基于N-乙酰转移酶研究槲皮素对大鼠体内异烟肼代谢的影响

Effects of Quercetin on Rat Isoniazide Metabolism via N-acetyltransferase Evaluation

目的基于N-乙酰转移酶(NAT)的表达及活性检测,研究槲皮素对大鼠体内异烟肼(INH)代谢及药动学特征影响。方法雄性Wistar大鼠单独灌胃给予INH(60 mg/kg)或槲皮素(50 mg/kg)联合INH(60 mg/kg)。分别于给药后不同时间收集血清,应用液质联用技术测定血清中INH及其代谢物乙酰异烟肼(Ac-INH)浓度并计算药动学参数;收集肝脏组织用于测定NAT蛋白表达及酶活性。结果与INH单独用药组相比,槲皮素给药可显著提高大鼠血清INH浓度(P<0.05),并显著降低Ac-INH浓度(P<0.05);且槲皮素与INH联合给药组药动学参数AUC0→t(60.15±9.69 vs 43.40±2.89)mg h/L和t1/2(3.09±1.56 vs 1.07±0.13)h均明显增高(P<0.05),而CL/F却明显降低(0.93±0.15 vs 1.38±0.11 L/h/kg,P<0.05)。与INH单独给药组相比,槲皮素给药动物肝脏中NAT活性显著降低(P<0.05),而NAT蛋白表达未见明显变化(P>0.05)。结论槲皮素可通过抑制NAT活性而减少INH代谢及Ac-INH生成,阐明槲皮素对INH体内药动学的影响及其分子机制有望为INH肝毒性防治提供重要线索。

Objective To investigate the effect of quercetin on the metabolic properties of isoniazide(INH)in rats by evaluating N-acetyltransferase(NAT).Methods Male Wistar rats were orally administered with INH(60 mg/kg)alone or in combination with quercetin(50 mg/kg).Serum samples were collected at the designated time points after INH administration.The serum concentrations of INH and its metabolite acetylisoniazid(Ac-INH)were determined using HPLC-MS,and the pharmacokinetic parameters were calculated.After that,liver samples were collected to determine the protein expression and enzyme activity of NAT in order to explore the underlying mechanism.Results Compared to the INH treated group,quercetin and INH co-administration significantly elevated the serum concentration of INH(P<0.05)L/h/kg,accompanied by markedly reduced concentration of Ac-INH(P<0.05).The pharmacokinetic parameters of AUC0→t(60.15±9.69 vs 43.40±2.89)mg h/L and t1/2(3.09±1.56 vs 1.07±0.13)h in quercetin pretreated rats were all significantly increased,while those of CL/F were markedly reduced(0.93±0.15 vs 1.38±0.11,P<0.05).Moreover,compared to the INH treated group,NAT activity rather than NAT expression in the quercetin and INH co-administration group was markedly reduced(P<0.05).Conclusion Quercetin can reduce the metabolism of INH and the concentration of Ac-INH by inhibiting NAT activity.This finding may provide an important clue to the prevention of INHinduced hepatotoxicity.