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Yolanda Freile-pelegrín - One of the best experts on this subject based on the ideXlab platform.
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The Tropical Brown Alga Lobophora variegata: A Source of Antiprotozoal Compounds
Marine drugs, 2010Co-Authors: Zulema Cantillo-ciau, R. Moo-puc, Leovigildo Quijano, Yolanda Freile-pelegrínAbstract:Lobophora variegata, a brown alga collected from the coast of the Yucatan peninsula, Mexico, was studied for antiprotozoal activity against Giardia intestinalis, Entamoeba histolytica and Trichomonas vaginalis. The whole extract showed the highest activity against T. vaginalis, with an IC50 value of 3.2 μg/mL. For the fractions, the best antiprotozoal activity was found in non-polar fractions. The chloroform fraction of the extract contained a major sulfoquinovosyldiacylglycerol (SQDG), identified as 1-O-palmitoyl-2-O-myristoyl-3-O-(6´´´-sulfo-α-D-quinovopyranosyl)-glycerol (1), together with small amounts of 1,2-di-O-palmitoyl-3-O-(6´´´-sulfo-α-D-quinovopyranosyl)-glycerol (2) and a new compound identified as 1-O-palmitoyl-2-O-oleoyl-3-O-(6´´´-sulfo-α-D- quinovopyranosyl)-glycerol (3). Their structures were elucidated on the basis of chemical and enzymatic hydrolysis and careful analysis of FAB-MS and NMR spectroscopic data. This is the first report on the isolation of SQDGs from L. variegata. The mixture of 1-3 showed good activity against E. histolytica and moderate activity against T. vaginalis with IC50s of 3.9 and 8.0 μg/mL, respectively, however, the activity of 1-3 is not as effective as metronidazole. These results afford ground information for the potential use of the whole extract and fractions of this species in protozoal infections.
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In vitro cytotoxic and antiproliferative activities of marine macroalgae from Yucatán, Mexico
Ciencias Marinas, 2009Co-Authors: R. Moo-puc, Daniel Robledo, Yolanda Freile-pelegrínAbstract:Extracts from 27 marine algal species (14 Rhodophyta, 5 Phaeophyta, and 8 Chlorophyta) from the Yucatan Peninsula (Mexico) were evaluated for cytotoxic and antiproliferative activity by 3(4,5-dimethylthiazole-2-yl)-2,5 diphenyltetrazolium bromide (MTT) and sulforhodamine B (SRB) assays, respectively. To determine the specificity of cytotoxic activity against tumor cells, the selective index (SI) was also calculated. The following cancer cell lines were employed: normal canine kidney (MDCK) cells, human laryngeal carcinoma (Hep-2) cells, human cervical adenocarcinoma (HeLa) cells, and human nasopharyngeal carcinoma (KB) cells. The results indicated that 44% and 51% of the algal species tested showed cytotoxic and antiproliferative activity, respectively. Most of the cytotoxic extracts were from species of Chlorophyta, with Udotea flabellum and U. conglutinate showing the highest cytotoxic activity against all the cancer cell lines. For Rhodophyta, the Bryothamnion triquetrum extract showed outstanding selective cytotoxicity against Hep-2 cells (CC50 8.29 μg mL–1, SI = 12.04). Two of the five species of Phaeophyta tested (Lobophora variegata and Dictyota caribaea) showed high cytotoxicity activity against the KB cell line. The data show that these species are a potential source of compounds for the treatment of certain cancer diseases. Los extractos de 27 especies de algas marinas (14 Rhodophyta, 5 Phaeophyta y 8 Chlorophyta) recolectadas en la peninsula de Yucatan (Mexico) fueron evaluados para probar su actividad citotoxica y antiproliferativa usando los ensayos de 3[4,5-dimetiltiazol-2-il]-2,5-bromuro de difeniltetrazolio (MTT) y sulforodamina B (SRB), respectivamente. Para determinar la especificidad de la actividad citotoxica en las celulas tumorales, el indice de selectividad (IS) fue tambien calculado. Para lo anterior fueron empleadas las siguientes lineas celulares: celulas normales de rinon caninino (MDCK), celulas de carcinoma humano laringeo (Hep-2), celulas de adenocarcinoma humano de la cervix (HeLa) y celulas de carcinoma humano nasoafaringeo (KB). Los resultados indicaron que 44% y 51% de las especies exhibieron actividad citotoxica y antiproliferativa, respectivamente. La mayoria de los extractos citotoxicos fueron de las especies pertenecientes a la division Chlorophyta, siendo Udotea flabellum y U. conglutinata las especies que mostraron la mayor actividad citotoxica selectiva sobre todas las lineas celulares tumorales. Para la division Rhodophyta, el extracto de Bryothamnion triquetrum tuvo una destacable citotoxicidad selectiva contra las celulas Hep-2 (CC50 8.29 μg mL–1 con SI = 12.04). Dos de las cinco especies de Phaeophyta probadas (Lobophora variegata y Dictyota caribaea) mostraron alta actividad citotoxica sobre la linea celular KB. Los resultados muestran que estos extractos son una fuente prometedora de compuestos para el tratamiento de algunos tipos de cancer.
