The stem bark of Kalopanax pictus NAKAI (Araliaceae), a deciduous tree growing in East Asian countries, 1) has been traditionally used for the treatment of rheumatoidal arthritis, neurotic pain and diabetes mellitus. The constituents such as hederagenin glycosides, syringin, liriodendrin and coniferylaldehyde glucosides have been isolated from this plant. 2,3)Our previous reports on anti-diabetic, 4) cytotoxic 5) and antifungal assays 6) have shown that the active components should be hederagenin monodesmosides. In addition, we also demonstrated that hederagenin bisdesmoside could be converted to its monodesmosides and its serial saponins by human intestinal bacteria and that these metabolites showed anti-diabetic activity. 7) Although several pharmacological effects of hederagenin monodesmosides as well as its serial saponins are reported, there have been very few reports on the effects of hederagenin monodesmosides on the antiinflammatory role. During inflammatory processes, large amounts of pro-inflammatory mediators, nitric oxide (NO) and prostaglandin E 2 (PGE 2 ) are generated by the inducible isoforms of NO synthase (iNOS) and cyclooxygenase (COX-2), respectively. 8) In mammailian cells, three isoforms of NOS, types I, II, and III, have been identified on the basis of physical and biochemical characteristics of the purified enzymes. Type I (neuronal NOS, nNOS) and type III (endothelial NOS, eNOS) have been classified as constitutive NOS (cNOS) because these are continuously present in the cells, whereas type II, an iNOS, is expressed only after exposure to specific stimulants such as cytokines, bacterial endotoxic lipopolysaccharide (LPS), and calcium ionophore in some cells.9-11) Cyclooxygenase (COX) is the enzyme which converts arachidonic acid to prostaglandins (PGs). Like NOS, COX has been found in two isoforms, and COX-2 is an inducible form responsible for the production of large amounts of proinflammatory PGs at the inflammatory site. 12)Our previous investigation concerning kalopanaxsaponin A demonstrated their anti-inflammatory syndromes in the rat induced by Freund's complete adjuvant reagent.13) Thus, as a prelude to reveal the underlying mechanisms for the anti-inflammatory effect of kalopanaxsaponin A, we evaluated and compared the effects of various hederagenin monodesmosides ( Fig. 1) isolated from stem bark of Kalopanax pictus NAKAI on LPS-induced NO, PGE 2 and tumor necrosis factora (TNF-a) release by the macrophage cell line RAW 264.7 in the present study. Moreover, we also examined if these hederagenin monodesmosides reduced iNOS and COX-2 enzyme expression. Wonju 220-702, Korea. Received October 30, 2001; accepted January 16, 2002 In the present study, effects of various hederagenin monodesmosides isolated from the stem bark of Kalopanax pictus NAKAI, such as hederagenin, d d-hederin, kalopanaxsaponin A, kalopanaxsaponin I, and sapindoside C, have been evaluated on lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E 2 (PGE 2 ) and tumor necrosis factor-a a (TNF-a a...
In the present study, liriodendrin isolated by activity-guided fractionation from the ethyl acetate (EtOAc) extracts of the stem bark of Acanthopanax senticosus, was evaluated for anti-inflammatory and antinociceptive activities. Liriodendrin (5, 10 mg/kg/day, p. o.) significantly inhibited the increase of vascular permeability induced by acetic acid in mice and reduced an acute paw edema induced by carrageenan in rats. When the analgesic activity was measured by the acetic acid-induced writhing test and hot plate test, liriodendrin showed a dose-dependent inhibition in animal models. In addition, syringaresinol, the hydrolysate of liriodendrin, more potently inhibited the LPS-induced production of NO, PGE 2 and TNF-alpha production of macrophages than liriodendrin. Consistent with these observations, the expression level of iNOS and COX-2 enzyme was decreased by syringaresinol in a concentration-dependent manner. These results suggest that the anti-inflammatory and antinociceptive effects of liriodendrin after oral administration were attributable to the in vivo transformation to syringaresinol, which may function as the active constituent.
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