Fig. 2

Mechanism of L-carnitine action on female fertility. LC enters the oocyte through OCTN2 and through its direct action on oocyte quality, it increases energy production by β-oxidation, eliminates excess palmitate from ER to reduce ER stress, scavenges free radicals to reduce oxidative damage and inhibits caspases to prevent apoptosis. It implies its indirect action through HPG axis by regulating the reproductive hormone levels and thus mitigates reproductive disorders such as PCOS and amenorrhea. In endometriosis, it improves hormonal balance, decreases the release of cytokines as well as apoptosis and thus ameliorates endometriosis. CPT1, carnitine palmitoyltransferase-1; CPT2, carnitine palmitoyltransferase-2; T, CoA, coenzyme-A; ER, endoplasmic reticulum; FFA, free fatty acid; FSH, follicle stimulating hormone; GnRH, gonadotropin releasing hormone; IMM, inner mitochondrial membrane; LC, L-carnitine; LH, luteinizing hormone; mPTP, mitochondrial permeability transition pore; OCTN2, organic cation transporter-2; OM, oocyte membrane; OMM, outer mitochondrial membrane; PCOS, polycystic ovary syndrome; PRL, prolactin; ROS, reactive oxygen species; T, translocase