In vitro antioxidant activities of selected seaweeds from Southeast coast of India

Objective:In vitro antioxidant activities of three selected Indian seaweeds viz.,Halimeda tuna(H.tuna),Turbinaria conoides(T.conoides) and Gracilaria foliifera(G.foliifera) were evaluated.Methods:Total antioxidant activity,total phenolic content,and reducing power of crude methanol and diethyl ether extracts were determined.Results:Total phenolic content and total antioxidant activity were higher(1.231±0.173 mg GAE/g,1.675±0.361 mg GAE/g) in T.conoides respectively.Reducing power of crude methanol extract increased with concentrations of the extract.The Fourier transform-infra red spectrum analysis revealed the presence of polyphenolic signals.The seaweed extracts displayed moderate antioxidant activity compared to gallic acid standard.Conclusions:The seaweeds could be considered for curing diseases from oxidative deteriorations.

Evaluation of phenolic contents and antioxidant activities of brown seaweeds belonging to Turbinaria spp.(Phaeophyta,Sargassaceae) collected from Gulf of Mannar

Objective:To evaluate the antioxidant activities and total phenolic contents of brown seaweeds belonging to Turbinaria spp.[Turbinaria conoides(T.conoides)and Turbinaria ornata(T.ornata)collected from Gulf of Mannar of southeastern coast of India in various in vitro systems.Methods:The antioxidant activity was evaluated using different in vitro systems,viz.,I,I-diphenyl-2-picrylhydrazyl(DPPH),2,2'-azino-bis-3 ethylbenzothiozoline-6-sulfonic acid diammonium salt(ABTS),H_20_2/H0 radical scavenging,Fe^(2+)ion chelating ability,and reducing potential.Folin-Ciocalteu method was used to determine the total phenolic content of the extracts,and the results were expressed as mg of gallic acid equivalents(GE)/g of the seaweed extracts.Thiobarbituric acid-reactive substances assay was employed to assess the ability of the seaweed extracts to inhibit lipid oxidation.Results:Ethyl acetate(EtOAc)fraction of T.conoides registered significantly higher phenolic content(105.97 mg GE/g)than that of T.ornata(69.63 mg GE/g).Significantly higher antioxidant potential as determined by DPPH(64.14%)radical scavenging activity was registered in EtOAc fraction of T.ornata.A higher ABTS(?)radical scavenging(IC_(50)3.16μg/mL),Fe^(2+)chelating(IC_(50)0.46 mg/mL),H_2O_2 scavenging(IC_(50)4.25 mg/mL),lipid peroxidation inhibitory(TBARS,IC_(50)0.21 mg/mL),and reducing abilities(IC_(50)52.67 mg/mL)(P<0.05)were realized in EtOAc fraction of T.ornata than other fractions.Conclusions:This study indicated the potential use of T.conoides and T.ornata as candidate species to be used as food supplements/functional foods to increase shelf-life of food items for human consumption,and nutraceuticals to deter deleterious free radical-induced life-threatening diseases.

Enoplus taipingensis,a new species of marine nematode from the rocky intertidal seaweeds in the Taiping Bay,Qingdao

One new species of free-living marine nematodes Enoplus taipingensis sp. nov. from the rocky intertidal seaweeds in the Taiping Bay, Qingdao is described and illustrated with scanning electron microscopy observation and 18S rRNA gene sequence analysis. Enoplus taipingensis is characterized by special arrangement of lateral setae on the tail, three cervical setae, distal structure on the supplement, and much longer body length with bigger De Man ratio ＂a＂. Type specimens are deposited in the College of Marine Life Science, Ocean University of China.

