Comparative Evaluation of Antioxidant Activity of Methanolic and Aqueous Extracts of Malus Domestica (Red Delicious Cultivar)

Abstract

Oxidative stress, caused by an excess of reactive oxygen species, is also known to play a role in the development of Cardiovascular, Metabolic, and Neurodegenerative disorders. Phytochemical compounds from plants, and in particular phenolics, are known to work as natural antioxidants in the diet that could limit oxidative stress. Malus domestica (Red Delicious cultivar) is very common and rich in polyphenols and Vitamin C. Hence, it could be an apt source for natural antioxidants. This study evaluated and compared the in-vitro antioxidant activities of methanolic and aqueous flesh extracts of M. domestica. Fruits were collected from Shagamu, Ogun State, Nigeria. Flesh extraction from the apple was performed using both methanol and water, and the concentration tested was 5-100 µg/mL. All the assays were done thrice, and the data was presented as mean ± SEM using one-way ANOVA analysis with p < 0.05. In both fractions, antioxidant activity increased with concentration. In the FRAP assay, the methanolic extract exhibited significantly higher ferric-reducing power than the aqueous extract at all tested concentrations, with values of 25.315 ± 0.149 mg TE/g and 18.619 ± 0.211 mg TE/g, respectively, at 100 µg/mL. In the ABTS•⁺ assay, the aqueous extract showed higher activity at 5 µg/mL (16.334 ± 0.045 mg TE/g) compared to the methanolic extract (8.821 ± 0.094 mg TE/g); however, the methanolic extract demonstrated greater activity at higher concentrations, reaching 44.923 ± 0.866 mg TE/g at 100 µg/mL compared to 27.951 ± 0.907 mg TE/g for the aqueous extract. These findings confirm the presence of measurable in vitro antioxidant activity in M. domestica flesh and highlight the influence of extraction solvent on antioxidant capacity.