Effects of melatonin on orofacial pain relief by regulating mitochondrial function in cell viability of peripheral sensory neurons

Abstract

Melatonin (MT) is involved in the pain regulation of peripheral neurons, which is relevant to cell viability. This study aimed to examine the cell proliferation, cell cycle, cell apoptosis and intracellular mitochondrial function of ND7/23 and PC-12 cells treated with different physiological concentrations of MT. Our results showed that MT at concentrations of 10−8, 10−10 and 10−12 M inhibited cell proliferation and promoted the apoptosis of two cell lines, with the most significant changes observed at a concentration of 10−12 M. Further, 10−12 M MT promoted mitochondrial respiratory electron transfer and increased mitochondrial function in ND7/23 and PC-12 cells through the non-membrane receptor pathway. Comparatively, 10−8 M MT enhanced the mitochondrial effects of ND7/23 cells but showed opposite effects in PC-12 cells. In summary, MT affected cell viability through the non-membrane receptor pathway in a concentration-dependent manner and might be associated with pain regulations.