Spermatozoid life-span of two brown seaweeds, Saccharina japonica and Undaria pinnatifida, as measured by fertilization efficiency

During sexual reproduction of seaweeds, spermatozoid (sperm) discharge is triggered by chemical messengers (pheromones) released by the female gametes. The chemotactic ability of the sperm ensures fertilization success. Using unialgal male and female gametophyte material under designated standard gametogenesis testing (SGT) conditions, the potential life-span of the sperm of two seaweeds, Saccharina japonica and Undaria pinnatifida, was assessed by their ability to fertilize eggs. Results show that within 20-30 min after being discharged, sperm of both species could complete fertilization without an apparent decline in fertilization rate. Although fertilization rate 60-120 min after sperm discharge dropped significantly in both species, some sperm were viable enough to fertilize the eggs. In S.japonica, at 12°C, some sperm were able to fertilize eggs up to 12 h after discharge. In both species, egg discharge rates (EDR) in the male and female mixed positive controls were significantly higher than those of all the sperm-testing groups. Doubling the seeded male gametophytes of S. japonica in the SGT tests significantly increased the EDR, further confirming the effect of the presence of the male on the female in terms of facilitating egg discharge from oogonia.

Jeju seaweeds suppress lipopolysaccharide-stimulated proinflammatory response in RAW 264.7 murine macrophages

Objective:To investigate the anti-inflammatory effects of Jeju seaweeds on macrophage RAW264.7 cells under lipopolysaccharide(LPS)stimulation.Methods:Ethyl acetate fractions were prepared from five different types of Jeju seaweeds,Dictyopteris divaricata(D.divaricata),Dictyopteris prolifera(D.prolifefa),Prioutis cornea(P.comea,Grateloupia laceolata(G,lanceolate,and Cralcloupia filicina(G.filicina)They were screened for inhibitory effects on proinflammatory mediators and cytokines such as nitric oxide(NO),prostaglandin E,,tumor necrosis factor-a(TNF-a),and interleukin-6(11.-6).Results:Our results revealed that D.divaricata,D.prolifera,P.cornea,G.lanceolata,and G.filicina potently inhibited I.PS-stimulaled NO production(IC_(50),values were 18.0,38.36,38.43,32.81 and 37.14μg/mL,respectively).Consistent with these findings,D.divtricata,D.prolifera,P.cornea,and G.fdicina also reduced the IPS-induced and prostaglandin E,production in a concentration-dependent manner.Expectedly,they suppressed the expression of inducible NO synthase and cyclooxygenase-2 at the protein level in a dose-dependent manner in the RAW264.7 cells,as detennined by western blotting.In addition,the levels of TNF-a and IL-6,released into the medium,were also reduced by D.divaricata,D.prolifera,P.cornea,G,lanceolata,and G.fdicina in a dose-dependent manner(IC_(50)values for TNF-a were 16.11,28.21,84.27,45.52 and74.75μg/mL,respectively;IC_(50),values for IL-6 were 37.35,80.08,103.28,62.53 and 84.28μg/mL,respectively).The total phlorotannin content was measured by the Folin-Ciocalteu method and expressed as phloroglucinol equivalents.The content was 92.0μg/mg for D.divaricata,151.8μg/mg for D.prolifera,57.2μg/mg for P.cornea,53.0 pg/mg for G.lanceolata,and 40.2μg/mg for G.fdicina.Conclusions:Thus,these findings suggest that Jeju seaweed extracts have potential therapeutic applications for inflammatory responses.

Green synthesis of iron oxide(Fe_3O_4)nanoparticles using two selected brown seaweeds:Characterization and application for lead bioremediation

