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.