Recent Reports on Bioactive Compounds from Marine Cyanobacteria in Relation to Human Health Applications.

The ocean is a valuable natural resource that contains numerous biologically active compounds with various bioactivities. The marine environment comprises unexplored sources that can be utilized to isolate novel compounds with bioactive properties. Marine cyanobacteria are an excellent source of bioactive compounds that have applications in human health, biofuel, cosmetics, and bioremediation. These cyanobacteria exhibit bioactive properties such as anti-inflammatory, anti-cancer, anti-bacterial, anti-parasitic, anti-diabetic, anti-viral, antioxidant, anti-aging, and anti-obesity effects, making them promising candidates for drug development. In recent decades, researchers have focused on isolating novel bioactive compounds from different marine cyanobacteria species for the development of therapeutics for various diseases that affect human health. This review provides an update on recent studies that explore the bioactive properties of marine cyanobacteria, with a particular focus on their potential use in human health applications.

In Vitro and In Vivo Photoprotective Effects of (-)-Loliode Isolated from the Brown Seaweed, Sargassum horneri.

Skin is the largest organ of humans. Overexposure to ultraviolet (UV) is the primary environmental factor that causes skin damage. The compound, (-)-loliode, isolated from the brown seaweed Sargassum horneri, showed strong antioxidant and anti-inflammatory activities in in vitro and in vivo models. To further explore the potential of (-)-loliode in cosmetics, in the present study, we investigated the photoprotective effect of (-)-loliode in vitro in skin cells and in vivo in zebrafish. The results indicated that (-)-loliode significantly reduced intracellular reactive oxygen species (ROS) level, improved cell viability, and suppressed apoptosis of UVB-irradiated human keratinocytes. In addition, (-)-loliode remarkably attenuated oxidative damage, improved collagen synthesis, and inhibited matrix metalloproteinases expression in UVB-irradiated human dermal fibroblasts. Furthermore, the in vivo test demonstrated that (-)-loliode effectively and dose-dependently suppressed UVB-induced zebrafish damage displayed in decreasing the levels of ROS, nitric oxide, lipid peroxidation, and cell death in UVB-irradiated zebrafish. These results indicate that (-)-loliode possesses strong photoprotective activities and suggest (-)-loliode may an ideal ingredient in the pharmaceutical and cosmeceutical industries.

Fucoidans as Scientifically and Commercially Important Algal Polysaccharides.

As a highly bioactive seaweed substance with many promising physiological activities, fucoidan has attracted attention from many industries all over the world [...].

Lipid Inhibitory Effect of (-)-loliolide Isolated from Sargassum horneri in 3T3-L1 Adipocytes: Inhibitory Mechanism of Adipose-Specific Proteins.

Sargassum horneri (S. horneri) is a well-known brown seaweed widely distributed worldwide. Several biological activities of S. horneri have been reported. However, its effects on lipid metabolism and the underlying mechanisms remain elusive. In the present study, we examined the inhibitory effect of the active compound "(-)-loliolide ((6S,7aR)-6-hydroxy-4,4,7a-trimethyl-5,6,7,7a-tetrahydro-1-benzofuran-2(4H)-one (HTT))" from S. horneri extract on lipid accumulation in differentiated adipocytes. MTT assays demonstrated that (-)-loliolide is not toxic to 3T3-L1 adipocytes in a range of concentrations. (-)-loliolide significantly reduced intracellular lipid accumulation in the differentiated phase of 3T3-L1 adipocytes as shown by Oil Red O staining. Western blot analysis revealed that (-)-loliolide increased the expression of lipolytic protein phospho-hormone-sensitive lipase (p-HSL) and thermogenic protein peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1). Additionally, (-)-loliolide decreased expression of adipogenic and lipogenic proteins, including sterol regulatory element-binding protein-1 (SREBP-1), peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding protein-α (C/EBP-α), and fatty acid-binding protein 4 (FABP4) in 3T3-L1 adipocytes. These results indicate that (-)-loliolide from S. horneri could suppress lipid accumulation via regulation of antiadipogenic and prolipolytic mechanisms in 3T3-L1 cells. Considering the multifunctional effect of (-)-loliolide, it can be useful as a lipid-lowering agent in the management of patients who suffer from obesity.

Sargachromenol Isolated from Sargassum horneri Inhibits Particulate Matter-Induced Inflammation in Macrophages through Toll-like Receptor-Mediated Cell Signaling Pathways.

