Antioxidants in Clinical Treatments

Abstract

The ability of antioxidants to scavenge free radicals is well known, but their possible therapeutic action is still unclear because so far most studies are in vitro on cultured cells (where the antioxidant concentrations are typically much larger than those that can be reached in the human body) or in vivo on animals. This chapter is focused on ascorbic acid (vitamin C). Vitamin C exhibits dual reactivity with pro-oxidant activity registered at concentrations above 1 mM while at lower concentrations it has an antioxidant effect. Vitamin C appears to be effective in preventing respiratory diseases, shortening recovery time after surgeries, increasing the efficiency of the immune response to infections, improving glycemic control in type 2 diabetes, decreasing the need for fluids in the treatment of burns, and protecting the skin. Although countless beneficial effects of antioxidants have been proposed, far more studies are required before most of these claims should be taken seriously, possibly to discover new antioxidants that are more effective against the disease.