Diverse Biological Functions of Myo-inositol: A Neuro-Metabolite, Osmoprotectant, and Diagnostic Marker

Inositols, regarded as a sugar-alcohol isomeric group, is a class of polyol compounds with six-carbon ring structure and each carbon being hydroxylated. Among different biologically active isomers of the group, myo-inositol (MI), is regarded one of the most widespread and versatile metabolite with occurrence in plants, animals, yeasts, and microorganisms. With respect to mammals, MI is particularly abundant in the brain and other organs such as kidneys, ovaries, heart, liver, and muscle tissues. Additionally, MI represents an important constituent of membrane phospholipids and mediating osmoregulation with its phosphorylated derivatives participating in several intracellular signalling pathways and other physiological processes. Of late, significance of MI has been also observed in medical research wherein altered levels of MI in the brains are associated with Alzheimer’s disease (AD), epilepsy, and psychiatric disorders. Moreover, MI supplements do help in preventing insulin resistance, decreasing hyperandrogenism, preventing polycystic ovarian syndrome, etc. Keeping in view the diverse roles of MI, the present chapter summarizes the current understanding on the role of MI as an osmolyte in response to hyperosmolarity, a cellular metabolite in the human brain and a biomarker for both healthy and disease conditions and an effective supplementation for treatment of wide variety of diseases such as polycystic ovary syndrome, cardiovascular diseases, respiratory distress syndrome, and neurological disorders. Future insights in this direction are also highlighted at the end of the chapter.