Krill oil protects PC12 cells against methamphetamine-induced neurotoxicity by inhibiting apoptotic response and oxidative stress

Abstract

Methamphetamine (METH) exposure can cause severe effects to the nervous system; however, the underlying molecular mechanism of neurotoxicity caused by METH is still unclear. Oxidative stress and apoptosis are linked in the pathophysiology of many neurodegenerative diseases. Krill oil (KO) benefits human health via its strong antioxidant ability. Therefore, we hypothesized that KO supplementation might effectively prevent METH-induced neurotoxicity via the inhibition of apoptotic responses and oxidative damages. In this study, PC12 cells were exposed to both METH (3 mmol/L) and KO (0.1, 0.2, 0.4, 0.8 μg/mL) in vitro for 24 h, and the following parameters were measured to detect apoptosis and oxidative stress responses that were triggered by METH: cell viability, the oxidative enzyme system, NO production, ROS production, apoptosis, mitochondrial membrane potential and protein expression of cleaved caspase-3. The results indicate that KO mitigates the apoptotic response post-METH exposure in PC 12 cells by increasing cell viability, decreasing protein expression of cleaved caspase-3, reducing apoptotic rates, and decreasing dissipation of mitochondrial membrane potential. In addition, the study revealed increases in SOD and GSH activity, and decreases in MDA content, NO and ROS production, suggesting that KO is beneficial in reducing oxidative stress, which may also play a role in the regulation of METH-triggered apoptotic response. Consequently, these data indicate that KO could potentially alleviate METH-induced neurotoxicity via the reduction of apoptotic responses and oxidative damages.

Keywords: Apoptosis; Krill oil; Methamphetamine; Neurotoxicity; Oxidative damage; PC12 cells.