Sargassum horneri is an invasive brown seaweed that grows along the shallow coastal areas of the Korean peninsula, which are potentially harmful to fisheries and natural habitats in the areas where it is accumulated. Therefore, the author attempted to evaluate the anti-inflammatory mechanism of Sargachromenol isolated from S. horneri against particulate matter (PM)-stimulated RAW 264.7 macrophages. PM is a potent inducer of respiratory diseases such as lung dysfunctions and cancers. In the present study, the anti-inflammatory properties of Sargachromenol were validated using enzyme-linked immunosorbent assay (ELISA), Western blots, and RT-qPCR experiments. According to the results, Sargachromenol significantly downregulated the PM-induced proinflammatory cytokines, Prostaglandin E2 (PGE2), and Nitric Oxide (NO) secretion via blocking downstream activation of Toll-like receptor (TLR)-mediated nuclear factor kappa B (NF-κB) and MAPKs phosphorylation. Thus, Sargachromenol is a potential candidate for innovation in various fields including pharmaceuticals, cosmeceuticals, and functional food.

Alginic Acid from Padina boryana Abate Particulate Matter-Induced Inflammatory Responses in Keratinocytes and Dermal Fibroblasts.

Particulate matter (PM) is a significant participant in air pollution and is hence an inducer of serious health issues. This study aimed to evaluate the dust protective effects of alginate from Padina boryana (PBA) via inflammatory-associated pathways to develop anti-fine dust skincare products. In between the external and internal environments, the skin is considered to be more than a physical barrier. It was observed that PM stimulates inflammation in the skin via activating NF-κB and MAPK pathways. The potential of PBA to inhibit the studied pathways were evident. The metal ion content of PM was considerably reduced by PBA and thus attributed to its chelation ability. Current research demonstrated the potential of P. boryana alginates to be implemented as a protective barrier against inflammation imposed with heavy metal and bacterial-derived endotoxin bound to the surface of the PM. Concisely, the results suggest that the bioactive components derived from the brown algae Padina boryana increased the cellular resistance to PM-stimulated inflammation-driven skin damage.

Particulate Matter-Induced Inflammation/Oxidative Stress in Macrophages: Fucosterol from Padina boryana as a Potent Protector, Activated via NF-κB/MAPK Pathways and Nrf2/HO-1 Involvement.

Fucosterol is a phytosterol that is abundant in marine brown algae and is a renowned secondary metabolite. However, its ability to protect macrophages against particulate matter (PM) has not been clarified with regard to inflammation; thus, this study aimed to illustrate the above. Padina boryana, a brown algae that is widespread in Indo-Pacific waters, was applied in the isolation of fucosterol. Isolation was conducted using silica open columns, while identification was assisted with gas chromatography-mass spectroscopy (GC-MS) and NMR. Elevated levels of PM led the research objectives toward the implementation of it as a stimulant. Both inflammation and oxidative stress were caused due the fact of its effect. RAW 264.7 macrophages were used as a model system to evaluate the process. It was apparent that the increased NO production levels, due to the PM, were mediated through the inflammatory mediators, such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and pro-inflammatory cytokines (i.e., interleukin-6 (IL-6), interleukin-1 (IL-1ß) and tumor necrosis factor-α (TNF-α), including prostaglandin E2 (PGE2)). Further, investigations provided solid evidence regarding the involvement of NF-κB and mitogen-activated protein kinases (MAPKs) in the process. Oxidative stress/inflammation which are inseparable components of the cellular homeostasis were intersected through the Nrf2/HO-1 pathway. Conclusively, fucosterol is a potent protector against PM-induced inflammation in macrophages and hence be utilized as natural product secondary metabolite in a sustainable manner.

Anti-Inflammatory Effects of Sulfated Polysaccharide from Sargassum Swartzii in Macrophages via Blocking TLR/NF-Κb Signal Transduction.

This study involves enzymatic extraction of fucoidan from Sargassum swartzii and further purification via ion-exchange chromatography. The chemical and molecular characteristics of isolated fucoidan is evaluated concerning its anti-inflammatory potential in RAW 264.7 macrophages under LPS induced conditions. Structural properties of fucoidan were assessed via FTIR and NMR spectroscopy. NO production stimulated by LPS was significantly declined by fucoidan. This was witnessed to be achieved via fucoidan acting on mediators such as iNOS and COX-2 including pro-inflammatory cytokines (TNF-α, IL-6, and IL-1ß), with dose dependent down-regulation. Further, the effect is exhibited by the suppression of TLR mediated MyD88, IKK complex, ultimately hindering NF-κB and MAPK activation, proposing its therapeutic applications in inflammation related disorders. The research findings provide an insight in relation to the sustainable utilization of fucoidan from marine brown algae S. swartzii as a potent anti-inflammatory agent in the nutritional, pharmaceutical, and cosmeceutical sectors.

