Determination of antioxidant potential of Acacia nilotica leaf extract in oxidative stress response system of Saccharomyces cerevisiae

Background: From ancient times, plants and plant-derived products have been used as folkloric medicines for a variety of health disorders owing to their tremendous therapeutic potential. The present study aimed to determine the antioxidant efficacy of crude Acacia nilotica extract in the oxidative stress response system of Saccharomyces cerevisiae as a model organism.

Results: Acacia nilotica showed significant antioxidant activity, with IC₅₀ values of 75.157 and 159.57 µg mL^-1 for 2,2-diphenyl-1-picrylhydrazyl radical and hydroxyl radical scavenging activities respectively at a concentration of 500 µg mL^-1 . The total antioxidant activity of A. nilotica showed an ascorbic acid equivalent of 152.79 ± 7.43 µg mL^-1 . The presence of phytoconstituents such as phytol and α-tocopherol from gas chromatography/mass spectrometry analysis confirmed the potential of A. nilotica as an antioxidant. The results were validated using the stress response mechanism in S. cerevisiae wild type and its isogenic deletion strains sod1Δ and tsa1Δ. Acacia nilotica substantially neutralized reactive oxygen species generated by hydrogen peroxide in mutant strains, as evident from spot assay and fluorescence assay using fluorescence microscopy and intensity studies.

Conclusion: The results suggested the efficacy of A. nilotica as a potent antioxidant in the S. cerevisiae system for the first time and its use in neutraceuticals/therapeutics. © 2017 Society of Chemical Industry.