ABSTRACT
Objective To research the protective effect of Ento-I against cerebral ischemia-reperfusion injury in rats, and to evaluate its analgesic and anticoagulating effects in mice. Methods The ischemic model was established with line embolism to block the middle cerebral artery of male rats. The 56 rats were randomly assigned into 7 groups of sham-operation, blank-matrix, normal saline, Ento-I plastic of 3 doses (6.67, 3.33, 1.67 mg/kg), and ozagrel sodium (8.3 mg/kg, ip). The effect of Ento-I plastic on anti-cerebral ischemia was measured by nervous function scores and the areas of cerebral infarction were determined by TTC staining for the calculation of cerebral infarction rates. The analgesic effect of Ento-I plastic was determined with acetic acid-induced twisting experiment. Sixty KM mice were randomly allocated into blank-matrix, aspirin, aspirin-plastic, and Ento-I plastic of 3 doses (5, 10 and 20 mg/kg), the number of mouse twisting were recorded right after intraperitoneal injection of 0.7% acetic acid solution at the time of 1 h after the last administration. Moreover, the anticoagulant activity of Ento-I plastic was tested by glass capillary method. Results The results of acetic acid-induced twisting experiment displayed that Ento-I plastic of all 3 dose groups (5, 10 and 20 mg/kg) could significantly reduce the number of body torsion and increase the inhibitory rates of twisting, compared with that of blank matrix group (the inhibitory rates of twisting for 3 dose groups were 21.79%, 48.89%, and 56.15%, respectively), with dose-response manner. According to the results of glass capillary test, the clotting time of mouse blood could be significantly prolonged by mid- (10 mg/ kg) and low-dose (5 mg/kg) of Ento-I plastic with corresponding clotting time of (155.20±54.19) s and (155.80±73.84) s, compared with normal saline group at (92.10±24.61) and blank-matrix group at (80.40±48.09, P<0.05). The experiment results of the isch emia-reperfusion injury by line embolism method in rats exhibited that Ento-I plastic in mid-dose (3.33 mg/kg) could significantly re duce the neurological scores after 24 h of reperfusion injury, from (2.33±0.52) of normal saline group to (1.00±0.00) of mid-dose group (P<0.01). The results from TTC staining revealed that the cerebral infarction rates of normal saline group and blank- matrix group were (24.89±7.24) % and (27.72±7.89)%, respectively, whereas those of 6.67 mg/kg and 3.33 mg/kg group of Ento-I plastic were (14.01±2.65) % and (14.73±4.94)%, respectively. Compared to the 2 negative-control groups, both the high- and mid-dose of Ento-I plastic could significantly reduce the cerebral infarction rates after ischemic reperfusion injury in rats (P<0.01). Conclusion Ento-I plastic demonstrates strong analgesic and anticoagulant effects, and could substantially reduce the neurological scores and reduce cerebral infarction rates for ischemia-reperfusion injured rats. These are likely to be the mechanism of action for Ento-I plastic realizing its anti-cerebral ischemia effect.