The exploitation of different plant materials for the biosynthesis of nanoparticles is considered a green technology because it does not involve any harmful chemicals. In this study, iron oxide nanoparticles（Fe3O4-NPs） were synthesized using a completely green biosynthetic method by reduction of ferric chloride solution using brown seaweed water extracts. The two seaweeds Padina pavonica（Linnaeus） Thivy and Sargassum acinarium（Linnaeus） Setchell 1933 were used in this study. The algae extract was used as a reductant of Fe Cl3 resulting in the phytosynthesis of Fe3O4-NPs. The phytogenic Fe3O4-NPs were characterized by surface plasmon band observed close to 402 nm and 415 nm; the obtained Fe3O4-NPs are in the particle sizes ranged from 10 to 19.5 nm and 21.6 to 27.4 nm for P. pavonica and S. acinarium, respectively. The strong signals of iron were reported in their corresponding EDX spectra. FTIR analyses revealed that sulphated polysaccharides are the main biomolecules in the algae extracts that do dual function of reducing the Fe Cl3 and stabilizing the phytogenic Fe3O4-NPs. The biosynthesized Fe3O4-NPs were entrapped in calcium alginates beads and used in Pb adsorption experiments. The biosynthesized Fe3O4-NPs alginate beads via P. pavonica（Linnaeus） Thivy had high capacity for bioremoval of Pb（91%） while that of S. acinarium（Linnaeus） Setchell 1933 had a capacity of（78%） after 75 min.The values of the process parameters for the maximum Pb removal efficiency by Fe3O4-NPs alginate beads synthesized via P. pavonica（Linnaeus） Thivy were also estimated.

Some Mechanism Seaweeds Employ to Cope with Salinity Stress in the Harsh Euhaline Oceanic Environment

In order to prevent salt damage because seaweed enzymes can only operate under hypohaline conditions (salinity ≈ 6‰ - 12‰) but also obtain for photosynthesis an in the aquatic environment—due to a 10,000 fold strongly limited carbon source—seaweeds developed several mechanisms to meet these vital demands for survival in the harsh euhaline oceanic environment (salinity range: 32‰ - 35‰), we tested this range of adaptation mechanisms in the euhaline oceanic collected water in combination with the seaweed moisture. We obtained under laboratory conditions at 10 bar mechanical pressure for four seaweed species: Ulva lactuca, Caulerpa sertularioides, Caulerpa cf. brachypus (all three green) and Undaria pinnatifidia (brown). Oceanic water and seaweed moisture were measured for salinity, pH and by Inductively Coupled Plasma Spectroscopy (ICP)-techniques concentrations for macro-elements: (Ca, Fe, K, Mg, Mn, Na, P, & S), micro-elements ≈ [HM]: (Al, As, Cd, Co, Cr, Cu, Mo, Ni, Pb & Zn) and nutrients (N-total & P-total). The [seawater compound X]/[oceanic compound X] ration is a reflection of an inward (uptake) or excretion mechanism over the seaweed cellular membrane which is operative. Our observations gave a clear dispersion to salinity stress with on one hand the green seaweed U. lactuca and on the other the brown seaweed U. pinnatifidia. Both Caulerpa spp. took in an intermediate position. Observed in compensatory responses to salinity stress was ranging Ulva sp. both Caulerpa spp.-Undaria sp.: 1) amount pressed seaweed moisture: [ml/g Fresh Weight];2) salinity: (in ‰);3) Na+ storage vacuole volume;4) Na+:K+ ratio (reflection of K+ as osmolyticum);5) ∑[HM] (as osmolyticum);6) pH (seaweed moisture);7) Nutrients (N & P);8) availability of essential metal elements for plants (Cu, Fe, Zn, Mn, Mo, Ni);9) transport direction of micro- and macro-elements. Finally, the role of brown vs. green seaweeds in the evolutionary eukaryotic tree of life in relation to the ability of the brown seaweeds to produce their own osmolyticum will be discussed.

Gross Chemical Profile and Calculation of Nitrogen-to-Protein Conversion Factors for Five Tropical Seaweeds

Despite decades of research on marine algae, there are still significant gaps in basic knowledge about chemical composition of these organisms, especially in tropical environments. In this study, the amino acid composition and contents of total nitrogen, phosphorus, lipid, carbohydrate and protein were determined in Asparagopsis taxiformis, Centroceras clavulatum, Chaetomorpha aerea, Sargassum filipendula and Spyridia hypnoides. The seaweeds showed low lipid contents (lower than 5.5% d.w. in all species) and were rich in carbohydrates (more than 16% d.w. in all seaweeds). The percentage of nitrogen, phosphorus and protein varied widely among species, which red algae showed the highest con-centrations. The amino acid composition was similar among the seaweeds, which glutamic acid, aspartic acid and leu-cine as the most abundant. All species are poor in histidine. An average of 24.2% of the total nitrogen is non-proteinaceous. From data of total amino acid and total nitrogen, specific nitrogen-to-protein conversion factors were calculated for each species. The nitrogen-to-protein conversion factors calculated ranged from 4.51 to 5.21, with an overall average of 4.86. These findings show that the traditional conversion factor of 6.25 should be avoided for seaweeds, since it overestimates the actual protein content.

