Search Results (6)

Fucosylated chondroitin sulfate (FCS) was prepared from Bohadschia ocellata using protease hydrolysis. The structural characteristics of FCS were confirmed through chemical composition analysis using FTIR spectroscopy, ¹H NMR, and ¹³C NMR. FCS from B. ocellata (FCS-Bo) exhibited an average molecular weight of approximately 122 kDa. The biological activities of FCS-Bo, including anticoagulant, anti-cancer, and Protein Tyrosine Phosphatase 1B (PTP1B) inhibition, were evaluated. FCS-Bo displayed potent anticoagulant properties, markedly extending activated partial thromboplastin time, prothrombin time, and thrombin time when compared to the heparin control. In anti-cancer bioactivity research, FCS-Bo efficiently inhibited colony formation in the colon cancer cell lines HCT-116, HT-29, and DLD-1, achieving inhibition rates of up to 65%. Additionally, FCS-Bo exhibited significant inhibition of PTP1B, with an IC₅₀ as low as 0.0326 µg/mL, suggesting its potential for improving insulin sensitivity and managing conditions such as type 2 diabetes and obesity. Full article

The interrelationship of the minerals calcium (Ca²⁺), magnesium (Mg²⁺) and silicon (Si) in the sediments and in the body walls of four tropical sea cucumber species was explored by modeling the concentrations of these minerals. The elemental concentrations of Ca²⁺, Mg²⁺ and Si were measured in the body walls and in the ambient sediments occupied by the sea cucumbers Holothuria scabra, H. leucospilota, H. atra and Bohadschia marmorata. The results indicate that the concentrations of Ca²⁺ and Mg²⁺ in the body walls of the four sea cucumber species are significantly different from each other, indicating a varying degree of biomineralization across sea cucumber taxa. In contrast, only B. marmorata showed a significant difference in the concentration of Si when compared to the rest of the species tested. Further analysis using linear mixed models revealed that the Ca²⁺, Mg²⁺ and Si concentrations in the body walls of the tested sea cucumber species are associated with the sediment concentrations of the same elements. The relatively high concentrations of Ca²⁺ and Mg²⁺ in the sediments indicate that these minerals are sufficiently high in sea cucumbers to support their biomineralization. The relationship between the Mg/Ca ratio in the body walls of the sea cucumbers and minerals in the sediments revealed that Si was the only mineral that was not correlated with the Mg/Ca ratio. Predicting the relationship of the elements Ca²⁺, Mg²⁺ and Si between the sediments and the body walls of sea cucumbers may be complex due to the various factors that influence the metabolism and biomineralization in sea cucumbers. Full article

Fucosylated chondroitin sulfates (FCSs) FCS-BA and FCS-HS, as well as fucan sulfates (FSs) FS-BA-AT and FS-HS-AT were isolated from the sea cucumbers Bohadschia argus and Holothuria (Theelothuria) spinifera, respectively. Purification of the polysaccharides was carried out by anion-exchange chromatography on DEAE-Sephacel column. Structural characterization of polysaccharides was performed in terms of monosaccharide and sulfate content, as well as using a series of non-destructive NMR spectroscopic methods. Both FCSs were shown to contain a chondroitin core [→3)-β-d-GalNAc-(1→4)-β-d-GlcA-(1→]_n bearing sulfated fucosyl branches at O-3 of every GlcA residue in the chain. These fucosyl residues were different in pattern of sulfation: FCS-BA contained Fuc2S4S, Fuc3S4S and Fuc4S at a ratio of 1:8:2, while FCS-HS contained these residues at a ratio of 2:2:1. Polysaccharides differed also in content of GalNAc4S6S and GalNAc4S units, the ratios being 14:1 for FCS-BA and 4:1 for FCS-HS. Both FCSs demonstrated significant anticoagulant activity in clotting time assay and potentiated inhibition of thrombin, but not of factor Xa. FS-BA-AT was shown to be a regular linear polymer of 4-linked α-L-fucopyranose 3-sulfate, the structure being confirmed by NMR spectra of desulfated polysaccharide. In spite of considerable sulfate content, FS-BA-AT was practically devoid of anticoagulant activity. FS-HS-AT cannot be purified completely from contamination of some FCS. Its structure was tentatively represented as a mixture of chains identical with FS-BA-AT and other chains built up of randomly sulfated alternating 4- and 3-linked α-L-fucopyranose residues. Full article

