Neuropharmacological studies on Panax ginseng

Panax ginseng root powder is extensively used in the Far East for a wide variety of clinical ailments and to improve general physical and mental wellbeing. It is now also being used in the Occident because of the adaptogenic activity of the plant. The present investigation was conducted to evaluate the neurophamacological profile of activity of P. ginseng (ginseng), since the available data were meagre and often controversial. Ginseng had a complex profile of activity, sometimes difficult to reconcile on the available neurochemical reports on the plant. Thus, it did not appear to affect pentobarbitone sleep induction or spontaneous motor activity but potentiated amphetamine-induced increase in motility. However, ginseng attenuated the other effects of amphetamine, namely, stereotypy and lethality in aggregated mice. The drug exhibited antinociceptive activity and potentiated the antinociceptive effects of both pentazocine and aspirin. Haloperidol catalepsy was potentiated while the behavioural responses of 5-hydroxytryptophan (5-HTP) and L-DOPA were both attenuated. Ginseng had no anticonvulsant action, nor did it potentiate the anticonvulsant effects of phenobarbitone and diazepam. The drug had per se hyperthermic effect and attenuated the hypothermic response of reserpine and 5-HTP induced hyperthermia. Ginseng exhibited significant aggression-inhibiting effect in doses which had no significant effect on spontaneous motility. The results have been discussed on the neurotransmitter function basis of the experimental paradigms and the likely effect of ginseng on these actions.