Phlorotannins, phenolic compounds produced exclusively by seaweeds, have been reported to possess various pharmacological properties. However, there have been few works on these compounds from Mediterranean seaweeds. In this study, we investigated the phytochemical analysis and pharmacological potential of phlorotannin-rich fractions from three brown seaweeds collected along the Tunisia coast: Cystoseira sedoides (PHT-SED), Cladostephus spongeosis (PHT-CLAD), and Padina pavonica (PHT-PAD). Phytochemical determinations showed considerable differences in total phenolic content (TPC) and phlorotannin content (PHT). The highest TPC level (26.45 mg PGE/g dry material (Dm)) and PHT level (873.14 μg PGE/g Dm) were observed in C. sedoides. The antioxidant properties of these three fractions assessed by three different methods indicated that C. sedoides displayed the highest total antioxidant activity among the three species (71.30 mg GAE/g Dm), as well as the free radical scavenging activity with the lowest IC value in both DPPH (27.7 μg/mL) and ABTS (19.1 μg/mL) assays. Furthermore, the pharmacological screening of the anti-inflammatory potential of these fractions using in vivo models, in comparison to reference drugs, established a remarkable activity of PHT-SED at the dose of 100 mg/kg; the inhibition percentages of ear edema in mice model and paw edema in rats model were of 82.55 and 81.08%, respectively. The content of malondialdehyde (MDA) in liver tissues has been quantified, and PHT-SED was found to remarkably increase the lipid peroxidation in rat liver tissues. In addition, in two pain mice models, PHT-SED displayed a profound antinociceptive activity at 100 mg/kg and has proved a better analgesic activity when used in combination with the opioid drug, tramadol.

BackgroundSeaweed 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.

BackgroundGorgonians of the genus Eunicella are known for possessing a wide range of pharmacological activities such as antiproliferative and antibacterial effect. The aim of this study was to evaluate the anti-inflammatory and gastroprotective effect of the organic extract and its semi-purified fractions from the white gorgonian Eunicella singularis and the isolation and identification of pure compound(s) from the more effective fraction.MethodsAnti-inflammatory activity was evaluated, using the carrageenan-induced rat paw edema test and in comparison to the reference drug Acetylsalicylate of Lysine. The gastroprotective activity was determined using HCl/EtOH induced gastric ulcers in rats. The purification of compound(s) from the more effective fraction was done by two chromatographic methods (HPLC and MPLC). The structure elucidation was determined by extensive spectroscopic analysis (1H and 13C NMR, COSY, HMBC, HMQC and NOESY) and by comparison with data reported in the literature.ResultsThe evaluation of the anti-inflammatory activity of different fractions from Eunicella singularis showed in a dependent dose manner an important anti-inflammatory activity of the ethanol fraction, the percentage of inhibition of edema, 3 h after carrageenan injection was 66.12%, more effective than the reference drug (56.32%). In addition, this ethanolic fraction showed an interesting gastroprotective effect compared to the reference drugs, ranitidine and omeprazol. The percentage of inhibition of gastric ulcer induced by HCl/ethanol in rats was 70.27%. The percentage of the reference drugs (ranitidine and omeprazol) were 65 and 87.53%, respectively. The purification and structure elucidation of compound(s) from this ethanolic fraction were leading to the isolation of five sterols: cholesterol (5α-cholest-5-en-3β-ol) (1); ergosterol (ergosta-5,22-dien-3β-ol) (2); stigmasterol (24-ethylcholesta-5,22-dien-3b-ol) (3); 5α,8α-epidioxyergosta 6,22-dien-3β-ol (4) and 3β-hydroxy-5α,8α-epidioxyergosta-6-ene (5); and one diterpenoid: palmonine D (6).ConclusionBased on data presented here, we concluded that diterpenoids and sterols detected in the ethanolic fraction can be responsible for its pharmacological activity.Electronic supplementary materialThe online version of this article (doi:10.1186/s40199-014-0064-7) contains supplementary material, which is available to authorized users.

