In Vitro Antioxidant Activity of Methanolic Extract of Piper retrofractum Vahl.

Cabai jamu (Piper retrofractum Vahl.), which is originally from Indonesia and is extensively cultivated and traditionally used in Sumenep, Madura possess high potential medicinal properties. Therefore, providing scientific rationale of their traditional usage would be necessarily required. This research aimed to investigate the antioxidant activity of methanolic extract of P. retrofractum Vahl. using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. This research was carried out using methanol concentrations of 0, 5, 15, 30, 45 and 60 ppm. In addition, ascorbic acid was used as the standard antioxidant. Meanwhile, the parameters measured are the extract yield, percentage of inhibition and IC50. The results showed that the DPPH activity of the extracts was increased in a dose dependent manner, which was found in the range of 0-31.53% as compared to ascorbic acid (0-43.19%). The IC50 values of methanol extract in DPPH radical was obtained to be 101. 74 ppm. Meanwhile, the IC50 value of the ascorbic acid was found to be 66.12 ppm. This result indicates that methanol extract of P. retrofractum possess mild antioxidant activity. Therefore, further investigation using other solvent extracts need to be carried out to evaluate the antioxidant compounds present in the plant extract