金荞麦多酚类成分在大鼠胃肠道中转化的初步研究

Primary Study of Biotransformation of Polyphenols in Rhizoma Fagopyri Dibotryis in Gastrointestinal Tract of Rats

目的:研究金荞麦多酚类成分在大鼠胃肠道的生物转化情况。方法:通过胃肠道体外转化实验,采用HPLC法测定低、中、高浓度金荞麦多酚溶液中原花青素B_2和表儿茶素的含量。结果:原花青素B_2和表儿茶素在胃中含量明显降低。低浓度溶液中原花青素B_2在十二指肠中含量降低,低、中、高浓度溶液中原花青素B_2在空肠中含量变化不明显,在结肠和回肠中含量增加,结肠更明显(P<0.01)。在肠道中,低浓度溶液中表儿茶素含量最低,且随着金荞麦多酚溶液浓度的增加有升高的趋势,同浓度溶液中表儿茶素含量在各肠段含量有升高的趋势。结论:金荞麦多酚类成分在大鼠胃肠道中的生物转化存在两种途径:一是金荞麦中所含的(-)-表儿茶素多聚体分解生成二聚体原花青素B_2,使原花青素B_2含量增加,另一条途径是原花青素B_2和表儿茶素在胃肠道中发生降解使其含量降低。胃中的pH值、酶可能会促进原花青素B_2和表儿茶素的降解,结肠是生成原花青素B_2的主要部位。

Objective：To Study the biotransformation of polyphenols in rhizoma fagopyri dibotryis in the gastrointestinal tract of rats. Methods：With the vitro gastrointestinal tract transformation experiments,the contents of proanthocyanidin B_2 and epicatechin in rhizoma fagopyri dibotryis polyphenols solution of low,middle and high concentration were detected by HPLC. Results：The contents of proanthocyanidin B_2 and epicatechin decreased significantly in the stomach. The content of proanthocyanidin B_2 in the low concentration solution decreased in the duodenum. The contents of proanthocyanidin B_2 in the low,middle and high concentration solution did not change significantly in the jejunum,but they increased in the colon and the ileum. The increase in the colon was more significant（P 〈0.01）. In the intestinal tract,the content of epicatechin in the low concentration solution was the lowest and it had an increasing trend with the increase of the concentration. The content of epicatechin in solution of the same concentration had an increasing trend in each intestinal segment. Conclusions：Polyphenols in rhizoma fagopyri dibotryis had two transformation ways in the gastrointestinal tract of the rats. One is that the（-）- poly- epicatechin in rhizoma fagopyri dibotryis degraded and generated dimeric proanthocyanidin B_2,which made the content of proanthocyanidin B_2 increase. The other is that proanthocyanidin B_2 and epicatechin degraded in the gastrointestinal tract,which made the content of proanthocyanidin B_2 and epicatechin decrease. The p H value and enzyme in the stomach may promote the degradation of proanthocyanidin B_2 and epicatechin. Colon was the main place to generate proanthocyanidin B_2.