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Antitrypanosomal in vitro activity of tropical marine algae extracts
Pharmaceutical Biology, 2009Co-Authors: Lorena V. León-deniz, R. Moo-puc, Eric Dumonteil, Yolanda Freile-pelegrínAbstract: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 Kutzing 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.
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Evaluation of selected tropical seaweeds for in vitro anti-trichomonal activity.
Journal of ethnopharmacology, 2008Co-Authors: R. Moo-puc, Daniel Robledo, Yolanda Freile-pelegrínAbstract:Abstract Ethnopharmacological relevance Human parasitic infections are a serious problem in tropical and sub-tropical developing countries. Trichomoniasis, responsible for the annual infection of 180 million people, is a common sexually transmitted disease caused by the protozoan Trichomonas vaginalis . Traditionally seaweeds have been used in folk medicine by coastal people in Asia and the Caribbean to treat parasitic infections and are a valuable source of novel anti-trichomonals. Aim of the study In our search for therapeutical alternatives to anti-protozoal chemotherapy, we collected a selection of 25 tropical seaweeds (12 Rhodophyta, 5 Phaeophyta and 8 Chlorophyta) from the coast of Yucatan (Mexico) in order to undertake ethnopharmacological and chemotaxonomic investigations. Materials and methods Organic algal extracts were tested for their anti-trichomonal properties on the growth inhibition of Trichomonas vaginalis . The cytotoxicity of seaweed extracts on mammal cell lines was also assessed. Results The results indicated that 44% of the seaweeds studied had high to moderate anti-trichomonal activity. Lobophora variegata and Udotea conglutinata showed the maximal anti-trichomonal activity with IC 50 values of 1.39 and 1.66 μg/ml, respectively, with good selectivity. Conclusions Lobophora variegata and Udotea conglutinata demonstrated promising anti-trichomonal potential and have been selected for further bio-guided fractionation and isolation of active anti-trichomonal compounds.
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Antileishmanial properties of tropical marine algae extracts.
Fitoterapia, 2008Co-Authors: Yolanda Freile-pelegrín, Daniel Robledo, Manuel Jesús Chan-bacab, Benjamín Otto Ortega-moralesAbstract: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 (LC50 values ranging from 10.9 to 49.9 μg/ml). No toxicity of algal extracts against Artemia salina was observed with LC50 ranging from 119 to ≥1000 μg/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. © 2008 Elsevier B.V. All rights reserved.
Ruth Brack-werner - One of the best experts on this subject based on the ideXlab platform.
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Aqueous Extracts of the Marine Brown Alga Lobophora variegata Inhibit HIV-1 Infection at the Level of Virus Entry into Cells
2016Co-Authors: Stephan Kremb, Markus Helfer, Birgit Kraus, Horst Wolff, Christian Wild, Martha Schneider, Christian R. Voolstra, Ruth Brack-wernerAbstract:In recent years, marine algae have emerged as a rich and promising source of molecules with potent activities against various human pathogens. The widely distributed brown alga Lobophora variegata that is often associated with tropical coral reefs exerts strong antibacterial and antiprotozoal effects, but so far has not been associated with specific anti-viral activities. This study investigated potential HIV-1 inhibitory activity of L. variegata collected from different geographical regions, using a cell-based full replication HIV-1 reporter assay. Aqueous L. variegata extracts showed strong inhibitory effects on several HIV-1 strains, including drug-resistant and primary HIV-1 isolates, and protected even primary cells (PBMC) from HIV-1-infection. Anti-viral potency was related to ecological factors and showed clear differences depending on light exposition or epiphyte growth. Assays addressing early events of the HIV-1 replication cycle indicated that L. variegata extracts inhibited entry of HIV-1 into cells at a pre-fusion step possibly by impeding mobility of virus particles. Further characterization of the aqueous extract demonstrated that even high doses had only moderate effects on viability of cultured and primary cells (PBMCs). Imaging-based techniques revealed extract effects on the plasma membrane and actin filaments as well as induction of apoptosis at concentrations exceeding EC50 of anti-HIV-1 activity by more than 400 fold. In summary, we show for the first time that L. variegata extracts inhibit HIV-1 entry, thereby suggesting this alga as promisin
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Aqueous extracts of the marine brown alga Lobophora variegata inhibit HIV-1 infection at the level of virus entry into cells.
