Minocycline protects melanocytes against H2O2-induced cell death via JNK and p38 MAPK pathways.

Vitiligo is an acquired and progressive disorder manifested by the selective destruction of melanocytes in the skin. An extremely high level of hydrogen peroxide (H 2 O 2 ) in plasma as well as in lesional skin has been reported in vitiligo patients. High H 2 O 2 level has been suggested to be responsible for the disappearance of melanocytes in vitiligo. JNK and p38 MAPK are strongly induced by oxidative stress and related to neuron loss in neurodegenerative disorders. Minocycline, an antibiotic possessing antioxidant activity, is capable of attenuating oxidative stress-induced neurotoxicity. To investigate whether minocycline rescues melanocytes from H 2 O 2 -induced apoptosis, cultured mouse melanocytes (B10BR) were treated with H 2 O 2 in the presence or absence of minocycline. Our data showed that H 2 O 2 decreases cell viability in a concentration-dependent manner which is attenuated by minocycline. Also, H 2 O 2 treatment activates JNK and p38 MAPK, and executive caspase 3 in B10BR cells. Minocycline significantly inhibits H 2 O 2 -induced activation of JNK, p38 MAPK and caspase 3. Collectively, we concluded that minocycline protects melanocytes against H202-induced apoptosis in vitro. Its protective effect is associated with the inhibition of JNK and p38 MAPK. Our findings suggest that minocycline, a clinically well-tolerated, safe antibiotic, may be used to prevent melanocyte loss in the early stage of vitiligo.