Turbinaria Turbinata Research Articles

Optimization and characterization of brown seaweed alginate for antioxidant, anticancer, antimicrobial, and antiviral properties

Alginate is a natural polysaccharide obtained from brown seaweeds and having advantageous health usefulness, was employed extensively in nutraceutical sectors and the pharmaceutical industry. This research was devoted for optimization of alginate extraction from different brown seaweeds. A Box-Behnken Design (BBD) was used for the optimization of alginate extraction from Padina pavonica by analyzing the influence of temperature (30, 40, and 50 °C), time (60, 120, and 180 min), and alkaline concentration (1 %, 2 %, and 3 %) on extraction yield and uronic acid content. The optimal conditions recorded to maximize the alginate yield and its uronic content were an alkali concentration of 2.5 % and a temperature of 39.95 °C for 102.5 min. The optimized parameters achieved from BBD were used to compare alginate extraction from P. pavonica, Sargassum cinereum, Turbinaria turbinata, and Dictyota dichotoma. FTIR, 1H NMR, and HPLC were used to characterize the extracted alginate. The bioactivity of alginate against free radicals, breast cancer cells (MCF-7), some pathogenic microbes, and SARS-CoV-2 viruses was tested. Under the optimized conditions, alginate was extracted from P. pavonica at a rate of 21.13 ± 2.47 % DW, S. cinereum at 24.08 ± 0.33 % DW g/L, T. turbinata at 17.47 ± 0.26 % DW, and D. dichotoma at a rate of 19.57 ± 3.60 % DW. The alginate extracted from D. dichotoma showed the highest antioxidant, anticancer, and antiviral activity.

Optimizing the fucoidan extraction using Box-Behnken Design and its potential bioactivity

Fucoidan is a sulfated polysaccharide that occurs naturally in the cell wall of brown seaweeds and has substantial biological efficacy. Optimizing the extraction of fucoidan from different brown seaweeds was the primary goal of this research. The optimization of fucoidan extraction was applied on the brown macroalga Turbinaria turbinata using a Box-Behnken Design (BBD) to inspect the impacts of different pH (3, 5, 7), temperature (70, 80, 90 °C) and extraction duration (60, 120, 180 min) on both the yield and sulfate content of fucoidan. The optimized parameters recorded to maximize the fucoidan yield and its sulfate content were a pH of 3.44 and a temperature of 82.26 °C for 60 min. The optimal conditions obtained from BBD were used for fucoidan extraction from T. turbinata, Sargassum cinereum, Padina pavonica, and Dictyota dichotoma. The highest average of fucoidan yield was derived from P. pavonica (40.76 ± 4.04 % DW). FTIR, 1H NMR, and HPLC were used to characterize extracted fucoidan. The extracted fucoidan's Physical characteristics, biochemical composition, antioxidant potential, antitumor effect against breast cancer cells (MCF-7), and antimicrobial and anticoagulant activity were assessed. The extracted fucoidan from D. dichotoma, followed by that extracted from S. cinereum, which had the highest sulphate content, depicted the highest antioxidant, anticancer, and anticoagulant activities. Fucoidan has demonstrated a strong antimicrobial action against some pathogenic microorganisms; Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, and Candida albicans. The anticoagulant properties of fucoidan from D. dichotoma were stronger than those of fucoidan from S. cinereum, T. turbinata, and P. pavonica due to its higher sulphate content. These findings could be used for various biomedical applications to improve the pharmaceutical industry.

Anticancer, antioxidant, and antimicrobial activities of nanoemulsions based on water-in-olive oil and loaded on biogenic silver nanoparticles