Isolation, Characterization, and Antioxidant Activity Evaluation of a Fucoidan from an Enzymatic Digest of the Edible Seaweed, Hizikia fusiforme.

The previous study suggested that the sulfated polysaccharides from Hizikia fusiforme (HFPS) possess strong antioxidant activity. The purpose of this study is to isolate fucoidan from HFPS and to investigate its antioxidant activity. A fucoidan (HFPS-F4) with a molecular weight of 102.67 kDa was isolated from HFPS. HFPS-F4 contains 99.01% of fucoidan (71.79 ± 0.56% of carbohydrate and 27.22 ± 0.05% of sulfate content). The fucoidan increased the viability of H2O2-treated Vero cells by 5.41, 11.17, and 16.32% at the concentration of 12.5, 25, and 50 µg/mL, respectively. Further results demonstrated that this effect act diminishing apoptosis by scavenging intracellular reactive oxygen species (ROS) via increasing the expression of the endogenous antioxidant enzymes, which was induced by elevating total nuclear factor (erythroid-derived 2)-like 2 (Nrf2) levels. In addition, the in vivo test results displayed that the pretreatment of fucoidan improved the survival rates and decreased heart-beating rate, ROS, cell death, and lipid peroxidation in H2O2-stimulated zebrafish. Taken together, these results demonstrated that fucoidan isolated from HFPS has strong in vitro and in vivo antioxidant activities and it could be utilized in pharmaceutical, nutraceutical, and cosmeceutical industries.

Octominin Inhibits LPS-Induced Chemokine and Pro-inflammatory Cytokine Secretion from RAW 264.7 Macrophages via Blocking TLRs/NF-κB Signal Transduction.

Inflammation is a well-organized innate immune response that plays an important role during the pathogen attacks and mechanical injuries. The Toll-like receptors (TLR)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a major signal transduction pathway observed in RAW 264.7 macrophages during the inflammatory responses. Here, we investigated the anti-inflammatory effects of Octominin; a bio-active peptide developed from Octopus minor in RAW 264.7 macrophages in vitro. Octominin was found to inhibit lipopolysaccharides (LPS)-stimulated transcriptional activation of NF-κB in RAW 264.7 cells and dose-dependently decreased the mRNA expression levels of TLR4. Specifically, in silico docking results demonstrated that Octominin has a potential to inhibit TLR4 mediated inflammatory responses via blocking formation of TLR4/MD-2/LPS complex. We also demonstrated that Octominin could significantly inhibit LPS-induced secretion of pro-inflammatory cytokine (interleukin-ß; IL-1ß, IL-6, and tumor necrosis factor-α) and chemokines (CCL3, CCL4, CCL5, and CXCL10) from RAW 264.7 cells. Additionally, Octominin repressed the LPS-induced pro-inflammatory mediators including nitric oxide (NO), prostaglandin E2, inducible NO synthase, and cyclooxygenase 2 in macrophages. These results suggest that Octominin is a potential inhibitor of TLRs/NF-κB signal transduction pathway and is a potential candidate for the treatment of inflammatory diseases.

Antioxidant Potential of Sulfated Polysaccharides from Padina boryana; Protective Effect against Oxidative Stress in In Vitro and In Vivo Zebrafish Model.

Elevated levels of reactive oxygen species (ROS) damage the internal cell components. Padina boryana, a brown alga from the Maldives, was subjected to polysaccharide extraction. The Celluclast enzyme assisted extract (PBE) and ethanol precipitation (PBP) of P. boryana were assessed against hydrogen peroxide (H2O2) induced cell damage and zebra fish models. PBP which contains the majority of sulfated polysaccharides based on fucoidan, showed outstanding extracellular ROS scavenging potential against H2O2. PBP significantly declined the intracellular ROS levels, and exhibited protection against apoptosis. The study revealed PBPs' ability to activate the Nrf2/Keap1 signaling pathway, consequently initiating downstream elements such that catalase (CAT) and superoxide dismutase (SOD). Further, ROS levels, lipid peroxidation values in zebrafish studies were declined with the pre-treatment of PBP. Collectively, the results obtained in the study suggest the polysaccharides from P. boryana might be a potent source of water soluble natural antioxidants that could be sustainably utilized in the industrial applications.