PloS one, 2014Co-Authors: Stephan Kremb, Markus Helfer, Birgit Kraus, Horst Wolff, Christian Wild, Martha Schneider, Christian R. Voolstra, Ruth Brack-wernerAbstract:In recent years, marine algae have emerged as a rich and promising source of molecules with potent activities against various human pathogens. The widely distributed brown alga Lobophora variegata that is often associated with tropical coral reefs exerts strong antibacterial and antiprotozoal effects, but so far has not been associated with specific anti-viral activities. This study investigated potential HIV-1 inhibitory activity of L. variegata collected from different geographical regions, using a cell-based full replication HIV-1 reporter assay. Aqueous L. variegata extracts showed strong inhibitory effects on several HIV-1 strains, including drug-resistant and primary HIV-1 isolates, and protected even primary cells (PBMC) from HIV-1-infection. Anti-viral potency was related to ecological factors and showed clear differences depending on light exposition or epiphyte growth. Assays addressing early events of the HIV-1 replication cycle indicated that L. variegata extracts inhibited entry of HIV-1 into cells at a pre-fusion step possibly by impeding mobility of virus particles. Further characterization of the aqueous extract demonstrated that even high doses had only moderate effects on viability of cultured and primary cells (PBMCs). Imaging-based techniques revealed extract effects on the plasma membrane and actin filaments as well as induction of apoptosis at concentrations exceeding EC50 of anti-HIV-1 activity by more than 400 fold. In summary, we show for the first time that L. variegata extracts inhibit HIV-1 entry, thereby suggesting this alga as promising source for the development of novel HIV-1 inhibitors.
Sunita Kumari - One of the best experts on this subject based on the ideXlab platform.
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Light and Electron Microscope Studies on Lobophora variegata (Lamouroux) Womersley ex Oliveira (Dictyotales, Phaeophyta)
Algae, 1998Co-Authors: Inderdeep Kaur, Sunita KumariAbstract:The plants of Lobophora variegata (Lamouroux) Womersley ex Oliveira are small, flat, fan-shaped and lobed at maturity. Growth of the plant occurs by means of a series of marginal initials resulting in a thallus composed of three tissues: epidermis, cortex and medulla. The walls of all cell types show a mixture of carboxylated and sulphated polysaccharides whereas the cytoplasm reveals differential distribution of physodes, vacuoles, proteins, polysaccharides and plastids. The tetrasporangia occur in groups and the associated hairs are absent. The present taxonomic status of Lobophora variegata, which had earlier been placed under the genus Dictyota is pointed out with reasonable certainty. The elucidation of asexual and sexual reproduction will provide further evidence of taxonomic status of Lobophora.
Bhavanath Jha - One of the best experts on this subject based on the ideXlab platform.
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On the biosorption, by brown seaweed, Lobophora variegata, of Ni(II) from aqueous solutions: equilibrium and thermodynamic studies
Biodegradation, 2010Co-Authors: Shaik Basha, Santlal Jaiswar, Bhavanath JhaAbstract:The biosorption equilibrium isotherms of Ni(II) onto marine brown algae Lobophora variegata , which was chemically-modified by CaCl_2 were studied and modeled. To predict the biosorption isotherms and to determine the characteristic parameters for process design, twenty-three one-, two-, three-, four- and five-parameter isotherm models were applied to experimental data. The interaction among biosorbed molecules is attractive and biosorption is carried out on energetically different sites and is an endothermic process. The five-parameter Fritz–Schluender model gives the most accurate fit with high regression coefficient, R ^2 (0.9911–0.9975) and F -ratio (118.03–179.96), and low standard error, SE (0.0902–0.0.1556) and the residual or sum of square error, SSE (0.0012–0.1789) values to all experimental data in comparison to other models. The biosorption isotherm models fitted the experimental data in the order: Fritz–Schluender (five-parameter) > Freundlich (two-parameter) > Langmuir (two-parameter) > Khan (three-parameter) > Fritz–Schluender (four-parameter). The thermodynamic parameters such as Δ G ^0, Δ H ^0 and Δ S ^0 have been determined, which indicates the sorption of Ni(II) onto L. variegata was spontaneous and endothermic in nature.
