关附甲素抗氧化和抗房颤作用

Antioxidant and anti-atrial fibrillation effects of Guanfu base A

研究关附甲素(Guanfu base A,GFA)的抗房颤和抗氧化作用。大鼠尾静脉注射乙酰胆碱-氯化钙混合液(Ca Cl210 mg/m L,Ach 66μg/m L),连续7 d建立房颤模型。SD大鼠分为正常组、模型组、GFA治疗组(6 mg/kg,12 mg/kg)、胺碘酮(Amiodarone,Ami)治疗组(50 mg/kg)以及洛伐他汀(Lovastatin,Lov)治疗组(10 mg/kg)。测定大鼠房颤持续时间和有效不应期(AERP),用实时荧光定量PCR方法和Western blot方法测定氧化应激相关基因表达,试剂盒测定抗氧化酶的活性。结果显示:与模型组相比,GFA(6 mg/kg,12 mg/kg,po)治疗4 d后能缩短房颤持续时间,延长AERP,超氧化物歧化酶的活力提高,丙二醛含量明显下降。心房肌p22phox、p47phox、p67phox、gp91phox表达下调,膜Rac-1与胞浆Rac-1比值显著下降,缝隙连接蛋白(connexin40)表达升高。提示GFA(6 mg/kg,12 mg/kg)能有效抑制房颤引起的大鼠心房氧化应激损害,抑制房颤发生。

This study aimed at evaluating the antioxidant effects of Guanfu base A （GFA） on acetylcholine （Ach）/CaCl2（CaCl2 10 mg/mL, Ach 66 μg/mL）-induced atrial fibrillation （AF） in rats. SD rats were rando- mized into normal group, model group, GFA treatment groups （6 mg/kg, 12 mg/kg）, Amiodarone （Ami） treatment group （50 mg/kg） and Lovastatin （Lov） treatment group （ 10 mg/kg）. The AF durations were measured by elec- trocardiogram （ECG）. The effective refractory periods （AERP） were measured in the left atrial appendage. Oxidative stress-related gene and protein expression was evaluated by RT-PCR and Western blot. The activity of antioxidant enzymes was measured by enzymatic assay. Results indicated that, in comparison with that in the vehicle-treated AF rats, treatment with GFA（6 mg/kg, 12 mg/kg, po）, significantly shortened the AF duration and prolonged the AERP in rats. In addition, treatment with GFA reduced the levels of plasma and myocardium malondialdehyde, increased the activity of plasma superoxide dismutase in a dose-dependent manner. Moreover, treatment with GFA mitigated AF-up-regulated p22phox, p47phox, gp91phox, and p67phox NADPH oxidase expression, and AF-increased ratios of membrane to cytosolic Rac-1 in the atrium. It also significantly prevented AF-down-regulated atrial connexin40 expression in rats. Data suggested that GFA （6 mg/kg, 12 mg/kg） has potent anti-oxidant activity and inhibits oxidative-stress-related AF in rats.