Starch/PVA electrospun nanoscaffolds loaded with ultrasonic-assisted green-synthesis of CuO nanoparticles from marine macroalgae (Gracilaria corticata) extract: Cytotoxicity and antioxidant analysis

Photosynthesis, photorespiration and ecophysiological interactions in marine macroalgae

Evaluation of antimicrobial, antioxidant and cytotoxicity potential of R-phycoerythrin extracted from Gracilaria corticata seaweed

Seaweeds are marine macroalgae that are rich in various secondary metabolites known to exhibit different biological activities such as anti-diabetic, anti-inflammatory, antioxidant, etc. This study aimed to determine the bioactive metabolites, as well as the antioxidant and anti-inflammatory activities of two red algae (Ceramium virgatum and Gracilaria corticata) and two green algae (Enteromorpha flexuosa and Ulva fasciata), which are prevalent in the coastal region of the Bay of Bengal. The total phenolic and flavonoid contents were determined using the Folin-Ciocalteu and aluminium chloride methods. Antioxidant and anti-inflammatory activities were evaluated using the ABTS assay and protein denaturation, LPS-induced RAW264.7 cells, respectively. The highest total phenolic (5.73±0.06mg GAE/g dry extract) and flavonoid (5.25±01.6mg QE/g dry extract) contents were found in C. virgatum, and it also shows good antioxidant activity with an IC50 value of 258.66µg/mL. The protein denaturation assay and NO production inhibition assay of C. virgatum showed the lowest IC50 value (65.39µg/mL) and lower NO level. Analysis of secondary metabolites using HR-LCMS reveals the presence of 12 phytoconstituents in C. virgatum extract. From these results, it is evident that C. virgatum can contribute to the development of antioxidant and anti-inflammatory agents.

The removal of malachite green dye from aqueous solution by Ulva lactuca, Sargassum crassifolium, and Gracilaria corticata has been demonstrated in order to examine their potential use as low-cost adsorbents. The optimum pH (8.0), temperature (25 °C), contact time (150 min), and biomass (2.0 g) for removal of dye by algae are reported. The maximum removal percentage of the dye ranged between 95.6% and 98.3% by using Sargassum crassifolium at the optimal conditions. Minimum removal of dye by algae (69%-77.1%) was observed with the high dye concentration of 35 mg L-1 at the optimal conditions. Adsorption of the dye by using the biomass was found to fit well with Langmuir and Freundlich isotherms. The adsorption reaction was spontaneous, exothermic, and highly favorable by the tested algae. The FT-IR analyses confirmed that hydroxyl, carboxyl, amino, and carbonyl groups were responsible for the dye binding process. Scanning electron microscopy showed great porosity on the algal surface, which allows the free passage of dye molecules. The biomass of brown algae was the most effective in the removal of malachite green, followed by green and red algae. The highest affinity of the brown biomass for dye removal may be due to its high binding site affinity, the negative free energy of adsorption, and the great pores on its surface.

Seaweeds, or marine macroalgae, are primitive, non-flowering photosynthetic organisms that inhabit intertidal and subtidal zones and constitute an important renewable marine resource. This study explored the diversity of seaweeds and the physicochemical characteristics of coastal waters in Kovalam (Hawaii) and Ernakulam (Nayarambalam and Kuzhupilli), Kerala. Understanding coastal water quality in relation to seaweed assemblages is crucial for biodiversity conservation and sustainable coastal resource management. Eight seaweed samples were collected from rocky intertidal substrata across these locations, with only two species documented from the Ernakulam region. Among the collected specimens, Ulva fasciata Delile, Caulerpa peltata J.V. Lamouroux, and Chaetomorpha antennina Kützing were identified as green algae, while Gracilaria corticata J. Agardh, Hypnea bullata Kundu & Patel, and Asparagopsis taxiformis Delile belonged to the red algae. The remaining two species—Scytosiphon lomentaria J. Agardh and Sargassum wightii (Greville) J. Agardh—were brown algae reported exclusively from Kovalam. Ulva fasciata Delile and Chaetomorpha antennina Kützing were the two green algal species recorded from the Ernakulam coastal waters. Evaluation of seven major physicochemical parameters (pH, total dissolved solids, salinity, temperature, dissolved oxygen, nitrate, and phosphate) revealed slightly alkaline, warm, and saline waters with elevated dissolved solids, conditions favorable for sustaining diverse macroalgal communities.

