Antiviral activity of the extracts of Rhodophyceae from Morocco

Fifty-five aqueous, methanolic, chloroforme-methanolic and dichloromethanolic extracts derived from sixteen species of marine Rhodophyta from the coast of Morocco have been screened for the presence of inhibitory compounds against Herpes simplex virus type 1 (HSV-1) by cell viability method. The aqueous extracts of Asparagopsis armata, Ceramium rubrum, Gelidium pulchellum, Gelidium spinulosum, Halopitys incurvus, Hypnea musciformis, Plocamium cartilagineum, Boergeseniella thuyoides, Pterosiphonia complanata and Sphaerococcus coronopifolius were capable of inhibiting the replication of HSV-1 in vitro at an EC50 (Effective Concentration 50%) ranging from <2.5 to 75.9 μg mL-1. No cytotoxic effect of the aqueous extracts on the Vero cells was observed in the range of the concentrations assayed for all extracts. The results corroborate that marine algae from Morocco can be a rich source of potential antiviral compounds.Keywords: Antiviral, Aqueous extracts, Organic extracts, Rhodophyceae, Herpes simplex viru

The antibacterial potential of the seaweeds (Rhodophyceae) of the Strait of Gibraltar and the Mediterranean Coast of Morocco

The antibacterial activity of extracts from 26 marine Rhodophyceae (8 Ceramiales, 7 Gelidiales, 9 Gigartinales, 1 Bonnemaisoniales and 1 Rhodymeniales) was studied to assess their potential in the pharmaceutical industry. Their bioactivity was analysed from crude methanolic extracts of dried samples against three gram-positive bacteria and two gram-negative bacteria using the disc diffusion technique. The samples were collected from Gibraltar and the Moroccan Mediterranean coast. Of the macroalgae analysed, 96% of extracts were active against at least one of the five test microorganisms. Staphylococcus aureus was the most susceptible microorganism. Methanolic extracts of all seaweed extracts tested in the present study exhibited a broad spectrum of antibacterial activity with inhibition diameters ranging from 10 to 35 mm. An extract of Hypnea musciformis exhibited high antibacterial activity against all the bacteria tested. The results of the present study confirmed the potential use of seaweed extracts as a source of antibacterial compounds.This work was supported by the SAIC (Spanish Agency of International Culture) Morocco-Spain, Project n° A/4931/06 and a grant from the Unesco-Oreal Organization

Antiviral Activities of Sulfated Polysaccharides Isolated from Sphaerococcus coronopifolius (Rhodophytha, Gigartinales) and Boergeseniella thuyoides (Rhodophyta, Ceramiales)

Water-soluble sulfated polysaccharides isolated from two red algae Sphaerococcus coronopifolius (Gigartinales, Sphaerococcaceae) and Boergeseniella thuyoides (Ceramiales, Rhodomelaceae) collected on the coast of Morocco inhibited in vitro replication of the Human Immunodeficiency Virus (HIV) at 12.5 μg/mL. In addition, polysaccharides were capable of inhibiting the in vitro replication of Herpes simplex virus type 1 (HSV-1) on Vero cells values of EC50 of 4.1 and 17.2 μg/mL, respectively. The adsorption step of HSV-1 to the host cell seems to be the specific target for polysaccharide action. While for HIV-1, these results suggest a direct inhibitory effect on HIV-1 replication by controlling the appearance of the new generations of virus and potential virucidal effect. The polysaccharides from S. coronopifolius (PSC) and B. thuyoides (PBT) were composed of galactose, 3,6-anhydrogalactose, uronics acids, sulfate in ratios of 33.1, 11.0, 7.7 and 24.0% (w/w) and 25.4, 16.0, 3.2, 7.6% (w/w), respectively

Activités biologiques de principes actifs de différents extraits d algues rouges marines (Rhodophyceae) de la côte atlantico-méditerranéenne du Maroc

