Acetyl-L-carnitine physical-chemical, metabolic, and therapeutic properties: relevance for its mode of action in Alzheimer's disease and geriatric depression

Acetyl-L-carnitine (ALCAR) contains carnitine and acetyl moieties, both of which have neurobiological properties. Carnitine is important in the p-oxid ation of fatty acids and the acetyl moiety can be used to maintain acetyl-C oA levels, Other reported neurobiological effects of ALCAR include modulati on of: (1) brain energy and phospholipid metabolism; (2) cellular macromole cules, including neurotrophic factors and neurohormones; (3) synaptic morph ology; and (4) synaptic transmission of multiple neurotransmitters. Potenti al molecular mechanisms of ALCAR activity include: (1) acetylation of -NH2 and -OH functional groups in amino acids and N terminal amino acids in pept ides and proteins resulting in modification of their structure, dynamics, f unction and turnover; and (2) acting as a molecular chaperone to larger mol ecules resulting in a change in the structure, molecular dynamics, and func tion of the larger molecule, ALCAR is reported in double-blind controlled s tudies to have beneficial effects in major depressive disorders and Alzheim er's disease (AD), both of which are highly prevalent in the geriatric popu lation.