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Biosorption of Cd(II) and Pb(II) onto brown seaweed, Lobophora variegata (Lamouroux): kinetic and equilibrium studies
Biodegradation, 2008Co-Authors: Bhavanath Jha, Santlal Jaiswar, Shaik Basha, Biswajit Mishra, Mukund C. ThakurAbstract:The present work deals with the biosorption performance of raw and chemically modified biomass of the brown seaweed Lobophora variegata for removal of Cd(II) and Pb(II) from aqueous solution. The biosorption capacity was significantly altered by pH of the solution delineating that the higher the pH, the higher the Cd(II) and Pb(II) removal. Kinetic and isotherm experiments were carried out at the optimal pH 5.0. The metal removal rates were conspicuously rapid wherein 90% of the total sorption occurred within 90 min. Biomass treated with CaCl_2 demonstrated the highest potential for the sorption of the metal ions with the maximum uptake capacities i.e. 1.71 and 1.79 mmol g^−1 for Cd(II) and Pb(II), respectively. Kinetic data were satisfactorily manifested by a pseudo-second order chemical sorption process. The process mechanism consisting of both surface adsorption and pore diffusion was found to be complex. The sorption data have been analyzed and fitted to sorption isotherm of the Freundlich, Langmuir, and Redlich–Peterson models. The regression coefficient for both Langmuir and Redlich–Peterson isotherms were higher than those secured for Freundlich isotherm implying that the biosorption system is possibly monolayer coverage of the L. variegata surface by the cadmium and lead ions. FT-IR studies revealed that Cd(II) and Pb(II) binding to L. variegata occurred primarily through biomass carboxyl groups accompanied by momentous interactions of the biomass amino and amide groups. In this study, we have observed that L . variegata had maximum biosorption capacity for Cd(II) and Pb(II) reported so far for any marine algae.
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Biosorption of Cd(II) and Pb(II) onto brown seaweed, Lobophora variegata (Lamouroux): kinetic and equilibrium studies.
Biodegradation, 2008Co-Authors: Bhavanath Jha, Santlal Jaiswar, Biswajit Mishra, Basha, Mukund C. ThakurAbstract:The present work deals with the biosorption performance of raw and chemically modified biomass of the brown seaweed Lobophora variegata for removal of Cd(II) and Pb(II) from aqueous solution. The biosorption capacity was significantly altered by pH of the solution delineating that the higher the pH, the higher the Cd(II) and Pb(II) removal. Kinetic and isotherm experiments were carried out at the optimal pH 5.0. The metal removal rates were conspicuously rapid wherein 90% of the total sorption occurred within 90 min. Biomass treated with CaCl2 demonstrated the highest potential for the sorption of the metal ions with the maximum uptake capacities i.e. 1.71 and 1.79 mmol g−1 for Cd(II) and Pb(II), respectively. Kinetic data were satisfactorily manifested by a pseudo-second order chemical sorption process. The process mechanism consisting of both surface adsorption and pore diffusion was found to be complex. The sorption data have been analyzed and fitted to sorption isotherm of the Freundlich, Langmuir, and Redlich–Peterson models. The regression coefficient for both Langmuir and Redlich–Peterson isotherms were higher than those secured for Freundlich isotherm implying that the biosorption system is possibly monolayer coverage of the L. variegata surface by the cadmium and lead ions. FT-IR studies revealed that Cd(II) and Pb(II) binding to L. variegata occurred primarily through biomass carboxyl groups accompanied by momentous interactions of the biomass amino and amide groups. In this study, we have observed that L. variegata had maximum biosorption capacity for Cd(II) and Pb(II) reported so far for any marine algae.
