Effects of the standardized extract of centella asiatica ECa233 on cognitive deficits induced by B-Amyloid Peptide (25 - 35) in mouse

Abstract

The present study aimed to investigate the effects of a standardized extract of Centella asiatica ECa 233 on cognitive deficits induced by an intracerebroventricular (i.c.v.) injection of β-amyloid peptide 25-35 (Aβ25-35) 9 nmol/mouse into male ICR mice weighing 25-35 g. Seven days after Aβ25-35 injection, we examined their behavioral changes by morris water maze test, step-down test and locomotor activity test. In addition, the level of lipid peroxidation in the cerebral cortex and the neuronal cell density was assessed using a cresyl violet staining. In comparison to sham-operated group, significant impairment of learning and memory, increased levels of brain lipid peroxidation and the loss of neuronal cell in CA1 and CA3 of hippocampus were observed in mice treated with Aβ25-35. The experiment was divided into two protocols. For the 1st protocol, pre-treatment by ECa 233 (10 and 30 mg/kg B.W., p.o., twice daily) was performed for 7 days before the injection of Aβ25-35 and throughout experiment. In the 2nd protocol of post-treatment ECa 233 (10 and 30 mg/kg B.W., p.o., twice daily) was orally given for 15 days after the injection of Aβ25-35. It has been shown that ECa 233 giving either pre-treatment or post-treatment could significantly improve deficits in learning and memory, assessed by Morris water maze test and step-down passive avoidance task, however, ECa 233 did not alter locomotor activity. In addition, ECa 233 could significantly improve increased levels of brain lipid peroxidation and decreased neuronal cell loss of hippocampus in mice receiving Aβ25-35. The results obtained suggested that pre-treatment and post-treatment of a standardized extract of Centella asiatica ECa 233 is effective in ameliorating cognitive deficits induced by an intracerebroventricular injection of Aβ25-35 in mice which is an animal model of Alzheimer's disease. Anti-oxidation property is likely to be at least, in part an underlying mechanism of the results observed. Further investigation should be conducted to determine the other possible mechanisms.