Effects of beans (Vigna unguiculata) consumption on anxiety and fear in Swiss white mice

Abstract

Beans, the staple diet of Nigerians contains serotonin and its precursor, 5-HTP in significant amount. It was therefore the aim of this study to find out whether long term consumption of cooked beans (Vigna unguiculata) diet has effects on some neurobehavioral parameters notably; anxiety and fear. Thirty (30) adult Swiss white mice (18-30g body weight), were used for the study. The elevated plus maze (EPM) was employed for the evaluation of anxiety and fear related behaviour. Mice in the control group (n=10) were fed normal rodent chow while mice in the cooked beans (n=10) and serotonin precursor fed group (n=10) were fed cooked beans diet (50%w/w) and (0.2mg/50g w/w) serotonin precursor diet for 4 weeks. All animals were allowed free access to clean drinking water. Daily food intake, water intake and body weight change were measured. In EPM, the duration in the open arm and centre square duration was significantly higher (p<0.001 and p<0.05 respectively) in the test group, while the frequency of grooming and defecation was lower in the test group (p<0.05 and p<0.001 respectively). Signifying a decrease in anxiety and fear, this was also observed in their head dips. There was also a significant (p<0.05) decrease in the duration of grooming in the elevated plus maze test for the cooked beans and serotonin precursor fed group when compared to the control. Thus, chronic consumption of cooked beans diet may decrease anxiety and fear related behavior.

Keywords: Cooked beans, Mood, Reflex, Anxiety, Fear, Serotonin, Plus Maze and Mice