Abstract Nanoemulsions (NEMs) are more stable and permeable than regular emulsions because of their increased surface area and smaller particle sizes, which are stabilized by emulsifiers and consist of nanometer-sized droplets. Utilization of an olive oil nanoemulsion (NEM-olive oil) loaded with silver nanoparticles (Ag-NPs) derived from marine alga Turbinaria turbinata may be effective against microorganisms and cancer cell lines. NEM-olive oil was made by mixing olive oil, surfactant (Span:Tween (28:72)), and D water (1:4:5). The marine alga Turbinaria turbinata was used for the synthesis of Ag-NPs (Tu-Ag-NPs), and combined with NEM-olive oil (1:1) to synthesize Ag-NPs loaded in olive oil–water nanoemulsion (Ag/NEM-olive oil). Transmission electron microscopy, energy-dispersive X-ray analysis, zeta potential, Fourier transform infrared, and X-ray powder diffraction spectroscopy were used to characterize the nanoparticles. Both NEM-olive oil and Ag/NEM-olive oil nanoparticles showed a negative surface charge and small diameter. The major components of NEM-olive oil are dodecanoic acid, 2-penten-1-yl ester, 9-octadecenoic acid, and oleic acid. All tested nanoparticles exhibited anticancer activity against the CACO-2 cell line and Hep G2, and antimicrobial activities against E. faecalis, S. aureus, E. coli, and C. albicans. The present research suggested that olive oil NEM loaded with marine algae Ag-NPs can be a safe and economical anticancer, antimicrobial, and drug delivery.

Antifungal Activities of Biogenic Silver Nanoparticles Mediated by Marine Algae: In Vitro and In Vivo Insights of Coating Tomato Fruit to Protect against Penicillium italicum Blue Mold.

In an attempt to reduce such decay induced by pathogenic causes, several studies investigated the effectiveness of nanoparticles (NPs) that play a vital role in saving food products, especially fruits. Current research delves into biogenic silver nanoparticles (using marine alga Turbinaria turbinata (Tt/Ag-NPs) and their characterization using FT-IR, TEM, EDS, and zeta potential. Some pathogenic fungi, which cause fruit spoilage, were isolated. We studied the impact of using Tt/Ag-NPs to protect against isolated fungi in vitro, and the influence of Tt/Ag-NPs as a coating of tomato fruit to protect against blue mold caused by Penicillium italicum (OR770486) over 17 days of storage time. Five treatments were examined: T1, healthy fruits were used as the positive control; T2, healthy fruits sprayed with Tt/Ag-NPs; T3, fruits infected with P. italicum followed by coating with Tt/Ag-NPs (pre-coating); T4, fruits coated with Tt/Ag-NPs followed by infection by P. italicum (post-coating); and T5, the negative control, fruits infected by P. italicum. The results displayed that Tt/Ag-NPs are crystalline, spherical in shape, with size ranges between 14.5 and 39.85 nm, and negative charges. Different concentrations of Tt/Ag-NPs possessed antifungal activities against Botrytis cinerea, Rhodotorula mucilaginosa, Penicillium expansum, Alternaria alternate, and Stemphylium vesicarium. After two days of tomatoes being infected with P. italicum, 55% of the fruits were spoilage. The tomato fruit coated with Tt/Ag-NPs delayed weight loss, increased titratable acidity (TA%), antioxidant%, and polyphenol contents, and decreased pH and total soluble solids (TSSs). There were no significant results between pre-coating and post-coating except in phenol contents increased in pre-coating. A particular focus is placed on the novel and promising approach of utilizing nanoparticles to combat foodborne pathogens and preserve commodities, with a spotlight on the application of nanoparticles in safeguarding tomatoes from decay.

Simultaneous production of biofuel, and removal of heavy metals using marine alga Turbinaria turbinata as a feedstock in NEOM Region, Tabuk

Depletion of fossil fuel and pollution by heavy metals are two major global issues. The cell wall of algae consists of polymers of polysaccharides such as cellulose, hemicellulose, alginate, starch, and many others that are readily hydrolyzed to monosaccharides and hence are amenable to fermentation into bioethanol. Moreover, algae contain lipids that may undergo trans-esterification to biodiesel, and can be absorbed by heavy metals. In this study, extraction of lipids from Turbinaria turbinata (common brown alga) from the beach of Sharma, NEOM, Tabuk, Saudi Arabia by different solvents hexane, methanol, and hexane: methanol (1:1), and trans-esterification was performed to obtain biodiesel and investigated by GC.MS. The alga residue after fats extractions by different solvents was used in bioremediation synthetic wastewater containing 50 ppm of As−3, Co+2, Cu+2, Fe+2, Mn+2, and Zn+2. The residue of defatted alga was hydrolyzed by 2% H2SO4 and then fermented to obtain bioethanol. The combination of hexane: methanol (1:1) gave the greatest amount of petroleum hydrocarbons, which contain Tetradecane, 5-methyl, Octacosane, Pentatriacontane, and a small amount of Cyclotrisiloxane, Hexamethyl. The most effective removal % was obtained with alga residue defatted by hexane: methanol (1:1), and methanol, 100% removal of As−3, 83% Co+2, 95% Cu+2, 97.25% Fe+2, Mn+2 79.69%, Zn+2 90.15% with 2 g alga /L at 3 hours. The lowest value of sugar was obtained with hexane: methanol residue but gave the highest bioethanol efficiency. Thus, it is possible to use Turbinaria turbinata, or brown alga as a feedstock to produce bio-diesel, and bioethanol, and to remove heavy metals from wastewater, which may have a great economic and environmental significance.

