Studies On Anti-Cerebral Ischemia Effects Of CXT

The effects of CXT on cerebral ischemia and the mechanism of action were studied preliminarily in this paper.The results indicated that the gasping time of mice(l0, 20 , 40 , 60mg/kg) which were cut heads were obviously prolonged and the survival time of hypoxic mice and mice which were ligated bilateral caratid artery were also prolonged after intravenous injection of CXT(15, 30, 60mg/kg). The index and water content of brain were decreased in rats which were pretreated with CXT(10, 20 , 40mg/kg). The neurological deficits were improved and the range of infarction were after MCAO in rats which were pretreated and treated with CXT(10, 20 , 40mg/kg). The contents of MDA of plasma and brain were decreased and SOD of plasma and brain were increased, and NO of plasma were increased and NO of brain were decreased after MCAO in rats which were treated with CXT(10, 20, 40mg/kg). The results indicated that CXT could improve brainABSTRACTedema and ischemic brain injury. The rates of death of encephalic thrombus in mice(15, 30,60mg/kg) and the thrombus weight in vivo in rats(l0, 20 , 40mg/kg) were decreased. The platelet aggregation induced by ADP and collagen in vitro in rabbits(50, 100, 200, 400 , 800mg/L) was inhibited. The result indicated that CXT has the inhibition effects on platelet aggregation. The plasma recalcification time (PRT) in rabbits(0.1 , 1 , 10mg/ml) was prolonged, and the bleed clot wet weight was lighted and euglobulin lysis time (ELT) was shorted in mice(15, 30, 60mg/kg). The results showed that CXT can inhibit thrombosis by reducing coagulation factor of plasma and increasing activity of plasminogen activator. Besides, CXT also improved blood rheology in rats after MCAO.The general pharmacology and acute toxicity of CXT were also investigated. The results of general pharmacology indicated that CXT(4, 8, 16mg/kg) has no significant effects on T, P and QRS wave duration, T ,S-T and P wave height, P-R and Q-T wave interphase duration, however heart rate, mean arterial pressure and respiratory frequency of anesthetized cats were decreased. The results of acute toxicity showed median lethal dose (LD50) of CXT is 488.3mg/kg.All experimental results above showed that the anti-cerebral ischemia effects of CXT. The mechanism maybe involved in decreasing brain energy exhaust, inhibiting platelet aggregation ,ABSTRACTreducing oxygen free radicals (OFR) by increasing the action of SOD and decreasing contents of MDA, improving ischemic brain injury and improving blood rheology.This study provided the experimental basis to the clinical application of CXT. However, the mechanisms accouted for the effects of CXT' s anti-cerebral ischemia deserve further study.