqueous extract of Rhei Radix et Rhizoma at dosage of 1.5 g·kg^-1 can notably reduce the index of temperature (TRI4) in endotoxemia rats (P<0.01, P<0.05), and apparently decrease MDA, H₂O₂ levels in serum (P<0.05), and significantly increased SOD, CAT vitality (P<0.05). Conclusion: Oxidative stress is an important link in the endotoxemia induced by LPS, Rhei Radix et Rhizoma play a certain protective effect on endotoxemia by increasing the activity of SOD and CAT to clear free radicals excessive accumulated in the body, and intervening the signal transduction of oxidative stress injury in endotoxemia rats.