Antioxidant activities, phenolics and piperine contents in four piper species from India

Abstract

The present investigation was carried to compare the antioxidant activities, phenolics and piperine contents in fruits of four Piper species namely P. longum, P. mullesua, P. nigrum and P. peepuloides. Hydroalcoholic extract of fruits of selected Piper species was prepared and total phenolics content in extract samples was determined by Folin-Ciocalteu method. Three assays namely DPPH free radical scavenging activity, ABTS free radical scavenging activity and reducing power were used to assess the antioxidant activities of extracts in vitro. Ascorbic acid was used as positive control for comparing the antioxidant activities of the extracts. Piperine content was estimated using a reversed phase high performance liquid chromatography-photo diode array detection (RP-HPLC-PDA) method. Extract yield (%) was maximum for P. peepuloides (26.56) and it was followed by P. nigrum (21.58), P. mullesua (15.86) and P. longum (13.34), respectively. Piperine could be quantified in P. longum (2.43±0.13%) and P. nigrum (0.73±0.04%) extracts only. Antioxidant activity was found to be concentration dependent in all three assays. Also, extracts of all four species exhibited weak antioxidant activity in all three assays.