Ceramium Virgatum Research Articles

Pressurized liquid extraction of bioactive extracts with antioxidant and antibacterial activity from green, red and brown Algerian algae

In this work, the protein, sugar, phenolic and phlorotannin contents, as well as the antioxidant and antibacterial activity of hydroethanolic extracts of six algae species from the west cost of Algeria (Padina pavonica, Halopteris scoparia, Cystoseira mediterranea, Ulva lactuca, Ulva intestinalis, and Ceramium virgatum), obtained by pressurized liquid extraction (PLE) were investigated. Ceramium virgatum PLE extracts showed the highest content of protein (4.36 ± 0.13 %), while the total sugar content was maximum in U. lactuca extract (23.89 ± 0.21 %). Likewise, P. pavonica PLE extract presented a relevant total phenolic content (49.82 ± 1.40 mg GAE/g extract). On the other hand, phlorotannins were only found in brown algae in a range of 1.84–2.93 mg PGE/g. Furthermore, P. Pavonica extract presented considerably higher antioxidant capacity of inhibiting ABTS radical (1.16 ± 0.023 mmol TE/g) and 50 % of DPPH (1,1-diphenyl-2-picryl hydrazyl) (IC50 = 57.03 ± 1.28 μg/mL) in comparison with the other studied algae. Regarding to the potential antimicrobial activity, the results showed that Cystoseira Mediterranea produced the lowest minimal inhibitory concentration on Salmonella typhi (0.83 ± 0.14 mg/mL), Escherichia coli (4.66 ± 0.57 mg/mL), Vibrio cholera (1.08 ± 0.14 mg/mL), and Candida albicans (2.16 ± 0.28 mg/mL). Besides, different carotenoids and phenolic compounds were tentatively identified by LC-DAD in the algae extracts which could be the responsible of the tested bioactivities. These findings show the potential of using PLE as green solvent extraction technique and the prolific bioactivities of Algerian seaweeds.

A proof of concept for inland production of the “sea-vegetable” Ulva compressa in Brandenburg (Central Europe) using regional saline groundwater

Global food security is a major challenge of this century as pointed out in the UN sustainable development goal (SDG) 2 for creating a world without hunger and malnutrition by promoting among others sustainable consumption and production pattern (SDG 12). With shrinking environmental resources there is a pressing need for alternative food sources such as edible macroalgae (“sea vegetables”). In recent years different research initiatives attempt to develop cultivation providing available freshly harvested macroalgal biomass in inland areas. In this context natural saline groundwater (brine) provides a promising solution for the cultivation of marine organisms. Here we tested firstly the suitability of regional brine from the area Brandenburg (Central Europe) for the indoor cultivation of two edible macroalgae (“sea vegetables”) the chlorophyte Ulva compressa (flat gut weed, also formerly known as Enteromorpha sp.) and the rhodophyte Ceramium virgatum (formerly known as C. rubrum). For the evaluation of brine-based media, we considered different life stages of the macroalgae (e.g., spores, germlings and reproductive thalli) determining differences in their growth rates and nutritional composition (e.g., carotenoid, chlorophyll, and fatty acid concentrations). Brine based media supported macroalgae growth and development, with differences in growth and nutritional composition depending on macroalgal species and life stage. U. compressa cultivated with brine showed a thallus development and nutritional composition comparable to that of specimen cultivated in commercial media. In contrast, results for C. virgatum were less conclusive, due to an overall low germination rate ≤ 13 % under experimental conditions. Given the high demand for fresh macroalgal biomass and limited access to costly cultivation media, we suggest that use of natural brine provides a promising approach to foster the cultivation of selected “sea-vegetables” in inland areas including urban places.

