Untitled

Abstract

A galactomannan (GMPOLY) isolated from lichen Ramalina celastri was complexed with vanadyl ion (IV;VO) forming the complex GMPOLY-VO. Both GMPOLY and GMPOLY-VO diminished the superoxide anion production by macrophages triggered with PMA, the complex giving rise to this effect at concentrations 100 times lower than GMPOLY. Macrophages treated with GMPOLY enhanced the nitric oxide production (40%), this effect not being observed when interferon-gamma (IFN-gamma) or IFN-gamma plus lipopolysaccharide (LPS) were present. No effect on nitric oxide production was observed by treatment of macrophage with GMPOLY-VO. Both GMPOLY and GMPOLY-VO exhibited leishmanicidal effects on the amastigote form of Leishmania amazonesis, but only GMPOLY-VO inhibited the growth of promastigote form.

Acid heteropolysaccharides with potent antileishmanial effects

“…2). Noleto [17] suggested that the increase in 40% on NO production was responsible for the leishmanicidal effects of GMPOLY. Ghosh [6] showed that the production of NO from macrophages treated with the antileishmanial drugs in the current use is necessary to their leishmanicidal activity.…”

“…The polysaccharide activity on intracellular amastigotes was measured as described by [17]. Peritoneal macrophages were plated in 24-well plates (5 × 10 5 cells/well) and left to adhere for 2 h. Non-adherent cells were removed and macrophages were infected with promastigotes (5 parasites per macrophage), followed by 12 h of incubation at 34 • C in the presence of 5% CO 2 .…”

“…In macrophages infected with Leishmania, this activation may culminate in killing the intracellular parasites. Accordingly, galactomannan (GMPOLY) isolated from lichen Ramalina celastri and an arabinomannose (Z-100) extracted from Mycobacterium tuberculosis have been classified as macrophage activators exhibiting leishmanicidal effect in vitro [17,18]. The use of the chitosan polymer as a vehicle in the preparations of meglumine antimoniate or doxorubicin for experimental leishmaniasis treatment has been investigated and promising results has been observed [19,20].…”

“…Considering the need to find alternative treatments for human leishmaniasis, the immunomodulatory effects exhibited by ARAGAL [12,16], the absence of study with sulphated heterorhamnan (Go3), iota-/nu-carrageenan fractions (G3d and EHW-I) on macrophages and Leishmania, and the leishmanicidal activity already observed in some polysaccharides [17,[26][27][28], this study investigated the effect of different polysaccharides on macrophage activation and on viability of amastigote forms of Leishmania (L.) amazonensis in vitro.…”

Complexation of vanadium(V) oxyanions with hexopyranose- and mannopyranoseuronic acid-containing polysaccharides: stereochemical considerations

“…8 Complexation occurred with Me 6Me-a-Galp and Me 2,6-Me 2 -a-Galp, which have 3,4-cis-diols, but not with Me 3Me-b-Galp, which contains free 4,6-OH groups. 8 As an aqueous solution of a complex of oxovanadium(IV) with a lichen galactomannan gave rise to activities related to peritoneal macrophages and leishmanicidal activity, 9 we now examine the formation of esters of selected polysaccharides with NaVO 3 without accompanying buffer, which could be biologically prejudicial. Tested were galactopyranose, mannopyranose-, and mannopyranoseuronic acid-containing polysaccharides, taking into account a surprising preliminary experiment, in which 51 V NMR spectroscopy showed an almost complete lack of complexation with methyl b-mannopyranoside (Table 1).…”