In vitro antiplasmodial activity of methanolic extracts from seaweeds of South West Coast of India

Objective:To identify the in vitro antiplasmodial activity of seaweed plants against Plasmodium falciparum strains.Methods:A total of eight seaweeds were collecled from Kanvakumari district,Tainilnadu,India.The in vitro antiplasmodial activity was performed in 96 well plates against Plasmodium falciparum,and preliminary phytochemcial analysis were performed for the extracts.Results:Of the selected plants Enteromorpha intestinalis(2.61%) showed maximum percentage of extraction.The minimum concentration of inhibitory(IC_(50)) value was observed with Chaetomorpha antennina[(26.37±4.14)μg/ml.]further,the positive controls such as chloroquine and artemether showed antiplasmodial activities(IC_(50)) with(19.10±5.93) and(6.03±0.21)μg/mL concentrations,respectively.The preliminary phytochemical analysis of the seaweed extracts showed a variety of phytochemical constituents such as carboxylic acids,phenols,protein, resins,steroids and sugars.Conclusions:The antiplasmodial activity of the seaweed extract might due to the presence of sugars and phenolic compounds.From the present findings,it is concluded that,the seaweed extract of Chaetomorpha antennina can be further used as a putative antiplasmodial drugs in near future.

Antimicrobial activities of three seaweeds extract against some human viral and bacterial pathogens

Microbial infections cause complicated health influences along with bad economic impacts.In the present investigation,three dominant seaweeds namely,Amphiroa anceps,Corallina officinalis and Sargassum filipendula were collected from different Egyptian sites at the Red Sea and Mediterranean Sea during autumn 2019.Organic extracts of the three algae were screened for their antibacterial activity against three pathogenic bacteria Salmonella typhiimurium,Staphylococcus aureus and Escherichia coli,in addition to in vitro antiviral activity against Rotavirus(RV),and Coxsackie virus B3(CVB3)that cause severe diseases in human.Organic extract of A.anceps,C.officinalis and S.filipendula inhibit E.coli cells by 57.1%,85.7%,and 91.4%,respectively.The highest level of concentration of the C.officinalis extract(100μg/mL)inhibits 100%of Staphylococcus aureus cells followed by S.filipendula and A.anceps extract which inhibit 82.5%and 75%of S.aureus.Similarly,the highest concentration of C.officinalis extract inhibits S.typhiimurium by 80%.The extract of A.anceps exhibited a high antiviral effect against RV infection with TI=22 and virus titers lessened by 2.75 log TCID_(50) followed by extractions of C.officinalis with TI=18.3 and virus titers reduced by 2.5 log TCID_(50).Against CVB3 infection,the extract of A.anceps causes the highest antiviral activity with TI=15 and reduce the viral titers by 2.5 log TCID_(50),followed by extractions of C.officinalis with TI=8.8 and inhibition of virus titers by 1.75 log TCID_(50).Extract of S.filipendula displayed the lowest antiviral effects against RV and CVB3 infection with TI=2.4 and 1.4,respectively.The obtained results clarified that the extract of three marine seaweeds maintains a potent antimicrobial activity,making them a future promising source of new antimicrobial drugs.

