葛根素激活Nrf2通路减轻心力衰竭大鼠氧化应激损伤的研究

目的 探讨葛根素对心力衰竭大鼠氧化应激损伤的保护作用及机制。方法 实验分为假手术组、心衰模型组、葛根素低剂量组（5 mg/ml）、葛根素高剂量组（40 mg/ml）。其中葛根素低、高剂量组给予尾静脉注射葛根素5 mg/ml或40 mg/ml，1 ml/次，每日1次，连续15 d。于治疗的第16 d检测4组大鼠血液中同型半胱氨酸（homocysteine，Hcy）、胱抑素C（cystatin C，Cys C）、脑钠肽（B - type natriuretic peptide，BNP）、Ｄ - 二聚体（D - Dimer）水平；测定心肌组织活性氧（reactive oxygen species，ROS）和丙二醛（malondialdehyde，MDA）水平，超氧化物歧化酶（superoxide dismutase，SOD）和谷胱甘肽过氧化物酶（glutathione peroxidase，GSH - Px）活性; qPCR法检测心肌组织核因子相关因子2（NF - E2 - related factor 2, Nrf2）、血红素氧化酶 - 1（heme oxygenase - 1，HO - 1）和醌氧化还原酶 - 1（NADPH quinone oxidoreductase - 1，NQO1）mRNA的表达；TUNEL法检测心肌细胞凋亡情况；western blot检测心肌组织凋亡相关蛋白Caspase - 3、Caspase - 8、Caspase - 12水平。结果 葛根素低剂量组、葛根素高剂量组均能下调血液中Hcy、Cys C、BNP、D - Dimer含量（P＜0.05）；降低心肌ROS、MDA水平及提高SOD、GSH - Px活力（P＜0.05）；上调心肌组织Nrf2、HO - 1和NQO1mRNA表达（P＜0.05）；减少凋亡蛋白Caspase - 3、8、12的表达（P＜0.05）；降低心肌细胞凋亡指数（P＜0.01）。结论 葛根素通过上调抗氧化应激Nrf2通路，抑制心肌损伤所致的氧化应激反应，进而对心力衰竭发挥保护作用。

Effect of puerarin on activation of Nrf2 pathway in relieving oxidative stress injury in rats with heart failure

Objective To investigate the protective effect and mechanism of puerarin on oxidative stress injury in rats with heart failure. Methods The rats were divided into sham operation group, heart failure model group, low dose of puerarin group(5mg/mL) and high dose of puerarin group(40 mg/ml). Pueraria low- or high-dose groups was respectively given puerarin 5 mg/ml or 40 mg/ml caudal vein injection of puerarin, 1 mL once daily for 15 days. Then we detected the level of homocysteine (Hcy), Cystatin C (Cys C), B-type natriuretic peptide (BNP), D-dimer (D-Dimer) in the blood of four groups, expression of reactive oxygen species (ROS) and malondialdehyde (MDA), activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) at the 16 d of treatment. The expression of nuclear factor-related factor 2 (Nrf2), Heme oxygenase-1 (HO-1) and NADPH quinone oxidoreductase-1 (NQO1) were detected by qPCR. The apoptosis of cardiomyocytes was detected by TUNEL. The levels of Caspase-3, caspase-8 and caspase-12 in myocardial tissue were detected by Western blot. Results The low dose of puerarin and high dose of puerarin down-regulated the content of Hcy, Cys C, BNP and D-Dimer in blood (P<0.05), reduced the levels of ROS and MDA and increased the activity of SOD and GSH-Px in myocardial tissue(P<0.05), up-regulated the expression of Nrf2, HO-1 and NQO1 mRNA in myocardial tissue(P<0.05). Also, both dose of puerarin decreased the expression of caspase-3, caspase 8, caspase 12 (P<0.05), and the apoptosis index of cardiomyocytes (P<0.01). Conclusion Puerarin exerts protective effect on heart failure by up-regulating the anti-oxidative stress Nrf2 pathway and inhibiting oxidative stress induced by myocardial injury.