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The immunomodulator ginsan induces resistance to experimental sepsis by inhibiting Toll-like receptor mediated inflammatory signals Eur. J. Immunol. 2006.

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Presentation on theme: "The immunomodulator ginsan induces resistance to experimental sepsis by inhibiting Toll-like receptor mediated inflammatory signals Eur. J. Immunol. 2006."— Presentation transcript:

1 The immunomodulator ginsan induces resistance to experimental sepsis by inhibiting Toll-like receptor mediated inflammatory signals Eur. J. Immunol. 2006. 36: 37–45 Ji-Yeon Ahn1,2, In-Soo Choi3, Ji-Young Shim1, Eun-Kyung Yun1, Yeon-Sook Yun1, Gajin Jeong2 and Jie-Young Song1

2 Ginseng contains multiple phytochemicals: Ginseng contains multiple phytochemicals: Two major classes: Two major classes: -Ginsenosides -Ginsenosides -Polysaccharides -Polysaccharides Organic extract contains mostly ginsenosides Organic extract contains mostly ginsenosides Aqueous extract contains less ginsenosides and more polysaccharidess Aqueous extract contains less ginsenosides and more polysaccharidess

3 What are ginsenosides? What are ginsenosides? What are polysaccharides? What are polysaccharides?

4 Basic structure of ginsenosides: Basic structure of ginsenosides: Glycoside = aglycone + sugar chain Glycoside = aglycone + sugar chain (glucose, maltose,fructose, saccharose attached at (glucose, maltose,fructose, saccharose attached at C3, C6 and C20) C3, C6 and C20) 3 major groups depending on their aglycones: 3 major groups depending on their aglycones: Group I - protopanaxadiol type Group I - protopanaxadiol type Group II - protopanaxtriol type Group II - protopanaxtriol type These are C-27 sterols (with a dammarane skeleton aglycone) Group III - oleanolic acid-type: C-30 triterpenoids. Group III - oleanolic acid-type: C-30 triterpenoids.

5 Water-soluble and acidic polysaccharides Water-soluble and acidic polysaccharides Ginsan, acidic polysaccharide with a M.W. of 150,000 Ginsan, acidic polysaccharide with a M.W. of 150,000 Cold- fX: poly-furanosyl-pyranosyl-saccharides Cold- fX: poly-furanosyl-pyranosyl-saccharides

6 GinsenosidesPS GinsenosidesPS -immunomodulatory + + + TNFTNF IL-1, IL-2, TNF -immunomodulatory + + + TNFTNF IL-1, IL-2, TNF -anti-inflammatory ? + -anti-inflammatory ? + -radioprotective + -radioprotective + -antioxidative + + -antioxidative + + reduce ROS and increase anti-oxidant levels reduce ROS and increase anti-oxidant levels -anti-tumor/ metastasis + + -anti-tumor/ metastasis + + -angiogenesis +/- ? -angiogenesis +/- ? Pharmacological activities

7 Sepesis: Microbial infection in blood---  excessive inflammatory response--  systemic organ failure Microbial infection in blood---  excessive inflammatory response--  systemic organ failure proinflammatory cytokines as mediators proinflammatory cytokines as mediators TNF, IL-1, IL-6 TNF, IL-1, IL-6 IL-12 + IL-18 –are important because they produce  IFN-gamma IL-12 + IL-18 –are important because they produce  IFN-gamma IFN + TNF- --  synergistic effects in LPS effect IFN + TNF- --  synergistic effects in LPS effect Gram-ve bacteria E. Coli--  LPS from cell wall: mediating agent Gram-ve bacteria E. Coli--  LPS from cell wall: mediating agent Gram +ve bacteria: S. aureus-  lipoteichoic acid, peptidoglycan from cell wall Gram +ve bacteria: S. aureus-  lipoteichoic acid, peptidoglycan from cell wall

8 Toll like-receptors: - Single membrane-spanning non-catalytic receptors, Innate immune system, -recognize threat, recognize molecules shared by pathogens but different from host molecules Function as dimers Need co-receptors Adaptor proteins ligands e.g. lipo-peptides, glycolipids.lipoteichoic acids,LPS, HSP70, zymosan, single or double-stranded RNA, fibrinogen, small xenobiotics Require kinases activation for signaling and modulation of gene expression

9 Rationale: Reducing a particular cytokine not effective in sepsis Reducing a particular cytokine not effective in sepsis Ginsan as effective Biological Response Modifier Ginsan as effective Biological Response Modifier Stimulate NK & T cells, induce cytokines, induce tumoricidal & antimicrobial activity in macrophages. Stimulate NK & T cells, induce cytokines, induce tumoricidal & antimicrobial activity in macrophages. Stimulate NO production in macrophages-in vitro  antisepticemic activity… by extension! Stimulate NO production in macrophages-in vitro  antisepticemic activity… by extension! But these mediators also enhance septic symptoms! But these mediators also enhance septic symptoms! Question: how does ginseng modulate plasma cytokine profile in septic animals and whether there are other mechanisms that protect animals from sepsis Question: how does ginseng modulate plasma cytokine profile in septic animals and whether there are other mechanisms that protect animals from sepsis

