Metabolism of ginsenoside Rg(1) by intestinal bacteria II. Immunological activity of ginsenoside Rg(1) and Rh-1

AIM: To compare the effect of ginsenoside Rg(1) and its metabolite Rh-1 on proinflammatory cytokines and their mRNA expression by THP-1 cells. METHODS : Human peripheral blood mononuclear cells (PBMC) were incubated with Rg(1) and Rh-1 at concentrations of 0.1, 1, 10, and 100 mg/L, and the cell proli feration was measured 24 h after incubation. Radioimmunoassay (RIA) was use d to detect the production of proinflammatory cytokines, TNF alpha, IL-1 al pha, and IL-8. TNF alpha mRNA level was detected by reverse transcription p olymerase chain reaction (RT-PCR) after administration of Rg(1) and Rh-1. R ESULTS: Rg(1) and Rh-1(at concentration of 0.1, 1, 10, 100 mg/L) had no eff ect on PBMC proliferation. Rh-1 1 mg/L could upregulate the productions of TNF (and IL-8 induced by lipopolysaccharides (LPS) 10 mg/L plus phorbol myr istate acetate (PMA) 200 nmol/L, however, Rg(1) showed an inhibitory effect on TNF alpha production induced by LPS 100 mg/L. Rg(1) 1 mg/L and Rh-1 100 mg/L enhanced the production of IL-1 alpha level in THP-1 cells in the pre sence of LPS 10 mg/L. RT-PCR revealed that Rh-1 stimulated TNF alpha mRNA e xpression in suitable stimulatory conditions. CONCLUSION: Rg(1) and Rh-1 ha ve different effects on the production of cytokines produced THP-1 cells st imulated by LPS and PMA.