Abstract

The effects of tobacco use on health are well known, and are documented in reliable scientific reports. The aim of this study is to investigate some of the effects of both ethanolic and smoke tobacco on the hippocampus and behaviour of mice. The presumably healthy 32 mice were used for this study, the animals were randomly divided into four groups, A, B, C and D, of eight animals each. Group A were given 10.72 mg /kg body weight of the extract in 0.2 ml of normal saline, group B 10.72 mg /kg body weight of the tobacco smoke exposure for 3 min, group C were given 0.2 ml of normal saline and group D were exposed to the smoke of equal weight (0.02 g) of cotton wool for 3 min for 21 experimental days. The mice were sacrificed by cervical dislocation and the brains excised, blotted, weighed and fixed in formol calcium for neurohistological analysis, using Haematoxylin and Eosin and Cresyl Fast Violet. There were significant decreases in the body weight, brain weight and relative brain weight, pyramidal and granular cell layers and neurological scores between nicotine administered groups compared to the control group (p<0.05). The results suggested that consumption of Nicotiana tabacum leaves, either through smoking or chewing may lead to some level of neurohistoarchitectural alterations, brain weight changes and neurobehavioural disruption or also help in reduction in weight.

Key words: Nicotiana tabacum, hippocampus, nicotine, neurohistoarchitecture, neurobehaviour.