Composition, physicochemical properties, and anti-fatigue activity of water-soluble okra (Abelmoschus esculentus) stem pectins.

Okra, Abelmoschus esculentus (L.) Moench, an annual herbaceous plant, is widely distributed in tropical and subtropical regions. Water-soluble pectic hydrocolloids from okra stems (HOS) were extracted and purified using polydivinylbenzene HP-20 resins. The sugar composition of the purified HOS with an weight-average molecular weight of 178.4 ± 2.1 kDa and a polydispersity index of 1.02 ± 0.02 contained galacturonic acid (34%), galactose (31%), rhamnose (21%), arabinose (4.2%), glucuronic acid (2.5%), xylose (1.2%), and other monosaccharides (6.1%) by weight. Its favorable rheological behaviors were evident on relatively higher concentrations (20, 25, and 30 mg/mL) and moderately lower pH levels (3 and 5) of HOS. The anti-fatigue experiments in vivo demonstrated that a high dose of HOS (450 mg/kg feed) prolonged the exhaustive swimming time of mice, significantly induced an increase in blood glucose and glycogen, and decreased lactic acid and serum urea nitrogen levels. HOS digestion in vivo was fairly conducive to the improvement of energy storage capacity and renal function for physically induced fatigue, compared with the conventional herbal supplement Panax quinquefolium. Accordingly, HOS exhibits potential for reutilization of okra stem waste.

Physicochemical Characterization, Antioxidant and Immunostimulatory Activities of Sulfated Polysaccharides Extracted from Ascophyllum nodosum.

Polysaccharides from Ascophyllum nodosum (AnPS) were extracted and purified via an optimized protocol. The optimal extraction conditions were as follows: extraction time of 4.3 h, extraction temperature of 84 °C and ratio (v/w, mL/g) of extraction solvent (water) to raw material of 27. The resulting yield was 9.15 ± 0.23% of crude AnPS. Two fractions, named AnP1-1 and AnP2-1 with molecular weights of 165.92 KDa and 370.68 KDa, were separated from the crude AnPS by chromatography in DEAE Sepharose Fast Flow and Sephacryl S-300, respectively. AnP1-1 was composed of mannose, ribose, glucuronic acid, glucose and fucose, and AnP2-1 was composed of mannose, glucuronic acid, galactose and fucose. AnPS, AnP1-1 and AnP2-1 exhibited high scavenging activities against ABTS radical and superoxide radical, and showed protective effect on H2O2-induced oxidative injury in RAW264.7 cells. Furthermore, the immunostimulatory activities of AnP1-1 and AnP2-1 were evaluated by Caco-2 cells, the results showed both AnP1-1 and AnP2-1 could significantly promote the production of immune reactive molecules such as interleukin (IL)-8, IL-1ß, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. Therefore, the results suggest that AnPS and its two fractions may be explored as a potential functional food supplement.

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.

Effect of ultrasonic degradation of hyaluronic acid extracted from rooster comb on antioxidant and antiglycation activities.

CONTENT: Recently, low-molecular-weight hyaluronic acid (LMWHA) has been reported to have novel features, such as free radical scavenging activities, antioxidant activities and dietary supplements. OBJECTIVE: In this study, hyaluronic acid (HA) was extracted from rooster comb and LMWHA was obtained by ultrasonic degradation in order to assess their antioxidant and antiglycation activities. MATERIALS AND METHODS: Molecular weight (Mw) and the content of glucuronic acid (GlcA) were used as the index for comparison of the effect of ultrasonic treatment. The effects on the structure were determined by ultraviolet (UV) spectra and Fourier transform infrared spectra (FTIR). The antioxidant activity was determined by three analytical assays (DPPH, NO and TBARS), and the inhibitory effect against glycated-BSA was also assessed. RESULTS: The GlcA content of HA and LMWHA was estimated at about 48.6% and 47.3%, respectively. The results demonstrate that ultrasonic irradiation decreases the Mw (1090-181 kDa) and intrinsic viscosity (1550-473 mL/g), which indicate the cleavage of the glycosidic bonds. The FTIR and UV spectra did not significantly change before and after degradation. The IC50 value of HA and LWMHA was 1.43, 0.76 and 0.36 mg/mL and 1.20, 0.89 and 0.17 mg/mL toward DPPH, NO and TBARS, respectively. Likewise LMWHA exhibited significant inhibitory effects on the AGEs formation than HA. DISCUSSION AND CONCLUSION: The results demonstrated that the ultrasonic irradiation did not damage and change the chemical structure of HA after degradation; furthermore, decreasing Mw and viscosity of LMWHA after degradation may enhance the antioxidant and antiglycation activity.

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.

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.

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.

[Structural characterization of a glucan isolated from Gastrodia elata].

OBJECTIVE: To study a glucan (GB II) isolated from Gastrodia elata. METHODS: The glucan was obtained with water extraction, alcohol precipitate, DEAE-Sepharose Fast Flow column and Sepharose CL-6B column chromatography; sugar composition analysis, IR and NMR were used to determine the structural feature. RESULTS: The molecular weight of the glucan was 4 300 dalton estimated by HPGPC; it contained 27 glucose residues, which mainly composed of alpha-D-(1-->4)-glucose with little glucuronic acid and branch O-6 points. CONCLUSION: The glucan was a new glucan for the first report from Gastrodia elata.

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.

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.

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.

[Isolation, purification and analysis of polysaccharides from Adenophora potaninii Korsh].

Polysaccharides, AP-1 and AP-3, were obtained through extraction of the roots of Adenophora potaninii Korsh by hot water, followed by the isolation and purification by DEAE-cellulose and Sephadex G-200 column chromatography. It was proved to be homogeneous by gel filtration chromatography and their average MW was estimated to be 8.3 x 10(4) and 6.3 x 10(4) respectively. Analysis of sugar composition showed that AP-1 is D-glucan, while AP-3 is composed of glucose, rhamnose, arabinose and glucronic acid in the molar ratio of 5:1:1:3.