Fatty acids composition and profiling of nine abundant marine Macroalgae, Egypt

This study analyzed the fatty acids composition and their profile qualitatively and quantitatively of the nine abundant macroalgal specimens collecting from Egyptian coasts. GC mass analysis identified 23 types, including 13 of saturated fatty acids (SFA) and 10 of monounsaturated fatty acids (MUSFA). SFA dominated with 78%, while MUFAs had 22%, and UFAs were negligible at 0.01%. MUSFA oleic acid (omega-9) was present in all species except green macroalgae Galaxura rugosa and Ulva fasciata, replaced by MUSFA linoleic acid (omega-6). Oleic acid methyl ester (omega-9) was registered in all the studied species, except red Hypnea cornuta & Jania rubens, and brown Hormophysa cuneiformis. Chlorophyta registered 35% of the fatty acid composition, followed by Rhodophyta (33%) and Phaeophyta (32%). Major SFAs were palmitic acid glycidyl ester, oleic acid glycidyl ester and palmitic methyl ester, comprising over half of total fatty acids. Red and brown macroalgae were richer in palmitic and oleic glycidyl esters, while green macroalgae had more palmitic methyl ester. Linoleic acid, nonadecylic acid, elaidic acid methyl ester, linoleic acid methyl, behenic acid, pentacosylic acid, palmitic acid, and trans-palmitoleic acid were exclusively identified in Chlorophyta. Lacceroic acid was distinguished in Rhodophyta, whereas pelargonic acid just appeared in brown alga Turbinaria turbinata. The maximum values of fatty acids were recorded in the green macroalga Caulerpa racemosa while reed macroalga Hypnea cornuta.was the minimum one. The research sheds light on the fatty acid composition and its potential implications for human health and nutrition.

Biosorption of Cu and Zn in a Batch System via Dried Macroalgae Halimeda opuntia and Turbinaria turbinata

Biosorption is the most favourable technique for the treatment of heavy metals as it is fast, powerful, and low cost, it takes place in a wide range of temperatures as well as it can be used for almost all types of heavy metals. In this study, the biosorption technique adsorbs Cu2+ and Zn2+ on the dried macroalgae (Halimeda opuntia and Turbinaria turbinata) in a batch system. Experimental parameters affecting the biosorption process are initial metal ion concentrations (5, 10, 15 and 25 mg/L), pH between (4.5 and 5.2), biomass dosage (1 gm) and agitation speed 150 rpm applied at contact time (30, 60 and 120 min). The significant-high average removals of Cu2+ by H.opuntia (> 96%) were recorded in concentrations of 10, 15 and 25 ppm at 120 min and the highest average removals by T.turbinata (81.07%, 78.32% and 74.7%) were recorded in concentrations of 5, 10 and 15 ppm at 120 min. The lowest average removal of Cu2+ 89.22% was recorded by H.opuntia and 49.9% was recorded by T.turbinata in a concentration of 25 ppm at 30 min. In the same way, significant-high average removals (>94%) were recorded in a concentration of 10 ppm at 120 min for H.opuntia and in a concentration of 5 ppm by at 60 min for T.turbinata. In conclusion, the dead biomass of marine algae can provide a promising and low-cost technique for removing heavy metal pollutants in medical industries.

