Introduction: 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.
Method: The effect of oxytocin on the toxic effects of glutamate in human
neuroblastoma SH-SY5Y cell line with the Neurotoxicity Screening Test
(NTT), apoptotic effects by Terminal Transferase dUTP Nick End Labeling
(TUNEL) method and cell viability test by 3-(4.5-dimethylthiazol-2-
yl)-2.5-diphenyltetrazolium bromide (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. Afterwards, when glutamate and different doses
of oxytocin were given, antiapoptotic effect was evaluated with the
apoptotic index.
Results: Glutamate was found to have a dose-dependent neurotoxic
effect and reduced neurite elongation by 50% at a concentration of 32
μM. It was shown that the inhibition of neurite elongation caused by
glutamate 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.
Conclusion: 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
effect, increases cell viability and has antiapoptotic effects.
Keywords: In vitro, neuroprotective, neurotoxicity, oxytocin, SY5Y