L -Se-methylselenocysteine: Synthesis, anticancer mechanisms and research progress

L-Se-methylselenocysteine (L-MSC), a natural organic selenium compound abundant in selenium-enriched vegetables and legumes, pre-clinically exhibits outstanding chemopreventive and therapeutic anti-tumor activity and biosafety. Metabolized into methylselenol by β-lyase in vivo, it has been shown to suppress tumor proliferation, angiogenesis, invasion and metastasis, regulates circadian rhythm to block malignant transformation, and delays castration resistance of hormone-dependent tumors. Combined with chemotherapeutics, has been demonstrated to enhance anti-tumor efficacy while alleviating chemotherapy-induced toxicities. Natural L-MSC content in plants is too low for large-scale use, so chemical synthesis and biosynthesis are developed for its production. Chemical synthesis yields high-purity products yet has drawbacks like chlorine residues and pollution; biosynthesis features mild conditions, eco-friendliness and high safety. This review summarizes L-MSC’s natural distribution, synthesis routes, anticancer mechanisms and applications, and prospects its development, aiming to support its future potential clinical and public-health application.