Fucoxanthin: a marine carotenoid has anticancer activities and apoptosis-inducing effect (a review)

Fucoxanthin, a natural xanthophyll carotenoid, is generally found in brown seaweeds, such as Sargassum duplicatum, Turbinaria turbinata, Padina australis, Undaria pinnatifida, and Laminaria japonica; and microalga or diatom such as Phaeodactylum tricornutum, Isochrysis galbana and Odontella sinensis. Fucoxanthin is a marine xanthophyll exhibiting several anticancer activities, such as anticancer activities against leukemia, prostate, cervical, hepatoma, colon, and lung cancer. Cancer disease is frequently considered to be a disease of the cell cycle. Then, apoptosis is a dominant form of cell death with particular relevance to cancer, characterized initially by a series of stereotypic morphological changes, such as condensation and fragmentation of chromatin shrinking of cytoplasmic (cell shrinkage), a decrease in cell volume and alterations to the plasma membrane, mitochondrial depolarization, membrane blebbing, and cell packaging into apoptotic bodies or formation of apoptotic bodies. In general, there are four techniques for the detection of apoptosis, namely: (1). morphological changes analysis using an inverted microscope, scanning electron microscope, fluorescent microscope, (2) gel electrophoresis, (3). immunohistochemistry (e.g., analysis of caspase-3), and (4) flow cytometry.

Evaluation of the insecticidal and antifeedant activities of some seaweed extracts against the Egyptian cotton leaf worm, Spodoptera littoralis, and the lesser grain borer Rhyzopertha dominica

Environmental safety and agricultural sustainability are important for survival on the Earth. Spedoptera littoralis and Rhyzopertha dominica are among the most destructive pests for economic crops in Egypt. Indiscriminate use of chemical pesticides called for safe alternatives. seaweeds are among these alternatives Hence, it is imperative to evaluate the efficacy of (Sargassum acinarium, Turbinaria turbinata, Petrocladia capillacea, and Cystoseira myrica ) extracts against S. littorlais third and fifth instar larvae and R. dominica adults. The seaweed extracts-insect contact method was used. Also the antifeediant activities of the tested sea weeds were recorded. All tested seaweeds exhibited insecticidal and antifeediant activities with S.littoralis third instar larvae being more susceptible. T. turbinata and P. capillacea exhibited the highest insecticidal and antifeddiant effects, respectively. C. myrica showed the lowest insecticidal and antifeediant activities at all. There was a direct relationship between the percent mortalities and seaweed concentrations. Sea weeds gas chromatogra¬phy-mass spectrometry analyses revealed different bioactive compounds, which might be responsible for their insecticidal properties.. finally the tested seaweeds can be used as ecofriendly and safe biopes¬ticides for control of S. littoralis and R. dominica and we recommend them to be involved in integrated pest management program.

ANTIOXIDANT ACTIVITY AND PHENOLIC CONTENTS OF SEVEN BROWN SEAWEED FROM DJIBOUTI COAST

Objective: This study focuses on the antioxidant potential of Djibouti brown seaweed and their phenolic contents.
 Methods: We evaluated the antioxidant potential by DPPH method (1,1-diphenyl-2-picrylhydrazyl) and their phenolic contents of seven Djibouti seaweed: Cytoseira myrica, Padina pavonica, Sargassum fluitans, Sargassum ilifolium, Sargassum sp, Turbinaria triquetra and Turbinaria turbinata. Also, we searched the secondary metabolites of these seaweeds.
 Results: We obtain a higher antioxidant activity at 60,7±0,9 % and a higher phenolic content at 199,01±0,5 μg equivalent phloroglucinol (PGE)/g dry matter for Padina pavonica. A good linear correlation (R2 = 0,898) is observed between the antioxidant activity and the phenolic content of the seaweed studied. Also, two Padina pavonica collected in two different locations have different biochemical concentrations and antioxidant activity, suggesting the influence of the marine environment on the biosynthesis of secondary metabolites and the biological activities of seaweed.
 The present study shows the presence of tannins, saponosides, flavonoids and steroid-terpenes.
 Conclusion: The species studied show interesting antioxidant activities and can be consumed to prevent oxidative stress.

Chemical structure investigation of tropical Turbinaria turbinata seaweeds and its derived carbon sorbents applied for the removal of hexavalent chromium in water

Biomass such as algae, has a great potential to simultaneously deliver renewable energy, bio-products and also better water quality. A pathway towards the realization of these benefits is through the development of valuable materials preferably inexpensive. This work reports on the successful exploitation of Turbinaria turbinata, a brown alga widely available in many tropical areas; which was used as sorbent for the removal of hexavalent chromium from aqueous media. By characterizing the surface material, we showed that the dried alga exhibits several polyfunctional metal-binding sites, enabled to use it as a raw material. Further surface modification (pre-treatment with acid) and structural modification (preparation of both chemically and physically activated carbons) was also carried out to enhance material adsorption properties. Significant improvement of metal uptake (up to 40 fold higher) was obtained, depending of the testing conditions. Based on a close examination of the surface chemistry and pH profiles, a mechanism describing the adsorption mechanism of the different systems was proposed.

