Dietary Supplements with Antioxidant Activity – Understanding Mechanisms and Potential Health Benefits: An Overview

Abstract

Compounds from food/supplements with antioxidant activity exert their effects by directly scavenging free radicals, chelating metal ions, activating endogenous antioxidant enzymes, regulating mitochondrial function, and reducing cellular inflammation. Consumption of natural foods rich in antioxidants such as fruits, vegetables, nuts, grains, and medicinal plants may provide a better option for health promotion and disease risk reduction compared to taking high doses of dietary antioxidant supplements. Many diet-derived substances can act as antioxidants. In addition to diet-derived antioxidants, there are also endogenously-synthesized primary and secondary antioxidant enzymes. The overall antioxidant defence in the human body depends on endogenously-synthesized antioxidant enzymes, which serve as the primary defence, whereas diet-derived antioxidants (food and supplements) are categorized as secondary defence. In this connection, the potential mechanisms of action of antioxidants from dietary supplements and natural sources in preventing numerous chronic diseases are highlighted. These include reducing lipid peroxidation, detoxifying free radicals, activation of endogenous antioxidant enzymes, and signaling pathways related to oxidative stress, as well as reducing levels of pro-inflammatory cytokines. This overview provides some important highlights about antioxidants from dietary supplements and natural sources by discussing their potential action mechanisms and health benefits.