Marine Brown Algae Research Articles

Anticancer, Enhanced Antibacterial, and Free Radical Scavenging Potential of Fucoidan- (Fucus vesiculosus Source) Mediated Silver Nanoparticles.

The present research displays the green synthesis of stable silver nanoparticles (AgNPs). The aqueous solution of Fucoidan from Fucus vesiculosus source (brown marine algae) is used as a reducing and capping agent. UV-Vis spectroscopy, XRD, FT-IR, SEM, EDX, and TEM with selected area electron diffraction are used to characterize the synthesized silver nanoparticles (AgNPs). The synthesized AgNPs exhibit a surface plasmon resonance at 430 nm after 24 h. The characterization results showed that AgNPs are crystalline in nature and exhibit mostly spherical shapes with an average diameter of 4-45 nm. Silver nanoparticles showed effective antibacterial activity against representative pathogens of bacteria. The activities of commercial antibiotics were enhanced by impregnation with the synthesized AgNPs. It also shows good fungicidal and anticancer activity against liver and lung cell lines and shows significant antioxidant efficacy (84%) at 10 μg/ml AgNP concentration against DPPH. The utilization of environmentally synthesized AgNPs offers numerous benefits of ecofriendliness and compatibility for biomedical applications.

Polyphenol containing Sargassum horneri attenuated Th2 differentiation in splenocytes of ovalbumin-sensitised mice: involvement of the transcription factors GATA3/STAT5/NLRP3 in Th2 polarization

Context Sargassum horneri (Turner) C. Agardh (Sargassaceae) is a brown marine alga used in oriental medicine to treat allergic conditions. Objective This study clarifies the effect of polyphenol-containing S. horneri ethanol extract (SHE) on T-helper type-2 (Th2) polarisation. Materials and methods All mice (BALB/c mice, n = 12) except in the healthy control group were first sensitised with an intraperitoneal injection of ovalbumin (OVA; 20 µg) and alum (2 mg) on Day 0 and Day 14. Similarly, phosphate-buffered saline (PBS) was injected according to the same schedule into the healthy control mice. After the final administration, splenocytes were obtained. OVA sensitised mice were challenged with OVA (100 µg/mL) in the absence or presence (62.5 and 125 µg/mL) of SHE while healthy control group remained untreated. Results SHE (0–1000 µg/mL) was not cytotoxic to splenocytes and demonstrated IC50 values of 3.27 and 3.92 mg/mL, respectively, at 24 and 48 h of incubation. SHE suppressed cell proliferation at concentrations ≥62.5 µg/mL. SHE treatment (125 µg/mL) subdued (by 1.8-fold) the population expansion of CD3+CD4+ helper T cells induced by OVA challenge. SHE attenuated the OVA-induced activation of respective transcription factors GATA3 and NLRP3. Simultaneously, highly elevated levels of cytokines interleukin (IL)-4 and IL-5 caused by OVA stimulation were removed completely and IL-13 suppressed by 1.5-fold. Conclusions SHE exhibits Th2 immune suppression under OVA stimulation via GATA3- and NLRP3-dependent IL-4, IL-5, and IL-13 suppression. Therefore, SHE could be therapeutically useful for alleviating the symptoms of allergen-mediated immune diseases.

Uptake of heavy metal Cd(II) from aqueous solutions using brown algae Sargassum myriocystum

The uptake of brown marine algae, Sargassum myriocystum has been utilized for the exclusion of Cd(II) metal from wastewater. Various parameters such as solution pH, optimum temperature, biomass concentration, the contact time and agitation speed have been analyzed for the effective biosorption of Cd(II). Desorption studies of Cd(II) have been performed with various desorbent such as H3PO4, HNO3, HCL, H2SO4, NaOH, NaCl, and H2O among which 0.1M/L HCl is found to be the better desorbing agent. SEM-EDX and FTIR analyses were utilized for metal-algal interaction study. The thermodynamic parameters such as free energy change (ΔG°), enthalpy change (∆Hº) and entropy change (∆Sº) have been calculated through the Van’t Hoff plot. A positive value of 14.72 ∆S Jmol-1K-1, a negative value of free energy (ΔG°) and 42.21 kJ/mol of ∆H kJmol-1 at all the temperatures indicated that the process is feasible and spontaneous. Hence, S. myriocystum is an effective and prosperous cost-effective biosorbent approach for Cd(II) from various industrial wastes due to its fast sorption rate, high selectivity and great uptake capacity.

