Soft Coral Dendronephthya Research Articles

Cytotoxic and anti-bacterial evaluation of two new aromatic A-ring steroids isolated from the Red Sea soft coral Dendronephthya spp.

A successful column chromatography of a CHCl3/MeOH crude extract of Dendronephthya spp. soft coral led to the isolation of two new aromatic A-ring steroids (1–2), together with three known compounds (3–5). Both 1 and 2 are 19-norsteroids. The chemical structures were elucidated based on extensive 1D, 2D NMR, and EIMS analyses. In cytotoxic bioassays, compounds 1–5 were tested against three cancer cell lines: MCF-7, NCI-1299, and HepG2, with IC50 in the ranges of 22.1–85.4, 26.9–88.7, and 25.9–93.7 μM, respectively. Compounds 1, 2, and 5 showed moderate degrees of inhibition against Escherichia coli and Pseudomonas sp. at 100 and 150 µg/mL, while exhibiting weak inhibition against Bacillus cereus and Staphylococcus aureus at 150 µg/mL.

On some commensal anomuran and brachyuran crabs (Crustacea: Decapoda) off Visakhapatnam, Northwestern Bay of Bengal.

Commensal anomuran and brachyuran crabs were collected from extensive exploratory surveys on rocky areas where soft corals, sea anemones and sponges are found off the Visakhapatnam coast. The present study includes nine species of commensal decapod crustaceans, comprising four porcellanid crabs (Petrolisthes lamarckii (Leach, 1820), Porcellanella triloba White, 1852, Polyonyx hendersoni Southwell, 1909 and Pisidia gordoni (Johnson, 1970)), one squat lobster (Allogalathea elegans (Adams, 1847) and four brachyuran crabs (Dorippoides facchino (Herbst, 1785), Quadrella coronata Dana, 1852, Quadrella maculosa Alcock, 1898 and Sphenomerides trapezioides (Wood-Mason & Alcock, 1891). Allogalathea elegans, Polyonyx hendersoni, Pisidia gordoni, Quadrella coronata and Quadrella maculosa are new records from off Visakhapatnam. The porcellanid crabs are associated with the sea pen Pteroeides esperi, desmosponges and black soft corals Antipathes sp. whereas the squat lobster was associated with the soft coral Dendronephthya sp. The brachyuran crabs were observed in association with Antipathes sp. Here, we provide details on the morphology, distribution, habitat and commensalism of decapod crustaceans studied.

Cytotoxic ketosteroids from the Red Sea soft coral Dendronephthya sp.

Abstract A marine specimen of the Red Sea soft coral Dendronephthya sp. was extracted with a mixture of n-hexane, diethyl ether, and methanol. One new cytotoxic steroid dendronestadione (1), five known steroids: dendronesterones A-C (2–4), dendrotriol (5), and cholesterol (6) along with 4-oxo-pentanoic acid (7) and a polyhydroxy alkane hexitol (8) were isolated from the Dendronephthya sp. extract. The chemical structures of the isolated metabolites were elucidated by the application of several spectroscopic techniques (1D, 2D NMR, IR, and UV) and mass spectrometry. The antiproliferative effect of the isolated compounds was assessed against a panel of human cancer cell lines including HepG2, HT-29, and PC. The obtained results indicated that compounds 1–4 (dendronesterones A–C) exhibited a higher cytotoxic effect than that of the other co-isolated ones. Among all examined dendronesterones, dendronesterone C showed the highest IC50 values of 19.1 ± 1.81, 32.4 ± 2.84, and 7.8 ± 0.80 µM against the three cancer cells under investigation. Interestingly, all isolated ketosteroids showed potent effects against prostate cancer cells. These findings highlight the role of ketosteroids as an antiproliferative agent against the examined cells in this study.

