Long-term Consumption of Kola-nut (Cola nitida) Diet Does Not Increase Anxiety Related Behaviour in Mice

Following long-term consumption of kola nut (Cola nitida) diet, anxiety related behaviour were studied in 16 Swiss white mice (18-28g body weight). The open field (OF) test, elevated plus maze EPM) and the light/light transition box (LD) tests were used. Swiss white mice were fed either control diet (rodent chow; n=8) or kola nut diet (50% w/w kola-nut diet; n=8) for 28 days. All animals were allowed free access to clean drinking water. Results showed that the frequency of rearing in the kola nut diet group was lower (p< 0.05) compared to control. The non-exploratory behaviours like grooming and genital licking were also lower in the test group compared to control (p<0.001, 0.05 respectively). In the EPM test, the duration in the open arm in the kola diet group was higher compared to control (p< 0.01). The duration of grooming in the test group was however higher in the closed arm compared with control (p< 0.01). The frequency of downward dips only correlated positively with the duration in the open arm in the control [r (16) = 0.855; p< 0.01]. The kola fed animals spent more time in the light region of the LD test (p< 0.01) rearing and walling (p<0.05), and spent less time in the dark region when compared with their control. In conclusion, long-term consumption of kola nut diet decreased anxiety–related behaviour in the mice.