Present Status, Limitations and Future Directions of Treatment Strategies Using Fucoidan-Based Therapies in Bladder Cancer.

Simple SummaryPrognosis of bladder cancer patients is often poor despite various intensive treatments are performed. Therefore, many investigators pay attention to the efficacy of natural product-based treatments to avoid additional adverse events in these patients. Here, we review the anti-cancer effects of fucoidan-based treatments and the protective effects against cancer-related disorders and cisplatin-induced toxicities.Bladder cancer (BC) is a common urological cancer, with poor prognosis for advanced/metastatic stages. Various intensive treatments, including radical cystectomy, chemotherapy, immune therapy, and radiotherapy are commonly used for these patients. However, these treatments often cause complications and adverse events. Therefore, researchers are exploring the efficacy of natural product-based treatment strategies in BC patients. Fucoidan, derived from marine brown algae, is recognized as a multi-functional and safe substrate, and has been reported to have anti-cancer effects in various types of malignancies. Additionally, in vivo and in vitro studies have reported the protective effects of fucoidan against cancer-related cachexia and chemotherapeutic agent-induced adverse events. In this review, we have introduced the anti-cancer effects of fucoidan extracts in BC and highlighted its molecular mechanisms. We have also shown the anti-cancer effects of fucoidan therapy with conventional chemotherapeutic agents and new treatment strategies using fucoidan-based nanoparticles in various malignancies. Moreover, apart from the improvement of anti-cancer effects by fucoidan, its protective effects against cancer-related disorders and cisplatin-induced toxicities have been introduced. However, the available information is insufficient to conclude the clinical usefulness of fucoidan-based treatments in BC patients. Therefore, we have indicated the aspects that need to be considered regarding fucoidan-based treatments and future directions for the treatment of BC.

Advances in Studies on the Pharmacological Activities of Fucoxanthin.

Fucoxanthin is a natural carotenoid derived mostly from many species of marine brown algae. It is characterized by small molecular weight, is chemically active, can be easily oxidized, and has diverse biological activities, thus protecting cell components from ROS. Fucoxanthin inhibits the proliferation of a variety of cancer cells, promotes weight loss, acts as an antioxidant and anti-inflammatory agent, interacts with the intestinal flora to protect intestinal health, prevents organ fibrosis, and exerts a multitude of other beneficial effects. Thus, fucoxanthin has a wide range of applications and broad prospects. This review focuses primarily on the latest progress in research on its pharmacological activity and underlying mechanisms.

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-1β) 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-1β), 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.

