Caffeine withdrawal retains anticataleptic activity but Withania somnifera withdrawal potentiates haloperidol-induced catalepsy in mice

Both caffeine and Withania somnifera (WS) are known to inhibit haloperidol-induced catalepsy and it is suggested that caffeine and WS may be used as adjuvant in pharmacotherapy of Parkinson's disease [1]. There are no studies on effect of haloperidol on mice withdrawn from caffeine or WS. The objective of the study was to evaluate the effect of withdrawal from 6 days treatment with WS extract (WS, 30 or 100mg/kg i.p.) and caffeine (3mg/kg i.p.) given either alone or in combination, on haloperidol-induced catalepsy in albino mice. In acute study, groups of mice (n=5) received vehicle or WS (30 or 100mg/kg) with or without caffeine 30min before haloperidol (1mg/kg i.p.) and catalepsy was measured for 180min using the Bar test. In another set of experiments, the mice were treated with vehicle or WS (30 or 100mg/kg) with or without caffeine for 6 days. After 24h the mice received haloperidol and the catalepsy was evaluated till 180min. In the acute study, both WS and caffeine, used alone and in combination significantly (P<0.01) inhibited catalepsy, whereas, in the subchronic study, only caffeine treated mice showed significant inhibition of catalepsy (P<0.01). The intensity of catalepsy increased in mice withdrawn from WS and WS reduced anticataleptic effect of caffeine. The study indicated that continued treatment with WS is necessary for anticataleptic activity and WS may not be a good adjuvant in pharmacotherapy of Parkinson's disease.

References: 1. Nair, V., Arjuman, A. (2007) Phytother Res. 22:243–246. 2. Ferre, S., Guix, T. (1990) Pharmacol Biochem Behav. 35:753–757.