Natural antioxidants

Abstract

An excess of reactive oxygen species (ROS) and other oxidant radicals has been associated with male infertility. The total oxyradical scavenging capacity (TOSC) is a recently developed assay measuring the overall capability of biological fluids or cellular antioxidants to neutralize the toxicity of various oxyradicals. The TOSC assay can discriminate between different forms of ROS, allowing to identify the role of specific antioxidants, or their pathway of formation in the onset of toxicological or pathological processes. The previous application of TOSC assay in andrology led us to show a reduced antioxidant efficiency in seminal fluid of infertile men with a significant correlation between the scavenging capacity towards hydroxyl radicals and parameters of sperm cell motility. Despite the fact that oxidative stress is well recognized as a cause of male infertility, the use of antioxidants as a treatment is still debated, and it is considered as a “supplementation” therapy, rather than an etiological or physiopathological therapy, since no clear correlation has been investigated between a real deficiency of a specific antioxidant and the effect of oral supplementation. Various models have been introduced to explore the protective role of different antioxidants in vitro, and some differences can be discovered regarding the protective effects exerted by specific enzymatic or non-enzymatic molecules. We focus our attention on two main natural antioxidants, the efficacy of which has been supported by clinical trials: Coenzyme Q 10 and carnitine.