Effects of asiatic pennywort (Centella asiatica) ethanol extract on impairment of learning and memory induced by cerebral ischemia and induced by scopolamine in mice

Abstract

The effects of crude ethanolic extracts of Centella asiatica (CE), a traditional medical plant, on learning and memory impairment induced by either cerebral ischemia (bilateral common carotid arteries: 2VO) or scopolamine, were investigated in mice. The 2VO caused an increase in the latency to find the platform in learning trial in Morris water maze (MWM), a reduction of step-down latency and an increment of number of errors in step-down test indicating that the 2VO could impair learning and memory. Treatment with oral administration of CE (300, 1000 and 1500 mg/kg. day body weight (B.W.)) once daily markedly shortened the latency of escaping onto the platform in MWM, prolonged the step-down latency and decreased the number of error significantly as compared with 2VO-operated mice. These results suggested that CE could improve learning and memory impairment induced by cerebral ischemia. In addition, the CE administration at all doses did not show anysignificant effect on spontaneous locomotor activity in 2VO mice. Furthermore, CE in doses of 100, 300, 1000 or 1500 mg/kg/day B.W. significantly reduced malondialdehyde (MDA) level in the brain of 2VO mice. On the other hand, scopolamine, though, caused an impairment of learning and memory did not increase the level of MDA. The administration of CE (100, 300, 1000 or 1500 mg/kg/day B.W.) did not attenuate learning and memory impairment induced by scopolamine in mice. This result suggested that CE might have no cholinomimetic activity in the CNS. Therefore, it is suggestive that antioxidative property of CE could, at least partly, contribute to its positive effect on memory deficit in 2VO mice. Thus, CE might be beneficial for memory impairment in which oxidative stress is an underlying cause. Further study is needed to identify the nature of compound (s) accounted for the positive effect of CE on memory