Objective: To investigate the effect of withania somnifera extract (WSE) on nicotine mediated reinforcement effect and withdrawal symptoms which attributed for the addiction liabilities of nicotine. Methods: In Swiss albino mice nicotine mediated locomotor sensitization and anxiogenic effects of chronic and acute nicotine treatment respectively was tested per se or in combination with WSE. In addition, nicotine withdrawal induced anxiety-like behavior was also studied. Locomotor sensitization was tested by employing open field test (OFT), while symptoms of anxiety were evaluated by subjecting mice to elevated plus maze (EPM). Results: Daily treatment with nicotine (subcutaneous) for 7 days showed gradual increase in the locomotor activity in OFT as compared to saline group indicating the development of locomotor sensitization. Following 3 days of drug free period, nicotine challenge on day 11 also showed rise in locomotor activity depicting expression of sensitization. WSE pretreatment inhibited the nicotine induced development and expression of locomotor sensitization. WSE+nicotine treated group showed decreased ambulations as compared to per se nicotine group on day 1-7 and day 8 (P<0.05). In EPM, acute nicotine treated mice spend more time in open arms as compared to saline indicating the anxiolytic behavior. WSE pretreatment reversed this anxiolytic effect. Nicotine withdrawal mice showed significant increase in the number of entries in arm and total time spend in closed arm indicating anxiety-like behavior. WSE treatment in nicotine withdrawal mice inhibited the nicotine withdrawal induced increased number of entries and time spend in closed arms. Conclusion: These results indicated that WSE may serve an effective herbal medicine in arresting nicotine mediated reinforcement and withdrawal signs
Differential housing and novelty response: Protection and risk from locomotor sensitization