Korean ginseng extract attenuates reserpine-induced orofacial dyskinesia and improves cognitive dysfunction in rats.

Reserpine-induced orofacial dyskinesia in rats is an animal model of tardive dyskinesia that has been linked with free radical generation and oxidative stress. In the present study, reserpine (1 mg kg(-1), s.c.) was given to rats on days 1, 3 and 5 to induce orofacial dyskinesia, which is characterised by increased vacuous chewing and tongue protrusion. Sub-chronic treatment with Korean ginseng extract from day 1 to day 21 along with reserpine on days 1, 3 and 5 significantly and dose-dependently (100 and 200 mg kg(-1)) reduced reserpine-induced vacuous chewing movements and tongue protrusions. Reserpine-treated animals also showed poor retention of memory in the elevated plus maze paradigm. The sub-chronic Korean ginseng extract administration significantly reversed reserpine-induced retention deficits. Biochemical analysis revealed that repeated reserpine treatment significantly induced lipid peroxidation and decreased glutathione (GSH) levels in the brains of rats. Reserpine-treated rats also showed decreased levels of antioxidant defence enzymes, superoxide dismutase (SOD), and catalase. Sub-chronic administration of Korean ginseng extract dose-dependently and significantly reduced lipid peroxidation and restored decreased GSH levels by repeated reserpine treatment. It also significantly reversed the reserpine-induced decrease in brain SOD and catalase levels in rats. The present study concludes that oxidative stress might play an important role in reserpine-induced abnormal oral movements, and Korean ginseng extract could be useful in the treatment of drug-induced dyskinesia and amnesia.

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

The previous study showed that chronic treatment with Withania somnifera extract (WS) inhibited haloperidol-induced catalepsy. It is suggested that caffeine and WS may be useful adjuvants in pharmacotherapy of Parkinson's disease. There are no studies on the effect of haloperidol on mice withdrawn from caffeine or W. somnifera. We therefore studied the effect of a single administration of standardised WS containing 5.1% total withanolides (WS, 30 or 100 mg kg(-1) i.p.) and/or caffeine (3 mg kg(-1) i.p.) and withdrawal from 6 days treatment with WS and/or caffeine, on haloperidol-induced catalepsy in albino mice. Single administration of both WS and caffeine, used either alone or in combination, significantly inhibited catalepsy. Mice withdrawn from caffeine significantly inhibited haloperidol-induced catalepsy, but mice withdrawn from WS showed increased catalepsy. The study indicated that withdrawal from WS does not retain anticataleptic activity, and caffeine but not WS may be a good adjuvant in pharmacotherapy of Parkinson's disease.