表没食子儿茶素没食子酸酯可减轻大鼠骨骼肌缺血再灌注损伤

Epigallocatechin gallate alleviates skeletal muscle ischemia-reperfusion injury in rats

背景:既往研究表明,骨骼肌缺血再灌注损伤在四肢再植术中是一个常见而且严重的临床问题,严重影响再植肢体术后存活率及功能。表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG)具有较强抗氧化性、抗炎及抑制细胞凋亡的作用。目的:探讨EGCG在大鼠下肢骨骼肌缺血再灌注损伤中的作用。方法:将雄性SD大鼠30只随机分为5组:假手术组、缺血再灌注组、EGCG组(10,100,200 mg/kg),除假手术组外,其他4组建立下肢缺血再灌注损伤模型,EGCG组在再灌注前30 min按照体质量腹腔注射EGCG。缺血4 h再灌注2 h后,取下腔静脉血和右腓肠肌组织,ELISA法检测血清中肿瘤坏死因子α和白细胞介素1β水平,腓肠肌组织中超氧化物歧化酶和髓过氧化物酶水平;苏木精-伊红染色法观察腓肠肌组织病理形态;TUNEL实验观察腓肠肌组织中细胞凋亡情况。结果与结论:①与缺血再灌注组比较,EGCG组(100,200 mg/kg)血清中肿瘤坏死因子α和白细胞介素1β水平及腓肠肌组织中髓过氧化物酶水平降低,超氧化物歧化酶水平升高,且与EGCG剂量呈正相关性;②苏木精-伊红染色结果显示EGCG组(100,200 mg/kg)肌纤维连续性及完整性、间质水肿程度等病理表现得到明显改善;③TUNEL实验结果显示EGCG组(100,200 mg/kg)凋亡细胞明显减少;④结果表明,EGCG通过减轻炎症反应、抗氧化应激及抑制组织细胞凋亡保护大鼠骨骼肌缺血再灌注损伤。

BACKGROUND:Skeletal muscle ischemia-reperfusion(I/R)injury is a serious problem commonly encountered in clinical practice which seriously impacts the function and survival rate of replanted limbs.Epigallocatechin gallate(EGCG)has been proved to be antioxidant,anti-inflammatory and anti-apoptotic.OBJECTIVE:To investigate the role of EGCG in I/R injury of rat skeletal muscle.METHODS:Thirty male Sprague-Dawley rats were randomly divided into five groups:sham operation group,I/R group,and three EGCG groups in which 10,100 and 200 mg/kg EGCG was intraperitoneally injected 30 minutes before reperfusion respectively according to the weight of the rats.A lower limb I/R injury model was made in each group except for the sham operation group.The levels of tumor necrosis factor-αand interleukin-1βin serum were measured and the levels of superoxide dismutase and myeloperoxidasein gastrocnemius muscle tissue were detected.Morphological changes of gastrocnemius muscle tissue were observed by hematoxylin-eosin staining.Cell apoptosis in gastrocnemius muscle tissue was observed by the TUNEL assay.RESULTS AND CONCLUSION:In the 100 and 200 mg/kg EGCG groups compared to the I/R group,there were the decreased levels of tumor necrosis factor-αand interleukin-1βin serum and myeloperoxidase in gastrocnemius muscle tissue and the increased level of superoxide dismutase in gastrocnemius muscle tissue,which were positively correlated with the EGCG dose.Hematoxylin-eosin staining results suggested an evident improvement in pathological manifestations ofgastrocnemius muscle,such as the continuity and integrity of muscle fibers and the degree of interstitial edema,in 100 and 200 mg/kg EGCG groups.TUNEL assay showed that 100 and 200 mg/kg EGCG inhibited cell apoptosis in gastrocnemius muscle tissue.To conclude,EGCG protects rat skeletal muscle from I/R injury by reducing inflammatory reaction,antioxidant stress and inhibiting apoptosis.