EFFECTS OF ETHANOL EXTRACT OF DENNETIA TRIPETALA ON LEARNING AND MEMORY IN SCOPOLAMINE TREATED RATS

Helyn Andonimye Ikem*, Daniel Ewa Ikpi, Umoh Sunday, Cecilia Agbo Peter, Blessing Dominic Peter and Uquetan Sam Uquetan

ABSTRACT

Dennettia tripetala (DT) fruits have been proven to have biochemical, anti- inflammatory and nutritional values. Dennettia tripetala, when eaten, causes mild stimulation in the brain which may affect neurobehavioral parameters. Whether it affects learning and memory is not yet certain. This study therefore investigated the effects of ethanol extract of Dennettia tripetala on learning and memory in scopolamine treated albino Wistar rats using the Novel Object Recognition test and Morris Water Maze, test. Twenty female wistar rats weighing between 100-150g were divided into four groups of five rats each. Group 1 served as the control group. Group 2(Scopolamine) received scopolamine (1mg/kg) intra-muscularly. Group 3(Scopolamine + Dennettia tripetala) received scopolamine (1mg/kg) for 1 week + Dennettia tripetala (200mg/kg) Extract orally for 2weeks. Group 4 (extract alone group) received 200mg/kg Dennettia tripetala orally for 2weeks. All the groups received rat chow and water daily. The animals were acclimatized for 2 weeks. There was no significant difference (p<0.05) in swim latency amongst the groups on acquisition days one and three. On day two, swim latency in scopolamine group was significantly increased (p<0.05) compared to control group and significantly decreased (p<0.05) in extract group compared to the scopolamine group. On day five and six of the reversal training days, there was a significant decrease (p<0.05) in swim latency in the extract group compared to control and scopolamine + extract group. Habituation index was decreased (p<0.05) in the extract group compared to control in short term memory, in long term memory, there was a significant decrease in extract group compared to control, scopolamine and scopolamine + extract group. Discrimination index in long term memory in the extract group was increased compared to control and scopolamine groups, this shows a preference of the rats for the novel object, hence better retention, and better memory in the extract group. This indicates that oral administration of Dennettia tripetala improved learning and memory in albino Wistar rats.

Keywords: Dennettia tripetala, Scopolamine, Learning, Memory, Morris.