Squalene deters drivers of RCC disease progression beyond VHL status

Identifying drug candidates to target cellular events/signaling that evades von Hippel-Lindau tumor suppressor (VHL) gene interaction is critical for the cure of renal cell carcinoma (RCC). Recently, we characterized a triterpene-squalene derived from marine brown alga. Herein, we investigated the potential of squalene in targeting HIF-signaling and other drivers of RCC progression. Squalene inhibited cell proliferation, induced cell dealth and reverted the cells' metastatic state (migration, clonal expansion) independent of their VHL status. Near-identical inhibition of HIF-1α and HIF-2α and the regulation of downstream targets in VHL wild type and mutant cell lines demonstrated squalene efficacy beyond VHL-HIF interaction. In a rat model of chemically induced RCC, squalene displayed chemopreventive capabilities by substantial reversal of lipid peroxidation, mitochondrial redox regulation, maintaining ∆ψm, inflammation [Akt, nuclear factor κB (NF-κB)], angiogenesis (VEGFα), metastasis [matrix metalloproteinase 2 (MMP-2)], and survival (Bax/Bcl2, cytochrome-c, Casp3). Squalene restored glutathione, glutathione reductase, glutathione-s-transferase, catalase, and superoxide dismutase and stabilized alkaline phosphatase, alkaline transaminase, and aspartate transaminase. The correlation of thiobarbituric acid reactive substance with VEGF/NF-κB and negative association of GSH with Casp3 show that squalene employs reduction in ROS regulation. Cytokinesis-block micronuclei (CBMN) assay in VHLwt/mut cells revealed both direct and bystander effects of squalene with increased micronucleus (MN) frequency. Clastogenicity analysis of rat bone marrow cells demonstrated an anti-clastogenic effect of squalene, with increased polychromatic erythrocytes (PCEs), decreased MNPCE,s and MN normochromatic erythrocytes. Squalene could effectively target HIF signaling that orchestrate RCC evolution. The efficacy of squalene is similar in VHLwt and VHLmut RCC cells, and hence, squalene could serve as a promising drug candidate for an RCC cure beyond VHL status and VHL-HIF interaction dependency. Summary: Squalene derived from marine brown algae displays strong anti-cancer (RCC) activity, functionally targeting HIF-signaling pathway, and affects various cellular process. The significance of squalene effect for RCC is highlighted by its efficiency beyond VHL status, designating itself a promising drug candidate. Graphical abstract.

Exploiting Mannuronan C-5 Epimerases in Commercial Alginate Production.

Alginates are one of the major polysaccharide constituents of marine brown algae in commercial manufacturing. However, the content and composition of alginates differ according to the distinct parts of these macroalgae and have a direct impact on the concentration of guluronate and subsequent commercial value of the final product. The Azotobacter vinelandii mannuronan C-5 epimerases AlgE1 and AlgE4 were used to determine their potential value in tailoring the production of high guluronate low-molecular-weight alginates from two sources of high mannuronic acid alginates, the naturally occurring harvested brown algae (Ascophyllum nodosum, Durvillea potatorum, Laminaria hyperborea and Lessonia nigrescens) and a pure mannuronic acid alginate derived from fermented production of the mutant strain of Pseudomonas fluorescens NCIMB 10,525. The mannuronan C-5 epimerases used in this study increased the content of guluronate from 32% up to 81% in both the harvested seaweed and bacterial fermented alginate sources. The guluronate-rich alginate oligomers subsequently derived from these two different sources showed structural identity as determined by proton nuclear magnetic resonance (1H NMR), high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and size-exclusion chromatography with online multi-angle static laser light scattering (SEC-MALS). Functional identity was determined by minimum inhibitory concentration (MIC) assays with selected bacteria and antibiotics using the previously documented low-molecular-weight guluronate enriched alginate OligoG CF-5/20 as a comparator. The alginates produced using either source showed similar antibiotic potentiation effects to the drug candidate OligoG CF-5/20 currently in development as a mucolytic and anti-biofilm agent. These findings clearly illustrate the value of using epimerases to provide an alternative production route for novel low-molecular-weight alginates.

