Indolyl-3-Acetic Acid for Medical Use (Review)

Therapeutic effect of many plants is associated with the presence of various bioactive substances in them. The plant hormones—phytohormones—can be distinguished among these substances. When ingested into the human body, they affect physiological processes such as inflammation, glucose uptake, cell division, and resistance to diseases. It is hypothesized that phytohormones may be used as drugs with no side effects. One of them could be the phytohormone indolyl-3-acetic acid (IAA), which is a heteroauxin and can be synthesized by some microorganisms and animals, including mammals. This phytohormone is an important derivative of indole, which is catabolized from dietary tryptophan by the intestinal microbiota. IAA can scavenge free radicals, inhibit oxidative stress, and reduce the production of proinflammatory cytokines. As a ligand of the aryl hydrocarbon receptor, IAA can regulate intestinal homeostasis and suppress inflammatory responses. This review summarizes the current literature data on the vital role of IAA in the treatment of cancer, type 2 diabetes, rheumatoid arthritis, liver disease, Alzheimer’s disease, dental diseases, and microbial skin diseases. The purpose of this review is to draw attention and interest to IAA as a promising therapeutic drug.