Three Uncommon Seaweeds of the Pacific Coast of Mexico

This report describes a new record and two unusual and rare species of marine algae collected from Oaxaca, Michoacán, Jalisco and Baja California Sur at Mexican Pacific coast. Boodleopsis verticillata is the first record in the Pacific shore of Mexico, in the case of Melobesia polystromatica, this is the sixth record at tropical Pacific while Litholepis sonorensisis reported for the third time in the Gulf of California. These results suggest that the taxonomic inventory of seaweed in the Pacific coast of Mexico is not yet complete, so attention must be given to the epiphytes, and other small and delicate species that inhabit the coast of Mexico. Morphological descriptions, distributional range, reproductive stage and samples examined are included.

Seaweeds as Biomonitoring System for Heavy Metal (HM) Accumulation and Contamination of Our Oceans

This research manuscript reports the heavy metal accumulation in four marine seaweeds sp. 1)?Caulerpa sertlatioides (Cuba);2) Caulerpa cf. brachypus;(Bali, Indonesia);3) Undaria pinnatifida (West-Donegal, Ireland);4) Ulva lactuca (Easters-Scheldt, the Netherlands). Mechanical pressure at 10 bar of fresh seaweed fronds casu quo biomass in the laboratory delivered seaweed moisture which was analyzed by Inductively Coupled Plasma Spectroscopy (ICP)-techniques for heavy-metals = [HM], (Al, As, Cd, Co, Cr, Cu, Fe, Mo, Ni, Pb & Zn). Three important observations were made: 1) The [HM] in the seaweed moisture is higher than in the surrounding seawater which directs to mechanism(s) of bio-accumulation;2) The accumulation factor [AF] is varying per metallic-cation with an overall trend for our four seaweeds and sampling locations for [HM] are: As & Co & Cu: 5000 - 10,000 μg/l;Ni & Zn: 3000 - 5000 μg/l;Cd: 2000 - 3000 μg/l;Cr: 1000 - 2000 μg/l;Al: 200 - 1000 μg/l;Mo & Pb & Fe: 0 - 200 μg/l range. 3) Seaweed moisture detected that [HM]: Pb & Zn & Fe—which all three could not be detected in the seawater—supports the view that seaweeds have a preference in their bio-accumulation mechanism for these three HM. Major conclusion is in general that “overall” for the macro-elements Ca, Fe, K, Mg, Mn, Na, P & S in the moisture of the four seaweed species the concentration is lower in the seaweed species, or equals the concentration, in comparison to the surrounding sea water. For the HM (Al, As, Cd, Co, Cr, Cu, Mo, Ni, Pb & Zn) the opposite is the case species and is the concentration “overall” higher in the seaweed species in comparison to the surrounding sea water. Further topics addressed include strategies of irrigation of the Sahara desert with the moisture out of seaweeds under conditions of low anthropogenic influences.

Review on Using of Macro Algae (seaweeds) in Fish Nutrition

Currently,the search is on for alternative sources of feed ingredients,the main reasons being the increasing cost and uncertainty about the continuous supply of common feed ingredients especially fishmeal and soybean meal.The importance of macro algae or seaweeds as a potential substitute protein source for fish nutrition cultured has been documented in recent years.Macro algae are receiving consideration for their essential amino acid content and high protein value,trace metals and vitamins in fish nutrition.In addition,macro algae or seaweeds could be a potential low cost source of protein for fishes.Furthermore,the economic comparison of feed cost revealed that the increase in the level of dried and fresh seaweeds in alternative feeding treatments,and commercial diets used for fish growth have decreased which led to a significant decrease in the cost of feed.From the results of previous studies,using of macro algae(seaweeds)in fish diets may improves growth performance,feed efficiency,physiological activity,carcass quality,disease resistance and reduced stress response.This review describes effects of using of macro algae(seaweeds)in diets on growth performance of fish.