Biogenic zinc oxide, copper oxide and selenium nanoparticles: preparation, characterization and their anti-bacterial activity against Vibrio parahaemolyticus

The present study investigates biogenic preparation of zinc oxide (ZnO), copper oxide (CuO) and selenium (Se) nanoparticles using the marine brown alga Sargassum swartzii. The prepared nanomaterials were characterized using X-ray diffraction pattern (XRD), scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDAX), transmission electron microscopy (TEM) and UV–Vis diffuse reflectance spectroscopy (DRS-UV) analysis. The particle size of biogenic ZnO, CuO and Se nanoparticles was ca. 32, 32 and 21 nm, respectively. The isolation of bacterial pathogenic strain Vibrio parahaemolyticus (V. parahaemolyticus) from the diseased shrimp and virulent genes (toxR and tlh) confirmed by PCR technique. Further, the molecular characterized using 16S ribosomal RNA gene sequences and identified new strain V. parahaemolyticus strain (GRCORNICRA001). Anti-bacterial activity of biogenic nanomaterials (ZnO, CuO and Se) was investigated against isolated V. parahaemolyticus using well diffusion method and growth inhibitory assay. The minimum inhibitory concentration (MIC) was 25, 25 and 10 µg mL−1 of ZnO, CuO and Se nanoparticles, respectively. The results show that there is a strong bacterial inhibition in a dose-dependent manner. Further, SEM analysis revealed that the interaction of nanomaterials with V. parahaemolyticus, resulted in a surface tension change that leads to membrane depolarization, formation of abnormal textures such as membrane rupture, membrane blebs, membrane clumping, and also caused cell death. Results of this effort highlighted the way for the future that these nanomaterials incorporated with shrimp feed for the management of aquatic diseases.

ANTIMICROBIAL PROPERTIES OF SEVEN BROWN ALGAE HARVESTED FROM THE COAST OF SIDI BOUZID (EL JADIDA-MOROCCO)

Objective: This work aims at the screening of the antimicrobial activity of the seven brown marine algae of theCoast of Sidi Bouzid (El Jadida-Morocco).
 Methods: The aim of this study was to evaluate the antimicrobial activity of seven brown marine algae against three Gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus and Streptococcus pyogenes). Three Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia) and two fungi (Aspergillus Niger and Candida tropicalis). Thus, 35 algal extracts were prepared with five organic solvents methanol/water, methanol, dichloromethane/methanol, dichloromethane and ethyl acetate. The antibacterial activity was evaluated through the disk diffusion method.
 Results: Data revealed that the Staphylococcus aureus bacteria was the most sensitive pathogen by showing the highest zone of inhibitions of 20 mm with the lowest Minimum Inhibitory Concentration (MIC) of 2 μgmL⁻¹ methanol/water extract of Cystoseira tamariscifolia. Whereas, antifungal activity, the highest zone of inhibitions of 21 mm and 22 mm with the lowest Minimum Inhibitory Concentration (MIC) of 5 μgmL-¹ was respectively shown in the methanol/water extract of Laminaria ochroleuca against Candida tropicalis and in the dichloromethanolic extract of Sargassum vulgare against Aspergillus niger.
 Conclusion: The results indicate that these algal extracts can further be analyzed and purified for relevant antibacterial and antifungal compounds which can be used in therapeutics and other applications.

Sulfated polysaccharide ascophyllan from Padina tetrastromatica enhances healing of burn wounds by ameliorating inflammatory responses and oxidative damage.

Sulfated polysaccharide ascophyllan from marine brown algae has been identified to have burn wound healing properties. Thus, we examined the effects of ascophyllan fraction (AF3) on the inflammatory response and oxidative damage in burn wounds. Full-thickness burn wounds in rats were then treated twice per day with topical AF3 ointment (5%), while control groups were treated with 10% povidone-iodine (positive control) and petroleum jelly-based ointment (negative control). The activity of cyclooxygenase-2 and myeloperoxidase and levels of C-reactive protein, nitric oxide, and proinflammatory cytokines (tumor necrosis factor-α, interleukin-6, and interleukin-1β) were observed to have significantly decreased in peripheral blood mononuclear cells, serum, and wound tissue of the group treated with AF3 ointment on day 8 after wounding. The expression of inducible nitric oxide synthase, endothelial nitric oxide synthase, and vascular endothelial growth factor at the mRNA level was determined to be upregulated in the wound tissue of the AF3 ointment-treated group. After treatment with AF3 ointment, the antioxidant enzyme activity and level of reduced glutathione were upregulated, whereas the content of thiobarbituric acid reactive substances decreased. Treatment of burn wounds using 5% AF3 ointment decreases oxidative damage associated with inflammation deceptively via inhibition of inflammatory enzymes, regulation of proinflammatory cytokines, upregulation of angiogenesis, and activity of antioxidant enzymes.

