Citrus paradisi is the botanical name of grapefruit, whose juice is widely known to affect drug bioavailability in humans. Grape- fruit juice contains flavonoids, a large class of plantpolyphenolic secondary metabolites that have various pigmental and antimicrobial functions, and which are also found in many other plants and vegetables. They are chemically classified as flavones, isoflavones, flavan-3-ols and anthocyanidins, and are studied for their antioxidant, anti-inflammatory and antimicrobial activity and ability to prevent cardiovascular disease [113,114]