Effect of puerarin on the expression of nuclear factor kappa B in rats with cerebral ischemia reperfusion / 中国组织工程研究

ABSTRACT

BACKGROUND: The studies in recent years proved that the inflammatory reaction is of the main reasons in the damage of cerebral ischemia reperfusion. The nuclear factor κB (NF-κB), as a kind of transcription factor, plays an important role in regulating the expressions of various inflammatory cell factors in the inflammatory reaction of cerebral ischemia reperfusion. The previous experiments show that puerarin functions to resist the oxidated free radicals and the apoptosis of nerve cells. In case it has the functions of anti-inflammation, its brain protection can be explained further.OBJECTIVE: To study the effect of puerarin on NF-κB for the rats with the damage of ischemia reperfusion.DESIGN: A random parallel controlled study.SETTING: The Emergency Department of Beijing Hospital, Emergency Department of Tongji Hospital, Pathology Department and Experimental Animal Center of Tongji Medical College, and Health Statistics Department of Public Health College of Huazhong University of Science and Technology.MATERIALS The experiment was started on April 12, 2003 in the Pathology Department of Tongji Medical College. The 75 healthy and clean Wistar rats were randomized into 3 groups with 25 in each, Sham operation group, cerebral ischemia reperfusion group, and puerarin group. Each group was reperfused at 2, 6, 12, 24, and 48 hours after ischemia and 5rats were used at each time point.METHODS: [1] Sham operation group Without electric coagulation of bilateral vertebral arteries, without blockage of bilateral common carotid arteries, without medicinal administration. [2] Cerebral ischemia reperfusion group Ten minutes after the blockage of bilateral common carotid arteries with non-invasive artery clamp, the reperfusion was given. At the beginning of reperfusion, the abdominal injection of normal saline 1 mL was applied and later every 6 hours the injection was repeated once. [3] Puerarin groupThe procedure was the same as for the reperfusion group, only with normal saline changed to puerarin 100 mg/kg.MAIN OUTCOME MEASURES: At the time points of 2, 6, 12, 24, and 48 hours after reperfusion, the activity of NF-κB and inhibitory protein κB(IP-κB) in the hippocampus CA1 region was examined with immunohistochemical method; the expression of tumor necrosis factor-α (TNF-α) mRNA was measured with in situ hybridization method; and the number of surviving neurons was detected with hematoxylin-eosin (HE) staining.RESULTS: After supplement, 75 rats entered the result analysis. [1] Activity of NF-κB In the ischemia reperfusion group, it was obviously increased at 2 hours after reperfusion, to the highest at 6 hours, and still higher than that of the sham operation group, (P ＜ 0.01). In the puerarin group, it was lower at each time point than that of the ischemia reperfusion group (P ＜ 0.01). [2] Expression of TNF-α mRNA In the ischemia reperfusion group, it was obviously increased at 2 hours after reperfusion, to the highest at 12 hours, and still higher than that of the sham operation group at 48 hours (P ＜ 0.01). In the puerarin group, it was lower than that of the ischemia reperfusion group at 6-48 hours (P ＜ 0.01). [3] Activity of IP-κBIn the ischemia reperfusion group, it was obviously decreased at 2 hours after reperfusion, to the lowest at 6 hours, and then gradually increased to the level of 12 hours. In the puerarin group, it was higher than that of the ischemia reperfusion group at each time point (P ＜ 0.01 or 0.05). [4] Number of surviving neurons In the ischemia reperfusion group, it was decreased gradually with the time prolonging after reperfusion (P ＜ 0.01). In the puerarin group, at each time point, it was higher than that of the ischemia reperfusion group (P ＜ 0.05 or 0.01).CONCLUSION: In the cerebral ischemia reperfusion, puerarin can protect the brain through decreasing the degradation of IP-κB, the activity of NF-κB, the expression of TNF-α mRNA, and the inflammatory reaction.