Temporal Variations of the Chemical Composition of Three Seaweeds in Two Tropical Coastal Environments

The seaweeds Chaetomorpha antennina, Gymnogongrus griffithsiae and Ulva fasciata were studied regarding tissue concentrations of total nitrogen, total phosphorus, total protein, hydrosoluble protein, total carbohydrate, chlorophyll a and total carotenoid throughout a 39-month survey in two coastal environments of Rio de Janeiro State, Brazil. One of the sites (Itapuca Stone) has high concentrations of dissolved nutrients and an intense long-term process of cultural eutrophication;the second site (Bananal Inlet) is thought to have lower concentrations of dissolved nutrients and no relevant anthropic impact. Seaweeds experienced changes in the concentrations of the substances in the thalli;however they did not show any cyclic seasonal pattern, except for pigments, with lower values in summer in both sites. The differences found for each species in each sampling at the sites were small (e.g. U. fasciata, more total nitrogen at Itapuca Stone) or absent (e.g. C. antennina, no significant differences for hydrosoluble protein in the sites). Differences in the concentrations of dissolved nutrients in the sites did not generate contrasting chemical profiles in the seaweeds. There is no evidence of nitrogen- or phosphorus-limitation in any season. It is presumable that the concentrations of dissolved nutrients at the nutrient-poorer site are sufficient to generate high concentrations of the substances in the thalli of the species tested, similar to the concentrations measured in the eutrophic site. Experimental data are needed to elucidate the factors that promote the success of the species tested under contrasting nutrient availability and environmental disturbance.

Antimicrobial potential of selected brown seaweeds from Vedalai coastal waters,Gulf of Mannar

Objective:To evaluate the antimicrobial activity of Turbinaria conoides(T.conoides).Padina gymnospora(P.gymnospora) and Sargassum tenerrimum against human bacterial and fungal pathogens.Methods:The antimicrobial activities of the extracts against various organisms were tested by using disc diffusion method.Results:The methanol extract showed the better result than the other extracts.Whereas,the strong antibacterial inhibition was noted in methanol extracts of P.gymnospora against Bacillus subtilus(26.33±1.86) and the mild inhibition of ethanol extracts from T.conoides against Klebsiella pneumoniae(2.33±0.51).Acetone extraction of P. gymnospora had strong antifungal inhibition against Cryptococcus neoformans(23.00±1.78), and acetone extract of T.conoides had mild inhibition against Aspergillus niger(3.00±0.89). Conclusions:The seven different solvent extracts of seaweeds used in the present study have shown significant bacterial action.Further,a detailed study on the principle compound in the seaweeds which is responsible for antimicrobial activity is still needed and it can be achieved by using advanced separation techniques.

STUDIES ON FREE RADICAL SCAVENGING ACTIVITY IN CHINESE SEAWEEDS PART I. SCREENING RESULTS

Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1,1 diphenyl 2 picrylhydrazyl(DPPH) to screen the free radical scavenging activity in 27 species of Chinese seaweed showed that 15 of them had significant activity in at least one of the organic solvent extracts. The most interesting seaweed species were Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres.

Mineral Components and Anti-oxidant Activities of Tropical Seaweeds

Seaweeds are known to hold substances of high nutritional value; they are the richest resources of minerals important to the biochemical reactions in the human body. Seaweeds also hold non-nutrient compounds like dietary fiber and polyphenols. However, there is not enough information on the mineral compounds of tropical seaweeds. Also we are interested in the antioxidant activities of seaweeds, especially those in the tropical area. In this study, Indonesian green, brown and red algae were used as experimental materials with their mineral components analyzed by using an atomic absorption spectrophotometer. The catechins and flavonoids of these seaweeds were extracted with methanol and analyzed by high performance liquid chromatography （HPLC） ; the anti-oxidant activities of these seaweeds were evaluated in a fish oil emulsion system. The mineral components of tropical seaweeds are dominated by calcium, potassium and sodium, as well as small amounts of copper, iron and zinc. A green alga usually contains epigallocatechin, gallocatechin, epigallocatechin gallate and catechin. However, catechin and its isomers are not found in some green and red algae. In the presence of a ferrous ion catalyst, all the methanol extracts from the seaweeds show significantly lower peroxide values of the emulsion than the control, and that of a green alga shows the strongest anti-oxidant extract of this alga, which is significantly different from activity. The highest chelation on ferrous ions is also found in the the other methanol extracts in both 3 and 24 h incubations.