Substantial advancement in aquaria rearing methods to assist recovery of an Endangered soft coral

Abstract The temperate soft coral Dendronephthya australis has been listed as Endangered in NSW, Australia, owing to its restricted geographic range, rapidly declining populations, and a number of escalating threats. Research to assess practical methods for aquarium cultivation of D. australis for rehabilitation of wild populations is considered a high priority. Previous attempts at restoration by transplanting D. australis fragments have had limited success, but identified key challenges, which included achieving attachment to substrates and identifying appropriate foods to maximize survival. This study presents the results of experiments promoting the attachment of cuttings (nubbins) removed from donor colonies to moveable substrates (small concrete discs). Using a balanced orthogonal experimental design, three feeding regimes were tested: live artemia, live rotifers and dry powdered zooplankton. Donor colony survival and growth were also monitored over a 6 month period in the field. An overall nubbin survival rate of 100% was achieved under all three feeding regimes. Attachment rates were similar across feeding treatments, although nubbin behavioural responses (percentage of open polyps before feeding) suggested some preference for live rotifers. The cutting removal process had no significant effect on donor colonies in the wild, indicating that this is a sustainable approach for restoration. Overall, this study substantially advances the methodology for maintaining an Endangered azooxanthellate soft coral in aquaria and provides valuable input for management programmes aimed at implementing transplantation into the wild to aid species recovery.

Genetic differentiation in the threatened soft coral Dendronephthya australis in temperate eastern Australia

AbstractThe endangered soft coral Dendronephthya australis faces substantial population decreases in central eastern Australian waters. Despite uncertainty about the cause of these declines, the population genetics of the species has not been investigated. Genetic analysis suggests that D. australis is a single species within the family Nephtheidae, confirming identifications based on morphological characteristics only. Soft coral colonies were distributed from Seahorse Gardens in Port Stephens to Jervis Bay in temperate Australian waters, a distance of some 400 km. Genetic differentiation was observed along this distribution using SNP genotyping. Relatively high levels of genetic differentiation were observed between Jervis Bay and the other sites, indicating limited gene flow between this location and others. Moreover, the genetic distinctiveness, low diversity and heterozygote excess at this southern location suggested that it was subjected to a recent population decline and genetic bottleneck. Colonies at Seahorse Gardens and Ettalong, approximately 150 km south of Seahorse Gardens, displayed greater genetic diversity, making these sites more likely to host ancestral populations and to have acted as refugia. Recent substantial decreases in population sizes at these locations are particularly concerning, and these locations require immediate conservation attention.

Hepatoprotective activity and free radical scavenging against induction of CCl4 in an experimental model using dendronaphthya crude extract loaded chitosan nanocarrier

The encapsulation of soft coral Dendronephthya gigantea (SCD) in biopolymers could be attributed to the nature of this extract. In the present work, chitosan nanoparticles (NCS) as natural biopolymer was prepared using sodium tripolyphosphate (TPP) via ionic gelation method and then encapsulated with SCD. Firstly, GC-MS was used to determine the components of the SCD. More than Forty-components of SCD, constituting 89.94%, were identified. Secondly, to enhance the entrapment efficiency and encapsulating degree, polyvinyl alcohol (PVA) was used to cap the whole product of NSC@SCD. The entrapment efficiency of PVA-capped NSC@SCD is higher than that of NSC@SCD and reached about 96%. Physical advanced tools such as TEM, DLS, and SEM were utilized to confirm the particle shape for the formed nanocomposite, affirming that the particles originated in a spherical shape with no noticeable agglomeration. Besides, PVA was found to protect the produced nanocomposite from agglomeration and exhibit the latter homogenous structure. After that, rats with approximately the same weight were divided into seven groups and treated with different formulas to evaluate hepatoprotective activity against induction of CCl4 of the prepared nanocomposites loaded with SCD. Form the obtained resultants, it can be observed that the nanocomposite has a positive effect on the treated rats via improving in the values of catalase activity (CA), reduced glutathione (GSH), and total antioxidant capacity (TAC) with a significant decrease in malondialdehyde (MDA) values. It was also observed that the level of liver enzymes closely resembles the untreated rat group. The obtained data also proved that nanocomposite based on NSC@SCD exhibited high albumin and total protein level. Thus, It can be concluded that the extract (SCD) loaded chitosan nanoparticles (NSC) is considered a promising formula to be used in medicinal domains.

A Steroid-Type Antioxidant Targeting the Keap1/Nrf2/ARE Signaling Pathway from the Soft Coral Dendronephthya gigantea.

