Antioxidant Profile of Anacardic Acid Derivatives and Their Effects on Oxidative Stress-Induced Diseases: An Update

Anacardic acid is the principal constituent of cashew nut shell liquid (CNSL), obtained as a byproduct in the cashew-processing industry. It represents a group of chemically related salicylic acid derivatives bearing a hydrophobic alk(en)yl side chain with varying degrees of unsaturation. Literature data indicate the antioxidant potential of anacardic acid, assessed by autoxidation assays, DPPH radical scavenging, superoxide anion generation assays, inhibition of uric acid formation by xanthine oxidase, and lipoxygenase inhibition. The available evidence suggests that the antioxidant activity of anacardic acid is primarily due to the inhibition of oxidative enzymes and suppression of superoxide anion generation, rather than direct reactive oxygen species (ROS) scavenging. Inhibition of soybean lipoxygenase-1–catalyzed linoleic acid peroxidation and the demonstrated metal-chelating ability of anacardic acid support its potential use as a preventive antioxidant in functional food formulations. Inhibition of xanthine oxidase by anacardic acid may help prevent the accumulation of uric acid, thereby reducing the risk of hyperuricemia and gout. Moreover, modulation of free radical generation and attenuation of oxidative stress by anacardic acid derivatives could contribute to protection against oxidative stress–related diseases. Finally, structure–activity relationship (SAR) studies summarized in this review provide a basis for the structural optimization of anacardic acid with the aim of designing more potent antioxidant derivatives.