Sargassum horneri (Turner) inhibit urban particulate matter-induced inflammation in MH-S lung macrophages via blocking TLRs mediated NF-κB and MAPK activation.

ETHNOPHARMACOLOGICAL RELEVANCE: Sargassum horneri is a nutrient rich edible brown seaweed with numerous biological properties found in shallow coastal areas of Korean peninsula. S. horneri traditionally used as a medicinal ingredient to treat several disease conditions such as hyperlipidemia, hypertension, heart disease, and inflammatory diseases (furuncle). However, to utilize S. horneri as an active ingredient for functional foods and human health applications requires to conform the bioactive properties and underlying mechanisms of those activities. AIM OF THE STUDY: Here, we investigated anti-inflammatory mechanisms of commercial grade 70% ethanol extract separated from S. horneri (SHE) on inflammatory response in particulate matter (PM)-induced MH-S lung macrophages; where PM in breathable air one of the major health concern in Korea. MATERIALS AND METHODS: We compared the anti-inflammatory effects of SHE on the activity of toll-like receptors (TLR) activation, NF-κB, MAPKs, and pro-inflammatory cytokine secretion in MH-S lung macrophages exposed to PM as a lung inflammation model. RESULTS: According to the results, PM-stimulation, induced the levels of NO, PGE2, TNF-α, IL-1ß, IL-6, iNOS, and COX2 (P < 0.05) in MH-S macrophages. In addition, phosphorylation levels of NF-κB and MAPKs were also increased with the PM stimulation through the upregulated expression of TLR. However, SHE treatment significantly repressed the secretions of inflammatory cytokines and reduced protein expression such as PGE2, TNF-α, IL-6, IL-1ß, NF-κB, and MAPKs from PM-activated macrophages. Specifically, SHE inhibited the upregulated mRNA expression levels of TLR2, TLR3, TLR4, and TLR7 in PM-induced MH-S cells; known biomarkers of downstream activation of NF-κB and MAPKs. CONCLUSION: These results suggested that SHE is a potential inhibitor of PM-induced inflammatory responses in lung macrophages. Thus, SHE could inhibit PM-induced chronic inflammation in lungs via blocking TLR/NF-κB/MAPKs signal transduction. Therefore, it was concluded that SHE may be a useful substance to develop as functional product to reduce inflammation against PM-induced inflammation.

The protective effect of Sargassum horneri against particulate matter-induced inflammation in lung tissues of an in vivo mouse asthma model.

Sargassum horneri is an edible brown seaweed with potential anti-inflammatory properties. The present study was designed to evaluate the anti-inflammatory properties of S. horneri using an in vivo mouse asthma model following exposure to particulate matter (PM). 7-8 week old BALB/c mice (20-25 g) were randomly divided into seven groups (n = 4) as follows: 1: no treatment, 2: OVA (ovalbumin) + PM, 3: OVA + PM + SHE (S. horneri ethanol extract) 200 mg kg-1, 4: OVA + PM + SHE 400 mg kg-1, 5: OVA + PM + prednisone 5 mg kg-1, 6: OVA only, and 7: PM only. All mice (except healthy controls) were sensitized on the first day by intraperitoneal injection of 10 µg OVA and 2 mg Al(OH)3 in 200 µL of saline. Starting from day 15, mice (except groups 1 and 6) were exposed to sonicated PM (5 mg m-3, 30 min day-1) through a nebulizer daily for 7 consecutive days. Mice exposed to PM and OVA showed up-regulated expression of MAPKs and pro-inflammatory cytokine production in the lungs. Furthermore, PM-exposed lungs had significantly reduced expression of Nrf2 and HO-1 genes. However, oral administration of the SHE reduced the phosphorylation levels of MAPKs, iNOS and COX2 expression levels, and mRNA expression levels of pro-inflammatory cytokines. In addition, SHE treated group mice had up-regulated anti-oxidant gene expression levels in the lungs compared to group 2. These findings demonstrate that oral administration of the SHE re-establishes PM-induced inflammation and oxidative stress in the lungs. Taken together, the SHE has therapeutic potential in preventing PM-induced inflammation and oxidative stress.

Free radical scavenging activity of the peptide from the Alcalase hydrolysate of the edible aquacultural seahorse (Hippocampus abdominalis).

