EFFECTS OF PIPE TOBACCO EXTRACT ON LOCOMOTOR-ACTIVITY AND BRAIN ACETYLCHOLINESTERASE LEVEL IN MICE

The effects of pipe tobacco extract on locomotory behaviour and brain acetylcholinesterase (AChE) activity were investigated in groups of male Swiss-Webster albino mice injected subcutaneously with 5, 10 or 20 mg/kg body weight in aliquotes of 0.1 mi normal saline. The behavioural indices namely numbers of squares crossed, squats as well as durations of locomotion and immobility were observed at 15, 30, 60 and 120 min post injection (PI). The mice were also allowed to cling to a wire and the time taken to fall down (clinging time) was used as an indication of myorelaxation. The brain AChE level was estimated at 30 and 120 min PI. A significant, dose-dependent suppressive effect of the extract was observed on all tested behavioural indices. The brain AChE activity was significantly elevated at lower doses, whereas it was initially inhibited with the high dose of 20 mg/kg body weight before returning to baseline. There seems to be some sort of correlation between the behavioural indices tested and brain AChE activity due to tobacco extract treatment.