Enhancement by sodium caprate and sodium deoxycholate of the gastrointestinal absorption of berberine chloride in rats

The aim of the investigation was to compare the effectiveness of two absorption enhancers, sodium caprate (C10) and sodium deoxycholate (SDC), in increasing the bioavailability of a poorly absorbed paracellar flux drug, berberine chloride, across the intestinal mucosae of rats in vivo, together with examination of their effects on mucosal damage. In addition, all four intestinal segments were collected after administration of the enhancers and sodium saline. The results of the bioavailability experiments showed the oral absorption of berberine chloride was poor and both C10 and SDC could significantly improve the very poor absorption of berberine chloride. After co-administration, the area under the plasma concentration-time curve of berberine chloride was increased 41.1-fold by C10 (100 mg/kg) and 35.3-fold by SDC (100 mg/kg) compared with that in the absence of C10 and SDC, respectively. Local toxicity experiment indicated that both enhancers caused no specific damage to the intact intestine. This study demonstrates that C10 and SDC could significantly promote the absorption of berberine chloride from the gastrointestinal tract with few toxic effects, which might be due mainly to relaxing the absorption limitation while inhibiting the efflux transporter of berberine chloride by the enhancers. Besides, this could lead to the development of new drug-enhancers.