Four new steroids, named 7-dehydroerectasteroid F (1), 11α-acetoxyarmatinol A (2), 22,23-didehydroarmatinol A (3), and 3-O-acetylhyrtiosterol (4), together with 11 previously described analogues, were isolated from a South China Sea collection of the soft coral Dendronephthya gigantea. The structures of the new steroids were elucidated by comprehensive spectroscopic analysis and by comparison with previously reported data. Compound 1 showed potent protection against H2O2-induced oxidative damage in neuron-like PC12 cells by promoting nuclear translocation of Nrf2 and enhancing the expression of HO-1. 1 represents the first steroid-type antioxidant from marine organisms.

Antiproliferative and apoptosis-inducing potential of 3β-hydroxy-Δ5-steroidal congeners purified from the soft coral Dendronephthya putteri

The exploration and identification of antiproliferative phytochemicals have received increased attention in medicinal chemistry. In particular, research focused on the toxicology of marine natural products has increased in recent years. Terpenoids, among many secondary metabolites, have been demonstrated to act as effective anticancer agents. Soft corals, a group of marine invertebrates, produce a variety of terpenoids with biofunctional properties. The current study presents the extraction, purification, and identification of sterol congeners from the soft coral Dendronephthya putteri. The method involves 50% chloroform-methanol extraction, polar column fractionation, and analysis through GC-MSn. Dose-dependent antiproliferative activity was observed within the sterol-rich fraction (DPCMH 2-4), which consisted of 3β-hydroxy-Δ5-steroidal congeners. This fraction inhibited the growth of HL-60 and MCF-7 cells with IC50 values of 25.27±1.43 and 22.81±0.15 μg/mL, respectively. Apoptotic body formation, DNA damage, cell cycle arrest, and apoptotic cell signaling pathway activation were also observed, reinforcing the dose-dependent antiproliferative and apoptosis-inducing activity of 3β-hydroxy-Δ5-steroidal congeners. To our knowledge, this is the first report of anticancer agent identification from the soft coral D. putteri. Based on the observations, these steroidal congeners are promising candidates for the development of anticancer drugs.

Soft Coral Dendronephthya puetteri Extract Ameliorates Inflammations by Suppressing Inflammatory Mediators and Oxidative Stress in LPS-Stimulated Zebrafish.

Marine-derived extract and/or bioactive compounds have attracted increasing demand due to their unique and potential uses as cures for various inflammation-based diseases. Several studies revealed anti-inflammatory candidates found in soft corals. However, the effects of soft corals on inflammation in an in vivo model remain to be determined. Therefore, the extract of soft coral Dendronephthya puetteri (DPE) was investigated for an in vivo anti-inflammatory effect in a lipopolysaccharide (LPS)-stimulated zebrafish model to determine its potential use as a natural anti-inflammatory agent. We also investigated whether DPE has toxic effects in a zebrafish model. No significant changes were observed in terms of survival, heart beat rate, or developmental abnormalities in the zebrafish embryos exposed to a concentration below 100 µg/mL of DPE. Treating the zebrafish model with LPS-treatment significantly increased the ROS, NO generation, and cell death. However, DPE inhibited this LPS-stimulated ROS, NO generation, and cell death in a dose-dependent manner. In addition, DPE significantly reduced the mRNA expression of both iNOS and COX-2 and markedly suppressed the expression levels of the proinflammatory cytokines, TNF-α and IL-6, in an LPS-stimulated zebrafish model. These findings demonstrate that DPE has profound anti-inflammatory effect in vivo, suggesting that DPE might be a strong natural anti-inflammatory agent.