Distribution and species composition of red algal communities in the northern Baltic Sea

Red algae are an important component of the Baltic Sea rocky shores. Within the Finnish marine area, in the northern Baltic Sea, red algal communities (on habitat level) are currently listed as endangered, due to eutrophication effects and potential future decrease in salinity. At species level, Rhodomela confervoides and Ceramium virgatum are red-listed. Despite their common use in different management contexts within the Baltic Sea, e.g. their depth distribution used as an indicator of the status of the sea areas, we know little about the commonness and more detailed distribution patterns of the red algal species. This limits the reliability of algae-based assessments. The aim of this study was to describe the general occurrence patterns, abundance and prevalence of erect perennial and annual red algae, based on extensive scuba-diving inventories within the Finnish marine area. Furthermore, the most representative areas for the red algal communities were identified. The results show high variation in depth distribution and prevalence across environmental gradients for many red algal species, e.g. for the relatively common perennial species Furcellaria lumbricalis and Vertebrata fucoides. In comparison to older data, reductions in depth penetration and occurrence were identified especially for deep-occurring species such as Rhodomela confervoides. With improved knowledge on the occurrence patterns of red algal species in relation to environmental variation, our results enable more reliable use of red algae as indicators of the status of the sea areas. By identifying areas where red algal communities are currently most representative, the results also allow better targeting of management efforts aiming to improve their status, such as areal protection measures or reducing nutrient input from point sources.

Мікроскопічні водорості водойм Кінбурнської піщаної коси (НПП «Білобережжя Святослава», Україна)

Taxonomical composition of microscopic algae of different reservoirs (Dnieper estuary, Kefalny, Guryansky and Cherepashy lakes, Yagorlytsky Bay) of the Kinburn sand spit of north-western part of the Black Sea (National Nature Park “Biloberezhzha of Svyatoslav”) is studied. Material tests that is collected on sandy and silty soils served as for researches, and also in becoming overgrown with of mussels Mytilus galloprovincialis Lamarck, Mya arenaria L., Cerastoderma lamarcki Reeve and Balanus improvisus Darwin, macroscopic algae (Ceramium virgatum Roth, Cladophora vagabunda (L.) Hoek, C. siwaschensis C.Meyer, Ulva intestinalis L., Polysiphonia elongata (Huds.) Harv.) of Kіnburnska braid from September in 2019 for October in 2021. On the whole it was collected and analysed 90 standards. 116 species of microscopic algae are educed, that to 74 genera, 52 families, 31 orders, 9 classes, 6 divisions, belong, 3 kingdoms and 2 empires. After systematic composition Bacillariophyta (76 species) prevailed above Cyanophyta (26), Chlorophyta (7), Dinophyta (3), Chrysophyta (3) and by Haptophyta (1). 86 species of algae were found in the microphytobenthos of Yagorlyk Bay, 56 in Dnieper estuary, 33 in Cherepashy, 22 in Guryansky and 17 in Kefalny lakes. As a result of researches it was educed 2 new and 4 rare species of microscopic algae for the aquatorium of the Black Sea.

Chemical Composition and Potential Practical Application of 15 Red Algal Species from the White Sea Coast (the Arctic Ocean).

Though numerous valuable compounds from red algae already experience high demand in medicine, nutrition, and different branches of industry, these organisms are still recognized as an underexploited resource. This study provides a comprehensive characterization of the chemical composition of 15 Arctic red algal species from the perspective of their practical relevance in medicine and the food industry. We show that several virtually unstudied species may be regarded as promising sources of different valuable metabolites and minerals. Thus, several filamentous ceramialean algae (Ceramium virgatum, Polysiphonia stricta, Savoiea arctica) had total protein content of 20–32% of dry weight, which is comparable to or higher than that of already commercially exploited species (Palmaria palmata, Porphyra sp.). Moreover, ceramialean algae contained high amounts of pigments, macronutrients, and ascorbic acid. Euthora cristata (Gigartinales) accumulated free essential amino acids, taurine, pantothenic acid, and floridoside. Thalli of P. palmata and C. virgatum contained the highest amounts of the nonproteinogenic amino acid β-alanine (9.1 and 3.2 μM g−1 DW, respectively). Several red algae tend to accumulate heavy metals; although this may limit their application in the food industry, it makes them promising candidates for phytoremediation or the use as bioindicators.

