<b>An anti-dengue and anti-herpetic polysulfated fraction isolated from the coenocytic green seaweed <i>Caulerpa cupressoides</i> inhibits thrombin generation in vitro

<b><i>In vitro</i> inactivation of thrombin generation by polysulfated fractions isolated from the tropical coenocytic green seaweed <i>Caulerpa racemosa</i> (Caulerpaceae, Bryopsidales)

“…Complete suppression of TG in intrinsic pathway-activated diluted human plasma was achieved in all the F II concentrations, except at 4.1 μg well-plate -1 that still had an inactivation at 31 min (49.34% PTh inhibition) ( Figure 2B) (Rodrigues et al, 2017b) compared with those of F I, which abolished TG at 41.6 and 83.3 μg well-plate -1 ( Figure 2A). These combined observations led to an intrinsic inhibition level of 10-fold higher than F II, reinforcing F I to be less potent in preventing in vitro clot formation due to its comparatively lower sulfate composition (Table 1) as previously confirmed the APTT assay (Table 2).…”

“…Such observations contrasted with those found for two SPs fractions from the green seaweed C. cupressoides var. lycopodium, where average molecular masses varying from 8 to > 100 kDa were observed by polyacrylamide gel electrophoresis (Rodrigues et al, 2013;Rodrigues et al, 2017b). Ghosh et al (2004) obtained a hot water crude SP from the red seaweed C. cupressoides and found apparent molecular weights of two major peaks (F 1 and F 2) to be 120 and 70 kDa, respectively, when a size exclusion chromatography (Sephacryl S-100 column) was used.…”

“…This was in conformity to the PTh and TPeak parameters (Nishino et al, 1999;Rodrigues et al, 2016;Rodrigues et al, 2017a;Rodrigues et al, 2017b;Salles et al, 2017), based on the amidolytic activity of thrombin that decayed immediately until a plateau was reached at 28 and the negative control without activators min (Mourão et al, 2001;Salles et al, 2017). The anticoagulant dynamic of the fractions was monitored for 60 min at 37°C in parallel with the control curve of UHEP used (Figure 2) (Rodrigues et al, 2017a;Rodrigues et al, 2017b;Salles et al, 2017).…”

“…The action of these compounds would be mediated by serpins (antithrombin and heparin II cofactor) (Rodrigues et al, 2013;Wang et al, 2014) because galactose-rich polysaccharides reveal as inhibitors of thrombin (Hayakawa et al, 2000;Ghosh et al, 2004), but the relationship between structure and anticoagulation still lacks in-depth details since the existence of complexity and heterogeneity of the algae glycans make comparison difficult with UHEP at molecular level and bioactivity (Athukorala et al, 2006;Pomin, 2012;Fidelis et al, 2014;Mourão, 2015;Rodrigues et al, 2016). TG assays may measure several feedback reactions to evaluate diverse classes of SPs regarding their anticoagulant dynamics (Nishino et al, 1999;Mourão et al, 2001;Glauser et al, 2009;Zhang et al, 2014;Rodrigues et al, 2017b;Salles et al, 2017).…”

“…The skin of Nile tilapia (Oreochromis niloticus) also contained SPs (dermatan sulfate-type glycosaminoglycans) with in vitro TG inhibition (Salles et al, 2017). To the best of our knowledge, there is only one report concerning the in vitro inhibitory effects of SPs isolated from Chlorophyta species on TG tests (Rodrigues et al, 2017b).…”