phycoerythrin is considered to be a predominant pigment in red algae. This pigment is at present used in food industry as colorant. Nevertheless, because of the spectral properties, it is used mainly in clinical and immunological analysis (Mensi et al.2012), in fluorescence microscopy and flux cytometry (Glazer and Stryer 1984;Kronick 1986). It is also reported that R-phycoerythrin and phycocyanin act as a part of protective mechanism in seaweeds in general (Sinha et al.1995) and in Gracilaria caudata particularly (Araujo et al.2014). To our best knowledge, few studies (Molloy and Bolton 1996;Mensi et al. 2009) were published regarding the effect of both depth and initial fragment weights on growth and proximate chemical composition of Gracilaria gracilis (previously known as G. verrucosa).Presently, there are neither large scale seaweed cultivation nor agar industry in Tunisia.Nevertheless, several attempts of Gracilaria farming were performed in the two last decades, using both spores (Ben Said and Aouini 2014) and cuttings/fragments (Ksouri et al.1999(Ksouri et al. , 2000 Mensi et al.2009). Four farming methods were used: ropes, sand filled plastic tubes, spade and suspended system in hoop-nets. On the other hand, some experimental agar extractions have been carried out on Gracilaria gracilis (Ben Said and Ksouri 1999; Ben Said et al.2015).This study aimed to determine the ability of Gracilaria gracilis to be cultivated at two different water depths in Bizerte lagoon, using net pockets. Additionally, relatively low initial fragment weights, compared with previously reported studies (Ksouri et al.1999(Ksouri et al. , 2000 Mensi et al.2009) were also tested in order to have an appreciable biomass with a high daily growth rate (DGR) in relation to environmental factors. The biomass could be firstly used for agar extraction and secondly for other potentially interesting compounds. Hence, agar yield, gel strength, gelling and melting temperatures were investigated because of their properties to

Strategy, Management and Health Policy Enabling Technology, Genomics, ProteomicsPreclinical ResearchPreclinical Development Toxicology, Formulation Drug Delivery, PharmacokineticsClinical Development Phases I‐III Regulatory, Quality, ManufacturingPostmarketing Phase IV The inability to cure many diseases, such as cancer and arthritis, has stimulated the need for the development of new drugs from natural sources. Of all natural sources, the marine environment is clearly the last great frontier for pharmaceutical and medical research. As part of our search for new anti‐inflammatory or anticancer potential drugs, organic fractions (chloroform, ethyl acetate and methanol) from the Mediterranean brown seaweed, Cystoseira compressa were evaluated for in vivo anti‐inflammatory activity, using the carrageenan‐induced rat paw edema model and in vitro antiproliferative effect in three human cancer cell lines (A549, lung cell carcinoma; HCT15, colon cell carcinoma; and MCF7, breast adenocarcinoma), using an MTT assay. The chloroform and ethyl acetate fractions exhibited dose‐dependent anti‐inflammatory activity, comparable with the reference drug acetylsalicylic–lysine (300 mg/kg; i.p.). The percent inhibition of edema, 3 h after carrageenan injection ranged from 63 to 76% and 65 to 78%, respectively. The organic fractions (F‐CHCl3, F‐EtOAC, and F‐MeOH) also exhibited antiproliferative activity against the three human cancer cell lines with IC50 values ranging from 78–82 μg/ml; 27–50 μg/ml and 110–130 μg/ml; respectively. Thus, the chloroform and ethyl acetate fractions of C. compressa evidenced an interesting anti‐inflammatory activity associated with significant antiproliferative activity, efficacies that correlated with their total phenol content. The purification and the determination of chemical structures of compounds of these active fractions are under investigation.

Aqueous and organic extracts from Dictyopteris membranacea collected from the Tunisian Mediterranean coast were studied for their anti-inflammatory, antioxidant and anti-microbial activities. All extracts had high anti-inflammatory activity in carrageenan-induced rat paw edema assays in Wistar rats, and their effects are comparable to acetylsalicylate lysine (300 mg kg-1, applied intraperitoneally) used as a reference drug. Dictyopteris membranacea extracts had inhibition percentages in the third hour of the assay of 65% at a dose of 100 mg kg-1, 51% at a dose of 50 mg kg-1, and 49% at a dose of 100 mg kg-1 in aqueous, chloroform and ethyl acetate extracts, respectively. Chloroform and ethyl acetate extracts exhibited 2,2-diphenyl-1-picrylhydrazyl radical scavenging with IC50 values (0.089±0.01 and 0.11±0.02 mg ml-1, respectively) equivalent to the activity of a powerful antioxidant standard, Trolox (IC50=0.09±0.02 mg ml-1). These extracts (chloroform and ethyl acetate) had reducing activity, and the total phenol contents were: 84.96 and 60.96 mg gallic acid equivalent per gram dried sample, respectively. Organic extracts had moderate antimicrobial activity (using the disc diffusion method) against three bacteria: Staphylococcus aureus, Staphylococcus epidermidis and Micrococcus luteus, and four species of a fungal genus: Candida albicans, C. krusei, C. dubliniensis and C. kefyr at 10 mg per disc, whereas the aqueous extract exhibited significant antibacterial activity against only Staphylococcus aureus and Listeria monocytogenes.

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