Protection of epigallocatechin-3-gallate on hippocampus under glucose reperfusion after hypoglycemia in rats

Objective To investigate the effects of epigallocatechin-3-gallate (EGCG) on apoptosis, oxidative stress and inflammation induced by glucose reperfusion after hypoglycemia in hippocampus in rats. Methods A total of 56 male Wistar rats (SPF grade) at the age of 8-10 weeks and weighing 300-350 g were used. Finally, 40 rats were included in the study and were randomly divided into control group(A group, n=11), glucose reperfusion after hypoglycemia group (B group, n=10), glucose reperfusion after hypoglycemia+ low dose EGCG group (C group, n=9), and glucose reperfusion after hypoglycemia+ high dose EGCG group (D group, n=10). Apoptosis in hippocampus were monitored by TUNEL method. P47phox protein levels were detected by Western blotting. Interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) levels were detected by ELISA. One-way analysis of variance was used for data analysis. Differences between the two groups were compared using t test. Results (1) Compared with group A, the apoptosis, membrane p22phox protein expression, membrane/cytoplasmic p47phox protein expression, IL-6 and TNF-α levels in group B increased [10.1±2.5 vs 72.5±12.6; 0.42±0.05 vs 0.79±0.12; 0.44±0.09 vs 1.10±0.16; (50±10) vs (128±22) ng/L; (121±22) vs (248±39) ng/L; t=6.292-16.111, all P<0.05].(2) The apoptosis, membrane p22phox protein expression, membrane/cytoplasmic p47phox protein expression, IL-6 and TNF-α levels of group C were decreased compared with group B (t=2.247-3.858, all P<0.05). (3) The apoptosis, membrane p22phox protein expression, membrane/cytoplasmic p47phox protein expression, IL-6 and TNF-α levels of group D were lower than those in group C (t=2.836-7.225, all P<0.05). Conclusion EGCG alleviates the apoptosis induced by glucose reperfusion after hypoglycemia in hippocampus in rats, and the mechanism may be related to the amelioration of oxidative stress and inflammation. Key words: Oxidative stress; Inflammation; Hypoglycemia; Epigallocatechin-3-gallate; Hippocampus