Neuro-protective effect of Carvedilol, an adrenergic antagonist against scopolamine-induced cognitive impairment in mice

The use of β- adrenoceptor blocking agents (β -blockers) in the clinical treatment of cardiovascular disorders and glaucoma are associated with enhancedvigilance, attention, reward, learning and memory. The present study was designed to explore the possible role of Carvedilol, an adrenergic antagonist in ameliorating scopolamine-induced neurotoxicity in rats. Mice were divided into control and treatment groups. Control mice for each test received 10 ml normal saline/kg while the treatment groups (n = 6) received Carvedilol (2.5, 5 and 10 mg/kg orally) and1 mg scopolamine/kg intraperitoneally). One hour after sildenafil and thirty minutes after scopolamine administration orally and intraperitoneally respectively, the animals were assessed for 5 minutes on elevated plus maze, Y-maze and open-field. The parametersmeasured on the EPM were memory acquisition and memory retention latencies with and without scopolamine while spontaneous alternation behaviour was measured in Y-maze. The effect of Carvedilol on locomotion was assessed in mice using open field.Carvedilol significantly (p<0.001) shortened memory acquisition and retrieval latencies in mice with scopolamine–induced cognitive deficit. Carvedilol produced significant (p<0.0001) increase in spontaneous alternation behaviour in both memory intact and memory deficit models. Carvedilol however, had no effect on locomotor activity of mice. The results suggest that Carvedilol enhanced memory acquisition and retrieval in cognitive deficit and cognitive intactmice.It also improved short term memory as indicated by increase in spontaneous alternation behaviour in mice.Carvedilol may therefore be useful in management of dementing disorders such as Alzheimer’s disease.