Pharmacokinetic properties of isorhamnetin, kaempferol and quercetin after oral gavage of total flavones of Hippophae rhamnoides L. in rats using a UPLC-MS method

An ultra performance liquid chromatography-mass spectrometric (UPLC-MS) method was developed to investigate the pharmacokinetic properties of isorhamnetin, kaempferol and quercetin from a total flavone extract of Hippophae rhamnoides L. (TFH) after single dose oral administration. Rat plasma samples were pretreated using liquid-liquid extraction, and chromatographic separation was performed on a C₁₈ column using a linear gradient of methanol and formic acid (0.1%). The pharmacokinetic parameters of isorhamnetin, kaempferol and quercetin from TFH in rats were quantitatively determined by UPLC with photodiode array detection (PDA). The qualitative detection of the three flavones was accomplished by selected ion monitoring in negative ion mode ESI-MS. Results of the pharmacokinetic study indicate that the three flavones in TFH were absorbed by passive diffusion in rats, and no “double-peak” phenomenon was observed in C-t curves of the three flavones from TFH except for quercetin. Results of this study indicate that the pharmacokinetic behaviors of isorhamnetin, kaempferol and quercetin when administered together in a complex herbal extract might be different than the individual behaviors of the same compounds administered in their pure forms. Results of this study also demonstrate that UPLC-MS is a rapid and practical method to determine the pharmacokinetic parameters of flavones present in an herbal extract.     

槲皮素对SI甘蓝授粉引起的PK活性及相关指标的影响

通过槲皮素处理,研究了自交不亲和甘蓝自花授粉和异花授粉与蛋白激酶的关系。结果表明,槲皮素能明显抑制自交不亲和甘蓝自花授粉引起的蛋白激酶活性,导致蛋白质磷酸化明显受阻,进而促进自花诱导的花粉萌发和花粉管生长,同时使SOD、POD、CAT活性升高,Ca2+含量下降,Ca2+在胞内的分布明显改变,而槲皮素对异花授粉抑制作