Effects of Ulva sp. Extracts on the Growth, Biofilm Production, and Virulence of Skin Bacteria Microbiota: Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes Strains.

Ulva sp. is known to be a source of bioactive compounds such as ulvans, but to date, their biological activity on skin commensal and/or opportunistic pathogen bacteria has not been reported. In this study, the effects of poly- and oligosaccharide fractions produced by enzyme-assisted extraction and depolymerization were investigated, for the first time in vitro, on cutaneous bacteria: Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes. At 1000 µg/mL, poly- and oligosaccharide fractions did not affect the growth of the bacteria regarding their generation time. Polysaccharide Ulva sp. fractions at 1000 µg/mL did not alter the bacterial biofilm formation, while oligosaccharide fractions modified S. epidermidis and C. acnes biofilm structures. None of the fractions at 1000 µg/mL significantly modified the cytotoxic potential of S. epidermidis and S. aureus towards keratinocytes. However, poly- and oligosaccharide fractions at 1000 µg/mL induced a decrease in the inflammatory potential of both acneic and non-acneic C. acnes strains on keratinocytes of up to 39.8%; the strongest and most significant effect occurred when the bacteria were grown in the presence of polysaccharide fractions. Our research shows that poly- and oligosaccharide Ulva sp. fractions present notable biological activities on cutaneous bacteria, especially towards C. acnes acneic and non-acneic strains, which supports their potential use for dermo-cosmetic applications.

Environmentally Friendly Valorization of Solieria filiformis (Gigartinales, Rhodophyta) from IMTA Using a Biorefinery Concept.

Marine macroalgae (seaweed) are an excellent source of novel bioactive metabolites. The biorefinery concept applied to seaweed facilitates the extraction of many chemical constituents from the same biomass ensuring that the resource is used fully, generating few residues through a succession of extraction steps. In the present study, the biomass of the carragenophyte Solieria filiformis (Rhodophyta, Gigartinales) cultured in an integrated multi-trophic aquaculture (IMTA) system was evaluated to obtain valuable products by a biorefinery approach. Enzymatic-assisted extraction (EAE) and microwave-assisted extraction (MAE) were the eco-friendly technologies used to ensure an environmentally friendly valorization of the biomass. Three valuable products were successfully recovered: a water-soluble extract rich in proteins and sulfated polysaccharides suitable as a food supplement; a lipid fraction rich in polyunsaturated fatty acids (PUFAs) with potential to be used in the nutraceutical industry; and a pure ι-carrageenan with a powerful antiviral activity against Herpes simplex virus (EC50 = 6.3 µg mL-1) comparable to the commercial antiviral acyclovir (EC50 = 3.2⁻5.4 µg mL-1).

Enzyme-assisted extraction of bioactive material from Chondrus crispus and Codium fragile and its effect on herpes simplex virus (HSV-1).

Codium fragile and Chondrus crispus are, respectively, green and red seaweeds which are abundant along the North Atlantic coasts. We investigated the chemical composition and antiviral activity of enzymatic extracts of C. fragile (CF) and C. crispus (CC). On a dry weight basis, CF consisted of 11% protein, 31% neutral sugars, 0.8% sulfate, 0.6% uronic acids, and 49% ash, while CC contained 27% protein, 28% neutral sugars, 17% sulfate, 1.8% uronic acids, and 25% ash. Enzyme-assisted hydrolysis improved the extraction efficiency of bioactive materials. Commercial proteases and carbohydrases significantly improved (p ≤ 0.001) biomass yield (40%-70% dry matter) as compared to aqueous extraction (20%-25% dry matter). Moreover, enzymatic hydrolysis enhanced the recovery of protein, neutral sugars, uronic acids, and sulfates. The enzymatic hydrolysates exhibited significant activity against Herpes simplex virus (HSV-1) with EC50 of 77.6-126.8 µg/mL for CC and 36.5-41.3 µg/mL for CF, at a multiplicity of infection (MOI) of 0.001 ID50/cells without cytotoxity (1-200 µg/mL). The extracts obtained from proteases (P1) and carbohydrases (C3) were also effective at higher virus MOI of 0.01 ID50/cells without cytotoxity. Taken together, these results indicate the potential application of enzymatic hydrolysates of C. fragile and C. crispus in functional food and antiviral drug discovery.

