Cholecystokinin-8 inhibits methamphetamine-induced neurotoxicity via an anti-oxidative stress pathway

As a powerful addictive psychostimulant drug, coupled with its neurotoxicity, methamphetamine (METH) abuse may lead to long-lasting abnormalities in brain structure and function. We found that pretreatment of cholecystokinin-8 (CCK-8) inhibited METH-induced brain cellular dopaminergic (DA) damage in the striatum and substantia nigra, and related behavioural deficits and hyperthermia. However, the mechanism of CCK-8 action on METH-induced toxicity is not clear. The aim of this study was to explore whether the possible protective effect of CCK-8 on METH-induced neurotoxicity involved anti-oxidative stress mechanisms. The subtypes of CCK receptors mediating the regulatory action of CCK-8 were also investigated. The present results revealed that CCK-8 dose-dependently inhibited METH-induced cytotoxic effect by activating the CCK2 receptor subtype in PC12 cells and CCK2 receptor stable transfected-HEK293 cells. Pre-treatment of CCK-8 before METH stimulation significantly attenuated the generation of reactive oxygen species and NADPH oxidase activation in PC12 cells. In conclusion, our study demonstrated a protective effect of CCK-8 on METH-induced neurotoxicity in vitro and suggested that a possible mechanism of this action was dependent on the activation of the CCK2 receptor to reduce the neurotoxicity and oxidative stress induced by METH stimulation.