A Comprehensive Review on L-carnitine: A Promising Nutraceutical

Abstract

L-carnitine (LC), also known as β-hydroxy γ-trimethyl-amino-butyric acid, is a quaternary amine synthesized within the liver and kidneys from the amino acid lysine and methionine. It is the pharmacologically active form of carnitine that plays a crucial role in energy production and the metabolism of long-chain fatty acids (LCFAs) through β-oxidation. Deficiency in the organic cation transporter-2 (OCTN2) can arise due to genetic mutations or in conjunction with other illnesses like hepatic or renal disease. Deficits in carnitine regulation can result in various diseases including endocrine disorders, cardiomyopathy, diabetes, malnutrition, aging, sepsis, and cirrhosis. LC has been reported to have antioxidant and anti-inflammatory effects. Supplementation of LC has shown benefits in improving inflammatory conditions by reducing levels of inflammatory mediators such as C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). Supplementation of LC is particularly useful for individuals with primary carnitine deficiencies, which can be life-threatening, as well as certain secondary deficiencies such as organic acidurias, muscle wasting, and weakness. Moreover, emerging evidence suggests that LC may hold therapeutic potential for various diseases including renal diseases, liver diseases, neurodegenerative disorders, cardiovascular diseases (CVDs), cancer, diabetes, cachexia, obesity, depression, epilepsy, and more.