Betaine protects human melanocytes from H2O2-induced dysfunction and degeneration

This study aimed to clarify the potential protective effects and mechanisms of betaine against H2O2-induced apoptosis and dysfunction in human melanocytes. Pretreatment with 2mM betaine increased proliferation, decreased apoptotic rates, and reduced intracellular oxidative damage in both normal and vitiligo melanocytes. It also reversed H2O2-induced cellular dysfunction in migration and melanogenesis. Betaine upregulated the expression of SCF/c-KIT/MITF signaling components, and its protective effects on melanocytes were partially blocked by c-KIT inhibitor treatment. Furthermore, betaine reduced the Bax/Bcl-2 ratio and the release of cleaved caspase-3 protein, and prevented the phosphorylation of ERK, p38, and JNK MAPKs in H2O2-treated melanocytes. Additionally, 5-methylcytosine immunodetection results indicated that betaine pretreatment reversed the enhancement of global DNA demethylation induced by H2O2 in melanocytes. These results demonstrate for the first time that betaine protects human melanocytes from H2O2-induced dysfunction and degeneration by modulating SCF/c-KIT, MITF, apoptosis, and MAPK pathways.