Protective effects of melatonin against morphine induced neurotoxicity in PC12 cells

Morphine has a high addictive potential and can be abused. Long-term use of morphine is associated with some pathological consequences including neurotoxicity, neuronal dysfunction, oxidative stress and apoptosis. Increasing evidence has shown that melatonin has antioxidant and antiapoptosis properties. However, its effects on morphine-induced neurotoxicity in PC12 cells have not been studied. This study was carried out to evaluate protective effect of melatonin against morphine-induced neurotoxicity in PC12 cells.

PC12 cells were treated for 24 h with several doses of melatonin (10, 25, 40, and 50 μM). The cells were then treated with 3.2 mM morphine for 24 h. The viability of PC12 cells was measured using MTT assay. The antioxidant activity of melatonin was evaluated by measuring the levels of reactive oxygen species (ROS), lipid peroxidation (LPO) and total thiol groups, and total antioxidant power (TAP).

Melatonin significantly enhanced the viability of PC12 cells and protected the cells against morphine-induced overproduction of ROS. Melatonin has increased TAP and total thiol groups and decreased LPO.

Melatonin attenuates neurotoxicity of morphine in PC12 cells via antioxidant activity.