In vitro anticancer activity of ethanolic extract of Stoechospermum marginatum against HT-29 human colon adenocarcinoma cells

Colorectal cancer is a one of the leading causes of death globally and its clinical management of cancer involves chemotherapy. Increase in the development of resistance to the drugs used in the cancer treatment and serious side effects associated with chemotherapeutic drugs are the major limitations in cancer therapy. Hence, there exists a huge need to develop safer natural therapeutic products for cancer therapy. In this study, ethanolic extract of Stoechospermum marginatum was evaluated for its anticancer activity. The cytotoxicity of S. marginatum extract was evaluated on HT-29 cells by MTT assay. Trypan blue cell viability was also carried out to evaluate cytotoxicity and antiproliferative effect. The apoptosis-inducing potential of the extract was analyzed by acridine orange and ethidium bromide dual staining method, mitochondrial membrane potential assay and FITC Annexin V-Propidium iodide staining method. The ethanolic extract of S. marginatum showed significant dose-dependent cytotoxicity in HT-29 cells Treatment with S. marginatum extract increased number of apoptotic cells in HT-29 cells and caused damage to mitochondrial membrane potential. The findings of the present study confirmed in vitro anticancer activity of ethanolic extract S. Marginatum

Antimicrobial activity screening of endophytic fungi extracts isolated from brown algae Padina sp.

This study aims to evaluate the antimicrobial activities of endophytic fungi from marine brown algae Padina sp.collected from Nirwana Beach, Padang, West Sumatera, Indonesia. The isolation of endophytic fungi was conductedusing dilution method with Sabouraud Dextrose Agar (SDA) + Chloramphenicol as a growth medium. Nine fungistrains have been isolated from this alga. Purely isolated fungi were cultivated using rice as a medium at roomtemperature for 3–4 weeks. The secondary metabolite produced by fungi was extracted using ethyl acetate (EtOAc)as a solvent. The antimicrobial activity of EtOAc extracts was tested against Staphylococcus aureus, Escherichiacoli, and Candida albicans by using the agar diffusion method. In this research, nine endophytic fungi were isolatedfrom the brown marine algae Padina sp. The results of antimicrobial activity screening showed that one fungal isolate(Nita3) was selected as the most active against S. aureus, E. coli, and C. albicans with a diameter of inhibition zone of20.98 ± 1.56 mm, 17.98 ± 6.58 mm, and 13.60 ± 0 mm, respectively. This selected fungus was identified molecularlyas Trichoderma harzianum. We conclude that T. harzianum can be a source of antimicrobial compounds. However,continuous research is needed to prove its bioactive action

Antimicrobial activity screening of endophytic fungi extracts isolated from brown algae Padina sp.

This study aims to evaluate the antimicrobial activities of endophytic fungi from marine brown algae Padina sp.collected from Nirwana Beach, Padang, West Sumatera, Indonesia. The isolation of endophytic fungi was conductedusing dilution method with Sabouraud Dextrose Agar (SDA) + Chloramphenicol as a growth medium. Nine fungistrains have been isolated from this alga. Purely isolated fungi were cultivated using rice as a medium at roomtemperature for 3–4 weeks. The secondary metabolite produced by fungi was extracted using ethyl acetate (EtOAc)as a solvent. The antimicrobial activity of EtOAc extracts was tested against Staphylococcus aureus, Escherichiacoli, and Candida albicans by using the agar diffusion method. In this research, nine endophytic fungi were isolatedfrom the brown marine algae Padina sp. The results of antimicrobial activity screening showed that one fungal isolate(Nita3) was selected as the most active against S. aureus, E. coli, and C. albicans with a diameter of inhibition zone of20.98 ± 1.56 mm, 17.98 ± 6.58 mm, and 13.60 ± 0 mm, respectively. This selected fungus was identified molecularlyas Trichoderma harzianum. We conclude that T. harzianum can be a source of antimicrobial compounds. However,continuous research is needed to prove its bioactive action.

Enzyme Detection and Metabolic Process Tracking of Ethanol Fermentation by a Natural Alginate Fermentation Strain

ABSTRACT Alginate is a major component of brown algae, but it cannot be utilized for ethanol fermentation by industrial microorganisms. A natural alginate degrading and ethanol producing strain was obtained in our previous research. However, the research on the ethanol metabolism process of the natural alginate fermentation strain is lacked. In this research, the key enzyme and metabolic process of ethanol fermentation were studied. Three kinds of key enzyme including alginate lyase, pyruvate dehydrogenase and ethanol dehydrogenase were determined. The enzyme activity in the metabolic process was relatively high at 60-96 h which was the most important period during the fermentation. Meanwhile the concentration change of the important substances including soluble sugar, reducing sugar, acidity, pyruvic acid and ethanol were tracked and analyzed. Total soluble sugar and reducing sugar change tendency during the fermentation was similar. In the whole fermentation process, the fermentation broth was acidic. The value of pyruvic acid content reached highest at 72 h. During 48-96 h, the growth of ethanol concentration was very obvious. The alginate metabolic process in natural alginate fermentation strain was to generate extracellular alginate lyase to degrade alginate to produce reducing sugar, and then some intermediate metabolites formed such as pyruvic acid. Finally under the effect of pyruvate dehydrogenase and ethanol dehydrogenase, ethanol was produced.

