模拟炮制及实验证据揭示知母盐炙后增强滋阴降火作用的机制

Mechanism of enhancing the nourishing yin and lessen fire effect of Anemarrhenae Rhizoma after salt stir-frying by simulated processing and experimental evidence

目的:研究知母盐炙后化学成分转化以及滋阴降火作用增强的机制。方法:首先采用HPLC法比较生知母和盐知母之间化学成分的差异,结合模拟炮制实验进行验证,阐明炮制引起的化学变化;其次建立甲状腺素诱导的大鼠肾阴虚模型,评价生、盐知母及增量成分芒果苷治疗肾阴虚的效果。采用Western Blot和RT-PCR检测药物对PI3K/AKT/mTOR信号通路的表达影响。结果:知母盐炙后新芒果苷含量下降,芒果苷含量升高;在模拟盐炙新芒果苷单体及饮片中均出现了芒果苷色谱峰,证明盐炙可促使新芒果苷向芒果苷转化;生知母、盐知母和芒果苷均可治疗肾阴虚证,但盐知母和芒果苷治疗肾阴虚证的效果明显优于生知母,证明芒果苷是知母发挥治疗肾阴虚作用的活性成分之一;生知母、盐知母和芒果苷均能上调肾阴虚证大鼠PI3K、AKT、mTOR mRNA和蛋白的表达,且芒果苷的作用明显优于生知母。结论:知母盐炙后芒果苷含量增加,并通过调控PI3K/AKT/mTOR信号通路增强知母对肾阴虚证的治疗作用。

Objective:To investigate the mechanism of chemical composition transformation and the enhancement of nourishing yin and lessen fire effect of Anemarrhenae Rhizoma(AR)after salt stir-frying.Methods:Firstly,the differences in chemical composition between AR and salt stir-fried Anemarrhenae Rhizoma(SAR)were compared by HPLC method and validated with simulated processing experiments to elucidate the chemical changes induced by concoction;secondly,a thyroxineinduced kidney yin deficiency model was established in rats to evaluate the effects of AR and SAR and the incremental ingredient mangostin in treating kidney yin deficiency.Western Blot and RT-PCR were used to detect the effects of drugs on PI3K/AKT/mTOR signaling pathway.Results:The content of nemangostin decreased and the content of mangostin increased after salt stirfrying of AR.The peaks of mangostin appeared in both the simulated salt-frying neomangostin monomer and the tablets,which proved that salt-frying could induce the conversion of neomangostin to mangostin;AR,SAR and mangostin could all treat kidney yin deficiency,but the effects of SAR and mangostin were significantly better than those of AR,which proved that mangostin was one of the active ingredients of AR in treating kidney yin deficiency.All of AR,SAR and mangostin could up-regulate the mRNA and protein expressions of PI3K,AKT and mTOR in rats with kidney-yin deficiency syndrome,and the effect of mangostin was significantly better than AR.Conclusion:Salt stir-frying of AR can increase the content of mangiferin and enhance the therapeutic effect of AR on kidney-yin deficiency syndrome by regulating the PI3K/AKT/mTOR signaling pathway.