Quercetin attenuates the reduction of parvalbumin in middle cerebral artery occlusion animal model

Abstract

Background: Calcium is a critical factor involved in modulation of essential cellular functions. Parvalbumin is a calcium buffering protein that regulates intracellular calcium concentrations. It prevents rises in calcium concentrations and inhibits apoptotic processes during ischemic injury. Quercetin exerts potent antioxidant and anti-apoptotic effects during brain ischemia. We investigated whether quercetin can regulate parvalbumin expression in cerebral ischemia and glutamate toxicity-induced neuronal cell death. Adult male rats were treated with vehicle or quercetin (10 mg/kg) 30 min prior to middle cerebral artery occlusion (MCAO) and cerebral cortical tissues were collected 24 h after MCAO. We used various techniques including Western blot, reverse transcription-PCR, and immunohistochemical staining to elucidate the changes of parvalbumin expression.

Results: Quercetin ameliorated MCAO-induced neurological deficits and behavioral changes. Moreover, quercetin prevented MCAO-induced a decrease in parvalbumin expression.

Conclusions: These findings suggest that quercetin exerts a neuroprotective effect through regulation of parvalbumin expression.

Keywords: Cerebral ischemia; Neuroprotection; Parvalbumin; Quercetin.

Fig. 1

Neurobehavioral scores (a), corner test (b), and proteomic analysis (c and d) of parvalbumin in vehicle + middle cerebral artery occlusion (MCAO), quercetin + MCAO, vehicle + sham, and quercetin + sham animals. Quercetin improves the neurological deficit score and tendency of turning towards to the right by ischemic stroke. Data (n = 16) are represented as the mean ± S.E.M. * p < 0.01, ** p < 0.05 vs. the vehicle + sham group, # p < 0.05 vs. vehicle + MCAO group. Squares indicate parvalbumin protein spots (c). Spot intensities were measured by PDQuest software. Spot intensities are reported as a ratio relative to vehicle + sham animals (d). Data (n = 4) are shown as means ± S.E.M. * p < 0.05. Mw and pI indicate molecular weight and isoelectric point, respectively

Fig. 2

Reverse transcription-PCR (a and b) and Western blot (c and d) of parvalbumin in vehicle + middle cerebral artery occlusion (MCAO), quercetin + MCAO, vehicle + sham, and quercetin + sham groups. Densitometric analyses from reverse transcription-PCR and Western blot are represented as a ratio of parvalbumin intensity to β-actin intensity. Each lane represents an individual animal. Data (n = 4) are shown as means ± S.E.M. * p < 0.05

Fig. 3

Immuno-staining of parvalbumin in vehicle + middle cerebral artery occlusion (MCAO), quercetin + MCAO, vehicle + sham, and quercetin + sham groups. Arrows indicate positive cells of parvalbumin (a). Scale bar = 100 µm. Parvalbumin-positive cells levels were expressed as percentage of the number of parvalbumin positive cells to that of total cells (b). Data (n = 4) are shown as means ± S.E.M. * p < 0.05