Apoptotic and antiproliferative effects of Stigmast-5-en-3-ol from Dendronephthya gigantea on human leukemia HL-60 and human breast cancer MCF-7 cells

The genus Dendronephthya encompasses marine soft corals that produce a wide spectrum of biofunctional terpenoids. Anticancer properties of these metabolites are widely exploited as potential chemotherapeutic agents. The present study reports the purification and isolation of a potential antiproliferative constituent, stigmast-5-en-3-ol from the 70% ethanol extract of the soft coral Dendronephthya gigantea. Among several other 3β-hydroxy-Δ5-steroidal congeners, stigmast-5-en-3-ol indicated prominent antiproliferative effects on HL-60 (leukemia) and MCF-7 (breast cancer) cell lines with IC50 values of 37.82 and 45.17 μg/ml respectively. Stigmast-5-en-3-ol increased apoptotic body formation, accumulation of sub G1 apoptotic cells, and DNA damage in HL-60 and MCF-7 cells. It increased the expression of Bax, caspases, and PARP cleavage while decreasing Bcl-xL levels in both cancer cell lines indicating that the effects are arbitrated via the mitochondria-mediated apoptotic pathway. Steroidal derivatives were identified by GC MS/MS and the identity of stigmast-5-en-3-ol was confirmed by NMR spectra. The present study suggests that stigmast-5-en-3-ol could be a promising candidate for anticancer drug research.

3β-Hydroxy-Δ5-steroidal congeners from a column fraction of Dendronephthya puetteri attenuate LPS-induced inflammatory responses in RAW 264.7 macrophages and zebrafish embryo model.

Bioactive compounds from marine organisms and their action mechanisms have provided new insights into medicinal and natural product research. Here, we report the identification of 3β-hydroxy-Δ5-steroidal congeners from a purified column fraction (DPCMH24) of the soft coral Dendronephthya puetteri harvested from Jeju, South Korea. DPCMH24 exerted strong anti-inflammatory effects through a dose-dependent decrease in the levels of nitric oxide (NO) in LPS-induced RAW 264.7 macrophages (IC50 value = 6.54 ± 0.38 μg mL−1). Further, DPCMH24 attenuated the levels of PGE2 and the pro-inflammatory cytokines, TNF-α, IL-1β, and IL-6. The above effects were mediated via the inhibition of nuclear factor κB activation and mitogen-activated protein kinase pathways. In vivo evaluation indicated that DPCMH24 reduced NO, iNOS, COX-2, ROS production and cell death in LPS-induced zebrafish embryos, confirming its anti-inflammatory potential. The constituent compounds were identified by GC-MS/MS analysis. These findings suggest that the steroidal congeners from D. puetteri may offer ample therapeutic potential against LPS-induced inflammation.

Developmental toxicity and anti-inflammatory effect of the soft coral Dendronephthya gigantea collected from Jeju Island in zebrafish model

Recent in vitro studies have demonstrated that extract of soft coral Dendronephthya gigantea (SCDE) had strong anti-inflammatory activities. However, the direct effects of SCDE on anti-inflammatory activities in vivo model remained to be determined. Therefore, the present study was designed to assess in vivo anti-inflammatory effect of SCDE using lipopolysaccharide (LPS)-stimulated zebrafish model. We also investigated whether SCDE has toxic effects in zebrafish model. The survival, heart beat rate, and developmental abnormalities were no significant change in the zebrafish embryos exposed to at a concentration below 100 μg/ml of SCDE. However, lethal toxicity was caused after exposure to 200 and 400 μg/ml of SCDE. Treating zebrafish model with LPS treatment significantly increased the reactive oxygen species (ROS) and nitric oxide (NO) generation. However, SCDE inhibited this LPS-stimulated ROS and NO generation in a dose-dependent manner. These results show that SCDE alleviated inflammation by inhibiting the ROS and NO generation induced by LPS treatment. In addition, SCDE has a protective effect against the cell damage induced by LPS exposure in zebrafish embryos. This outcome could explain the profound anti-inflammatory effect of SCDE both in vitro as well as in vivo, suggesting that the SCDE might be a strong anti-inflammatory agent.

