Effects of oxytocin on glutamate mediated neurotoxicity in neuroblastoma cell culture

Aim: We aimed to investigate the effects of oxytocin on neurite growth, cell viability, cell proliferation and apoptosis to demonstrate its neuroprotective effect on glutamate induced neurotoxicity in human neuroblastoma SH-SY5Y cell culture. Materials and Methods: Toxic effects of oxytocin and glutamate were examined by Neurotoxicity Screening Test (NTT), apoptotic effects by TUNEL method and cell viability test by MTT method. In the NTT test; Neurotoxicity was induced by adding glutamate at a concentration of 32 µM to the cell culture. Oxytocin was added at 1, 3, 10, 30 and 100 µM concentrations and its effect on neurite elongation was investigated. It was demonstrated by TUNEL method that application of glutamate caused apoptosis in the SH-SY5Y cell line. Afterwards when glutamate and different doses of oxytocin were given, antiapoptotic effect was evaluated with the apoptotic index. Findings: Glutamate was found to have a dose-dependent neurotoxic effect in SH-SY5Y cell culture and reduced neurite elongation by 50% at a concentration of 32 μM. It was shown that the inhibition of neurite elongation caused by glutamate in SH-SY5Y cells decreased in a dose-dependent manner by applying oxytocin. Especially oxytocin was found to significantly reduce neurite inhibition and show a neuroprotective effect starting from 10 µM concentrations. The concentration at which glutamate reduces cell proliferation by 50% was determined as 54 µM in MTT. Subsequently, it was observed that the adverse effect of glutamate on cell proliferation significantly decreased with oxytocin administration, depending on the dose. Results: It was found that different concentrations of glutamate have a significant toxic effect on cell proliferation and viability, glutamate inhibits neurite elongation in a dose-dependent manner; oxytocin reduces neurite inhibition caused by glutamate, has a neuroprotective and has antiapoptotic effects. In addition, it was detected that oxytocin inhibits the neurotoxic effect of glutamate in SH-SY5Y cells previously administered oxytocin and increases cell viability.