Immune-mediated parasite clearance in mice infected with Plasmodium berghei following treatment with manzamine A.
ABSTRACT Manzamine A, a sponge-derived alkaloid, was recently shown to possess in vivo antimalarial activity against the blood stages of the rodent malaria parasite Plasmodium berghei. A single intraperitoneal dose of 100 micromol/kg of manzamine A suppressed parasite growth but was followed by parasite recrudescence. Forty percent of mice with recrudescing parasites were able to recover and clear the fulminating parasitaemia. Examination of sera from these mice revealed that infected mice treated with manzamine A had a suppressed IFN-gamma production but an increase in their IL-10 and IgG production. The prolonged survival of infected mice treated with manzamine A and the eventual clearance of recrudescing parasites in some of these mice involve a down-regulation of Thl responses and a switch to antibody dependent-Th2 responses.
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ABSTRACT: Chemical investigation of the Red Sea sponge Dragmacidon coccinea led to the isolation of a new nucleoside, dragmacidoside (1), along with eight known compounds: adenosine (2), inosine (3), deoxycytidine (4), methyl-α-d-glucopyranoside (5), clionasterol (6), stigmasterol (7), campesterol (8) and brassicasterol (9). The compounds were isolated from chloroform and ethyl acetate fractions of the methanolic extract of the sponge, and their structures were established based on various spectroscopic data including MS, 1D and 2D NMR (COSY, HSQC and HMBC). Biological testing revealed that the chloroform fraction possesses significant anti-inflammatory activity in the carrageenan-induced hind paw oedema in rats.Natural product research 05/2014; 28(15):1-8. DOI:10.1080/14786419.2014.915828 · 1.23 Impact Factor
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ABSTRACT: Manzamine A, a member of the manzamine alkaloids, was originally isolated from marine sponges of the genus Haliclona. It was recently shown to have activity against pancreatic cancer cells, but the precise mechanism of action remained unclear. To further our understanding of the mechanism of action of manzamine A, chemogenomic profiling in the yeast S. cerevisiae was performed, suggesting that manzamine A is an uncoupler of vacuolar ATPases. Fluorescence microscopy confirmed this effect on yeast vacuoles, where manzamine A produced a phenotype very similar to that of the established v-ATPase inhibitor bafilomycin A1. In pancreatic cancer cells, 10 µM manzamine A affected vacuolar ATPase activity and significantly increased the level of autophagosome marker LC3-II and p62/SQSTM1 as observed by western blot analysis. Treatment with manzamine A in combination with bafilomycin A1 (inhibitor of autophagosome-lysosome fusion) did not change the levels of LC3-II when compared to cells treated with bafilomycin A1 alone, suggesting that manzamine A is a potential inhibitor of autophagy by preventing autophagosome turnover. As autophagy is essential for pancreatic tumor growth, blocking this pathway with manzamine A suggests a promising strategy for the treatment of pancreatic cancer.Marine Drugs 09/2013; 11(9):3500-16. DOI:10.3390/md11093500 · 3.51 Impact Factor
Article: Anti-malarials from marine sponges[Show abstract] [Hide abstract]
ABSTRACT: Malaria, which is caused by multiplication of the protozoan parasite Plasmodium falciparum in erythrocytes, is a major health problem in many southern countries. There is an urgent need to discover new antimalarials, due to the spread of chloroquinine resistance and the limited number of available drugs. Among marine invertebrates, Porifera (sponges) are potential source of novel bioactive compounds to provide future drugs against malaria, cancer and a range of viral diseases. A number of sponge-derived antimalarials have been discovered during the last decade. The compounds are mostly nitrogen containing ones (proteins, pyridines, tyrosine-based metabolites, alkaloids, indoles and amides) and also non-nitrogenous compounds (terpenes, polyketides and polysaccharides).