Protection of Staphylococcus aureus-infected septic mice by suppression of early acute inflammation and enhanced antimicrobial activity by ginsan.
Ginsan, an acidic polysaccharide prepared from Panax ginseng, demonstrated multiple immunomodulatory effects in previous studies. This study was conducted to elucidate the antiseptic mechanism induced by ginsan in mice infected with Staphylococcus aureus. When mice were treated with ginsan before the bacterial challenge with S. aureus, they were highly protected from sepsis-induced death. The numbers of S. aureus recovered from ginsan-treated mice were considerably lower than those recovered from nontreated mice. The in vivo depletion of monocytes/macrophages caused more S. aureus to be recovered from the bacteria-infected mice. Nevertheless, mice treated with both etoposide and ginsan were able to maintain an antibacterial activity. In addition, the phagocytic activity of ginsan-treated macrophage against S. aureus was considerably enhanced. The synthesis of inflammatory cytokines, such as tumor necrosis factor-alpha interleukin (IL)-1beta, IL-6, IFN-gamma, IL-12, IL-18 and interferon gamma, was significantly downregulated at the early phase of sepsis in mice that were treated with ginsan before the bacterial challenge. Expression of Toll-like receptors (TLRs), including TLR2, TLR4, and TLR9, as well as the adaptor molecule MyD88, was considerably reduced in peritoneal macrophages that were treated with ginsan before a subsequent contact with S. aureus. These data indicated that ginsan protected mice from S. aureus-induced sepsis through the suppression of acute inflammatory responses at an early phase and the enhancement of antimicrobial activities at subsequent phases of infection.
Ahn
Ji-Yeon
JY
Laboratory of Immunology, Korea Institute of Radiological & Medical Sciences, Seoul, Korea.
Song
Jie-Young
JY
Yun
Yeon-Sook
YS
Jeong
Gajin
G
Choi
In-Soo
IS
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D015536:Down-Regulation; D006801:Humans; D007249:Inflammation / Q000188:drug therapy / Q000276:immunology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D005894:Panax / Q000737:chemistry; D010587:Phagocytosis; D008517:Phytotherapy; D010936:Plant Extracts / Q000276:immunology / Q000494:pharmacology; D011134:Polysaccharides / Q000276:immunology / Q000494:pharmacology; D018805:Sepsis / Q000188:drug therapy* / Q000276:immunology / Q000382:microbiology / Q000401:mortality; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000276:immunology / Q000382:microbiology / Q000401:mortality; D013211:Staphylococcus aureus / Q000187:drug effects*
D000276:Adjuvants, Immunologic; D000900:Anti-Bacterial Agents; D016207:Cytokines; D010936:Plant Extracts; D011134:Polysaccharides; C111520:ginsan