Abstract. Scania AE, Chasani AR. 2021. The anti-bacterial effect of phenolic compounds from three species of marine macroalgae. Biodiversitas 22: 3412-3417. Bacterial infection is still a serious problem in human health due to many bacteria that are resistant to synthetic antibiotics. Natural antibiotics are needed for substituting synthetic antibiotics such as antibiotics derived from marine macroalgae. Marine macroalgae respond to extreme environmental conditions by producing secondary metabolites containing bioactive substances. Bioactive substances such as phenolic compounds in marine macroalgae may have an antibacterial effect on bacteria. Our research was aimed to detect the presence of phenolic compounds in three species of marine macroalgae (Ulva lactuca (Chlorophyta), Sargassum polycystum (Phaeophyta), Palmaria palmata (Rhodophyta)), and also to determine the most effective inhibition of phenols-contained extracts of marine macroalgae to the growth of Escherichia coli and Salmonella typhi. Our research was conducted through field sampling for collecting samples and laboratory work for identifying and extracting samples including qualitative testing of phenolic compounds, rejuvenating bacteria, preparing the tested bacteria, and determine the inhibition index of extracts against E.coli and S.typhi. Our results indicated that the extract of U. lactuca, S. polycystum, and P.palmata contained phenolic compounds. Phenols-contained extract of Sargassum polycystum is the most effective in inhibiting the growth of E. coli and S. typhi. The incubation temperature, the type of bacteria influence the antibacterial activity of marine macroalgae.

Introduction: Biofilms cause human health-related issues like chronic infections and affect the performance of materials in the aquatic environment. Natural products are considered a potential agent for controlling biofilm growth on surfaces. Marine macroalgae are a good source of novel bioactive metabolites. In this study, the antibiofilm activity of extracts from Dictyota dichotoma (brown alga), Ulva reticulata (green alga), and Acanthophora spicifera (red alga) was analyzed against biofilm-forming bacteria isolated from marine waters. This study aimed to analyze the phytochemical composition and antibiofilm activity of three macroalgal extracts. Methods: Antibiofilm activity was assessed against two biofilm-forming strains. The phytochemical components, such as chlorophyll a, carotenoids, carbohydrates, proteins, lipids, and total polyphenols, were analyzed to understand their contribution to biofilm inhibition. The secondary metabolite composition of the extracts was identified using GC-MS, and the detected compounds were used for molecular docking against the Biofilm-associated protein (Bap) of Staphylococcus aureus. Results: The results revealed strong antibiofilm activity (more than 50% inhibition) in all three algal species, with higher activity recorded for the brown alga. Macroalgal extracts altered cell surface hydrophobicity and reduced the extracellular polymeric substance production in biofilm bacteria. Results indicated that A. spicifera (red alga) had high carbohydrate content, while U. reticulata (green alga) had high protein content. The carotenoids and chlorophyll a contents were higher in the green alga. GC-MS analysis showed a greater number of compounds for the brown alga, followed by the red and green algae. Discussion: Most of the identified compounds were predicted to be potential antibiofilm agents (with biofilm inhibition efficiency > 60%) based on aBiofilm database. Strong binding affinities were observed between some of the metabolites and the biofilm-associated protein of S. aureus in molecular docking analysis. result: The results revealed strong antibiofilm activity (above 50% of inhibition) in all three algal species with higher activity recorded in brown alga. Treatment macroalgal extracts resulted a change in cell surface hydrophobicity and reduction in extracellular polymeric substance production in biofilm bacteria. Results indicated a high carbohydrate content in red alga A. spicifera and protein content in green alga U. reticulata. The carotenoids and chlorophyll-a contents were high in the green algal samples. GC-MS analysis showed a greater number of compounds in brown alga followed by red and green algae. Most of compounds identified in the extracts are predicted as potential antibiofilm agents (biofilm inhibition efficiency of >60%) using abiofilm database. Strong binding affinities between some of the metabolites and biofilm-associated protein of S. aureus was observed in molecular docking analysis. Conclusion: The results suggest that the Red Sea macroalgae are good sources of antibiofilm compounds that could be used for both pharmacological and environmental applications.

The biologically active compounds (fatty acids, pigments, phenolics, and flavonoid content) were studied in supercritical fluid extracts from the biomass of marine (Ulva clathrata, Cladophora glomerata, Polysiphonia fucoides, and their multi-species mixture) and freshwater (C. glomerata) macroalgae. Different extraction techniques were used in order to compare differences in the biologically active compound composition of the macroalgal extracts. The results indicated that the saturated and unsaturated fatty acids ranged from C9:0 to C22:0. The analysis of differences in the composition of unsaturated to saturated fatty acids in extracts showed that palmitic acid (C16:0) and oleic acid (C18:1, n-9) reached the highest value not only in marine monospecies and multi-species biomass but also in the freshwater macroalga C. glomerata. When comparing the similarity between the concentration of fatty acids and the ratio of the concentration of unsaturated fatty acids to saturated in macroalgal extracts, we found small but not statistically significant variations in values between years (up to 10%). This is acceptable for applications as a stable raw material for industrial purposes. Significantly higher values of fatty acids, carotenoids, and chlorophylls were obtained in the case of SC-CO2 extraction. The active ingredients of polyphenols, possessing antioxidant activity ranged from approximately 2–4%. Moreover, flavonoids represented less than 10% of the total content of polyphenolic compounds. The extraction efficiency of polyphenols was higher from a mixture of marine algae for the ultrasound-assisted extraction compared to freshwater. All these findings show that marine and freshwater macroalgae, as a raw material, have the optimal biologically active compounds composition for cosmetics.

