In Vitro Antioxidant Activity of Methanol Fruit Extracts of Grape

Student: Abdulsamad Ayofe Ibrahim (Project, 2025)
Department of Biochemistry and Molecular Biology
Usmanu Danfodio University, Sokoto, Sokoto State


Abstract

Grape (vitis Vinefera) is a fruit widely known for its nutritional and medicinal benefits. This study assesses the antioxidant activity of methanol grape fruit extract, using different in vitro assays including 1,1-Diphenyl-2-picrylhydrazyl (DPPH), Ferric ion reducing antioxidant power (FRAP), Total antioxidant capacity (TAC), Hydrogen peroxide scavenging activity with ascorbic acid as a reference. The DPPH assay showed that the extract possess an IC50 value of 1.7mg/mL compared to Ascorbic acid which had IC50 value of 0.71mg/mL. In the FRAP assay, its IC50 was 0.97mg/mL lower than that of Ascorbic Acid (0.7mg/mL). The TAC analysis showed average antioxidant capacity of 164.577 ± 0.91 mg/mL which is less potent than Ascorbic Acid (260.995 ± 0.45mg/mL) and Hydrogen peroxide scavenging activity of 35.988 ± 8.62% surpassing that of ascorbic acid (28.870 ± 0.001%). These findings suggest that grape extract is a potent natural antioxidant, comparable to or exceeding the activity of synthetic antioxidants in certain assays, these highlight its potential application in the development of functional foods, nutraceuticals, and therapeutic products aimed at mitigating oxidative stress.

Keywords
antioxidant activity ascorbic grape fruit extract vitro methanol assays capacity