Les potentialités biologiques des algues benthiques des côtes marocaines sont méconnues. Dans le but de la valorisation de cette ressource, une évaluation de l activité antibactérienne, cytotoxique, antivirale, antioxydante et anti-algale a été réalisée à partir de 130 extraits de polarité différente issus de 29 espèces de Rhodophycées (1 Bonnemaisoniales, 8 Céramiales, 3 Corallinales, 7 Gélidiales, 9 Gigartinales, 1 Rhodymeniales). Les extraits ont été testés contre 11 bactéries Gram-négatif et 10 bactéries Gram-positif par la méthode de diffusion par disque. Soixante-quinze pourcent des extraits sont actifs sur au moins une souche bactérienne. L évaluation de l activité antioxydante a été réalisée à travers 3 tests différents. Lors du test au DPPH, 4 extraits méthanoliques ont permis la transformation du radical de DPPH en forme réduite avec une CE50 située entre 96 et 862 g.mL-1. Dans le cadre du test au b-carotène, 7 extraits méthanoliques ont montré une activité contre les radicaux peroxydes avec une CE50 entre 9 et 176 g.mL-1. Dans le test au désoxyribose, le pourcentage d inhibition des radicaux du groupe hydroxyle varie entre 25 et 68% pour 5 extraits aqueux dont le plus important est l extrait d Asparagopsis armata. L évaluation de l activité antialgale vis-à-vis des Diatomophycées, Cylindrotheca fusiformis, C. closterium et Amphora coffeaeformis, par l analyse de la chlorophylle-a a montré que la concentration effective 50% varie entre des valeurs inférieures à 10 g.mL-1 et d autres supérieures à 1000 g.mL-1. L évaluation de l activité antivirale sur le modèle virus d Herpes simplex de type-1/Cellules Véro par viabilité cellulaire met en évidence que les extraits aqueux sont capables d'empêcher in vitro la réplication de VHS-1 à une CE50 (concentration effective 50%) qui varie de <2,5 à < 75,9 g.mL-1. Aucun effet cytotoxique n a été observé avec les extraits aqueux sur les cellules Véro dans la gamme des concentrations étudiées 2,5 et 250,0 g.mL-1. Deux polysaccharides sulfatés isolés de Sphaerococcus coronopifolius (Gigartinales) et Boergeseniella thuyoides (Céramiales) respectivement présentent in vitro une inhibition de la réplication de Virus de l'Immunodéficience Humaine (VIH) par mesure de l enzyme transcriptase inverse dans les cellules CEM et la formation de syncitia dans les cellules MT4 après 3 jours à 12,5 g.mL-1. Ils sont aussi capables d inhiber également in vitro la réplication du VHS-1 dans les cellules Véro avec une concentration effective (CE50), respectivement, de 4,1 à 17,2 g.mL-1. Aucune toxicité supérieure à 200,0 g.mL-1 n a été observée sur les cellules Véro et MT4. L activité des polysaccharides contre le VIH-1 et le VHS-1 se manifeste juste après l infection. La purification par Chromatographie de Partage Centrifuge (CPC) de l extrait chloroforme-méthanol d Asparagopsis armata a permis d obtenir des fractions contenant deux à quatre composés. Les techniques de résonance magnétique nucléaire (RMN) et la spectrométrie de masse (SM) ont mis en évidence la présence des acides gras, des acides aminés et des composés aromatiques. Des signaux de phénols et des composés polysaccharidiques ont également été caractérisés. La présence continue des acides gras dans toutes les fractions actives analysées, nous permet de déduire qu ils pourraient contribuer dans l activité antibactérienne.The biological potentialities of seaweeds benthic of the Moroccan coast are not recognized. With the aim of the valuation of this resource, an evaluation of the antibacterial activity, cytotoxic, antiviral, antioxidant and anti-algal was realized from 130 extracts of different polarity stemming from 29 species of Rhodophyceae (1 Bonnemaisoniales, 8 Ceramiales, 3 Corallinales, 7 Gelidiales, 9 Gigartinales, 1 Rhodymeniales). Extracts were tested against 11 bacteria Gram-negatives and 10 bacteria Gram-positives by the method of diffusion by disk. Seventy-five percent of the extracts are active on at least a bacterial strain. The evaluation of the antioxidant activity was realized through 3 different tests. During the test in the DPPH, 4 methanolic extracts allowed the transformation of the radical of DPPH in shape reduced with EC50 situated between 96 and 862 g.mL-1. Within the work of the test in b-carotene, 7 methanolic extracts showed an activity against the peroxide radicals with EC50 between 9 and 176 g.mL-1. In the test in the deoxyribose, the percentage of inhibition of the radicals of the group hydroxyls varies between 25 and 68 % for 5 aqueous extracts, of which most important is the extract of Asparagopsis armata. The evaluation of the anti-algal activity towards Diatomophyceae, Cylindrotheca fusiformis, C. closterium and Amphora coffeaeformis, by the analysis of chlorophyll-a showed that the effective concentration 50 % varies between values lower than 10 g.mL-1 and the other superiors in 1000 g.mL-1. The evaluation of the antiviral activity on the model virus of Herpes simplex of type-1 / Vero cells by cellular viability revealed that the aqueous extracts are capable of preventing in vitro the replication of VHS-1 in a EC50 (effective concentration 50 %) which varies of < 2.5 at < 75.9 g.mL-1. No cytotoxic effect was observed with the aqueous extracts on Vero cells in the range of the studied concentrations 2.5 and 250 g.mL-1.Two sulfated polysaccharides isolated of Sphaerococcus coronopifolius (Gigartinales) and Boergeseniella thuyoides (Ceramiales) present in vitro an inhibition of the replication of Human Immunodeficiency Virus (HIV) respectively by measure of the reverse transcriptase enzyme in cells CEM and formation of syncitium in cells MT4 after 3 days in 12.5 g.mL-1. They are also capable of inhibiting also in vitro the replication of the HSV-1 in cells Vero with an effective concentration (EC50), respectively of 4.1 and 17.2 g.mL-1. No toxicity superior to 200.0 g.mL-1 was observed on Vero cells and MT4. The activity of polysaccharides against the HIV-1 and the HSV-1 appears just after the infection.The purification by Centrifugal Partition Chromatography (CPC) of the chloroform-methanol extract of Asparagopsis armata allowed obtaining containing fractions two in four compounds. The techniques of nuclear magnetic resonance (NMR) and the mass spectrometry (MS) revealed the presence of fatty acids, amino acids, aromatic compounds. Signals of phenols and polysaccharidic compounds also characterized. The continuous presence of the fatty acids in all the analyzed active fractions allows us to deduct that they could contribute in the antibacterial activity.LORIENT-BU (561212106) / SudocSudocFranceF