Characterization of alginate extracted from Sargassum latifolium and its use in Chlorella vulgaris growth promotion and riboflavin drug delivery.

Alginates derived from macroalgae have been widely used in a variety of applications due to their stability, biodegradability and biocompatibility. Alginate was extracted from Egyptian Sargassum latifolium thallus yielding 17.5% w/w. The chemical composition of S. latifolium is rich in total sugars (41.08%) and uronic acids (47.4%); while, proteins, lipids and sulfates contents are 4.61, 1.13 and 0.09%, respectively. NMR, FTIR and TGA analyses were also performed. Crystallinity index (0.334) indicates alginate semicrystalline nature. Sodium alginate hydrolysate was evaluated as Chlorella vulgaris growth promoter. The highest stimulation (0.7 g/L biomass) was achieved by using 0.3 g/L alginate hydrolysate supplementation. The highest total soluble proteins and total carbohydrates were 179.22 mg/g dry wt and 620.33 mg/g dry wt, respectively. The highest total phenolics content (27.697 mg/g dry wt.), guaiacol peroxidase activity (2.899 µmol min-1 g-1) were recorded also to 0.3 g/L alginate hydrolysate supplementation. Riboflavin-entrapped barium alginate-Arabic gum polymeric matrix (beads) was formulated to achieve 89.15% optimum drug entrapment efficiency (EE%). All formulations exhibited prolonged riboflavin release over 120 min in simulated gastric fluid, followed Higuchi model (R2 = 0.962-0.887) and Korsmeyer-Peppas model with Fickian release (n ranges from 0.204 to 0.3885).

Chitosan/Hyaluronic acid/Alginate and an assorted polymers loaded with honey, plant, and marine compounds for progressive wound healing-Know-how.

Biomaterials are being extensively used in regenerative medicine including tissue engineering applications, as these enhance tissue development, repair, and help in the process of angiogenesis. Wound healing is a crucial biological process of regeneration of ruptured tissue after getting injury to the skin and other soft tissue in humans and animals. Besides, the accumulation of microbial biofilms around the wound surface can increase the risk and physically obstruct the wound healing activity, and may even lead to amputation. Hence, in both acute and chronic wounds, prominent biomaterials are required for wound healing along with antimicrobial agents. This review comprehensively addresses the antimicrobial and wound healing effects of chitosan, chitin, cellulose acetate, hyaluronic acid, pullulan, bacterial cellulose, fibrin, alginate, etc. based wound dressing biomaterials fabricated with natural resources such as honey, plant bioactive compounds, and marine-based polymers. Due to their excellent biocompatibility and biodegradability, bioactive compounds derived from honey, plants, and marine resources are commonly used in biomedical and tissue engineering applications. Different types of polymer-based biomaterials including hydrogel, film, scaffold, nanofiber, and sponge dressings fabricated with bioactive agents including honey, curcumin, tannin, quercetin, andrographolide, gelatin, carrageenan, etc., can exhibit significant wound healing process in, diabetic wounds, diabetic ulcers, and burns, and help in cartilage repair along with good biocompatibility and antimicrobial effects. Among the reviewed biomaterials, carbohydrate polymers such as chitosan-based biomaterials are prominent and widely used for wound healing applications followed by hyaluronic acid and alginate-based biomaterials loaded with honey, plant, and marine compounds. This review first provides an overview of the vast natural resources used to formulate different biomaterials for the treatment of antimicrobial, acute, and chronic wound healing processes.

Alginate from Sargassum siliquosum Simultaneously Stimulates Innate Immunity, Upregulates Immune Genes, and Enhances Resistance of Pacific White Shrimp (Litopenaeus vannamei) Against White Spot Syndrome Virus (WSSV).

Although alginate is known as an immunostimulant in shrimp, the comprehensive and simultaneous study on its activity to resolve the relationship of the hematological parameters, upregulation of immune-related gene expression, and resistance to pathogen has not been found in shrimp. We performed experiments to evaluate the effect and mechanism of alginate from S. siliquosum on Pacific white shrimp immune system. Hematological parameters were examined after oral administration of Na alginate in the shrimp. White spot syndrome virus (WSSV) was injected to the shrimp at 14 days, and its copy number was examined quantitatively (qRT-PCR). Immune-related gene expression was evaluated by qRT-PCR. Alginate increased some hematological immune parameters of shrimp. Before WSSV infection, expression levels of Toll and lectin genes were upregulated. The lectin gene were upregulated post infection, and the Toll gene in all the treatments were downregulated, except the shrimps fed with alginate at 6.0 g kg-1 at 48 h post infection (hpi). The shrimps fed with alginate at 6.0 g kg-1 were the most resistant and gave the least WSSV copy number at 48 hpi. Resistance of shrimps fed the alginate-supplemented diets against WSSV was significantly higher compared to that of the control treatment with 56% and 10% of survival rates, respectively. Oral administration of alginate did not affect the growth and total protein plasma. At 120 h post challenge, alginate treatment at 6.0 g kg-1 exhibited the highest survival rate. It is concluded that oral administration of alginate enhanced the innate immunity by upregulating immune-related gene expression. Consequently, the enhancement of the shrimp innate immunity improves the resistance against WSSV infection.

