Pinacidil and levamisole prevent glutamate-induced death of hippocampal neuronal cells through reducing ROS production

Activators of both adenosine 5'-triphosphate (ATP)-sensitive K+ (K-ATP) channel and cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel have significant in vivo and in vitro neuroprotection against glutamate-induced death of some neuronal cells. Here, the effect of the K-ATP channel activator, pinacidil, and the CFTR Cl- channel opener, levamisole, against glutamate-induced oxidative stress were investigated in mouse hippocampal cells, HT22. The results from cell viability assay (WST-1) showed that pinacidil and levamisole weakly protected cells against glutamate-induced toxicity at 10 mu M and their effect increasedin a dose-dependentmanner till reachmaximumprotection at 300 mu M. Pretreatment with pinacidil or levamisole significantly suppressed the elevation of reactive oxygen species (ROS) triggered by glutamate through stabilising mitochondrial membrane potential and subsequently protected HT22 cells against glutamate-induced death. HT22 cells viability was maintained by pinacidil and levamisole in presence of glutathione inhibitor, BSO. Also, pinacidil and levamisole pretreatment did not induce recovery of glutathione levels decreased by glutamate. Expectedly, this protection was abolished by the K-ATP and CFTR Cl- channels blocker, glibenclamide. Thus, both pinacidil and levamisole protect HT22 cells against glutamate-induced cell death through stabilising mitochondrial membrane potential and subsequently decreasing ROS production.