Comparative efficacy of plant-derived antioxidants against oxidative stress

Abstract

This investigation evaluated comparative efficacy of eight plant-derived antioxidants against oxidative damage using standardised in vitro assays. The antioxidants included quercetin, resveratrol, curcumin, EGCG, α-tocopherol, ascorbic acid, β-carotene, and gallic acid. Research was conducted at University of Vienna between April 2022 and February 2023 using six methodologies: DPPH, ABTS, FRAP, lipid peroxidation inhibition, SOD mimetic activity, and metal chelation. EGCG exhibited highest overall capacity with 91.4% DPPH and 88.7% ABTS scavenging at 100 μM. Ascorbic acid showed exceptional FRAP (91.3%) but limited lipid peroxidation inhibition (52.6%). α-Tocopherol displayed modest radical scavenging (62.7% DPPH) but superior lipid peroxidation protection (89.2%). IC50 values ranged from 23.7 μM (EGCG) to 67.4 μM (β-carotene). These findings support combining compounds with complementary mechanisms for optimal protection.