Seahorses, Hippocampus abdominalis, have a long history in traditional Chinese medicine as an important healthy ingredient in foods. This study evaluated the antioxidant activity of an enzymatic hydrolysate prepared from a seahorse bred in Jeju, South Korea. Experiments were performed in vitro using electron spin resonance spectrometry (ESR) to determine the free radical scavenging activity and in vivo using a zebrafish model to determine the protective effects against 2,2-azobis hydrochloride (AAPH)-induced oxidative damage. H. abdominalis protein hydrolysate (HPH) exhibited peroxyl radical scavenging activity (IC50  = 0.58 mg/ml) generated by the water-soluble AAPH (azo initiator of peroxyl radicals). HPH reduced dose-dependently both intracellular reactive oxygen species (ROS) levels in AAPH-induced cells and cell death in AAPH-induced zebrafish embryos. The antioxidant peptide purified from HPH was identified as a tripeptide (alanine-glycine-aspartic acid) using Q-TOF ESI mass spectroscopy. Thus, this study demonstrated that HPH contains antioxidant peptides that exhibit a strong antioxidant activity. PRACTICAL APPLICATIONS: Hippocampus abdominalis is one of the largest seahorse species and cultivated in many countries. Because of its large body size compared to other seahorse species, H. abdominalis has acquired considerable consumer attraction in the global market. Owing to its biologically useful properties, it recently gained attention as the natural products obtained from H. abdominalis have varied applications in the field of medicine, health care products, and functional foods. Thus, commercial products of this particular seahorse species are popular among customers, especially in China. The purpose of this study was to evaluate the antioxidant property of H. abdominalism, cultured in a commercial seahorse farm in Jeju Island. Owing to its prominent antioxidant activity, it could be used as an ingredient in medicinal preparations, nutraceuticals, and functional foods.

Isolation and purification of fucoidan fraction in Turbinaria ornata from the Maldives; Inflammation inhibitory potential under LPS stimulated conditions in in-vitro and in-vivo models.

Fucoidan, referred to as fucose containing sulfated polysaccharides (FCSP), is a polymer from brown algae cell wall that is reported to exhibit potential anti-inflammatory activity. In the present study, the fucoidans are extracted from Turbinaria ornata (TO) from the Maldives. The method involves enzyme assisted extraction and is modified in order to improve the effectiveness and purity of final product. Purified fucoidan fraction was identified as F10, and its chemical properties were verified via FTIR, 1H NMR and monosaccharide analysis. Selected inflammatory mediators were studied to evaluate the anti-inflammatory potential using RAW 264.7 macrophages. F10 successfully inhibited NO production (IC50 = 30.83 ±â€¯1.02 µg mL-1). F10 dose-dependently down-regulated iNOS, COX-2, and pro-inflammatory cytokines including PGE2 levels. The in vivo experiments were assisted by zebrafish embryo model. This exhibited reduction in ROS, NO expression levels. To our knowledge, this is the first report to illustrate potential anti-inflammatory activity of FCSPs' extracted from the brown algae T. ornata. Concisely, the results suggest that fucoidan purified from T. ornata increases the macrophage cellular and zebrafish embryo resistance against LPS-induced inflammation. Based on the observations, the fucoidans are promising candidates to be used in the pharmaceutical and cosmeceutical sectors.

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 3ß-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.

Anti-inflammatory potential of alginic acid from Sargassum horneri against urban aerosol-induced inflammatory responses in keratinocytes and macrophages.

The airborne particulate pollutants originating in the deserts of Mongolia and China which becomes contaminated with industrial effluents and traffic emissions while moving with the wind currents towards East Asia has recently become a serious environmental and health issue in the region. They cause asthma, collateral lung tissue damage, oxidative stress, allergic reactions, and inflammation. The current study was undertaken to evaluate the protective effects of alginate extracted from the invasive alga Sargassum horneri (SHA) against fine dust collected from Beijing, China (Chinese fine dust; CFD). It was found that CFD induces inflammation in HaCaT keratinocytes and inhibits macrophage activation. All of the particulate matter (PM) comprising CFD was < PM13 majority being < PM2.5 which is defined for mineral elements and polycyclic aromatic hydrocarbons. SHA attenuated PGE2 levels in CFD-induced HaCaT keratinocytes. The IC50 for SHA was 36.63 ±â€¯4.11 µg mL-l. SHA also reduced the levels of COX-2, IL-6, and TNF-α, and inhibited certain key molecular mediators of the NF-κB and MAPK pathways in keratinocytes. SHA substantially reduced the levels of CFD-derived metal ions like Pb2+ and Ca2+ in keratinocytes attributable to its metal ion chelating properties. CFD-induced HaCaT keratinocyte culture media increased inflammatory responses in RAW 264.7 macrophages. These cells presented with increased levels of NO, iNOS, COX-2, PGE2, and pro-inflammatory cytokines. It was found that the aforementioned effects could be reversed in RAW 264.7 macrophages when keratinocytes were treated with SHA. Therefore, SHA could be used against fine dust-induced inflammation in keratinocytes.