10 Results 1. Ginsan (IV) 24 hr pretreatment protected mice from acute sepsis (3 models) - S. aureus induced lethality (10% to 88% survival) - S. aureus induced lethality (10% to 88% survival) -E.coli induced lethality -E.coli induced lethality -CLP induced lethality -CLP induced lethality 25 ug/kg effective, quite low dose 2. Ginsan enhanced clearance of bacteria from blood, spleen and kidney

11 3. Ginsan increased bactericidal activity of peritoneal- macrophages. Normal mice  isolated PM-  incubated with ginsan in vitro 3 hr -  partially killed labeled bacteria--  analysed by FACS for uptake of bacteria by macrophages -  index of phagocytosis. Normal mice  isolated PM-  incubated with ginsan in vitro 3 hr -  partially killed labeled bacteria--  analysed by FACS for uptake of bacteria by macrophages -  index of phagocytosis. But PM isolated from 24 hr pretreatment with ginsan with or without infection showed samall if any increase of phagocytosis. Major weakness of lack of in vivo effect! But PM isolated from 24 hr pretreatment with ginsan with or without infection showed samall if any increase of phagocytosis. Major weakness of lack of in vivo effect! May be PM is not the major site of bacterial clearance May be PM is not the major site of bacterial clearance

12 Ginsan enhances phagocytosis in S. aureus-infected macrophages. (A) Phagocytic activity was evaluated in PM isolated from intact mice and incubated with ginsan for 3 h. (B) PM were obtained from non-treated (dotted line) and S. aureus-infected mice treated with or without ginsan (25 lg/kg, bold and solid lines, respectively), and were then stimulated with heat-killed S. aureus for 30 min at 37C.

13 4. Ginsan attenuates pro- and anti-inflammatory cytokine production in S. aureus-infected mice. Serum cytokine levels were determined at 0, 2, 4, 8, 11, and 24 h after the challenge with 1.5 108 CFU S. aureus (No effect on Th2 cytokines IL-2 and IL-4 Ginsan also reduced anti-inflammatory IL-10 Note: -Cytokines are not detectable in control animals and ginsan did not stimulate any! -Not consistent with hypothesis.

14 5. Ginsan suppresses the expression of TLR and theadaptor MyD88 molecule in PM activated by S. aureus. In vitro only PM isolated and treated with ginsan (0.1 ug/ml) for 6 hrs. Cells were washed, treated heat-killed S.aureus for 6 hrs. Measured by RT-PCR for RNA transcripts for TLR2, 4, 9 and MyD88

15 6. Ginsan inhibits S. aureus-induced MAPK and NF-kB activation in PM. PM were pretreated with ginsan (0.1 ug/mL) for 6 h and were subsequently treated with heat-killed S. aureus for 40 min. (A)MAPK phosphorylation was detected using Western blot analysis with antibodies specific for JNK 1/2, p38, and ERK1/2. (B) The concentration of NF-kB in nuclear extracts was determined using electrophoretic mobility shift assay. S.aureus stimulate phosphorylation of JUN1/2 and MAPK in PM and suppressed by 0.1 ug/ml ginsan (detected by Western Blot using antibodies for JNK1/2, P38, and ERK1/2 ) D-R study to look for correlation?

16 Points for discussion 1. Low effective dose: 25 ug/kg Given by IV! Given by IV! 2. Explanation of changes in pro-inflammatory and anti-inflammatory cytokines not very convincing. “ ginsan eventually restore the balance between the proinflammatory and anti- inflammatory arms of the cytokine network in sepsis. Different time of infection is critical to the profiles but they did not show that. (No effect on Th2 cytokines IL-2 and IL-4 Ginsan also reduced anti-inflammatory IL-10 Note: -Cytokines are not detectable in control animals and ginsan did not stimulate any! -Not consistent with hypothesis.

17 Back to the rationale: Back to the rationale: Stimulate NO production in macrophages-in vitro  antisepticemic activity… by extension! Stimulate NO production in macrophages-in vitro  antisepticemic activity… by extension! But these mediators also enhance septic symptoms! But these mediators also enhance septic symptoms! Question: how does ginseng modulate plasma cytokine profile in septic animals and whether there are other mechanisms that protect animals from sepsis Question: how does ginseng modulate plasma cytokine profile in septic animals and whether there are other mechanisms that protect animals from sepsis Discussion: Discussion: Unpublished data from author: Unpublished data from author: Ginsan stimulated TLR in normal macrophages (not shown in present study) but down regulate them in septic macrophages….suggest ginsan could induce tolerance against septic challenges. Ginsan stimulated TLR in normal macrophages (not shown in present study) but down regulate them in septic macrophages….suggest ginsan could induce tolerance against septic challenges. Other: sublethal dose LPS pretreatment protect subsequent LPS induced lethality by reducing proinflammatory cytokines Other: sublethal dose LPS pretreatment protect subsequent LPS induced lethality by reducing proinflammatory cytokines Major weakness; not show effect of ginsan in present study to test the hypothesis Major weakness; not show effect of ginsan in present study to test the hypothesis

18 Tripterygium Wifordii Extracts [EA & PS] on LPS- induced NO production in macrophages Nitrite production (µM) µg / ml Nitrite production (µM) µg / ml EA also inhibited COX-2 m-RNA expression and PGE2 production Others showed inhibition of cytokines production


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