Notas sobre las algas marinas de la Reserva Internacional de Biosfera Seaflower, Caribe colombiano VI: nuevos registros de algas pardas (Phaeophyceae) / Notes on the marine algae of the international biosphere reserve seaflower, caribbean colombia vi: new records of brown algae (phaeophyceae)

ABSTRACT Two species ofbrown algae (Phaeophyceae), Bachelotia antillarum and Dictyota humifusa are reported for the first time for the Archipelago of San Andrés, Providencia and Santa Catalina, part of the International Biosphere Reserve Seaflower.

RESUMEN Dos nuevos registros de algas pardas (Phaoephyceae), Bachelotia antillarum y Dictyota humifusa son registradas por primera vez para el Archipiélago de San Andrés, Providencia y Santa Catalina, Reserva Internacional de la Biosfera Seaflower.

Alginate overproduction and biofilm formation by psychrotolerant Pseudomonas mandelii depend on temperature in Antarctic marine sediments

Background: In recent years, Antarctica has become a key source of biotechnological resources. Native microorganisms have developed a wide range of survival strategies to adapt to the harsh Antarctic environment, including the formation of biofilms. Alginate is the principal component of the exopolysaccharide matrix in biofilms produced by Pseudomonas, and this component is highly demanded for the production of a wide variety of commercial products. There is a constant search for efficient alginate-producing organisms. Results: In this study, a novel strain of Pseudomonas mandelii isolated from Antarctica was characterized and found to overproduce alginate compared with other good alginate producers such as Pseudomonas aeruginosa and Pseudomonas fluorescens. Alginate production and expression levels of the alginate operon were highest at 4°C. It is probable that this alginate-overproducing phenotype was the result of downregulated MucA, an anti-sigma factor of AlgU. Conclusion: Because biofilm formation is an efficient bacterial strategy to overcome stressful conditions, alginate overproduction might represent the best solution for the successful adaptation of P. mandelii to the extreme temperatures of the Antarctic. Through additional research, it is possible that this novel P. mandelii strain could become an additional source for biotechnological alginate production.

Evaluation of Cytotoxic Activity of Sargassum vulgare From the Lebanese Coast Against Jurkat Cancer Cell Line.

The discovery of cancer drugs that effectively destroy cancer cells or stop their growth without toxicity to normal cells is a challenge to enhance the therapeutic effects and reduce side effects. Many papers have highlighted the implication of marine algae that show anticancer activity. In this report, we assessed the cytotoxic activity of two different crude extracts from Sargassum vulgare (Sargassaceae), a marine brown algae collected from the Lebanese coast, against Jurkat human cancer cell line using trypan blue exclusion test. Both extracts, water: ethanol extract and chloroform: ethanol extract, showed cytotoxic activity against Jurkat cancer cell line with IC50 values of 136.907 μg/ mL and 49.056 μg/ mL, respectively after 72 hours of treatment. Further research designed to isolate and identify novel and efficient anticancer drug candidates from these seaweed extracts need to be explored.

Antibacterial Activity of Two Brown Algae (Cystoseira compressa and Padina pavonica) Against Methicillin-Resistant Staphylococcus aureus.

Aqueous and ethanolic extracts obtained from two brown algae (Cystoseira compressa (Esper) Gerloff et. Nizamuddin) and Padina pavonica (Linnaeus) Thivy) have been investigated for their ability to inhibit 35 hospital isolates of methicillin-resistant Staphylococcus aureus (MRSA). Both aqueous and ethanolic extracts of the plant were effective on MRSA. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of the ethanolic extract with the greatest antibacterial activity were those of Cystoseira compressa MIC 3.2-6.3mg/mL and MBC 6.3-25mg/mL, respectively.

Dynamic Cr(III) uptake by Macrocystis pyrifera and Undaria pinnatifida biomasses

Background: The increased industrial activity has resulted in the discharge of large amount of pollutants including non-degradable metals into the environment. Chromium is produced in several industrial processes and it can be found in the environment in two stable oxidation states, Cr(VI) and Cr(III). Cr(VI) is more hazardous due to its carcinogenic and mutagenic effects on living organisms. Although much less toxic, Cr(III) can also exert genotoxic effects under prolonged or severe exposure. It can be separated from the solution by precipitation but biosorption using brown algae seems to be an effective and sustainable treatment technique owing to its cost-effectiveness and environmental friendly characteristics. Macrocystis pyrifera and Undaria pinnatifida are two marine brown macroalgae with high capability of removing heavy metals including Cr(III) in batch mode of operation. In this work packed bed biosorption of Cr(III) by M. pyrifera and U. pinnatifida biomasses was evaluated. Results: The shapes of the breakthrough curves were rather different for each biomaterial. Parameters like the breakthrough time (t b) andzone mass transfer (MTZ) showed that U. pinnatifida has greater affinity for Cr(III). The maximum adsorption capacity at the exhaustion operating time (t e) demonstrated that M. pyrifera has higher retention capacity of Cr(III). The experimental data were fitted to Thomas, Yoon-Nelson and Dose-Response models. The best correlation coefficient (0.94 or 0.96) was obtained with Dose-Response that accurately describes the uptake behaviour of Cr(III) on the seaweed biomasses under different experimental conditions. The FT-IR spectra evidenced that Cr(III) adsorption occurred mainly by interaction between metal and carboxylate groups present on both the seaweed surfaces. Conclusions: M. pyrifera and U. pinnatifida biomasses are efficient biosorbents for Cr(III) adsorption under a continuous mode of operation although differences between uptake capacities suggest different mechanisms involved in the biosorption.

