The Bioavaliability of Hepatoprotective Flavoniods in Hypericum Japonicum Extract

Abstract

Purpose: To study the absorption of main flavonoids in Hypericum japonicum extract (HJE) with liver protective property; Method: HPLC-ESI-MS was introduced to identify and evaluate the flavonoids in HJE; Caco-2 cell monolayer model was established and validated, and the compounds in HJE, including quercetin (Q), quercetin-3-Orhamnoside (Q-3-R), quercetin-7-O-rhamnoside (Q-7-R) and quercetin-3-O-glucoside (Q-3-G) were administrated in individual, paired or mixed form of the compounds to the monolayer to evaluate their apparent permeability coefficients (Papp value). The transport of HJE was also investigated, mixture of pure components and HJE Inhibitor was added to investigate the transport mechanism of the compound mixture. The absorption of the four main ingredients in HJE was then investigated in vivo. Result: transportation of Q, Q-3-R Q-3-G but not Q-7-R through Caco-2 monolayer was observed when they were administrated individually. Increase of the transport of Q-3-G and Q-7-R and decrease in Q were observed when the four compounds were given in paired form; when the four flavonoids were given as a whole (either in mixture of pure compounds or in HJE), mass permeability of Q-3-R, Q-7- R and Q-3-G was found. In vivo study identified the in vitro investigation that the major active components of HJE could be absorbed after orally administrated to mice. Conclusion: The increased transport of mixed active components in HJE gives rise to the enhanced hepatoprotetive effect of HJE, and therefore supports the use of botanical drugs.