Responses of Dendronephthya australis to predation by Dermatobranchus sp. nudibranchs

The soft coral Dendronephthya australis occurs only in large abundance within the tidal-dominated Port Stephens estuary in eastern Australia. In recent years, substantial declines in the spatial extent of D. australis within Port Stephens has led to calls for the species to be listed as ‘threatened’. The causes for these declines are likely to include a range of anthropogenic impacts, as well as natural effects such as predation by the nudibranch Dermatobranchus sp., which can be abundant in winter and spring. The responses of D. australis to the presence of Dermatobranchus sp. were studied at two sites in Port Stephens, using time-lapse and still photography combined with visual surveys. Dermatobranchus sp. was observed consuming D. australis polyps, and colony inflation and polyp expansion were both reduced when Dermatobranchus sp. was present. Although predation by Dermatobranchus sp. is a natural impact, our observations suggest that interactions with additional anthropogenic stressors may exacerbate its overall impact on the spatial extent and survival of the geographically restricted soft coral D. australis.

Identification of sterols from the soft coral Dendronephthya gigantea and their anti-inflammatory potential

Exploration of anti-inflammatory phytochemicals has received tremendous attention worldwide owing to the rapid increase in inflammatory diseases. Current study reveals the identification of eight 3β-hydroxy-Δ5-steroidal congeners from a nonpolar column fraction of the ethanol solubles from the soft coral Dendronephthya gigantea collected from Jeju Island South Korea, using GC–MS/MS analysis. The sterol-rich fraction (DGEH21) showed a significant anti-inflammatory activity as exhibited by the inhibition of NO production (IC50 4.33±0.50μg/mL) and PGE2 production in LPS-stimulated RAW 264.7 macrophages. It also suppressed the expression levels of proinflammatory cytokines, TNF-α, IL-1β, and IL-6 in a dose-dependent manner. Furthermore, DGEH21 effectively downregulated the expression levels of iNOS, and COX-2 and reduced NO and ROS production as well as cell death in LPS-stimulated in-vivo zebrafish embryo model. However, DGEH21 at relatively high concentrations indicated cytotoxicity in both RAW cells and zebrafish embryos with RAW cell viability being nearly 80% after treatment with 25μg/mL DGEH21. This study highlights the synergistic anti-inflammatory activity of several steroids found in D. gigantea. Their actions may be useful in the development of anti-inflammatory cosmeceuticals, pharmaceutical agents, and other consumer products.

Developing a habitat classification typology for subtidal habitats in a temperate estuary in New South Wales, Australia

Effective estuarine management depends on adequate data about the ecology, extent and biodiversity of component habitats. However, these data are often scant, as exemplified by the Port Stephens estuary, part of the Port Stephens–Great Lakes Marine Park (NSW, Australia), for which even basic descriptions of habitat types and extent are lacking. Herein we present the results of the first quantitative assessment of subtidal benthic communities within the estuary, involving 130km of towed video transects over an area exceeding 50km2. We identified previously undocumented macroalgae-dominated habitat types and found strong correlations between habitat types and depth. The soft coral Dendronephthya australis habitat is of particular interest because this was found to occur exclusively outside current sanctuary (no take) zones. The habitat map of Port Stephens generated during the study provides the basis for more objective representative planning in future iterations of zoning in the estuarine section of the marine park. The study also suggests that depth may be a useful proxy for estuarine habitat types where specific data are lacking. The classification methodology developed during the study was cost-effective, generated robust data and consequently has potential for wider application in other large estuarine bays.

Ontogenetic and sex-based differences in habitat preferences and site fidelity of White's seahorse Hippocampus whitei.

The aim of this study was to determine and compare habitat preferences for male and female adult and juvenile White's seahorse Hippocampus whitei and assess their movements and site fidelity over 4 years. Data were collected from three sites along 1.5 km of estuarine shoreline in Port Stephens, New South Wales, Australia, from 2006 to 2009 using H. whitei that had been tagged with visible implant fluorescent elastomer. Relative availability of 12 habitats and habitat preferences of H. whitei was determined, based on the habitat that H. whitei used as a holdfast. Hippocampus whitei occurred in nine different habitats; adults preferred sponge and soft coral Dendronephthya australis habitats with no difference between male and female habitat preferences whilst juveniles preferred gorgonian Euplexaura sp. habitat. There was a significant preference by adults for D. australis colonies with height >40 cm and avoidance of colonies <20 cm. Neither adults nor juveniles used sand or the seagrasses Zostera muelleri subsp. capricorni and Halophila ovalis. Hippocampus whitei showed cryptic behaviour with c. 50% of adult sightings cryptic and c. 75% for juveniles with crypsis occurring predominantly in Sargassum sp. for adults and Euplexaura sp. habitat for juveniles. Within sites, females moved significantly longer distances (maximum of 70 m) than males (maximum of 38 m) over 20 months. Strong site fidelity was displayed by H. whitei with males persisting at the same site for up to 56 months and females for 49 months and no H. whitei moved between sites. The longest period that an H. whitei was recorded on the same holdfast was 17 months for a male and 10 months for a female. As this species displays strong site fidelity, specific habitat preferences and has a limited distribution, future management needs to minimize the risk of habitat disturbance as loss of key habitats could have a negative effect on species abundance and distribution.