Bohadschia argu is a kind of sea cucumber with high economic value; it is the only undisputed species in the genus Bohadschia. In this study, the complete mitochondrial genome (mitogenome) of B. argus was acquired through high-throughput sequencing. The mitochondrial genome of B. argus was 15,656 bp in total length and contained a putative control region (CR) and 37 typical genes of animal mitochondrial genomes, including 13 protein-coding genes (PCGs), 2 ribosomal RNA genes (rrnS and rrnL) and 22 transfer RNA genes (tRNA). The sizes of the PCGs ranged from 168 bp to 1833 bp, and all PCGs except nad6 were encoded on the heavy chain (H). Both rrnS and rrnL were also encoded on the H chain. Twenty-two tRNA genes had positive AT skew and GC skew. All tRNAs had a typical cloverleaf secondary structure except for trnI, in which an arm of dihydrouridine was missing. B. argus shared the same gene arrangement order (the echinoderm ground pattern) as other species in Aspidochirotida. Phylogenetic analysis clearly revealed that B. argus belongs as a member of the Holothuriidae, and it is closely related to members of Actinopyga and Holothuria. Full article

Sea cucumbers are bottom dwelling invertebrates, which are mostly found on subtropical and tropical sea grass beds, sandy reef flats, or reef slopes. Although constantly exposed to fouling communities in these habitats, many species are surprisingly free of invertebrate epibionts and microfouling algae such as diatoms. In our study, we investigated the anti-fouling (AF) activities of different crude extracts of tropical Indo-Pacific sea cucumber species against the fouling diatom Cylindrotheca closterium. Nine sea cucumber species from three genera (i.e., Holothuria, Bohadschia, Actinopyga) were selected and extracted to assess their AF activities. To verify whether the sea cucumber characteristic triterpene glycosides were responsible for the observed potent AF activities, we tested purified fractions enriched in saponins isolated from Bohadschia argus, representing one of the most active anti-fouling extracts. Saponins were quantified by vanillin-sulfuric acid colorimetric assays and identified by LC-MS and LC-MS/MS analyses. We were able to demonstrate that AF activities in sea cucumber extracts were species-specific, and growth inhibition as well as attachment of the diatom to surfaces is dependent on the saponin concentration (i.e., Actinopyga contained the highest quantities), as well as on the molecular composition and structure of the present saponins (i.e., Bivittoside D derivative was the most bioactive compound). In conclusion, the here performed AF assay represents a promising and fast method for selecting the most promising bioactive organism as well as for identifying novel compounds with potent AF activities for the discovery of potentially novel pharmacologically active natural products. Full article

To avoid predation, holothuroids produce feeding-deterrent molecules in their body wall and viscera, the so-called saponins. Five tropical sea cucumber species of the family Holothuriidae were investigated in order to study their saponin content in two different organs, the body wall and the Cuvierian tubules. Mass spectrometry techniques (MALDI- and ESI-MS) were used to detect and analyze saponins. The smallest number of saponins was observed in Holothuria atra, which contained a total of four congeners, followed by Holothuria leucospilota, Pearsonothuria graeffei and Actinopyga echinites with six, eight and ten congeners, respectively. Bohadschia subrubra revealed the highest saponin diversity (19 congeners). Saponin mixtures also varied between the two body compartments within a given animal. A semi-quantitative approach completed these results and showed that a high diversity of saponins is not particularly correlated to a high saponin concentration. Although the complexity of the saponin mixtures described makes the elucidation of their respective biological roles difficult, the comparisons between species and between body compartments give some clues about how these molecules may act as predator repellents. Full article