Effect of Ethanolic Extract of Urtica dioica (Stingy Nettle) on Motor Coordination, Fear and Anxiety in Swiss White Mice

Introduction: Natural products, like plant extracts either as pure compounds or as standardized extracts, provide unlimited opportunities for new drug discoveries because of their unmatched availability of chemical diversity. Scientific evidence from clinical trials to authenticate the neurophysiological importance of this herb is scanty. Hence, the need for further research to ascertain its efficacy and safety since unregulated or inappropriate use of traditional medicines and practices can have negative or dangerous effects. Objective: This study was carried out to investigate the effect of administration of Urtica dioica on motor coordination, fear and anxiety behavior. Methods: A total of 30 apparently healthy Swiss male albino mice weighing 20-25g were used in the study. After the 14 days of acclimatization, the mice were randomly separated into three (3) groups of ten (10) animals each and were housed in separate cages. The mice in group one (1) serves as the control for the research work and were given water and normal animal feed. Group two (2) of the mice were given feed mixed 400mg/kg of the extract while group three (3) mice were given feed mixed with 800 mg/kg of the extract. The Walking Beam, Light and Dark Transition Box maze were employed for the evaluation of related behaviors while the extracts were mixed with the animals’ feed. So, the extracts were administered to the mice orally. The extracts were administered for a duration of 28days (4 weeks). Results: On line crossing, the control and the low dose group show great similarity and hence, no significance difference between both. However, the high dose group showed a significant reduction in the frequency of line crossing compared to control and low dose group (P≤0.001). Urtica dioica also induced a reduction in the frequency of turns in the Beam walking apparatus at a P≤0.05. High dose showed a significant decrease in the frequency of transition to about 3±0.32 at P≤0.05. Conclusion: These results indicate that repeated administration of Urtica dioica enhances motor function, by reducing oxidative stress and enhancing neuron function, which are critical for movement control. On fear/anxiety study, the animals treated with high dose of the extract significantly spent less time in the light chamber indicating anxiety/fear, thereby showing that the extract of Urtica dioica at high dose can have inhibitory effect on the treated mice whereas at low dose, the effect can be excitatory.