Rapid biosorption and reduction removal of Cr(Ⅵ) from aqueous solution by dried seaweeds

Four types of common seaweeds(Laminaria japonica,Undaria pinnatifida,Porphyra haitanensis,and Gracilaria lemaneiformis) were examined to remove Cr(Ⅵ) ions from aqueous solution.The experimental parameters that affected the biosorption process including pH,biomass dosage,contact time and temperature were investigated via batch experiments.The surface characteristics of seaweeds before and after Cr(Ⅵ) adsorption were studied with scanning electron microscopy and Fourier transform infrared spectroscopy.The results show that an initial solution with the pH of 1.0 is most favorable for Cr(Ⅵ) adsorption.Rapid adsorption is observed in the initial stage and adsorption equilibrium state is reached within 1 h.The adsorption efficiency by Porphyra haitanensis is the maximum among four types of seaweed powders,followed by Laminaria japonica and Undaria pinnatifida with biosorption efficiency up to 90%.The removal rate of Gracilaria lemaneiformis is less than 60%.The kinetic data obtained using the seaweeds are found to follow pseudo-second order kinetic model.Experimental sorption data adequately correlate with the Langmuir model.FTIR indicates that amino and carboxyl groups play an important role in the process of Cr(Ⅵ) adsorption and a large percentage of Cr(Ⅵ) ions are reduced by reductive groups on the surface of seaweeds.

Antiviral activities of extracts from Hong Kong seaweeds

We extracted six Hong Kong brown seaweed species with hot water for their antiviral properties. The cytotoxicity and antiviral activity of these extracts were tested by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenlytetrezolium bromide] method, cytopathic effect reduction assay, and plaque reduction assay. The antiviral effect was further determined by flow cytometric analysis. The results showed that most of these extracts inhibited the propagation of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2) standard strains with very low cytotoxicity to the host cells. The extracts of Hydroclathrus clathratus and Lobophora variegata showed more potential anti-HSV activities than the extracts of the other four seaweeds. They also had moderate anti- respiratory syncytial virus (RSV) activities but could not inhibit influenza A virus. Hydroclathrus clathratus was further extracted by diluted acid and alkali and the antiviral effects of the extracts were also detected. The result showed that the hot water extract contained the main carbohydrate components that exhibited the antiviral activities against various strains of HSV, including the acyclovir-resistant strain. HI-3, a compound fractionated from this hot water extract, showed a dose-dependent anti-HSV activity in flow cytometric analysis and plaque reduction assay.

The Application of the Seaweeds in Neutralizing the “Ocean Acidification” as a Long-Term Multifaceted Challenge

The global effects of ocean acidification (OA) on coral reefs are of growing concern. Carbon dioxide released into the atmosphere as a result of burning fossil fuels, not only has an effect on “global warming”, but also on OA which is called the “other CO2 problem”. OA combined with high ocean temperatures has resulted in a massive bleaching of coral reefs in the Indian Ocean and throughout Southeast Asia over the past decade, which is ultimately lethal. Here we discuss the option if innovative seaweed bio-technology—the Ulva lactuca bioreactor option, with its H+ ion-absorbing capacity and its huge green biomass production of around 50 MT/ha/year—which can stabilize our “World Ocean” and our global coral reefs. From our calculations, we came to the conclusion that an area covered with “Ulva lactuca bioreactors” with a production capacity of 250 × 1016 ha of seaweed per year is needed to remove all H+ ions that cause OA in our “World Ocean” since the beginning of the “Industrial Revolution” ≈ 250 years ago. This is a daunting task and therefore we have opted for a multi-faceted approach including variability in seaweed species, avoidance of eutrophication & heavy-metal accumulation, prevention of global warming by more green-biomass production and a better estimation of the huge Kelp seaweed populations in temperate zones in order to protect our coral reefs for the short term.