Green Nanoparticles Engineering on Root-knot Nematode Infecting Eggplants and Their Effect on Plant DNA Modification.

Background Root-knot nematodes are known to cause significant damage to eggplants. New approaches by green silver nanoparticles (GSN) are used to control plant-parasitic nematode to avoid chemical nematicide hazards. Objectives Analyses of the incorporation of different concentrations of nanoparticles on two different algae (Ulva lactuca and Turbinaria turbinata) were carried out. Furethermore, the effect of GSN on the eggplant DNA profile was studied using RAPD and EST molecular markers. Materials and Methods Green Silver Nanoparticles (GSN) have been synthesized and characterized using the algal extract solution prepared from two algal genera. Nematicidal effect of the GSN was evaluated in greenhouse on eggplants (Solanum melongena cv. Login). Genomic DNA was extracted for use in molecular analysis. Both RAPD and EST molecular markers were used to study the GSN effect on eggplant DNA modification. Results GSN (17 mg.mL-1) obtained from U. lactuca was more effective in reducing second-stage juveniles (J2s) of M. javanica (69.44%) population in soil. All treatments improved eggplants growth parameters. Change in DNA profile using of both RAPD and EST markers was noted. Conclusions GSN (12.75 mg.100 mL-1) were effective on controlling the root-knot nematode (both T. turbinata and U. lactuca algae), similar to chemical control in eggplants. GSN did not cause any phototoxicity in eggplants under treatment.

Chemical structure of sulfated polysaccharides from brown seaweed (Turbinaria turbinata)

ABSTRACTThe chemical structure of three sulfated polysaccharides fractions (TtF1, TtF2, and TtF3) obtained from anion-exchange separation of aqueous extracts of brown seaweed (Turbinaria turbinate) were studied. The infrared spectra patterns showed that the fractions possess functional groups similar to that of sulfated polysaccharides. The sulfated polysaccharides fractions exhibited molecular weights of 223.5, 495.5, and 326.05 kDa, respectively, for TtF1, TtF2, and TtF3. 1H NMR spectra of TtF2 and TtF3 contain α-anomeric protons (5–5.6 ppm), ring protons (3.4–4.4), and methyl protons (1–1.3 ppm) while that of TtF1 only exhibited ring protons and methyl protons. Rheological data were fitted to power law which revealed that the fractions were Newtonian and/or presented weak pseudoplastic behavior. Consistency values increased with concentration in all fractions. Consistency values of TtF2 were the highest, followed by TtF1 and then TtF3. Thermal degradation patterns of TtF1 and TtF2 were similar but different from that of TtF3. This study confirmed that chemical and physical characteristics of sulfated polysaccharides fractions are interrelated and provided in-depth understanding of sulfated polysaccharides of brown algae.

Microencapsulation of Fucoxanthin by Water-in-Oil-in-Water (W/O/W) Double Emulsion Solvent Evaporation Method: A Review

Fucoxanthin is a major xanthophyll present in brown seaweeds such as Sargassum binderi, S. duplicatum, Turbinaria turbinata, Padina australis, Undaria pinnatifida and Hijkia fusiformis. This carotenoid has a unique structure including oxygenic functional group such as, two hydroxy, keto, epoxy (5,6-monoepoxide), and an allenic bond. Fucoxanthin has some anticancer activities such as, exhibits inhibitory property on colon cancer cells and human hepatic carcinoma HepG2 cell line. This xanthophyll also induces apoptosis of human leukemia cancer HL-60 cells, human prostate cancer PC-3 cell, human lung cancer H1299 cell line etc. Unfortunately, the poor solubility of this carotenoid in water hinders it to be a drug candidate. Fucoxanthin is also a pigment that is sensitive to temperature and light. One of the possible ways to circumvent the problem with light and temperature is by microencapsulating it. Microencapsulation (ME) in biodegradable polymers, e.g. poly(D,L-lactic-co-glycolic acid) (PLGA) is a promising approach to protect any potential drug from rapid degradation. Solvent evaporation method is the most popular technique of preparing PLGA microsphere (MS) and this technique has been extensively studied in recent years for the preparation of MS. In the water-in-oil-in-water (w/o/w) double emulsion solvent evaporation method, stability of the primary emulsion (PE) is a critical factor. When the PE is unstable, encapsulation efficiency (EE) is low. Stability of PE can be enhanced by including emulsifying agent or stabilizers such as polyvinyl alcohol (PVA). The presence of a stabilizer/ emulsifier plays a significant role in influencing particle size (PS), external morphology of microsphere and colloidal stability.