Essential oils and crude extracts from Chrysanthemum trifurcatum leaves, stems and roots: chemical composition and antibacterial activity.

The essential oils from the leaves, stems and roots of Chrysanthemum trifurcatum (Desf.) Batt. and Trab. var. macrocephalum (viv.) were obtained by hydrodistillation and their chemical compositions were analysed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS), in order to get insight into similarities and differences as to their active composition. A total of fifty compounds were identified, constituting 97.84%, 99.02% and 98.20% of total oil composition of the leaves, stems and roots, respectively. Monoterpene hydrocarbons were shown to be the main group of constituents of the leaves and stems parts in the ratio of 67.88% and 51.29%, respectively. But, the major group in the roots oil was found to be sesquiterpene hydrocarbons (70.30%). The main compounds in leaves oil were limonene (26.83%), γ-terpinene (19.68%), α-pinene (9.7%) and α-terpenyl acetate (7.16%). The stems oil, contains mainly limonene (32.91%), 4-terpenyl acetate (16.33%) and γ-terpinene (5.93%), whereas the main compounds in roots oil were α-calacorene (25.98%), α-cedrene (16.55%), ß-bourbobene (14.91%), elemol (7.45%) and 2-hexenal (6.88%). The crude organic extracts of leaves, stems and roots, obtained by maceration with solvents of increasing polarity: petroleum ether, ethyl acetate and methanol, contained tannins, flavonoids and alkaloids. Meanwhile, essential oils and organic extracts were tested for antibacterial activities against eight Gram-positive and Gram-negative strains, using a microdilution method. The oil and methanolic extact from C. trifurcatum leaves showed a great potential of antibacterial effect against Bacillus subtilis and Staphylococcus epidermidis, with an IC50 range of 31.25-62.5 µg/ml.

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.

Isolation of a sulphated polysaccharide from a recently discovered sponge species (Celtodoryx girardae) and determination of its anti-herpetic activity.

Exopolysaccharides (EPS) were extracted from a sponge, Celtodoryx girardae recently discovered in the Golfe du Morbihan in 2000. Sponge samples were collected monthly from November 2007 to May 2008. SEC analysis of EPS samples showed that they exhibit a unique molecular weight of approximately 800 kDa. However, infrared analysis revealed that structural seasonal variations occur. EPS fractions also exhibit significant sulphate contents and were screened in vitro for a potential antiviral activity against Herpes simplex virus type 1 (HSV-1). The best result was obtained with a sample collected in January which exhibits an EC(50) of 5.9 microg/mL without cytotoxicity on the Vero cell line. Experiments carried out to elucidate the mechanism of the EPS showed that the sulphated groups of EPS interact with the glycoproteins on the surface of the virus' membrane.

Antimicrobial activities of four Tunisian Chrysanthemum species.

BACKGROUND & OBJECTIVE: Tunisian Chrysanthemum species are known to have medicinal activity and some of the species are used in traditional medicine. We have earlier shown the use of C. trifurcatum flowerheads in Tunisian traditional medicine to treat constipation. In the present study we investigated the anti microbiol activity of four Tunision Chrysanthemum species. METHODS: Different parts (flowers, leaves, stems, roots, leaves and flowers and leaves and stems) of four Tunisian Chrysanthemum species, were extracted with solvents of increasing polarity to obtain aqueous and organic extracts. These extracts were tested in vitro for their antimicrobial activity against 14 bacteria and four yeasts, using agar diffusion and microdilution methods. Activity was evaluated by measuring the zones of inhibition against the tested organisms and minimum inhibitory concentrations (MIC) were determined from the lowest concentrations of extracts to inhibit the growth of microorganisms. Cytotoxity and antiviral activities against Herpes simplex virus type 1 (HSV-1), were evaluated using the neutral red incorporation method. RESULTS: Extracts of the 4 Chrysanthemum species showed some degree of activity against one or more of the microbial strains with MIC ranging from 0.625 to 1.25 mg/ml. Most of the extracts were well tolerated by Vero cells with CC(50) > 500 microg/ml. The petroleum ether extract of C. trifurcatum stems and leaves protected infected cells with EC(50) of 100 microg/ml. INTERPRETATION & CONCLUSION: Our findings showed that some Chrysanthemum extracts exhibited antimicrobial and/or anti-HSV-1 activities. Further studies aimed to the isolation and identification of active substances from the extracts which exhibited interest activities, need to be done.