Diphlorethohydroxycarmalol (DPHC) Isolated from the Brown Alga Ishige okamurae Acts on Inflammatory Myopathy as an Inhibitory Agent of TNF-α.

Inflammation affects various organs of the human body, including skeletal muscle. Phlorotannins are natural biologically active substances found in marine brown algae and exhibit anti-inflammatory activities. In this study, we focused on the effects of phlorotannins on anti-inflammatory activity and skeletal muscle cell proliferation activity to identify the protective effects on the inflammatory myopathy. First, the five species of marine brown algal extracts dramatically inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 cells without toxicity at all the concentrations tested. Moreover, the extracts collected from Ishige okamurae (I. okamurae) significantly increased cell proliferation of C2C12 myoblasts compared to the non-treated cells with non-toxicity. In addition, as a result of finding a potential tumor necrosis factor (TNF)-α inhibitor that regulates the signaling pathway of muscle degradation in I. okamurae-derived natural bioactive compounds, Diphlorethohydroxycarmalol (DPHC) is favorably docked to the TNF-α with the lowest binding energy and docking interaction energy value. Moreover, DPHC down-regulated the mRNA expression level of pro-inflammatory cytokines and suppressed the muscle RING-finger protein (MuRF)-1 and Muscle Atrophy F-box (MAFbx)/Atrgoin-1, which are the key protein muscle atrophy via nuclear factor-κB (NF-κB), and mitogen-activated protein kinase (MAPKs) signaling pathways in TNF-α-stimulated C2C12 myotubes. Therefore, it is expected that DPHC isolated from IO would be developed as a TNF-α inhibitor against inflammatory myopathy.

Studies On Invitro Analysis Of Sargassum Wightii Against Human Simplex Virus (HSV)

Introduction: Human simplex viruses are ulcerative diseased found in skin and genital organs dependingupon the strain. It affects an individual at least once in a lifetime by direct contact with an infected person.There are two strains of HSV predominantly found are HSV-1 and HSV-2. HSV-1 infects the pharynx andoral region, whereas HSV-2 infects the genital areas of sexual contact.Materials and Method: The crude extract of S. wightii on the proliferation of Vero cells was assessed bythe neutral dye uptake method. Various fold of serially diluted solvent crude extracts showed cytotoxicconcentration50 (CC50) at 750 and 500mg/mL of ethyl acetate and methanol extract, respectively.Results: The Antiviral activity of solvent crude extract against HSV-1 showed significant reduction of viruson Vero cells. Among the solvent crude tested, the ethyl acetate showed effective IC50 against HSV-1 at 300mg/mL.Conclusion: The seaweed S. wightii is a natural source in treating the pathogen HSV-1 and it clearlyindicated that, the marine brown algae S. wightii possess strong antiviral activity with slight cytotoxic effect.

Alginate: From Food Industry to Biomedical Applications and Management of Metabolic Disorders.

