Protective effect of Grape seed proanthocyanidin on learning disabilities in a rat model with radiation brain injury

Abstract

Objective To observe the protective effect of grape seed proanthocyanidin extract (GSPE) on learning disabilities after radiation injury brain in rats. Methods 120 male Wistar rats were divided into control group, model group, high and low dose GSPE groups. The radiation injury brain models were established using a method of linear accelerator irradiation in 22 Gy. The morphological changes of neurons in hippocampus were observed with HE staining; the expression of phosphorylated extracellular signal regulated kinase 1/2 (ERK1/2) and growth associated protein-43(GAP-43) were detected by immunohistochemistry; the contents of malonalde hyde(MDA) and superoxide dismutase(SOD) were measured respectively by thiobarbituric acid(TBA) and xanthine oxidation(XTO) methods; the learning ability was assessed with shuttle box. Results Compared with the model group, the GSPE groups showed a decreased degree of nerve cell morphological injury; and increased ERK1/2 activities((13.20±1.45)/view, (27.40±2.52)/view, (19.80±1.30)/view), GAP-43 expression level((52.93±2.07)/view, (66.50±0.77)/view, (73.05±2.40)/view) and SOD activities((79.82±5.26) U/mg, (76.20±6.86) U/mg, (80.12±5.76) U/mg)(P<0.05); and decreased the contents of MDA((71.62±1.88) μmol/g, (76.41±1.94) μmol/g, (72.32±1.98) μmol/g)(P<0.05). Shuttle box testing showed that the active avoidance reaction rate was increased(7 d: (56.23±2.56)%; 14 d: (44.66±2.79)%; 28 d: (50.40±2.16)%)(P<0.05)and passive avoidance latency was shorted(7 d: (34.11±1.57)s; 14 d: (45.52±1.88)s; 28 d: ( 39.52±1.79)s)(P<0.05) in GSPE groups.The above mentioned changes were more significant in high dose of GSPE(P<0.05). Conclusion GSPE has protective effect on learning disabilities of radiation injuries brain, which is related to enhance ERK1/2 activity and the expression of GAP-43. Key words: Radiation injuries brain; Learning; Extracellular signal regulated kinase; Growth associated protein-43