Carnitine: A Novel Health Factor- An Overview

Abstract

Carnitine term comprises L-carnitine, acetyl –L-carnitine and Propionyl –L-carnitine. Carnitine in greater amount obtained from animal dietary sources as compared to plant sources. The endogenous synthesis of carnitine takes place in animal tissues like liver, kidney and brain using precursor amino acid lysine and methionine by iron, vitamin C, niacin, pyridoxine dependent pathway. This is the basis of vegans generally depending on carnitine in larger proportion through in vivo synthesis than omnivorous subjects. The concentration of Tri methyl lysine residues and the tissue specificity of Butyro betaine Dehydrogenase will play a significant role in regulating the carnitine biosynthesis. Carnitine transport from the site of synthesis to target tissue occurs via blood. Therefore, the measurement of normal plasma carnitine concentration represents the balance between the rate of synthesis and rate of excretion through specific transporter proteins. The cellular functional role of carnitine depends on the uptake in to cells through carnitine transport proteins and transport in to mitochondrial matrix. The function of carnitine is to traverse Long chain Fatty Acids across inner mitochondrial membrane for β-oxidation for rapid production of ATP. The carnitine level in plasma or tissue is done by spectro photometric, HPLC, or Tandem Mass Spectro photometry methods. Carnitine deficiency results in muscle disorders, there are two types of deficiency states such as primary and secondary deficiency. The primary is of systemic or myopathic, characterized by defect of high affinity organic cation transporter protein present on the plasma membrane of liver and kidney and also due to dysfunction of carnitine reabsorbtion through similar transport proteins in renal tubules. However, secondary carnitine deficiency associated with mitochondrial disorders and also defect of β-oxidation such as CPT-II and acyl CoA Dehydrogenase, several other causes are vitamin c deficiency, valaproate therapy, fancony syndrome, liver dysfunction, and kidney disease. Both these conditions results in recurrent muscle cramp, muscle weakness and fatigue, non ketotic hypoglycemia, encephalopathy, hepatomegaly, muscle necrosis, etc. Therefore, In view of the life threatening events of carnitine deficiency, Food drug administration considered L-carnitine as a drug to treat the primary and secondary carnitine deficiency. In recent times, carnitine has been extensively studied in various research activities to explore the therapeutic benefit. Thus, carnitine justifies as a novel health factor.