Initially used extensively as an additive and ingredient in the food industry, alginate has become an important compound for a wide range of industries and applications, such as the medical, pharmaceutical and cosmetics sectors. In the food industry, alginate has been used to coat fruits and vegetables, as a microbial and viral protection product, and as a gelling, thickening, stabilizing or emulsifying agent. Its biocompatibility, biodegradability, nontoxicity and the possibility of it being used in quantum satis doses prompted scientists to explore new properties for alginate usage. Thus, the use of alginate has been expanded so as to be directed towards the pharmaceutical and biomedical industries, where studies have shown that it can be used successfully as biomaterial for wound, hydrogel, and aerogel dressings, among others. Furthermore, the ability to encapsulate natural substances has led to the possibility of using alginate as a drug coating and drug delivery agent, including the encapsulation of probiotics. This is important considering the fact that, until recently, encapsulation and coating agents used in the pharmaceutical industry were limited to the use of lactose, a potentially allergenic agent or gelatin. Obtained at a relatively low cost from marine brown algae, this hydrocolloid can also be used as a potential tool in the management of diabetes, not only as an insulin delivery agent but also due to its ability to improve insulin resistance, attenuate chronic inflammation and decrease oxidative stress. In addition, alginate has been recognized as a potential weight loss treatment, as alginate supplementation has been used as an adjunct treatment to energy restriction, to enhance satiety and improve weight loss in obese individuals. Thus, alginate holds the promise of an effective product used in the food industry as well as in the management of metabolic disorders such as diabetes and obesity. This review highlights recent research advances on the characteristics of alginate and brings to the forefront the beneficial aspects of using alginate, from the food industry to the biomedical field.

Screening of anti-oxidant and anti-bacterial metabolites from brown algae Turbinaria ornata for inhibits the multi-drug resistant P. aeruginosa

In this study, the anti-oxidant and anti-bacterial activity of marine brown algae Turbinaria ornata (T. ornate) extract was purified by soxhlet apparatus method. The invitro studies of total anti-oxidant activity and DPPH hydroxyl scavenging activity assays were suggested that the T. ornata extract has more anti-oxidant activity. Agar well diffusion and minimum inhibition concentration results were exhibited excellent inhibition effect of T. ornata extract against P. aeruginosa at 300 µg/mL concentration. The time-dependent bacterial inhibition assay was also confirmed the 300 µg/mL concentration at 24 h. Further, the increased death cells and extracellular shape alteration results were observed by confocal laser scanning electron microscope and scanning electron microscope. Therefore, our result was suggested that the T. ornata extract as a promising anti-bacterial agent for multi-drug resistant P. aeruginosa.

Marine Algae as a Potential Source for Anti-diabetic Compounds - A Brief Review.

Diabetes Mellitus (DM) is a major chronic metabolic disorder characterized by hyperglycemia that leads to several complications such as retinopathy, atherosclerosis, nephropathy, etc. In 2019, it was estimated that about 463 million people had diabetes, and it may increase up to 700 million in 2045. Marine macroalgae are the rich source of bioactive compounds for the treatment of diabetes mellitus. This review summarizes the recent epidemiology and possible use of marine macroalgae-derived bioactive compounds for the protection against chronic metabolic disease, diabetes mellitus and marine macroalgae as a nutraceutical supplement. The present therapies available for diabetes treatment are oral medicines and insulin injections. But continuous use of synthetic medicines provides low therapeutic with many side effects. In continuing search of anti-diabetic drugs, marine macroalgae remain as a promising source with potent bioactivity. Among existing marine algae, red and brown algae are reported to show anti-diabetic activity. Hence, the present review focuses on the epidemiology, diabetes biomarkers and different secondary bioactive compounds present in marine macroalgae to treat diabetes mellitus.

Sargassum horneri (Turner) C. Agardh containing polyphenols attenuates particulate matter-induced inflammatory response by blocking TLR-mediated MYD88-dependent MAPK signaling pathway in MLE-12 cells

