Anti-apoptotic effects of melatonin in retinal pigment epithelial cells.

Recent studies have revealed that melatonin exerts strong anti-apoptotic effects. Retina secretes melatonin, and melatonin receptors are distributed in almost all the layers of retina, including the layer of retinal pigment epithelial (RPE) cells. However, it is not known whether melatonin inhibits apoptosis through its anti-oxidant effects and how it works in RPE cells. Here, we show that melatonin decreases H2O2-induced apoptosis in RPE cells partially through protection of mitochondria. Melatonin decreased reactive oxygen species in mitochondria and mitochondrial DNA damage, alleviated structural damage and inhibited cytochrome C release.