A disulfide derivative of octanoic acid, it exhibits several biologic effects, which include the quenching of ROS, metal chelation, interaction, and the regeneration of other antioxidants, redox regulation of protein thiol groups, and effects on gene expression and apoptosis (43). Thioctic acid has been reported to prevent UV-induced photo-oxidative damage, mainly through the down-modulation of NF-kappa B activation and to inhibit tyrosinase activity probably by chelating the copper ions (44).
Dihydrolipoic acid, lipoid acid, and resveratrol reduced microphthalmia-associated transcription factor and tyrosinase promoter activities. Dark skinned Yucatan swine treated with these agents showed visible skin lightening, which was confirmed histological, whereas ultraviolet B-induced tanning of light skinned swine was inhibited using these agents (45).