Nicotine protects against the dexamethasone potentiation of kainic acid-induced neurotoxicity in cultured hippocampal neurons

To elucidate the neuroprotective effect of nicotine, we investigated whether nicotine may attenuate dexamethasone potentiation of kainic acid-induced neurotoxicity. Primary hippocampal culture was pre-treated with nicotin for 24 h followed by dexamethasone (10⁻⁴ M) for 24 h. Then, cultures were exposed with kainic acid (10⁻⁴ M) and cellular viability was determined by LDH effluxmetry. Nicotine pre-treatment (10⁻⁹−10⁻⁷ M) dose-dependently attenuated dexamethasone potentiation of kainic acid-induced neurotoxicity. These results may support the epidemiological data suggesting a neuroprotective effect of cigarette smoking on Alzheimer's disease or Parkinson's disease.