Cytotoxicity and inhibition of nitric oxide syntheses in LPS induced macrophage by water soluble fractions of brown seaweed

A study on the anti-inflammatory role of ethanolic precipitates and supernatants of water soluble extracts of 5 brown seaweed species of Malaysian origin (Sargassum duplicatum, Sargassum binderi, Sargassum fulvellum, Padina australis and Turbinaria turbinata) on inhibition of Nitric oxide (NO) secretion in lipopolysaccharide (LPS) induced RAW 264.7 murine macrophage was conducted. Results showed that fractions obtained varied in yield and chemical compositions, such as uronic acid, sulfate ion, monosaccharide, polyphenol and total sugar. In terms of yield percentage, precipitate obtained from T. turbinata contained the highest, ∼25%. All precipitates contained reasonable amount of fucose, mannose, galactose, glucose and xylose, but trace amount of arabinose. The precipitates inhibited NO secretion in a dose dependent manner. Precipitate of P. australis and T. turbinata, dosed at 200 μg/ml, down-regulated (more than 80%) NO secretion. Among the supernates, that of T. turbinata, which contain highest fucose, gave highest inhibition of NO synthesis. Results also showed that all the extracts obtained gave more than 80% cell proliferation except the precipitate of S. duplicatum. Data from this study also indicated that water soluble extracts of seaweed can be explored for alternative anti-inflammatory drug.

Preparation of activated carbon from Turbinaria turbinata seaweeds and its use as supercapacitor electrode materials

Turbinaria turbinata brown seaweeds were tested as carbon electrode material in symmetric, electrochemical supercapacitors. The electrochemical properties of the carbon materials were characterised for their application as supercapacitors using cyclic voltammetry, galvanostatic charge/discharge method and electrochemical impedance spectroscopic analyses. Our initial results showed that the optimal behaviour was obtained for the sample prepared by pyrolysis at 800 °C. The average surface area of the carbon was 812 m2/g. Electrochemical tests with an organic electrolyte gave the following interesting results: a capacitance of 74.5 F/g, a specific series resistance of 0.5 Ω cm2 and an ionic resistivity of 1.3 Ω cm2. These results show the promising capacitive properties of carbon derived from seaweeds and their application in electrochemical supercapacitors.

Textural characteristics, physiochemical properties and adsorption efficiencies of Caribbean alga Turbinaria turbinata and its derived carbonaceous materials for water treatment application

The adsorptive removal capacities of highly available Turbinaria turbinata alga and its derived carbonaceous products (i.e. pyrolyzed, physically and chemically activated carbons) were investigated in this study. Several textural and chemical characterizations were performed on the alga and its activated carbons (ACs). Besides, kinetics and isotherms assays were performed and modeled in order to monitor the sorption capacities and dynamic behaviors.The main results showed that the raw Turbinaria biomass has a non porous structure. Then, after thermo-chemical treatments, a porous matrix starts to develop and the total pore volume drastically increased from 0.001cm3/g for the algal precursor (turb-raw) to 1.316cm3/g for its derived chemically AC (turb-P1). As well, the specific surface area improved from m2/g for (turb-raw) to 1307m2/g for (turb-P1). Consequently, the maximum sorption capacity went from 63mg/g for the algal biomass up to 411mg/g for the chemically ACs.Moreover, the removal rate was taken into consideration in order to set a more reliable and realistic approach to figure out the most efficient AC.Thus, based on those criteria, it was found that the chemically activated carbon “turb-P1” is the most efficient Turbinaria-derived sorbent to adsorb and remove methylene blue (MB) molecules from aqueous solutions with 169g of the dye using 1kg of raw alga (considering an AC production yield of 49%).

