ABSTRACT
Objective To optimize the therapeutic dose and time window of picroside Ⅱ in treating cerebral ischemic injury in rats by orthogonal test. Methods The forebrain ischemia models were established by bilateral common carotid artery occlusion (BCCAO) method. The successful models were randomly grouped according to orthogonal experimental design and treated by injecting picroside Ⅱintraperitoneally at different ischemic time with different doses. The concentrations of MDA, NO and H2O2 in serum and brain tissue were respectively determined by thiobarbituric acid assay, nitratase reductase assay and chemiluminescence immunoassay. Results The optimized composition of the therapeutic dose and time window of picroside Ⅱ in cerebral ischemic injury were ischemia 1.5 h with 10 mg/kg, 1.5 h with 20 mg/kg and 1.5 h with 10 mg/kg body weight according to the expressions of MDA, NO and H2O2 in serum, and ischemia 1.5 h with 10 mg/kg, 1.5 h with 20 mg/kg and 1.5 h with 20 mg/kg body weight according to the expressions of MDA, NO and H2O2 in brain tissue. Conclusion On the basis of the principle of lowest therapeutic dose with longest time window, the optimized composition of the therapeutic dose and time window in cerebral ischemic injury is injecting picroside Ⅱ intraperitoneally with 10-20 mg/kg body weight at ischemia 1.5 h.