虎杖提取物中虎杖苷及白藜芦醇在大鼠胃肠道吸收的动力学分析

Gastrointestinal Absorption Kinetics of Polydatin and Resveratrol from Polygoni Cuspidati Rhizoma et Radix Extract in Rats

目的：研究虎杖提取物在大鼠胃及小肠中的吸收特性。方法：采用大鼠在体单向肠灌流法,以虎杖苷和白藜芦醇含量作为评价指标,采用HPLC测定灌流高、中、低剂量虎杖提取物后指标成分的含量变化,研究二者在胃、小肠中的吸收动力学。结果：虎杖提取物在胃内吸收量与药物浓度成正比,经SPSS 17.0软件分析,低剂量组虎杖提取物中虎杖苷的吸收速率与中、高剂量组比较具有显著性差异（P〈0.05）,中剂量组与高剂量组比较则无显著性差异;不同组别之间白藜芦醇吸收速率分析结果为F=609.724,P〈0.05。当虎杖提取物给药剂量为600 mg·L^-1时,虎杖苷和白藜芦醇在大鼠肠道的吸收速率常数（Ka）分别为0.925,0.575 h-1;不同剂量组中虎杖苷和白藜芦醇的Ka及吸收率均无显著性差异。结论：虎杖提取物中虎杖苷在胃内吸收具有浓度饱和现象,可能是主动吸收或易化扩散机制;而白藜芦醇在胃内的吸收率随着提取物浓度的增加而增大,提示其吸收机制可能是被动转运;不同质量浓度虎杖提取物对虎杖苷和白藜芦醇的肠吸收没有影响,吸收无浓度饱和现象,提示其在肠道内的吸收可能是被动扩散机制。

Objective： To study on the absorption characteristics of polydatin and resveratrol from Polygoni Cuspidati Rhizoma et Radix extract in the stomach and small intestine of rats. Method： In situ single pass intestinal perfusion model in rats was adopted,taking contents of polydatin and resveratrol as indexes,HPLC was employed to determine contents of polydatin and resveratrol before and after being perfused Polygoni Cuspidati Rhizoma et Radix extract for investigating their absorption characteristics in the stomach and small intestine of rats.Result： The absorption rate of Polygoni Cuspidati Rhizoma et Radix extract was proportional to drug concentration in the stomach. Absorption rate of polydatin in Polygoni Cuspidati Rhizoma et Radix extract with low dose showed significant difference（P〈0. 05） when compared with the middle and high dose groups, but there was no significant difference between the middle dose group and the high dose group. The absorption rates of resveratrol at different dose groups indicated significant deviation by SPSS 17. 0（F = 609. 724,P〈0. 05）. When the dose of Polygoni Cuspidati Rhizoma et Radix extract was 600 mg·L^-1,the absorption rate constants（Ka） of polydatin and resveratrol were 0. 925,0. 575 h-1,respectively. The Kaand absorption rates of polydatin and resveratrol in different dose groups were not significantly different. Conclusion： Polydatin in Polygoni Cuspidati Rhizoma et Radix extract has a concentration saturation phenomenon in the stomach, its mechanism may be an active absorption or facilitated diffusion; while the absorption rate of resveratrol in the stomach increased with the increase of extract concentration,this suggests that the resveratrol might be absorbed in the stomach via passive transport mechanism. Different concentrations of Polygoni Cuspidati Rhizoma et Radix extract had no effect on the intestinal absorption of polydatin and resveratrol,and absorption is not saturated,this suggests that polydatin and resveratrol may be absorbed in intestine via passive diffusion mechanism.