Mechanism by which moxibustion pretreatment attenuates oxidative stress injury in a rat model of cerebral ischemia-reperfusion / 中国组织工程研究

ABSTRACT

BACKGROUND:Pretreatment with moxibustion is a preventive treatment in traditional Chinese medicine.Pretreatment with moxibustion at the onset of prodromal symptoms can significantly reduce the symptoms and delay the onset of many diseases,but the exact mechanism remains to be studied. OBJECTIVE:To investigate the mechanism of SIRT1/FoxO3 pathway in moxibustion pretreatment to ameliorate oxidative stress injury in cerebral ischemia-reperfusion model rats. METHODS:Forty-eight Sprague-Dawley rats were randomly divided into sham-operated group,model group,moxibustion pretreatment group,and moxibustion pretreatment+EX527(SIRT1 inhibitor)group,with 12 rats in each group.The moxibustion pretreatment group was given moxibustion with seed-sized moxa cone at Baihui,Dazhui,and Zusanli before modeling,three moxa-cones per acupoint,once a day for 7 days.In the model group,moxibustion pretreatment group and moxibustion pretreatment+EX527 group,the rat model of middle cerebral artery occlusion was made by suturing of the middle cerebral artery 30 minutes after the last moxibustion.After 2 hours of cerebral ischemia,the middle artery suture was removed and the rats were reperfused for 12 hours.In the sham-operated group,only the common carotid artery,internal carotid artery,and external carotid artery were dissected without suturing the middle cerebral artery.In the moxibustion pretreatment+EX527 group,EX527(15 mg/kg)was given intraperitoneally 30 minutes before each moxibustion.After 12 hours of reperfusion,the rats were scored for neurological deficits,and the cerebral infarct volume was calculated by 2,3,5-triphenyltetrazolium chloride staining method.The levels of oxidative stress factors in the infarcted tissues were detected by the kit method,and western-blot method was used to detect the expression levels of SIRT1,FoxO3,p-FoxO3 and brain-derived neurotrophic factor in the ischemic area of the cerebral cortex. RESULTS AND CONCLUSION:After 12 hours of reperfusion,the neurobehavioral score in the model group was significantly higher than that in the sham-operated group(P＜0.01),while the score in the moxibustion pretreatment group was significantly lower than that in the model group(P＜0.01)and moxibustion pretreatment+EX527 group(P＜0.05).There were no obvious infarct foci in the brain tissue of the sham-operated rats,but obvious ischemic foci were observed in the right side of the brain tissue of the rats in the model group(P＜0.01).The right infarct volume in the moxibustion pretreatment group was significantly reduced compared with the model group(P＜0.01),while the right infarct volume in the moxibustion pretreatment+EX527 group was significantly enlarged compared with the moxibustion pretreatment group.After 12 hours of reperfusion,the level of malondialdehyde was significantly elevated(P＜0.01)and the expression of superoxide dismutase was significantly decreased(P＜0.01)in the model group compared with the sham-operated group.The levels of malondialdehyde was significantly decreased(P＜0.01,P＜0.05)and the expression of superoxide dismutase was significantly increased(P＜0.01,P＜0.05)in the moxibustion pretreatment group compared with the model group and the moxibustion pretreatment+EX527 group.Western blot results showed that the expression levels of SIRT1,FoxO3,p-FoxO3,and brain-derived neurotrophic factor proteins were significantly higher in the model group compared with the sham-operated group(P＜0.01);compared with the model group,the expression levels of SIRT1,FoxO3,and brain-derived neurotrophic factor were significantly higher in the moxibustion pretreatment group(P＜0.01),and p-FoxO3 expression was significantly lower(P＜0.01);compared with the moxibustion pretreatment+EX527 group,the expression levels of SIRT1,FoxO3,and brain-derived neurotrophic factor were elevated in the moxibustion pretreatment group(P＜0.05),and no statistically significant difference was found in the p-FoxO3 expression(P＞0.05).To conclude,moxibustion pretreatment can significantly improve neurological function in rats after cerebral ischemia-reperfusion,and the mechanism may be related to the activation of SIRT1/FoxO3 pathway to reduce oxidative stress injury in the rat model of cerebral ischemia-reperfusion.