莲子心生物碱类成分的大鼠在体单向灌流肠吸收

Intestinal Absorption of Three Alkaloids in Plumula Nelumbinis by Rat Single-Pass Perfusion in situ Model

目的考察莲子心提取物中莲心碱、异莲心碱、甲基莲心碱3种生物碱类成分在大鼠的肠吸收性质。方法以酚红为标示物,运用在体单向肠灌流模型并采用HPLC测定莲心碱、异莲心碱、甲基莲心碱在大鼠十二指肠、空肠、回肠及结肠灌流液中的浓度变化。结果莲心碱、异莲心碱、甲基莲心碱在全肠道均有吸收,且吸收存在饱和现象。与低浓度比较,3种成分在中、高浓度下的吸收速率常数(Ka)和/或有效渗透系数(Peff)大多存在显著性差异(P<0.05)。在各肠段的吸收中,莲心碱、异莲心碱、甲基莲心碱均以回肠和结肠的吸收较好,而在十二指肠和空肠的吸收大多无显著性差异(P>0.05);在中浓度(117.3μg·mL-1)组,结肠中以甲基莲心碱吸收最好,其他肠段的Ka和Peff大小依次是:甲基莲心碱>莲心碱>异莲心碱。结论莲心碱、异莲心碱、甲基莲心碱在机体内的转运方式可能是主动转运或促进扩散。

OBJECTIVE To investigate the intestinal absorption behaviors of three main active components, liensinine, isoliensinine and neferine in Plumula Nelumbinis extracts in intestine of rats. METHODS With phenol red as the indicator, in situ single pass intestinal perfusion （SPIP） model was used and the concentrations of the alkaloids in perfusion solution in different intestinal seg- ments （duodenum, jejunum, ileum, and colon） were determined by HPLC. RESULTS Liensinine, isoliensinine and neferine were absorbed in whole intestinal segments with saturation phenomena. The absorption rate constant （K~） and/or effective permeability val- ues （P~） of the three alkaloids mostly had significant difference （P 〈 0. 05 ） at middle and high concentrations of perfusion solution vs those at low concentrations. Liensinine, isoliensinine and neferine possessed better absorption in ileum and colon of intestine. The ab- sorption in duodenum and jejunum mostly displayed no significant difference （P 〉 0. 05 ）. In middle concentration group （ 117.3 μg . mL^- l ）, neferine was absorbed best among the three alkaloids in colon ; in other intestinal sections, the Ka and Peff of the three alka- loids were sequenced as follows ： neferine 〉 liensinine 〉 isoliensinine. CONCLUSION The transport mechanism of liensinine, iso- liensinine and neferine in vivo may be active transport or facilitated diffusion.