Bioavailability enhancing activities of natural compounds from medicinal plants

There is an increasing interest and medical need for the improvement of bioavailability of a large number of drugs. Of the promising approaches, the co-administration of therapeutic agents with natural compounds possessing absorption improving activities has gained great interest in oral drug delivery. Many natural compounds from medicinal plants have demonstrated capacity to enhance the bioavailability of co-administered drugs by inhibiting efflux pumps or oxidative metabolism, and perturbing the intestinal brush border membrane. These natural compounds include quercetin, genistein, naringin, sinomenine, piperine, glycyrrhizin and nitrile glycoside. This article reviews the improvement of drug bioavailabilities exhibited specially by natural compounds from plants mentioned above.