Piper betle Linn. a maligned Pan-asiatic plant with an array of pharmacological activities and prospects for drug discovery

Piper betle L. is one of the important plants in the Asiatic region which ranks second to coffee and tea in terms of daily consumption. Though the plant is known for abuse, in recent years several reports have been published on the effects of the plant extract and chemical constituents on different biological activities in vitro and in vivo. The leaf extract, fractions and purified compounds are found to play a role in oral hygiene, anti-diabetic, cardiovascular, anti-inflammatory/immunomodulatory, anti-ulcer, hepato-protective and anti-infective, etc. Patents were also awarded for some of the biological activities like anti-inflammatory, anti-cancer and immunomodulatory associated with leaf extracts and purified compounds. The active compounds isolated from leaf and other parts are hydroxychavicol, hydroxylchavicol acetate, allypyrocatechol, chavibetol, piperbetol, methylpiperbetol, piperol A and piperol B. Phenol-rich leaves of P. betle show high antioxidant activities. A number of biologically active compounds from P. betle have potential for use as medicines, neutraceuticals and industrial compounds. Since the traditional use of P. betle involves chewing, it offers possibilities of use in drug delivery through buccal mucosa bypassing the gastric route