V-TOL

The inositol stereoisomers, myo-inositol (MI) and D-chiro-inositol (DCI), are hexahydroxycyclohexanes, with the same molecular formula as glucose. They are the two most abundant members of a family of nine steroisomericinositols, and are found widely in nature.

Present in fruits and beans, the inositols are incorporated into cell membranes as phosphatidyl-MI, which is a precursor of inositol triphosphate (InsP3). InsP3 is a second messenger for many hormones including insulin and follicle-stimulating hormone (FSH). Defects in this pathway can lead to impaired insulin signaling and cause insulin resistance. This is the rationale for the suggested use of inositols in the management of insulin resistance syndromes, including polycystic ovary syndrome (PCOS).

Insulin has multiple effects on metabolism, which can be classified as metabolic and mitogenic. Metabolic effects can be further divided into those related to glucose transport and to glycogen synthesis. These dual metabolic effects sometimes occur in discordance with each other.

This suggests the existence of more than one downstream insulin signaling pathway. While the dominant action occurs though the insulin receptor tyrosine kinase and its primary tyrosine phosphorylated substrates (insulin receptor substrate protein family) second messengers, inositol glycans also mediate many metabolic actions of insulin. The inositol glycans are insulinomimetic, and have an activating/sensitizing effect.