title: Evaluation of sulfated polysaccharides from the brown seaweed Dictyopteris justii as antioxidant agents and as inhibitors of the formation of calcium oxalate crystals.
abstract: Oxalate crystals and other types of crystals are the cause of urolithiasis, and these are related to oxidative stress. The search for new compounds with antioxidant qualities and inhibitors of these crystal formations is therefore necessary. In this study, we extracted four sulfated polysaccharides, a fucoglucoxyloglucuronan (DJ-0.3v), a heterofucan (DJ-0.4v), and two glucans (DJ-0.5v and DJ-1.2v), from the marine alga Dictyopteris justii. The presence of sulfated polysaccharides was confirmed by chemical analysis and FT-IR. All the sulfated polysaccharides presented antioxidant activity under different conditions in some of the in vitro tests and inhibited the formation of calcium oxalate crystals. Fucan DJ-0.4v was the polysaccharide that showed the best antioxidant activity and was one of the best inhibitors of the crystallization of calcium oxalate. Glucan DJ-0.5v was the second most potent inhibitor of the formation of oxalate crystals, as it stabilized dehydrated oxalate crystals (less aggressive form), preventing them from transforming into monohydrate crystals (more aggressive form). The obtained data lead us to propose that these sulfated polysaccharides are promising agents for use in the treatment of urolithiasis.
authors.affiliation: Laboratório de Biotecnologia de Polímeros Naturais (BIOPOL), Departamento de Bioquímica, Centro de Biociências, Universidade Federal do Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte 59072-970, Brazil. hugo@cb.ufrn.br.
authors.forename: Karoline Rachel Teodosio
authors.initials: KR
authors.lastname: Melo
authors.forename: Rafael Barros Gomes
authors.initials: RB
authors.lastname: Camara
authors.forename: Moacir Fernandes
authors.initials: MF
authors.lastname: Queiroz
authors.forename: Arthur Anthunes Jacome
authors.initials: AA
authors.lastname: Vidal
authors.forename: Camila Renata Machado
authors.initials: CR
authors.lastname: Lima
authors.forename: Raniere Fagundes
authors.initials: RF
authors.lastname: Melo-Silveira
authors.forename: Jailma
authors.initials: J
authors.lastname: Almeida-Lima
authors.forename: Hugo Alexandre Oliveira
authors.initials: HA
authors.lastname: Rocha
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D002129:Calcium Oxalate / Q000737:chemistry*; D002614:Chelating Agents / Q000737:chemistry; D003300:Copper; D003460:Crystallization; D005609:Free Radicals / Q000037:antagonists & inhibitors; D007501:Iron; D007502:Iron Chelating Agents / Q000737:chemistry / Q000494:pharmacology; D050866:Liquid Crystals; D010084:Oxidation-Reduction / Q000187:drug effects; D000459:Phaeophyceae / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry / Q000494:pharmacology; D012624:Seaweed / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000975:Antioxidants; D002614:Chelating Agents; D005609:Free Radicals; D007502:Iron Chelating Agents; D011134:Polysaccharides; D002129:Calcium Oxalate; D003300:Copper; D007501:Iron