Ethnopharmacological relevanceSargassum horneri (Turner) C. Agardh (S. horneri), an edible brown marine algae, is known to have immunomodulatory effects and has been used in oriental medicine to treat inflammatory diseases. It is well known that ambient particulate matter (PM) is closely related to increased respiratory diseases inducing lung inflammation. AimConsidering the use of Sargassum horneri in traditional medicine to treat inflammatory diseases, we hypothesized and investigated the use of Sargassum horneri containing polyphenols against PM-induced inflammatory responses. Materials and methodsIn this study, we evaluated the impact of PM (majority <2.5 μm in diameter) on deep bronchial penetration ability upon inhalation and a therapeutic approach to mitigate its harmful effects using an ethanol extract of Sargassum horneri, an edible brown algae, containing polyphenols on a type II alveolar epithelial cell line, MLE-12. ResultsPM triggered mRNA expression of toll-like receptors (TLRs) TLR2/4/7, and those TLRs were significantly attenuated by Sargassum horneri extract (SHE). SHE further attenuated the phosphorylation of mitogen-activated protein kinase (MAPK) p38, extracellular signal-regulated kinase 1/2 (Erk1/2), and c-Jun NH (2)-terminal kinase (JNK), which were also activated in PM-exposed cells. Altogether, SHE subdued the PM-induced mRNA expression of pro-inflammatory cytokines (interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-6) and lung epithelial cell derived-chemokines (IL-8, monocyte chemoattractant protein-1 (MCP-1), and chemokine (C–C motif) ligand 5 (CCL5)). SHE also suppressed the mRNA expression of PM-induced pro-allergic cytokines thymic stromal lymphopoietin (TSLP) and interleukin (IL)-33. Furthermore, we showed that SHE suppressed the MAPK-dependent signaling pathway by attenuating receptor-associated factor (TRAF) 6 activation of proteins MyD88 and TNF. ConclusionTaking all the data together, we suggest that the anti-inflammatory potential of SHE on PM-exposed MLE-12 cells is mediated by the inhibition of PM-triggered downstream signaling along the TLR2/4/7–MyD88–TRAF6 axis of MAPK signaling.

Biosorption of Sr2+ and Cs+ onto Undaria pinnatifida: Isothermal titration calorimetry and molecular dynamics simulation

In this paper, the biosorption of strontium and cesium ions onto a marine brown alga Undaria pinnatifida (also known as wakame), was studied using isothermal titration calorimetry and molecular dynamics simulation. Different adsorption performance of cesium and strontium ions was evaluated. The adsorption kinetics of cesium and strontium ions followed to pseudo second-order and pseudo first-order models, respectively. The maximum adsorption capacity was 1.10 and 2.17 mmol g−1 for cesium and strontium ions, respectively, calculated by the Sips isotherm. The main active sites for metal ion adsorption were carboxyl, sulfate, amine and amide. The isothermal titration calorimetry indicated that strontium ion was more competitive than cesium ion for binding sodium alginate. The molecular dynamics simulation revealed a stronger interaction energy between sodium alginate and strontium ion than that of cesium ion. This study revealed underlying mechanisms of different performances of cesium and strontium adsorptions by both experimental and computational approaches, suggesting the potential application of Undaria pinnatifida for adsorptive removal of cesium and strontium ions from aqueous solution.

Predicting the combustion behaviour of compression ignition engine fuelled with biodiesel from Stoechospermum marginatum, a macro algae.

Biodiesel is one among the recent developments in the field of renewable energy research. To enhance the combustion characteristics of compression ignition engine, industry and academicians were working towards clean and renewable energy resource. Algal biodiesel was one of the major research arenas in the recent decade of renewable energy. Bio-oil from marine brown macro algae, Stoechospermum marginatum was used as the test fuel in this study. The purpose of this numerical study was to analyse the combustion behaviour of compression ignition engine when fuelled with Stoechospermum marginatum biodiesel as a fuel. The numerical study was performed using the zero-dimensional combustion model by incorporating the dynamic combustion duration during the heat transfer using the MATLAB Simulink software. The developed model which incorporated the instantaneous combustion duration was a novel approach. Validations of the numerical results on combustion features like in-cylinder pressure, rate of pressure rise, rate of heat release, and cumulative heat release were done by comparing it with the experimental data. The deviation between the numerical and experimental values was found to be within 5 to 6%.