ABSTRACT
The mushroom known as Reishi (Ganoderma lucidum) has been used as an herbal medicine for tumor treatment and immune system activation. Because its effects on the differentiation of effector T helper cells have not yet been fully understood, we investigated the effects of Reishi and those of its principal ingredient, ß-glucan, on the activation of dendritic cells and the differentiation of Th17 cells. Reishi extracts as well as purified ß-glucan (Curdran) activated DCs and caused them to produce large amounts of IL-23. ß-glucan also enhanced and sustained the transcription of IL-23p19. The MEK-ERK signaling pathway positively regulates IL-23p19 transcription in ß-glucan-stimulated DCs. In a mixed leukocyte reaction, Reishi-stimulated DCs preferentially induced Th17 cells. Furthermore, orally-administrated Reishi increased the percentages of Th17 cells and the transcription levels of antimicrobial peptides. Our results show that Reishi and ß-glucan activate DCs to produce large amounts of IL-23, which induces Th17 differentiation both in vitro and in vivo.
Subject(s)
Dendritic Cells/drug effects , Galactans/pharmacology , Lymphocyte Activation/drug effects , Reishi/chemistry , Th17 Cells/drug effects , beta-Glucans/pharmacology , Animals , Antimicrobial Cationic Peptides/genetics , Dendritic Cells/immunology , Interleukin-12/metabolism , Interleukin-23/metabolism , Interleukin-23 Subunit p19/genetics , MAP Kinase Signaling System , Mice , Mice, Inbred C57BL , Th17 Cells/immunology , Transcription, Genetic/drug effectsABSTRACT
NT-702 (parogrelil hydrochloride, NM-702), 4-bromo-6-[3-(4-chlorophenyl)propoxy]-5-[(pyridin-3-ylmethyl)amino]pyridazin-3(2H)-one hydrochloride, a novel phosphodiesterase (PDE) inhibitor synthesized as a potent vasodilatory and antiplatelet agent, is being developed for the treatment of intermittent claudication (IC) in patients with peripheral arterial disease. We assessed the efficacy of NT-702 in an experimental IC model as compared with cilostazol and additionally investigated the pharmacological property in vitro and ex vivo. NT-702 selectively inhibited PDE3 (IC(50)=0.179 and 0.260 nM for PDE3A and 3B) more potently than cilostazol (IC(50)=231 and 237 nM for PDE3A and 3B) among recombinant human PDE1 to PDE6. NT-702 inhibited in vitro human platelet aggregation induced by various agonists (IC(50)=11 to 67 nM) and phenylephrine-induced rat aortic contraction (IC(50)=24 nM). Corresponding results for cilostazol were 4.1 to 17 microM and 1.0 microM, respectively. NT-702 (3 mg/kg or more) significantly inhibited ex vivo rat platelet aggregation after a single oral dose. For cilostazol, 300 mg/kg was effective. In a rat femoral artery ligation model, NT-702 at 5 and 10 mg/kg repeated oral doses twice a day (BID) for 13 days significantly improved the reduced walking distance while the lowered plantar surface temperature was improved at 2.5 mg/kg and more. Cilostazol also improved the walking distance and surface temperature at 300 mg/kg BID but significant difference was only observed for surface temperature on day 8. These results suggest that NT-702 can be expected to have therapeutic advantage for IC.
