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Abstract: Sulfated polysaccharides from 11 species of tropical marine algae (one edible specie of Rhodophyta, six species of Phaeophyta and four species of Chlorophyta) collected from Natal city coast (Northeast of Brazil) were evaluated for their anticoagulant, antioxidant and antiproliverative in vitro activities. In the activated partial thromboplastin time (APTT) test, which evaluates the intrinsic coagulation pathway, seven seaweeds presented anticoagulant activity. Dictyota cervicornis showed the highest activity, prolonging the coagulation time to double the baseline value in the APTT with only 0.01mg/100μl of plasma, 1.4-fold lesser than Clexane®, a low molecular weight heparin. In the protrombin time (PT) test, which evaluates the extrinsic coagulation pathway, only Caulerpa cupresoides showed anticoagulant activity. All species collected showed antioxidant activities. This screening emphasized the great antioxidant potential (total capacity antioxidant, power reducing and ferrous chelating) of four species: C. sertularioide; Dictyota cervicornis; Sargassum filipendula and Dictyopteris delicatula. After 72h incubation, HeLa cell proliferation was inhibited (p <0.05) between 33.0 and 67.5% by S. filipendula; 31.4 and 65.7% by D. delicatula; 36.3 and 58.4% by Caulerpa prolifera and 40.2 and 61.0% by Dictyota menstrualis at 0.01–2mg/mL algal polysaccharides. The antiproliferative efficacy of these algal polysaccharides were positively correlated with the sulfate content (r =0.934). Several polysaccharides demonstrated promising antioxidant, antiproliferative an/or anticoagulant potential and have been selected for further studies on bioguided fractionation, isolation and characterization of pure polysaccharides from these species as well as in vivo experiments are needed and are already in progress. [Copyright &y& Elsevier]

Background Insoluble polysaccharide (IP) has been associated with caries prevalence in young children. However, the power of IP to predict ECC needs to be demonstrated. Aims To assess the relationships between early childhood caries (ECC) and extracellular insoluble polysaccharides (IP) in dental plaque, sugar exposure and cariogenic microorganisms. Design Visible plaque on maxillary incisors was recorded, followed by caries diagnosis in 65 preschoolers (3–4 years) at baseline and after 1 year. Plaque was collected for mutans streptococci (MS), total microorganism (TM) and lactobacilli (LB) enumerations in selective media, as well as for IP analysis, which was later assessed by colorimetry. Sugar/sucrose exposure was assessed by a diet chart. Results Positive correlations were found among the prevalence of caries and MS, TM, LB, solid sucrose and visible dental plaque. Additionally, children with IP concentrations in dental plaque higher than 2.36 μg/mg (odds ratio-OR = 6.8), with visible plaque on maxillary incisors (OR = 4.3), harbouring LB (OR = 13) and exposed to solid sugar more than twice/day (OR = 5) showed higher risk of developing caries ( p < 0.05). Conclusion Extracellular insoluble polysaccharides, solid sugar/sucrose, visible dental plaque and cariogenic microorganisms could predict caries development, partially explaining the ECC pattern. [ABSTRACT FROM AUTHOR]