Effect of Vietnamese Ginseng on the phagocytosis in vitro and in vivo

The effects of Vietnamese ginseng crude extract (VG extract), total saponin (VG saponin) and its major saponin component, majonoside-R2, on phagocytosis were examined in mice by bactericidal and carbon clearance tests. Escherichia coli (E. coli) ATCC 25922 was used to induce the acute toxicity and activate the phagocytic activity of phagocytes in both in vitro and in vivo bactericidal tests. Pretreatment with VG extract (500 mg/kg, oral administration, p.o.) and majonoside-R2 (50 mg/kg, intraperitoneal administration, i.p.) protected the animals from the acute toxicity of E. coli ATCC 25922 and significantly increased the phagocytic index in both in vitro and in vivo bactericidal tests. Moreover, VG extract (100-500 mg/kg, p.o.), VG saponin (25 mg/kg, i.p.) and majonoside-R2 (10 mg/kg, i.p.), as well as zymosan A, a non-specific phagocytic stimulant, also increased the phagocytic index evaluated by the carbon clearance test. These results indicate that Vietnamese ginseng enhances the phagocytic activity of phagocytes, and suggest that majonoside-R2 plays an important role in this effect.