Evaluation of Prebiotic Potential of Three Marine Algae Oligosaccharides from Enzymatic Hydrolysis.

Alginate oligosaccharides (AlgO), agarose oligosaccharides (AO), and κ-carrageenan oligosaccharides (KCO) were obtained by specific enzymatic hydrolysis method. The molecular weight distributions of the three oligosaccharides were 1.0⁻5.0 kDa, 0.4⁻1.4 kDa, and 1.0⁻7.0 kDa, respectively. The culture medium was supplemented with the three oligosaccharides and fermented by pig fecal microbiota in vitro, for 24 h. Each oligosaccharide was capable of increasing the concentration of short-chain fatty acids (SCFAs), especially butyric acid, and altering the microbiota composition. Linear discriminant analysis effect size (LEfSe) analysis results showed that the opportunistic pathogenic bacteria Escherichia, Shigella, and Peptoniphilus, were significantly decreased in AlgO supplemented medium. AO could improve the gut microbiota composition by enriching the abundance of Ruminococcaceae, Coprococcus, Roseburia, and Faecalibacterium. Besides, KCO could increase the abundance of SCFA microbial producers and opportunistic pathogenic flora. Therefore, these results indicate that AlgO and AO can be used as gut microbial regulators and can potentially improve animal/human gastrointestinal health and prevent gut disease, whereas the physiological function of KCO needs further evaluation.

Wound healing property of a gel prepared by the combination of Pseudomonas aeruginosa alginate and Alhagi maurorum aqueous extract in rats.

Although alginate has been known to be a good wound dressing, it does not have antimicrobial properties, has low availability, and is expensive. To overcome these problems, the present study was conducted, where the extraction of this material from an available small factory Pseudomonas aeruginosa and the improvement of its wound healing property by its combination with herb extract, Alhagi maurorum, done. Nineteen P. aeruginosa strains were isolated and identified from burned skin, and the one isolated strain with the highest ability of alginate production was selected. A. maurorum aqueous extract was prepared, and the toxicity of each material was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide assay. A mixture of nontoxic doses of each substance was then prepared. Thirty-two Wistar rats were divided into four groups (n = 8). The control group and the rest three groups, which were treated by alginate, A. maurorum extract, and alginate- A. maurorum extract. Throughout the 21 days of treatment, the open wound sites were checked. Finally, the rats were sacrificed and the effect of each substance on their skin tissue was evaluated. The results showed that the high alginate production without any toxic effect was obtained from the P. aeruginosa strain K1. A. maurorum aqueous extract had dose-dependent toxicity. The aqueous solution of alginate- A. maurorum extract complex group showed the best wound healing activity in both macroscopic and microscopic examinations. Recent research has introduced a new type of wound dressing with high wound healing properties. This could decrease the time for re-epithelialization and increase wound contraction percentage.

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.

Anti-inflammatory and antioxidant potential of alginic acid isolated from the marine algae, Sargassum wightii on adjuvant-induced arthritic rats.

The present study evaluated the anti-inflammatory and antioxidant potential of alginic acid isolated from brown algae Sargassum wightii in arthritic rats. Arthritis was induced in male Sprague-Dawley rats by intradermal injection of complete Freund's adjuvant into the right hind paw, produce inflammation of the joint tissue. Paw edema volume, enzymes linked to inflammation such as cyclooxygenase, lipoxygenase and myeloperoxidase, and the level of ceruloplasmin, C-reactive protein and rheumatoid factor were evaluated in all the experimental groups. Oxidative stress during inflammation was analyzed by estimating lipid peroxidation and the activities of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and non-enzymatic antioxidant, reduced glutathione. Alginic acid treatment (100 mg/kg) in arthritic rats exhibited reduced paw edema volume along with reduced activities of enzymes such as cyclooxygenase, lipoxygenase and myeloperoxidase. Reduction in the level of C-reactive protein, ceruloplasmin and rheumatoid factor were also observed in arthritic rats treated with alginic acid along with reduced lipid peroxidation and enhanced activities of antioxidant enzymes, which suggest the antioxidant potential of the compound. Histopathological analysis of paw tissue showed that alginic acid treatment reduced paw edema and inflammatory infiltration in arthritic rats. Overall results suggest that alginic acid isolated from Sargassum wightii exhibits potent anti-inflammatory and antioxidant activity, and can develop this marine alga as an alternative source for therapy and can be used as a drug candidate for the development of anti-inflammatory agent.

