黄连提取物中盐酸小檗碱及药根碱大鼠在体肠吸收特征的研究

目的:研究黄连提取物中盐酸小檗碱(berberine,BER)、盐酸药根碱(jatrorrhizine,JAT)在大鼠肠段的吸收动力学特征。方法:采用大鼠在体肠段回流实验,主要从吸收部位、药物浓度两方面对黄连提取物中BER和JAT的肠段吸收特征进行研究。结果:黄连提取物中BER和JAT在十二指肠、空肠、回肠和结肠的吸收速率常数分别为0.154 0,0.116 0,0.979 3,0.679 5 h-1和0.074 3,0.056 4,0.045 6,0.023 4 h-1;BER和JAT在肠道中的吸收按十二指肠、空肠、回肠、结肠的顺序依次下降,小肠中上部对BER和JAT的吸收具有明显的优势;黄连提取物在22~88 mg.L-1,BER和JAT的吸收量与浓度呈线性关系,无高浓度饱和现象,Ka值基本保持不变。结论:盐酸小檗碱和盐酸药根碱在大鼠肠道中均有吸收,其吸收呈一级动力学过程,吸收机制为被动扩散。

In situ intestinal absorption kinetics of berberine and jatrorrhizine fromextractive Rhizoma Coptidis in rats

Objective : To investigate the in situ absorption kinetics of berberine (BER) and jatrorrhizine(JAT)at different intestine segments in rats. Method : The intestinal perfusion experiment was performed on rats in vivo to observe the effects of absorption sites and drug concentration on the intestinal absorption characteristics of BER and JAT. Result : The apparent absorption rate constants (K_a) of BER and JAT at duodenum, jejunum, ileum and colon were 0.154 0, 0.116 0, 0.979 3, 0.679 5 h^-1 and 0.074 3, 0.056 4, 0.045 6, 0.023 4 h^-1, respectively. The absorption of BER and JAT decreased according to the turn of duodenum, jejunum, ileum and colon. Compared to the lower segment, BER and JAT were better absorbed at the upper and middle segments of intestine in rats. The K_a of BER and JAT had no significant difference when the concentration of the extractive Rhizoma Coptidis was at 22-88 mg·L^-1. However, the absorption quantity of BER and JAT were proportional to the concentration respectively and the saturated phenomena were not observed. Conclusion : Both the BER and the JAT is can be absorbed in whole intestine and the results indicated that the absorption of BER and JAT compiled with the first order kinetics through passive diffusion mechanism.