Allopurinol attenuated the chemically-induced hypoxia (hypoxia-reoxygenation) injuries via down-regulation of the transcription factor HIF-1α in neuroblastoma cells

Abstract Hypoxia and reoxygenation (H/R) conditions cause molecular injuries in neuronal tissues. This study was designed to validate an in vitro model of H/R conditions in Neuro-2A cells and the neuroprotective mechanism(s) of allopurinol on H/R-induced injuries. Hypoxia was induced by using 2-deoxy glucose and Antimycin A and cell viability, intracellular ATP content, reactive oxygen species and nitric oxide concentrations were determined. The expression of hypoxia inducible factor-1 α (HIF-1α) was evaluated by quantitative PCR. Hypoxia resulted in 80% ATP depletion, while more than 80% of the cells remained viable. Co-exposure to H/R and allopurinol protected cells from ATP depletion. Allopurinol treatment significantly ( p   0.05) reduced the H/R-induced reactive oxygen species (ROS) and nitric oxide (NO) production. Allopurinol (63.5 μM) lowered the hypoxia-induced upregulation of HIF-1α. Data suggest that chemically-induced hypoxia could be a useful research tool to evaluate neuroprotective agents and that the protective effects of allopurinol against H/R-induced molecular injuries are attributed to the regulation of HIF-1α.