IC50 Value & Target: Others: Ginsenoside Rg3 is one of the main active components responsible for ginseng actions. Ginsenoside Rg3 was the most potent fraction of ginseng saponins and a more marked inhibitor of IBa2+ than is ginsenoside Rf. ginsenoside Rg3 as a new active component is well consistent with results of the previous study which examined the effects of ginsenosides on neuroprotection in cultured cortical cells (Kim et al., 1998). They found ginsenoside Rg3 to be one of the major active components for inhibiting glutamate-induced neuronal cell death and Ca2+ influx through glutamate receptors [1]. The effect of paclitaxel orally co-administered with 20(s)-ginsenoside Rg3 against human tumour MCF-7 xenografts in nude mice was also evaluated. Paclitaxel (20 mg/kg) co-administered with 20(s)-ginsenoside Rg3 (10 mg/kg) exhibited an effective anti-tumour activity with the relative tumor growth rate (T/C) values of 39.36% (p <0.05). The results showed that 20(s)-ginsenoside Rg3 enhanced the oral bioavailability of paclitaxel in rats and improved the anti-tumour activity in nude mice, indicating that oral co-administration of paclitaxel with 20(s)-ginsenoside Rg3 could provide an effective strategy in addition to the established i.v. route [2].