Protective effect of hydro-alcoholic extract of Salvia haematodes Wall root on cognitive functions in scopolamine-induced amnesia in rats

Diminished cholinergic transmission may be responsible for development of amnesia. Hence, the present study was undertaken to investigate the possible protective effect of hydro-alcoholic extract of Salvia haematodes Wall root (HESH) on cognitive functions in scopolamine-induced amnesia in adult Sprague Dawley rats. The rats were divided randomly into five groups each consisting of five rats (n = 5). Rats of the groups I, II, III, IV, and V received orally normal saline (10 ml/kg b. wt.), normal saline (10 ml/kg), standard drug rivastigmine (1.5 mg/kg), HESH (20 mg/kg), and HESH (40 mg/kg), respectively once a day for fourteen days. Then, they were subjected to single dose of scopolamine (1 mg/kg b. wt. ip) except in group I on fourteenth day 60 min after respective normal saline or drug administration. They were observed for the effects on step down latency (SDL), locomotor activity and brain AChE activity for the learning and memory. The acquisition SDL, retention SDL and locomotor activity were significantly (p < 0.01) decreased while AChE activity was significantly (p < 0.01) increased in scopolamine-treated group II as compared to normal control group I. The acquisition SDL, retention SDL and locomotor activity were significantly (p < 0.01) increased while, AChE activity was significantly (p < 0.01) decreased with all the doses of HESH and in rivastigmine-treated group as compared to scopolamine-treated group II. Hydro-alcoholic extract of S haematodes root possesses protective effect on cognitive functions and may prove to be a useful memory restorative agent in the management of cognitive dysfunctions as in amnesia and Alzheimer's diseases.