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Estimation of Isotherm Parameters for Biosorption of Cd(II) and Pb(II) onto Brown Seaweed, Lobophora variegata
Journal of Chemical & Engineering Data, 2008Co-Authors: Basha, Bhavanath JhaAbstract:The biosorption equilibrium isotherms of Cd(II) and Pb(II) from aqueous solution onto both raw and treated biomass of Lobophora variegata were studied and modeled. To predict the biosorption isotherms and to determine the characteristic parameters for process design, 19 one-, two-, three-, four-, and five-parameter isotherm models were applied to experimental data. Results show that in general the accuracy of models to fit experimental data improves with the number of parameters. Biosorption isotherm modeling shows that the interaction of Cd(II) and Pb(II) with the L. variegata surface is localized to monolayer sorption. The interaction among biosorbed molecules is repulsive, and there is no association between them. Biosorption is carried out on energetically different sites and is an endothermic process. The five-parameter Fritz−Schluender model gives the most accurate fit with high R2 (0.9960 to 0.9978), low standard error (SE) (0.0334 to 0.0129), and residual or sum of square error (SSE) (0.0066 to 0....
Mukund C. Thakur - One of the best experts on this subject based on the ideXlab platform.
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Biosorption of Cd(II) and Pb(II) onto brown seaweed, Lobophora variegata (Lamouroux): kinetic and equilibrium studies
Biodegradation, 2008Co-Authors: Bhavanath Jha, Santlal Jaiswar, Shaik Basha, Biswajit Mishra, Mukund C. ThakurAbstract:The present work deals with the biosorption performance of raw and chemically modified biomass of the brown seaweed Lobophora variegata for removal of Cd(II) and Pb(II) from aqueous solution. The biosorption capacity was significantly altered by pH of the solution delineating that the higher the pH, the higher the Cd(II) and Pb(II) removal. Kinetic and isotherm experiments were carried out at the optimal pH 5.0. The metal removal rates were conspicuously rapid wherein 90% of the total sorption occurred within 90 min. Biomass treated with CaCl_2 demonstrated the highest potential for the sorption of the metal ions with the maximum uptake capacities i.e. 1.71 and 1.79 mmol g^−1 for Cd(II) and Pb(II), respectively. Kinetic data were satisfactorily manifested by a pseudo-second order chemical sorption process. The process mechanism consisting of both surface adsorption and pore diffusion was found to be complex. The sorption data have been analyzed and fitted to sorption isotherm of the Freundlich, Langmuir, and Redlich–Peterson models. The regression coefficient for both Langmuir and Redlich–Peterson isotherms were higher than those secured for Freundlich isotherm implying that the biosorption system is possibly monolayer coverage of the L. variegata surface by the cadmium and lead ions. FT-IR studies revealed that Cd(II) and Pb(II) binding to L. variegata occurred primarily through biomass carboxyl groups accompanied by momentous interactions of the biomass amino and amide groups. In this study, we have observed that L . variegata had maximum biosorption capacity for Cd(II) and Pb(II) reported so far for any marine algae.
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Biosorption of Cd(II) and Pb(II) onto brown seaweed, Lobophora variegata (Lamouroux): kinetic and equilibrium studies.
Biodegradation, 2008Co-Authors: Bhavanath Jha, Santlal Jaiswar, Biswajit Mishra, Basha, Mukund C. ThakurAbstract:The present work deals with the biosorption performance of raw and chemically modified biomass of the brown seaweed Lobophora variegata for removal of Cd(II) and Pb(II) from aqueous solution. The biosorption capacity was significantly altered by pH of the solution delineating that the higher the pH, the higher the Cd(II) and Pb(II) removal. Kinetic and isotherm experiments were carried out at the optimal pH 5.0. The metal removal rates were conspicuously rapid wherein 90% of the total sorption occurred within 90 min. Biomass treated with CaCl2 demonstrated the highest potential for the sorption of the metal ions with the maximum uptake capacities i.e. 1.71 and 1.79 mmol g−1 for Cd(II) and Pb(II), respectively. Kinetic data were satisfactorily manifested by a pseudo-second order chemical sorption process. The process mechanism consisting of both surface adsorption and pore diffusion was found to be complex. The sorption data have been analyzed and fitted to sorption isotherm of the Freundlich, Langmuir, and Redlich–Peterson models. The regression coefficient for both Langmuir and Redlich–Peterson isotherms were higher than those secured for Freundlich isotherm implying that the biosorption system is possibly monolayer coverage of the L. variegata surface by the cadmium and lead ions. FT-IR studies revealed that Cd(II) and Pb(II) binding to L. variegata occurred primarily through biomass carboxyl groups accompanied by momentous interactions of the biomass amino and amide groups. In this study, we have observed that L. variegata had maximum biosorption capacity for Cd(II) and Pb(II) reported so far for any marine algae.