Chemical and Biological Properties of Sodium Alginates Isolated from Tow Brown Algae Dictyopteris Membranaceae and Padina Pavonica

Polysaccharides are known to have interesting biological activities. To date polysaccharides extracted from Tunisian seaweed have not been fully studied. In this paper we tried to isolate sodium alginate from two brown algae and evaluate their biological activities. Two brown seaweeds Dictyopteris membranaceae and Padina pavonica were treated with selective solvents to extract sodium alginate. Analyses were performed to determine their IR spectra, uronic acid’s content and biological properties (antioxidant and gastroprotective activities). Results showed that sodium alginate extracted from D. membranaceae contained 65% of uronic acid while this extracted from P. pavonica contained only 9% of uronic acid. These polysaccharides showed also variation in the structure and the activities. Sodium alginate extracted from D. membranaceae had the highest antioxidant activity with ED50 of 20µg/ml in the DPPH test. Additionally, this polysaccharide had the most important gastroprotective activity with a percent of 97% at dose 50mg/kg. Our finding suggested that sodium alginates extracted from D. membranaceae and P. pavonica could be used as a natural source of antioxidant and gastroprotective agents. &nbsp

Anti-inflammatory and analgesic activities with gastroprotective effect of semi-purified fractions and isolation of pure compounds from Mediterranean gorgonian Eunicella singularis.

Abstract Objective To explore anti-inflammatory activities of organic extract and its semi-purified fractions (ethanol, acetone, methanol/dichloromethane) from the Mediterranean gorgonian Eunicella singularis. Methods The anti-inflammatory and analgesic activities were evaluated, using the carrageenan-induced rat paw edema model and the acetic acid writhing test in mice. The gastroprotective activity was determined using HCl/EtOH induced gastric ulcers in rats. The purification and structure elucidation of compound(s) from the more effective fraction were determined by chromatographic and spectroscopic methods and in comparison with data reported in the literature. Results The fraction F–EtOH showed an important anti-inflammatory activity associated with significant analgesic and gastroprotective properties. The purification and structure elucidation of compound(s) from this fraction lead to the identification of one diterpenoid and four sterols. Conclusions These results suggested that components from the active fraction can be used to treat various anti-inflammatory diseases

Antimalarial and cytotoxic activities of chiral triamines.

Chiral triamine antimalarial compounds have been identified following the screening of mixture-based positional scanning libraries made up of 31,320 compounds against P. falciparum. The library, namely N-methyl triamine (TPI 762) was generated following exhaustive reduction of resin-bound acylated dipeptides. Using the PSCL approach, individual compounds were rapidly identified which were only 10 times less active than the standard drugs chloroquine (CQ) and Artemisinin (Artes)

Anticonvulsant and analgesic activities of crude extract and its fractions of the defensive secretion from the Mediterranean sponge, Spongia officinalis.

International audienceABSTRACT: This study progresses in the direction of identifying component(s) from the Mediterranean sponge, Spongia officinalis with anticonvulsant and analgesic activities. We investigated the efficacy of crude extract and its semi-purified fractions (F1-F3) of the defensive secretion from Spongia officinalis for their in vivo anticonvulsant activity using the pentylenetetrazole (PTZ) seizure model and analgesic activity using the writhing test in mice. Among the series the crude extract exhibited interesting analgesic activity in a dose dependent manner. Similarly the fraction F2 showed a partial protection of mice from PTZ-induced seizure and interesting analgesic activity in a dose dependent manner. The purification and the determination of chemical structure(s) of compound(s) of this active fraction are under investigation

Optimized extraction of pectin-like polysaccharide from Suaeda fruticosa leaves: Characterization, antioxidant, anti-inflammatory and analgesic activities

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Anti-inflammatory, analgesic activities and gastro-protective effects of the phenolic contents of the red alga, Laurencia obtusa

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Microwave-assisted extraction and pharmacological evaluation of polysaccharides from Posidonia oceanica

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Physico-chemical characterization and pharmacological evaluation of sulfated polysaccharides from three species of Mediterranean brown algae of the genus Cystoseira

International audienceBackgroundSeaweed polysaccharides are highly active natural substances having valuable applications. The present study was conducted to characterize the physico-chemical properties of sulphated polysaccharides from three Mediterranean brown seaweeds (Cystoseira sedoides, Cystoseira compressa and Cystoseira crinita) and to evaluate their anti-radical, anti-inflammatory and gastroprotective activities.MethodsThe different rates of neutral sugars, uronic acids, L-fucose and sulphate content were determined by colorimetric techniques. The different macromolecular characteristics of isolated fucoidans were identified by size exclusion chromatography equipped with a triple detection: multiangle light scattering, viscometer and differential refractive index detectors, (SEC/MALS/VD/DRI). Anti-inflammatory activity was evaluated, using the carrageenan-induced rat paw edema test in comparison to the references drugs Acetylsalicylate of Lysine and Diclofenac. The gastroprotective activity was determined using HCl/EtOH induced gastric ulcers in rats and to examine the antioxidant effect of fucoidans in the three species, the free radical scavenging activity was determined using 1,1-diphenyl-2-picrylhydrazyl.ResultsThe pharmacological evaluation of the isolated fucoidans for their anti-inflammatory, and their gastroprotective effect established that these products from C. sedoides, C. compressa and C. crinita exhibited a significant anti-inflammatory activity at a dose of 50 mg/kg, i.p; the percentages of inhibition of the oedema were 51%, 57% and 58% respectively. And, at the same dose, these fucoidans from C. sedoides and C. compressa showed a significant decrease of the intensity of gastric mucosal damages compared to a control group by 68%, whereas, the fucoidan from C. crinita produced a less gastroprotective effect. Furthermore, the isolated fucoidans exhibited a radical scavenging activity.ConclusionThe comparative study of fucoidans isolated from three species of the genus Cystoseira showed that they have similar chemicals properties and relatives anti-radical, anti-inflammatory and gastroprotective activities which are found to be promising