Antitrypanosomal in vitro activity of tropical marine algae extracts

Trypanosomiasis is one of the most important parasitic diseases worldwide. The undesirable side effects and low efficacy of classical trypanocidal drugs underline the necessity of the development of new drugs from natural products. Although marine algae have been recognized as attractive sources of known and novel bioactive compounds, very little research has been focused on antiprotozoal activity. Aqueous and organic extracts of 29 species of marine algae (14 species of Rhodophyta, seven species of Phaeophyta, and eight species of Chlorophyta) collected from the Gulf of Mexico and Caribbean coast of the Yucatan Peninsula (Mexico) were evaluated for their antiprotozoal activity in vitro against Trypanosoma cruzi trypomastigotes. The toxicity of these extracts was evaluated using brine shrimp (Artemia salina). The cytotoxicity on mammalian cells was also assessed by the MTT viability assay. The organic extracts from Dictyota caribea Horning & Schnetter, Lobophora variegata (J.V. Lamouroux) Womersley, Turbinaria turbinata Linnaeus, and Laurencia microcladia Kützing possess promising in vitro activity against T. cruzi trypomastigotes. The toxicity displayed by Laurencia microcladia against Artemia salina and the high cytotoxicity exhibited by T. turbinata must be taken into account in further studies.

UVB radiation may ameliorate photoinhibition in specific shallow-water tropical marine macrophytes

Anthropogenic stratospheric ozone depletion causes an increase in UVB radiation impinging on the earth's surface, which is a threat to plants not adapted to higher UVB irradiances. Investigations were carried out among tropical marine macrophytes, Turbinaria turbinata, Sargassum polyceratium var. ovatum, Padina sanctae-crucis, Lobophora variegate, Dictyota spec., Halimeda discoidea, Udotea flabellum, Thalassia testudinum and Syringodium filiforme collected from 0.3 to 26 m depths at the Belizean barrier reef, where ultraviolet radiation (UV)-irradiances are naturally high. Photoinhibition was induced under full solar, UV (UVA + UVB), and UVA only-depleted radiation conditions. Photosynthetic activity during high radiation stress and during recovery in reduced solar radiation was determined in vivo by measuring fluorescence changes using a PAM fluorometer device. Generally, UV caused an additional decrease of photosynthetic performance during high light stress which varies according to species, depth of growth and UV penetration at the site of collection; an observation in concordance with the conventional harmful UV-radiation effects on phototrophs. When solar radiation was reduced by 50%, significant photosynthetic recovery was observed. However, some shallow water species which are adapted to high UV were observed to recover less under treatment with depleted solar UVB radiation. Our result supports earlier reports that UVB causes not only negative effects on photosynthesis, but may also facilitate or induce recovery processes in aquatic macrophytes acclimated to high solar radiation which grow at the upper shoreline. Among the eulittoral macroalgae, e.g. Dictyota spec., P. sanctae-crucis, and H. discoidea and the seagrass T. testudinum, initiation of photosynthetic recovery processes in the presence of low irradiance of short UV-wavelengths may present an ecophysiological advantage compared to macrophytes which initiate photosynthetic recovery process during low light or in the absence of UV.

Antileishmanial properties of tropical marine algae extracts

Aqueous and organic extracts of twenty-seven species of marine algae (14 species of Rhodophyta, 5 species of Phaeophyta and 8 species of Chlorophyta) collected from the Gulf of Mexico and Caribbean coast of the Yucatan Peninsula (Mexico) were evaluated for their antileishmanial in vitro activity against Leishmania mexicana promastigote forms. The cytotoxicity of these extracts was also assessed using brine shrimp. Organic extracts from Laurencia microcladia (Rhodophyta), Dictyota caribaea, Turbinaria turbinata and Lobophora variegata (Phaeophyta) possessed promising in vitro activity against L. mexicana promastigotes (LC(50) values ranging from 10.9 to 49.9 microg/ml). No toxicity of algal extracts against Artemia salina was observed with LC50 ranging from 119 to >or=1000 microg/ml. Further studies on bio-guided fractionation, isolation and characterization of pure compounds from these species as well as in vivo experiments are needed and are already in progress.