title: Antiadhesive activity of polysaccharide-rich fractions from Lithothamnion muelleri.
abstract: Red seaweeds are known sources of polysaccharides, some of which possess antiadhesive properties by inhibition of P-selectin-mediated leukocyte rolling. We here report the chemical composition and the antiadhesive activity of polysaccharide-rich fractions from the red alga Lithothamnion muelleri (Hapalidiaceae). The crude fractions enriched in polysaccharides B1 and B2 were obtained, respectively, by sequential extraction with 1% and 2% (w/v) Na2CO3 solution, at 60 degrees C. Fractionation of B1 and B2 by gel permeation chromatography afforded three polysaccharide-rich fractions each, whose compositions were characterized by chemical analysis (total contents of carbohydrates, proteins, sulfate, and uronic acid); their molecular weights were estimated by high-performance gel permeation chromatography (HPGPC). The antiadhesive activity of B1-derived fractions was assayed by visualizing lipopolysaccharides-induced leukocyte rolling under intravital miscroscopy. The intravenous injection of fractions B1a and B1b in mice, at the dose of 10 mg/kg body weight, reduced leukocyte rolling by approximately 90%; fucoidan (10 mg/kg body weight) employed as positive control induced a similar response. Therefore, the sulfated polysaccharides of L. muelleri deserve further evaluation as potential templates for the development of new anti-inflammatory agents.
authors.affiliation: Department of Pharmaceutical Products, Faculty of Pharmacy, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Cristiane M
authors.initials: CM
authors.lastname: Soares
authors.forename: Bruna G
authors.initials: BG
authors.lastname: Malagoli
authors.forename: Gustavo B
authors.initials: GB
authors.lastname: Menezes
authors.forename: Vanessa
authors.initials: V
authors.lastname: Pinho
authors.forename: Danielle G
authors.initials: DG
authors.lastname: Souza
authors.forename: Mauro M
authors.initials: MM
authors.lastname: Teixeira
authors.forename: Fernão C
authors.initials: FC
authors.lastname: Braga
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011134:Polysaccharides / Q000494:pharmacology*; D000461:Rhodophyta / Q000737:chemistry*
chemical_list: D011134:Polysaccharides