Alginic acid isolated from Sargassum wightii exhibits anti-inflammatory potential on type II collagen induced arthritis in experimental animals.

The present study evaluated the anti-inflammatory potential of alginic acid isolated from the brown algae Sargassum wightii in type II collagen induced arthritic rats, a well established arthritic model that resembles more closely to human rheumatoid arthritis in its clinical, pathological, immunological and histological aspects. Type II collagen induced arthritic rats showed increased activities of inflammatory marker enzymes like cycloxygenase-2 (COX-2), lipoxygenase (5-LOX), xanthine oxidase (XO) and myeloperoxidase (MPO) along with increased concentration of rheumatoid factor (RF), ceruloplasmin and C-reactive protein (CRP). Treatment with alginic acid significantly reduced the activities of COX-2 and 5-LOX along with reduction in MPO, XO, RF and CRP. Alginic acid treatment reverted to the altered levels of hematological parameters like RBC count, WBC count and ESR in arthritic rats. Concentrations of proinflammatory cytokines like IL-1 ß, TNF α and IL-6 were significantly higher in arthritic rats which were reduced on treatment with alginic acid. Increased activities of lysosomal enzymes that manifest the systemic damage during arthritis were significantly reduced by the treatment with alginic acid which indicates the reduction in the rupture and degradation of connective tissue. Histopathology of knee joint tissues showed that extensive bone degradation and synovial hyperplasia along with infiltrating cells and treatment with alginic acid reversed the histopathological changes which indicate the protective potential of alginic acid in rheumatoid arthritis.

Novel tamarind seed polysaccharide-alginate mucoadhesive microspheres for oral gliclazide delivery: in vitro-in vivo evaluation.

Novel tamarind seed polysaccharide (TSP)-alginate mucoadhesive microspheres were prepared using TSP and alginate as blend in different ratios with different calcium chloride (CaCl(2)) concentration as a cross linker by ionotropic gelation. The prepared microspheres were of spherical shape having rough surfaces, and average particle sizes within the range of 752.12 ± 6.42 to 948.49 ± 20.92 µm. The drug entrapment efficiency of these microspheres were within the range between 58.12 ± 2.42 to 82.78 ± 3.43% w/w. Fourier transform infrared (FTIR) studies indicated that there were no reactions between gliclazide, and polymers (TSP, and sodium alginate) used. Different formulations of gliclazide loaded TSP-alginate microspheres showed prolonged in vitro release profiles of gliclazide over 12 hours in both stomach pH (pH 1.2), and intestinal pH (pH 7.4). It was found that the gliclazide release in gastric pH was comparatively slow and sustained than intestinal pH. These TSP-alginate microspheres also exhibited good mucoadhesivity. The in vivo studies on alloxan-induced diabetic rats (Animal Ethical Committee registration number: IFTM/837ac/0160) demonstrated the significant hypoglycemic effect of selected formulation of TSP-alginate mucoadhesive microspheres containing gliclazide on oral administration. This developed gliclazide loaded new TSP-alginate mucoadhesive microspheres may be very much useful for prolonged systemic absorption of gliclazide for proper maintaining blood glucose level and advanced patient compliance.

The contribution of exopolysaccharides induced struvites accumulation to ammonium adsorption in aerobic granular sludge.

Aerobic granular sludge from a lab-scale reactor with simultaneous nitrification/denitrification and enhanced biological phosphorus removal processes exhibited significant amount of ammonium adsorption (1.5 mg NH4+-N/g TSS at an ammonium concentration of 30 mg N/L). Potassium release accompanied ammonium adsorption, indicating an ion exchange process. The existence of potassium magnesium phosphate (K-struvite) as one of potassium sources in the granular sludge was studied by X-ray diffraction analysis (XRD). Artificially prepared K-struvite was indeed shown to adsorb ammonium. Alginate-like exopolysaccharides were isolated and their inducement for struvite formation was investigated as well. Potassium magnesium phosphate proved to be a major factor for ammonium adsorption on the granular sludge. Struvites (potassium/ammonium magnesium phosphate) accumulate in aerobic granular sludge due to inducing of precipitation by alginate-like exopolysaccharides.

Preventive effects of low molecular mass potassium alginate extracted from brown algae on DOCA salt-induced hypertension in rats.

