Phytochemical Investigations of Pomegranate ( Punica granatum ) Rind and Aril Extracts and their Antioxidant, Antidiabetic and Antibacterial Activity

Rind and aril of pomegranate (Punica granatum) were freeze-dried and extracted using solvents of varying polarity: petroleum ether, dichloromethane, ethyl acetate, methanol and water. Phytochemical investigations included qualitative detection of phytochemicals including phenols and tannins, flavonoids, anthocyanins, coumarins, quinones, saponins, steroids, triterpenoids, and alkaloids. Total phenolic and flavonoid content of each extract were determined quantitatively. Methanolic and aqueous pomegranate rind extracts showed highest amount of phenolic and flavonoid content. The presence of gallic acid in pomegranate rind and aril was determined by GCMS. Medicinal studies comprised of evaluating the antioxidant, antidiabetic and antibacterial potential of the prepared extracts. According to 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay for antioxidant potential, methanolic and aqueous extracts of pomegranate rind and methanolic extract of pomegranate rind showed antioxidant activity of above 80%. Aqueous extract of pomegranate aril showed highest inhibition of alpha-amylase which was taken as antidiabetic activity according to 3,5-dinitrosalicylic acid assay (DNSA assay). Methanolic and aqueous extracts of pomegranate rind were most effective in inhibiting the growth of a number of bacteria according to the disc diffusion method.