Structure and anti-dengue virus activity of sulfated polysaccharide from a marine alga
ABSTRACT A sulfated polysaccharide, named fucoidan, from the marine alga Cladosiphon okamuranus is comprised of carbohydrate units containing glucuronic acid and sulfated fucose residues. Here we found this compound potently inhibits dengue virus type 2 (DEN2) infection. Viral infection was inhibited when DEN2, but not other serotypes, was pretreated with fucoidan. A carboxy-reduced fucoidan derivative in which glucuronic acid was converted to glucose did not inhibit viral infection. Elimination of the sulfated function group from fucoidan significantly attenuated the inhibitory activity on DEN2 infection with <1% fucoidan. DEN2 particles bound exclusively to fucoidan, indicating that fucoidan interacts directly with envelope glycoprotein (EGP) on DEN2. Structure-based analysis suggested that Arg323 of DEN2 EGP, which is conformationally proximal to one of the putative heparin binding residues, Lys310, is critical for the interaction with fucoidan. In conclusion, both the sulfated group and glucuronic acid of fucoidan account for the inhibition of DEN2 infection.
SourceAvailable from: Karla Morán-Santibañez[Show abstract] [Hide abstract]
ABSTRACT: Canine distemper virus (CDV) is a morbillivirus related to measles virus that infects dogs and other carnivores. CDV has a significant global impact on animal health; however, there is no current antiviral treatment for CDV infection. In recent years, it has been demonstrated that sulfated polysaccharides exhibit antiviral properties both in vivo and in vitro, despite their low cytotoxicity to host cells. Fucoidan is a sulfated polysaccharide found in the cell wall matrix of brown algae. In this study, we evaluated in vitro anti-CDV activity of fucoidan, which was derived from Cladosiphon okamuranus. Fucoidan actively inhibited CDV replication in Vero cells at a 50 % inhibitory concentration (IC50) of 0.1 lg/ml. The derived selectivity index (SI50) was [20,000. This polysaccharide likely inhibits viral infection by interference in the early steps and by inhibiting CDV-mediated cell fusion. Fucoidan may be useful in development of pharmacological strategies to treat and control CDV infection.10/2014; 25(4). DOI:10.1007/s13337-014-0228-6
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ABSTRACT: The use of indigenous or remote popular knowledge to identify new drugs against diseases or infections is a well-known approach in medicine. The inhabitants of coastal regions are known to prepare algae extracts for the treatment of disorders and ailments such as wounds, fever and stomach aches, as for the prevention of arrhythmia. Recent trends in drug research from natural sources have indicated that marine algae are a promising source of novel biochemically active compounds, especially with antiprotozoal activity. Algae survive in a competitive environment and, therefore, developed defense strategies that have resulted in a significant level of chemical structural diversity in various metabolic pathways. The exploration of these organisms for pharmaceutical and medical purposes has provided important chemical candidates for the discovery of new agents against neglected tropical diseases, stimulating the use of sophisticated physical techniques. This current review describes the main substances biosynthesized by benthic marine algae with activity against Leishmania spp., Trypanosoma cruzi and Trypanosoma brucei; the causative agents of leishmaniasis, Chagas disease and African trypanosomiasis, respectively. Emphasis is given to secondary metabolites and crude extracts prepared from marine algae.Revista Brasileira de Farmacognosia 06/2014; 24(3):265–276. DOI:10.1016/j.bjp.2014.07.001 · 0.80 Impact Factor
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ABSTRACT: The inhibitory activities of microalgal extracts against the expression of three EBV antigens, latent membrane protein (LMP)1, Epstein-Barr nuclear antigen (EBNA)1 and Z Epstein-Barr reactivation activator (ZEBRA) were assessed by immunocytochemistry. The observation that the methanol extracts and their fractions from Ankistrodesmus convolu-tus, Synechococcus elongatus and Spirulina platensis exhibited inhibitory activity against EBV proteins in three Burkitt's lymphoma cell lines at concentrations as low as 20 µg/ml suggests that microalgae could be a potential source of antiviral compounds against EBV. INTRODUCTION Algae are a potential source of yet to be fully ex-plored antiviral compounds. The sulfated polysac-charides from the red algae Porphyridium sp., and the blue green algae Spirulina platensis were found to inhibit the replication of herpes simplex virus-1 and -2 (HSV-1 and HSV-2), varicella zoster virus (VZV) and human immunodeficiency virus type 1 (HIV-1) (Hayashi et al., 1996; Huleihel et al. 2001; Huleihel et al., 2002; Barron et al., 2008). The com-pounds griffithsin and fucoidan isolated from the red seaweed Griffithsia sp. and brown algae, respectively, were found to inhibit the entry of human immu-nodeficiency virus-1 (HIV-1) into host cells (Wang and Ng 2001; Hayashi et al., 2008; Hidari et al., 2008; Micewicz et al., 2010). Despite many antiviral studies on algal compounds, there are few reports about the effects of these compounds against the Epstein-Barr virus (EBV). The EBV is an etiological factor in Burkitt's lymphoma (BL) and other EBV-related malignan-cies, such as nasopharyngeal carcinoma, Hodgkin's disease and infectious mononucleosis (Rickinson and Kieff, 2006; Rezk and Weiss, 2007). During la-tent infection, several of the nine viral latent gene products, such as the Epstein-Barr nuclear antigenArchives of Biological Sciences 10/2014; 66:1009-1024. DOI:10.2298/ABS1403009K · 0.61 Impact Factor