Inhibition of marine bacteria by extracts of macroalgae: potential use for environmentally friendly antifouling paints

In vitro protective activity of South Australian marine sponge and macroalgae extracts against amyloid beta (Aβ1–42) induced neurotoxicity in PC-12 cells

This study aims to identify effective antialgal allelochemicals from marine macroalgae that inhibit the growth of red tide microalgae. Practically, new algicidal agents were developed to control red tide. The growth inhibitory effects of 5 marine macroalgae Porphyra tenera, Laminaria japonica, Ulva pertusa, Enteromorpha clathrata, and Undaria pinnatifida on Skeletonema costatum were evaluated by adding crude seawater extracts of macroalgal dry tissue into the culture medium containing S. costatum. The half-effective concentrations at 120 h (EC50, 120 h) of the seawater extracts were 0.6, 0.9, 1.0, 1.0, and 4.7 g/L for the five macroalgae above, respectively. E. clathrata, L. japonica and U. pertusa showed strong allelopathic effect on the growth of S. costatum. There have been no previous reports with regard to the allelopathic effects of the former two macroalgae so far. The possible allelochemicals of 21 compounds of the E. clathrata were detected using Gas chromatography-mass spectrometry (GC-MS) analysis. Unsaturated fatty acids, acrylic acid (C3H4O2), and linolenic acid (C18H30O2) were the most likely allelochemicals in E. clathrata.

Effects of starvation and macroalgae extracts on the survival and growth of quahog parasite unknown (QPX)

Some infections caused by pathogenic microorganisms might shows high prevalence in farmed shrimp environments, compromising production and causing economic losses. Therefore, the search for compounds with antibiotic activity has become intensive, following the record of new antimicrobial-resistant bacteria. The study of those bioactive compounds in marine macroalgae has produced satisfactory results, such as the discovery of antibacterial activity against multiresistant strains. Accordingly, this study aims to research antibiotic activity in macroalgae extracts of Chlorophyta, Phaeophyta and Rhodophyta found in the coast of Ceara and also to evaluate the cytotoxicity activity against bacterial strains ( Vibrio sp.) from shrimp farms ( Litopenaeus vannamei ). The extracts cytotoxicity was also evaluated. The results prove that there was antibacterial activity in ethanolic, acetonic, hexanic and methanolic extracts against bacterial strains of Vibrio with multiple resistance profile as well as displaying low cytotoxicity.

Natural extracts of macroalgae are widely recognized for their antioxidant properties. In this work, the antioxidant capacity of various aqueous and hydroalcoholic extracts obtained from red and green marine algae and from one marine lichen collected from different sites in southern Spain (intertidal and estuarine waters) was evaluated by different methods: ABTS free radical scavenging assay, DPPH assay, and beta-carotene bleaching method (BBM). Contents of total lipids, total carbohydrates, and UV photoprotectors with antioxidant capacity, such as mycosporine-like amino acids and phenolic compounds, were determined. Among the extraction solvents, the highest extraction yield was observed in H2O and 20% MeOH (v/v). The highest antioxidant activity was found in the extracts of the red macroalgae Hydropuntia cornea, Gracilariopsis longissima, Halopithys incurva, and Porphyra umbilicalis, whereas the lowest activity was detected in the green macroalga Ulva rotundata. In general, the antioxidant activity was higher using DPPH than BBM and ABTS. Even so, the ABTS assay is an easy and quick test that provides a comprehensive view of the entire extract in both the lipophilic medium and hydrophilic medium. The antioxidant activity was related to the composition of bioactive compounds and synergistic action is not discarded. The biotechnological use of macroalgal extracts with high antioxidant capacity is discussed.

Background:Marine algae, also called seaweeds, are abundantly present in the coastal area of Iran, especially in Persian Gulf. These plants contain important phytochemical constituents and have potential biological activities. The present study investigated the presence of phytochemical constituents and total phenolic quantification of the seaweeds Gracilaria salicornia and Gracilaria corticata. Cytotoxicity of seaweeds was tested against HT-29, HeLa, and MCF-7 cell lines. Antioxidant potential of these two Gracilaria species was also analyzed.Materials and Methods:Extracts of G. salicornia and G. corticata were subjected to phytochemical and cytotoxicity tests. Phytochemical screenings were employed to identify the chemical constituents and total phenolic content. Cytotoxicity was characterized by IC50 of human cancer cell lines (MCF-7, HeLa, and HT-29) using sulforhodamine assay. Antioxidant activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl.Results:The analysis revealed that tannins were the most abundant compounds in G. corticata while sterols and triterpenes were the most abundant ones in G. salicornia, but the total phenolic content of the two seaweeds was similar. Cytotoxic results showed that both species could inhibit cell growth effectively, especially against HT-29 cell line.Conclusion:Considerable phytochemicals, high antioxidant potential, and moderate cytotoxic activity of G. salicornia and G. corticata make them appropriate candidates for further studies and identification of their bioactive principles.