Dendronephthols A–C, new sesquiterpenoids from the Red Sea soft coral Dendronephthya sp.

Three new ylangene-type sesquiterpenoids: dendronephthol A (7,13-dihydroxy-3,4-dihydro-α-ylang-5-one) (1), dendronephthol B (6,7,13-trihydroxy-3,4-dihydro-α-ylangene) (2), and dendronephthol C (6,7,13-trihydroxy-α-ylang-5-one) (3), together with two known compounds: dendronesterone A and cholesterol were isolated from the CHCl3 fraction of Red Sea soft coral Dendronephthya sp. (Nephtheidae). The structures of the new compounds were established on the basis of one- and two-dimensional NMR spectroscopic studies (1H, 13C, DEPT, COSY, HSQC, HMBC, and NOESY) as well as MS spectroscopy and by comparison of the spectral data with those of related known compounds. Compounds 1 and 3 showed cytotoxic activity against the murine lymphoma L5187Y cancer cell line with ED50 values of 8.4 and 6.8 μg/mL, respectively.

Isolation, Identification and Growth Optimization of Microalgae Derived from Soft Coral Dendronephthya sp.

Despite its beauty in shape and color, soft coral Dendronephthya sp. is less interesting commercially as an ornamental coral commodity due to its low chances of survival in artificial habitats. Unlike other corals, this species is azooxhantellae, and thus, it depends on external feeding. The aim of this research is to isolate, identify, and cultivate the microalgae derived from Dendronephthya sp. The microalgae was isolated from digestive tract, followed by genomic DNA isolation and Polymerase Chain Reaction. The algae cultivation was conducted using the nitrogen sources as proven treatment. Five species of microalgae (Amphora sp., Navicula salinicola, Meyerella planktonica, Nannochloris sp., and Nitzschia inconspicua) were successfully isolated. The highest biomass of Amphora sp. was obtained when ammonium was added as nitrogen source. Meanwhile, the highest biomass of N. inconspicua was obtained through the addition of nitrate. Finally, the highest biomass of N. salinicola was acquired when a combination of ammonium and nitrate was used.

Sterols from a soft coral, Dendronephthya gigantea as farnesoid X-activated receptor antagonists

Three new steroids 3-oxocholest-1,22-dien-12β-ol (1), 3-oxocholest-1,4-dien-20β-ol (2), 3-oxocholest-1,4-dien-12β-ol (3), and three known steroids (20S)-20-Hydroxyergosta-1,4,24(28)-trien-3-one (4) [7a], 5α,8α-Epidioxycholesta-6,22-dien-3β-ol (5) [10] and 5-cholestene-3β,12β-diol (6) [11] were isolated from a soft coral Dendronephthya gigantea. Their chemical structures and relative stereochemistry were elucidated by the analysis of HRMS and 2-D NMR spectroscopic data. The steroids 1 and 2 showed notable inhibitory activity against farnesoid X-activated receptor (FXR) with IC50’s 14 and 15μM.

Steroids with Aromatic A-Rings from the Hainan Soft Coral Dendronephthya studeri Ridley

Eight new marine steroids, characterized by either the presence of an aromatic ring or a cross-conjugated dienone system in ring A, were isolated from the Hainan soft coral Dendronephthya studeri Ridley. Their structures were elucidated on the basis of detailed spectroscopic analysis and by comparison of their NMR data with those reported in the literature.