Available evidence indicates that brown algae may be beneficial for the treatment of high blood pressure. Our recent study demonstrated that low molecular mass potassium alginate (L-PA), one of the major polysaccharides extracted from brown algae, decreased systolic blood pressure (SBP) in spontaneous hypertensive rats. The present study investigated the effects of L-PA on deoxycorticosterone acetate (DOCA) salt-induced hypertension in rats. Hypertension was induced by biweekly subcutaneous injections of 50mg/kg DOCA plus 1% NaCl in drinking water. The control group received saline injections. L-PA (250 or 500 mg/kg), KCl (239 mg/kg), or volume-matched solvent was administered orally once daily for 30 days. DOCA salt administration significantly increased SBP, sodium excretion, serum sodium content, circulating plasma volume (CPV), plasma atrial natriuretic peptide (ANP) content, heart and renal weight indices, and mortality and decreased plasma aldosterone (ALD) and serum potassium levels in the vehicle-treated DOCA salt group compared with the control group. However, L-PA dose-dependently normalized the above changes induced by DOCA salt, with the exception of further increasing sodium excretion, while KCl did not affect the changes caused by DOCA salt, with the exception of slightly ameliorating hypokalemia and mortality. These findings suggest that L-PA may offer a novel form of potassium supplementation with greater antihypertensive and sodium excretion actions than KCl and may likely be beneficial for the primary prevention and treatment of hypertension and its cardiovascular sequelae.

Enhanced phenol degradation by Pseudomonas sp. SA01: gaining insight into the novel single and hybrid immobilizations.

In this work, Pseudomonas sp. SA01 cells were immobilized in a series of singular and hybrid immobilization techniques to achieve enhanced phenol removal. The singular immobilization strategies consisted of various concentrations of alginate (2-4%) and pectin (3-5%), while the hybrid strategies incorporated polyvinyl alcohol (PVA)-alginate and glycerol-alginate beads and alginate-chitosan-alginate (ACA) capsules. Immobilization protected cells against phenol and resulted in remarkable reduction (65%) in degradation time by cells immobilized in either alginate (3%) beads, in a hybrid PVA-alginate beads, or in ACA capsules compared to freely suspended cells. Cells immobilized in PVA-alginate and ACA provided the best performance in experiments using elevated phenol concentrations, up to 2000 mg/L, with complete degradation of 2000 mg/L phenol after 100 and 110 h, respectively. Electron microscopy examination indicated that cell loading capacity was increased in PVA-alginate hybrid beads through reduced cell leakage, resulting in higher activity of PVA-alginate hybrid beads compared to all other immobilization methods.

Manipulation of the acetylation degree of Azotobacter vinelandii alginate by supplementing the culture medium with 3-(N-morpholino)-propane-sulfonic acid.

AIMS: The aim of this study was to characterize the influence of 3-(N-morpholino)-propane-sulfonic acid (MOPS) on alginate production by Azotobacter vinelandii and its chemical composition (particularly its acetylation degree), as well as on the rheological behaviour of alginate-reconstituted solutions. METHODS AND RESULTS: Cultures were grown in 500-ml flasks containing 90 ml of medium supplemented with MOPS in concentrations ranging from 0 to 13.6 mmol l(-1). The acetylation degree of the alginate was significantly influenced by the MOPS concentration, obtaining an alginate with an acetylation degree of 1.4% when 13.6 mmol l(-1) of MOPS was added to the medium. This value was twice as high as that obtained when no MOPS was used. The higher acetylation of the polymer resulted in higher viscosity of alginate solutions, having a more pronounced pseudoplastic behaviour. CONCLUSIONS: MOPS added to the culture medium determines the acetyl content of the alginate and thus, the physico-chemical properties of the polymer. SIGNIFICANCE AND IMPACT OF THE STUDY: These changes in the functional properties of the polymer can be very valuable in specific applications of alginate in the food and pharmaceutical fields.

[Functional properties of alginates and their use in therapeutic-prophylactic nutrition]. / Funktsional'nye svoistva al'ginatov i ikh ispol'zovanie v lechebno-profilakticheskom pitanii.

Adsorbability of alginic acid and its salts extracted from brown seaweeds and character of their biological action were studied. The results of clinical tests alginic acid and its salts as well as of preparations and food-stuffs, prepared from Laminaria japonica Arech, were reflected. The potentialities of use of alginates and food-stuffs containing them in therapeutic nutrition was shown.

Composition of alginate synthesized during the growth cycle of Pseudomonas aeruginosa.

A mucoid P. aeruginosa isolated from the sputum of a cystic fibrosis patient was grown in batch culture on a complex medium. During the growth cycle the amount of alginate produced was estimated and its composition was determined by proton magnetic resonance (1H-n.m.r) spectroscopy. Exopolysaccharide production occurred mainly during the exponential phase of growth. The alginate samples isolated varied little in composition and were characterized by being highly acetylated, high mannuronate (0.83-0.93 mole fraction) polymers. Guluronate was present only within heteropolymeric regions of the polysaccharides which all displayed a complete absence of polyguluronate. Ca2+ ion supplementation of the medium was not observed to increase the levels of guluronate in the alginates produced.