In vitro and in vivo anti-inflammatory activities of high molecular weight sulfated polysaccharide; containing fucose separated from Sargassum horneri: Short communication.

Recent studies on crude and pure compounds from Sargassum horneri have shown promising bioactive properties. However, anti-inflammatory potentials of fucose-rich sulfated polysaccharides from S. horneri have not yet been discovered. In the present study, we evaluated the in vitro and in vivo anti-inflammatory activities of four polysaccharide fractions separated from membrane filters according to their molecular weights (<5kDa (f1), 5-10kDa (f2), 10-30kDa (f3), and >30kDa (f4)). According to the results, F4 fraction inhibited the lipopolysaccharides (LPS)-induced nitric oxide (NO) (IC50=87.12µg/mL) and prostaglandin E2 production as well as pro-inflammatory cytokine production in RAW 264.7 cells through down-regulating nuclear factor-κB signaling cascade. According to the results, f4 has a potential to down-regulate LPS-induced toxicity, cell death and NO production levels in LPS-induced in vivo zebrafish embryo model. These results suggest that f4 fraction has the potential to develop functional materials or drugs to treat inflammatory diseases.

Reduction of heavy metal (Pb2+) biosorption in zebrafish model using alginic acid purified from Ecklonia cava and two of its synthetic derivatives.

Heavy metal contamination has become a major problem that causes severe environmental and health issues due to their biosorption, bioaccumulation, and toxicity. This study was designed to evaluate heavy metal chelating abilities of alginic acid (AA) extracted from the brown seaweed Ecklonia cava and two of its derivatives prepared by the partial oxidation of the 2° OH groups (OAA) and partial carboxylation of the monomeric units (CAA) upon reducing the heavy metal biosorption in zebrafish (Danio rerio) modal. Metal ions were quantified using ICP-OES and biopolymers were characterized by FTIR and XRD analysis. All investigated biopolymers indicated potential ability for chelating Pb2+, Cu2+, Cd2+, As3+, and Ag+. The sorption capacities were in the order of CAA>OAA>AA. All biopolymers indicated a comparatively higher chelation towards Pb2+. AA, OAA, and CAA could effectively reduce Pb2+ induced toxicity and Pb2+ stress-induced ROS production in zebrafish embryos. Besides, they could reduce the biosorption of Pb2+ in adult zebrafish which could lead to bioaccumulation. Since alginic acid purified from E. cava and its derivatives could be utilized as seaweed derived biopolymers to purify heavy metals contaminated water and as a dietary supplement to reduce heavy metal biosorption in organisms.

Apoptotic and antiproliferative properties of 3ß-hydroxy-Δ5-steroidal congeners from a partially purified column fraction of Dendronephthya gigantea against HL-60 and MCF-7 cancer cells.

Organisms belonging to the genus Dendronephthya are among a group of marine invertebrates that produce a variety of terpenoids with biofunctional properties. Many of these terpenoids have been proven effective as anticancer drugs. Here, we report the antiproliferative effect of 3ß-hydroxy-Δ5-steroidal congeners against the proliferation of HL-60 human leukemia cells and MCF-7 human breast cancer cells. The sterol-rich fraction (DGEHF2-1) inhibited the growth of HL-60 and MCF-7 cells with IC50 values of 13.59 ± 1.40 and 29.41 ± 0.87 µg ml-1 respectively. Treatment with DGEHF2-1 caused a dose-dependent increase in apoptotic body formation, DNA damage and the sub-G1 apoptotic cell population. Moreover, DGEHF2-1 downregulated the expression of Bcl-xL while upregulating Bax, caspase-9, and PARP cleavage in both HL-60 and MCF-7 cells. The steroid fraction was found to act via the mitochondria-mediated apoptosis pathway. Identification of the sterols was performed via gas chromatography-tandem mass spectrometry analysis. Studying the mechanism of the anticancer effect caused by these sterol derivatives could lead to the identification of other natural products with anticancer properties.