Comparison of antioxidant potential in pulp and peel extracts of Manilkara zapota (L.) P. Royen

Free radical scavenging ability of both pulp and peel of Manilkara zapota (sapota) were tested against 2,2-diphenyl-1-picryl hydrazyl (DPPH), 2,2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS+), peroxynitrites  and lipid peroxidation generated in vitro. Both ethanolic and methanolic extracts of pulp and peel of sapota were subjected to in vitro free radical scavenging assays like DPPH, ABTS+, nitric oxide and lipid peroxidation inhibition assays.  Total antioxidant capacity assay to confirm the antioxidant potential and preliminary phytochemical screening and phytochemical content like total phenols and flavonoids was also carried out by standard methods. In this study, the results indicates that peel extracts of sapota showed highest radical scavenging potential and high antioxidant activity compared to pulp extracts. In addition, ethanolic extract of peel exhibited highest flavonoid and total phenol contents. Among the ethanolic and methanolic extracts of sapota, ethanolic peel exhibited least IC50 value which indicates high potential for multiple radical scavenging activity. The preliminary study carried out confirms the significant free radical scavenging potential of the sapota peel extracts which indicates its potential health benefits.   Key words: Free radicals, antioxidants, 2,2-diphenyl-1-picryl hydrazyl (DPPH), ABTS, lipid peroxidation, flavonoids, total phenols