Effect of butylphthalide on brain edema and the expression of phosphorylated myosin light chain in peri-infarct tissue in focal cerebral ischemic rats

Abstract

Objective To investigate the effect of butylphthalide on brain edema and the expression of phosphorylated myosin light chain in peri-infarct tissue in focal cerebral ischemic rats.Methods A total of 212 adult male Sprague-Dawley rats were divided into a sham operation group （n =12）,a cerebral ischemia group （n =100）,and a butylphthalide group （n =100） （40 mg/kg,1/day,gavage） according to the random number table.Both the cerebral ischemia group and the butylphthalide group were redivided into 6 h,12 h,1 d,3 d,and 7 d groups （n =20 for each time point）.A rat model of focal cerebral ischemic model was induced by photochemical method; 2,3,5-triphenyl tetrazolium chloride （TTC） staining was used to detect infarct volume （n =5）; wet-dry weight method was used to detect the water content in brain tissue （n =5）;immunohistochemistry （n =5） and Western blot （n =5） were used to detect the protein expression of periinfarct cortical p-MLC.Results TTC staining showed that no infarcts were observed in the sham operation group.The infarct volumes at each time points in the butylphthalide group were significantly less than those at the same time points in the cerebral ischemia group （all P 〈0.05）.Wet-dry weight method showed that the water contents in brain tissue in the cerebral ischemia group and the butylphthalide group were significantly higher than that in the sham operation group （all P 〈 0.05）,but the water contents in brain tissue at each time points in the butylphthalide group was significantly lower than those at the same time points in the cerebral ischemia group （all P 〈 0.05）.Both immunohistochemistry and Western blot showed that the expressions of peri-infarct cortical p-MLC in both the cerebral ischemia group and the butylphthalide group were upregulated significantly compared to the sham operation group （all P〈 0.05）,but the expressions of peri-infarct cortical p-MLC at each time points in the butylphthalide group was significantly lower than those at the same time points in the cerebral ischemia group （all P〈 0.05）.Conclusions Butylphthalide can be up-regulated by reducing the expression of p-MLC caused by cerebral ischemia and reduce cerebral edema,and then reduce the infarct volume,and thus play a neuroprotective effect. Key words: Brain Ischemia; Myosin Light Chains; Benzofurans; 3-n-butylphthalide; Brain Edema; Blood-Brain Barrier; Disease Models,Animal; Rats