The antioxidant and anticoagulant activities of polysaccharides isolated from the brown algae Dictyopteris polypodioides growing on the Lebanese coast.

In this study, we attempt to isolate the polysaccharides from the brown seaweed Dictyopteris polypodioides (Dp) growing on the Lebanese coast. The percentages of the main polysaccharide alginic acid were 4.6% in May and 6.25% in July. The extracted yields of Fucoidan, Laminaran and Mannuronan (FLM) and Mannuronan (M) alone were respectively 0.75% and 0.38% in May and 1.15% and 0.67% in July. We performed the infrared spectroscopy in order to reveal the functional groups of alginate and mannuronan. Moreover, a non-destructive technique ¹ H NMR was used to determine the structure of alginate and the distribution of guluronic (G) and mannuronic acid (M) in the chain, allowing us therefore to calculate the ratio M/G. The latter was 0.96 showing a strong ability of alginate to capture heavy metals. The analysis of trace elements showed great amounts of K, Si, Na and Mg in both seasons. Moreover, Dictyopteris appears to be rich in fatty acids (10 items) with palmitic and oleic acids as main fatty acids. Furthermore, the anticoagulant activity of polysaccharides was investigated by activated partial thromboplastin time (APTT) clotting assay and the antioxidant activity was studied by electrolysis method. It has been shown that the FLM and M fractions of Dictyopteris polypodioides have a significant antioxidant and anticoagulant activities. Further investigations are imperative in order to develop new molecules based on these polysaccharides to be used as drugs or for healthcare in general.

HIV-1 Reverse Transcriptase: a potential target for marine products

HIV-1 reverse transcriptase (HIV-1 RT) is a therapeutic target for the treatment of HIV-positive individuals or those already showing AIDS symptoms. In this perspective, the identification of new inhibitors for this enzyme is of great importance in view of the growing viral resistance to the existing treatments. This resistance has compromised the quality of life of those infected with multidrug-resistant strains, whose treatment options are already limited, putting at risk these individuals lives. The literature has recognized marine organisms and their products as natural sources for the identification of new therapeutic options for different pathologies. In this brief review, we consider the structure of HIV-1 RT and its most common inhibitors, as well as some marine diterpenes originally reported as HIV-1 RT inhibitors to encourage the identification and development of new marine antiviral prototypes.

Evaluation of antioxidant properties of a new compound, pyrogallol-phloroglucinol-6,6'-bieckol isolated from brown algae, Ecklonia cava

In this study, antioxidant and free radical scavenging activities of the natural antioxidative compound, pyrogallol-phloroglucinol-6,6'-bieckol (PPB) isolated from brown algae, Ecklonia cava was assessed in vitro by measuring the radical scavenging activities (DPPH, alkyl, hydroxyl, and superoxide) using electron spin resonance (ESR) spectrometry, intracellular reactive oxygen species (ROS) scavenging activity, and DNA damage assay. According to the results of these experiments, the scavenging activity PPB against difference radicals was in the following order: DPPH, alkyl, hydroxyl, and superoxide radicals (IC50; 0.90, 2.54, 62.93 and 109.05 microM). The antioxidant activities of PPB were higher than that of the commercial antioxidant, ascorbic acid. Furthermore, PPB effectively inhibited DNA damage induced by H2O2. These results suggest that the natural antioxidative compound, PPB, can be used by the natural food industry.

Studies on antioxidative activity of high molecular weight polyphenols from two kinds of brown algae / 中草药

Object To evaluate the antioxidative activity of the high molecular weight polyphenols from Sargassum thunbeergii Kuntze and Sargassum kjellmanianum Yendo. Methods Three kinds of evaluation systems for antioxidative activity were adopted to test their efficiency to scavenge radicals (including hydroxyl free radical ?OH, superoxide redical O? 2 and DPPH? free radical). Results The high molecular weight polyphenols from the two kinds of brown algae had strong activity to scavenge the radicals above. Furthermore, they acted almost as the same level. Conclusion The high molecular weight polyphenols from the two kinds of brown algae had strong antioxidative activity, thus they are the potential, natural and marine antioxidants.

Recent progress in the study of some chemical constituents from marine brown algae / 中国海洋药物

Many constituents with novel structures have been isolated from marine brown algae,some of which possess various bioactivities.The terpenoids,lipids,steroids,phlorotannins and some other compounds isolated from brown algae through 1993~2000 were reviewed in this article.