ABSTRACT: Quercetin is a ubiquitous fl avonoid found in many plants. Neuroprotective effects of quercetin have been shown in several in vitro and in vivo studies, but its mechanism of action has not been fully defi ned yet. Brain-derived neurotrophic factor (BDNF) is a fundamental neurotrophin with vital functions in the survival of neuronal cells. In the present study, we aimed to investigate the effects of quercetin on expression of BDNF mRNA in the hippocampus of rat brain. METHODS: Male rats were daily gavaged with quercetin (10, 20 or 50 mg/kg·bwt) for 30 days. Hippocampal levels of the BDNF transcripts were assessed using quantitative (q) RT-PCR. RESULTS: Quercetin at doses of 20 and 50 mg/kg caused a signifi cant increase in the mRNA expression of BDNF as compared with the control group. Quercetin treatment at a dose of 10 mg/kg failed to cause any signifi cant changes in the levels of BDNF mRNA CONCLUSION: Our fi ndings suggest that the neuroprotective effects of quercetin may be at least partly due to its .Author: Farideh Jalali Mashayekhi inducing effects on the expression levels of the BDNF mRNA