Protective effect of ethyl pyruvate on brain tissues in neonatal rats with hypoxic-ischemic brain damage

AIM: To study the effects of ethyl pyruvate(EP) on brain tissues in neonatal rats with hypoxic-ischemic brain damage(HIBD) and its underlying mechanisms.METHODS: A total of 165 seven-day-old Sprague-Dawley(SD) rats were randomly divided into 3 groups: sham operation group(n = 43),HIBD group(n = 61) and HIBD + EP group(n = 61).The rats in HIBD + EP group were intraperitoneally injected with EP(50 mg / kg) 30 min before operation,and once a day after surgery.Superoxide dismutase(SOD) activity and malondialdehyde(MDA) content in brain homogenate,water content of brain and apoptotic cells in cortex were detected 3 days later.Ischemic and non-ischemic brain tissues were weighed to assess the extent of brain atrophy 14 days later.RESULTS: Higher level of SOD [(125.78 ± 18.35) × 103 U /(g protein) ] and lower level of MDA [(4.42 ± 1.04) μmol /(g protein) ] in HIBD + EP group than that in HIBD group [(97.84 ± 15.50) × 103 U /(g protein) and(6.02 ± 0.89) μmol /(g protein),respectively]was observed(P 0.05).In addition,the water content of ischemic hemisphere was significantly higher than that of non-ischemic one in HIBD group(P 0.05),and was indistinguishable from that of non-ischemic one after EP treatment(P 0.05),indicating the protective effect of EP against brain edema.The apoptotic cells in cortex and hippocampus in HIBD + EP group [(96.63 ± 10.08) / field and(41.91 ± 9.96) / field,respectively] were obviously decreased compared with HIBD group [(111.54 ± 1.64) / field and(51.73 ± 1.77) / field,respectively],but still higher than those in sham operation group(P 0.05).The atrophy ratio of ischemic hemisphere in HIBD + EP group was(13.25 ± 5.19) %,significantly lower than that in HIBD group [(20.32 ± 5.10) %,P 0.05].CONCLUSION: Ethyl pyruvate is neuroprotective against HIBD in neonatal rats via increasing SOD level,decreasing MDA level,attenuating brain edema,decreasing apoptotic cells in cortex and alleviating atrophy of hypoxic-ischemic hemisphere.