Resveratrol prevents brain injury and neurogranin expression in rats exposed to gaseous formaldehyde

Abstract

Objective To explore the effects of gaseous formaldehyde exposure on male Sprague-Dawley rat brain function and synaptic protein expression, as well as the neuroprotective effects of resveratrol. Methods Eighty-four male Sprague-Dawley rats were randomly divided into seven group with 12 in each group: control group (N), gaseous formaldehyde accumulation low concentration group (FL group), gaseous formaldehyde accumulation medium concentration group (FM group), gaseous formaldehyde accumulation high concentration group (FH group), gaseous formaldehyde accumulation low concentration + resveratrol group (FLR group), gaseous formaldehyde accumulation concentration + resveratrol group (FMR group) and gaseous formaldehyde accumulation high concentration + resveratrol group (FHR group). The animal model of gaseous formaldehyde accumulation was established by gas formaldehyde exposure method.Learning and memory function was tested by Morris water maze. Cortical and hippocampal neurogranin (Ng) protein expression in brain cortex and hippocampus was measured by Western blot. Results (1) Compared with the escape latency and original platform retention time of rats in group N ((19.75±4.08) s, (43.47±2.43) s), the escape latency of rats in FM and FH groups was prolonged ((25.52±2.98) s, (27.45±2.39) s, t=-4.97, -5.82; both P<0.01), the retention time of the original platform was shortened ((30.99±4.21) s, (18.70±2.58) s, t=10.24, 25.71; both P<0.01). Compared with the corresponding formaldehyde accumulation groups such as the FM and FH groups, the escape latency of the rats in the FMR and FHR groups was significantly longer ((21.37±3.80) s, (24.26±3.56) s, t=1.86, 3.93; both P<0.05), the retention time of the original platform was significantly prolonged ((40.33±3.63)s, (23.46±4.73)s, t=-7.50, -3.95; both P<0.01). (2) Compared with the expression of Ng in cortex and hippocampus of rats in group N ((0.99±0.03), (1.07±0.03)), the expression of Ng protein in cortex and hippocampus of rats in FM and FH groups was significantly reduced((0.62±0.06), (0.39±0.03), (0.77±0.09), (0.46±0.10), t=11.55, 14.08, 11.51, 13.17; all P<0.01). Compared with the corresponding formaldehyde accumulation groups such as the FM and FH groups, the expressions of Ng in the cortex and hippocampus of the rats in the FMR and FHR groups were significantly increased ((0.94±0.11), (0.48±0.04), (0.95±0.05), (0.60±0.09), t=-5.26, -2.09, -5.32, -2.21; all P<0.05). Conclusion Resveratrol can improve the learning and memory function of rats caused by the accumulation of gaseous formaldehyde.The mechanism may be related with the upregulation of Ng. Key words: Gaseous formaldehyde accumulation; Neurogranin; Learning and memory; Resveratrol; Rat