Objective: To investigate suitable oral absorption enhancer (s) for Ophiopogon japonicas polysaccharides (OJP) and provide bases of utilizing the absorption enhancer to realize the oral administration of OJP.
Method: The absorption enhancement effects and cytotoxicity of clove oil, peppermint oil, borneol, Sanqi saponins, Maidong saponins, Ginseng saponin Rg1, Sanqi saponin R1 and sodium caprate (SC) were evaluated via Caco-2 cell culture model. The absorption of OJP from rat intestinal segments and the absorption enhancement effect of SC were investigated by in situ experiments of rat intestinal segments.
Result: SC was an effective and safe absorption enhancer. However, the absorption enhancement effects of clove oil, peppermint oil and Maidong saponins were highly correlated with their cytotoxicity. OJP alone was poorly absorbed from all the rat intestinal segments. It was rapidly absorbed when co-administered with SC, and the absorption increase was significant and the best absorption enhancing site of SC for OJP was colon.
Conclusion: The absorption enhancement effects of absorption enhancers are often correlated with their cytotoxicity. Co-administrating a powerful and safe absorption enhancer is an effective and valuable method of enhancing oral absorption of OJP.