Induction of nitric oxide synthase by saponins of heat-processed ginseng.
Total saponin of heat-processed ginseng (TSHG) stimulated the production of nitric oxide (NO) in interferon-gamma (IFN-gamma)-primed macrophages through the increased expression of inducible nitric oxide synthase (iNOS). However, TSHG by itself had a very weak effect on the NO synthesis without IFN-gamma priming. The saponins of white ginseng inhibited the NO production in lipopolysaccharide (LPS)/IFN-gamma activated macrophages rather than the stimulation of NO production found in IFN-gamma primed macrophages. The NO production by TSHG-stimulated macrophages was inhibited by the NOS inhibitor (N(G)-monomethyl-L-arginine (L-NMMA)) and nuclear factor-kappaB inhibitor (pyrrolidine dithiocarbamate (PDTC)). TSHG showed different serum-dependence from LPS on the activation of IFN-gamma primed macrophages. This property of TSHG may explain the intensified anti-tumor properties of heat-processed ginseng through its immunostimulating activity.
Kim
Ji Yeon
JY
College of Pharmacy, Sookmyung Women's University, Seoul, Korea.
Lee
Hwa Jin
HJ
Kim
Ji Sun
JS
Ryu
Jae-Ha
JH
D000818:Animals; D002460:Cell Line; D004790:Enzyme Induction / Q000187:drug effects; D008070:Lipopolysaccharides; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology; D009569:Nitric Oxide / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D005894:Panax / Q000737:chemistry*; D012503:Saponins / Q000494:pharmacology*
D008070:Lipopolysaccharides; D012503:Saponins; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase