Effects of Buyang Huanwu Tang and its main components on pyroptosis in brain tissue of rats with middle cerebral artery occlusion and reperfusion
BACKGROUND:Cellular pyroptosis is an important pathological mechanism of cerebral ischemia/reperfusion injury.Buyang Huanwu Tang is a classic formula for the clinical treatment of ischemic stroke in traditional Chinese medicine,and cellular pyroptosis may be an effective target of Buyang Huanwu Tang in the treatment of cerebral ischemia/reperfusion injury.OBJECTIVE:To observe the effect and mechanism of Buyang Huanwu Tang on pyroptosis in brain tissues of middle cerebral artery occlusion/reperfusion rats.METHODS:Forty-eight Sprague-Dawley rats were randomly divided into sham operation group,model group,Astragalus membranaceus group and Buyang Huanwu Tang group.Except for the sham operation group,all groups were subjected to middle cerebral artery occlusion for ischemia for 2 hours and reperfusion for 72 hours.The rats in the Astragalus membranaceus group and Buyang Huanwu Tang group were continuously gavaged with the corresponding volume of drugs until ischemia and reperfusion for 72 hours after awakening from the modeling,once in the morning and once in the evening.Zea Longa score was used to observe the neurological deficits of rats.TTC staining was performed to observe cerebral infarct size in rats.Hematoxylin-eosin staining was used to observe the pathological changes of the brain tissue.Immunofluorescence was used to observe the co-expression of Tunel and Cleaved-Caspase-1 in the brain tissue and the expression of the junction protein ASC.Immunohistochemistry and western blot were used to detect the expression of pyroptosis-related proteins in rat brain tissues.RESULTS AND CONCLUSION:(1)Compared with the sham operation group,the neurological deficit score of rats was significantly higher in the model group(P<0.01),and compared with the model group,the neurological deficit score of rats was significantly lower in the Buyang Huanwu Tang group and the Astragalus membranaceus group(P<0.01).(2)Compared with the model group,the volume ratio of cerebral infarction was lower in the Astragalus membranaceus group and Buyang Huanwu Tang group(P<0.01).(3)In the model group,the nuclei of neuronal cells in the brain tissue were deeply stained or lysed,and arrangement of the cells was disorganized.Compared with the model group,the pathologic damage of the brain was less severe in the Buyang Huanwu Tang group and the Astragalus membranaceus group.(4)Compared with the sham operation group,the number of Tunel and Cleaved-Caspase-1 double-positive cells and immunofluorescence intensity of ASC in the brain tissue was significantly increased in the model group,and the expression of Cleaved-Caspase-1,NLRP3,interleukin 18,and interleukin 1β was significantly elevated in the model group(P<0.01).Compared with the model group,the number of Cleaved-Caspase-1 and Tunel double-positive cells,immunofluorescence intensity of ASC,and the expression of Cleaved-Caspase-1,NLRP3,interleukin 18,and interleukin 1β were all significantly decreased in the Buyang Huanwu Tang group and the Astragalus membranaceus group(P<0.01).The results indicate that Buyang Huanwu Tang and its monarch drug Astragalus membranaceus can effectively alleviate brain tissue injury in rats with middle cerebral artery occlusion and reperfusion,and its mechanism may be related to the inhibition of neuronal cell pyroptosis.