The macroalgal ensemble of Golfo Nuevo (Patagonia, Argentina) as a potential source of valuable fatty acids for nutritional and nutraceutical purposes

The purpose of the present work was to study lipid content and fatty acid profile in fifteen macroalgal species typical of the coastal environments of northern Patagonia, Argentina. Total lipid content was observed to range between 2 and 12% of dry biomass, reaching an average of 7‐–12% in some abundant and globally distributed species, such as Ulva spp., Codium spp., Ceramium virgatum, and Undaria pinnatifida. Total fatty acid content was found to exceed neither 3% of dry biomass nor 30% of total lipids in any of the species studied. Polyunsaturated fatty acids (PUFAs) were dominant in all the brown species under study, particularly in the sporophyll of U. pinnatifida. Ceramium virgatum and Ulva sp. (tubular enteromorphoid thallus) were also rich in PUFAs. Essential fatty acids (linoleic acid and α-linolenic acid) and other valuable long-chain PUFAs, such as eicosapentaenoic acid, stearidonic acid, and arachidonic acid, were abundant in these species, arachidonic acid reaching up to 10 mg g−1 in U. pinnatifida sporophyll. In contrast, docosahexaenoic acid was only recorded at trace levels. Taken together, the results from the present study lead to conclude that the high levels of lipid content are indicative of potential applications of some of the most abundant species in the Patagonian coasts as biomass feedstock for lipid-based bioproducts. In line with this conclusion, eicosapentaenoic, stearidonic and arachidonic acid from the species studied could, in particular, be used for nutritional and nutraceutical purposes.

The Catalase Activity of the Red Alga Ceramium virgatum Roth, 1797 as a Marker of the Quality of the Marine Environment Based on the Example of the Coastal Zone of Southwestern Crimea

This study determined the range of conditionally normal values of the catalase activity (СA) in the Black Sea red macroalga Ceramium virgatum. The level of CА in the alga corresponded to its conditionally normal functioning (26.79 ± 10.32 μg H2O2/(g wet weight min)). The minimum concentrations of hydrochemical parameters that correspond to the sensitivity threshold of CА in C. virgatum were found; these minimum values are 40 μM/L for organic nitrogen, 0.03 μM/L for nitrites, 0.3 μM/L for nitrates, 0.12 μM/L for inorganic phosphorus, and 0.47 μM/L for organic phosphorus.

Seasonal changes of macroalgae assemblages on the rocky shores of the Cape Horn Biosphere Reserve, Sub-Antarctic Channels, Chile

The Magellanic Sub-Antarctic Channels ecoregion supports one of the greatest number of macroalgae species in South America. In this ecoregion, the majority of macroalgae research has been associated with spatial ecology. In contrast, the temporal scale has received little attention. Here, we report the seasonal changes of taxa richness, wet biomass and assemblage structure for intertidal macroalgae in Robalo Bay (55 °S), situated within the Cape Horn Biosphere Reserve. Overall, forty-nine macroalgae taxa were identified. We found a higher taxa richness and wet biomass in the summer than in the winter, but the strength of seasonal variations varied spatially across intertidal sites and levels. A similar seasonal pattern was detected with multivariate analysis. The seasonal changes are explained by the rise of seasonal algae such as Adenocystis utricularis. In turn, we found temporally-persistent algae such as Ceramium virgatum and Nothogenia fastigiata which did not show sharp seasonal variation. In conclusion, we suggest that macroalgal seasonality might be strongly modulated by coupled factors such as light, nutrient availability, sea surface temperature, relative humidity, and species composition. These factors would support an increase of taxa richness and wet biomass in the summertime on the rocky shores in high latitudes of South America.

Rheological Characterization of Algal Suspensions for Bioethanol Processing

The paper has aimed at studying the rheology of macroalgae aqueous suspensions in the presence of cellulase enzyme relevant to bioethanol processing by a subsequent fermentation. Rheological measurements of aqueous suspensions of Ceramium virgatum and Cladophora vagabunda macroalgae species were performed using a Couette geometry rotational viscosimeter. The effects of operation temperature (t=25, 50 �C), cellulase/dried algae ratio (R=0, 16 U/mgda), and algal suspension mass concentration (c=5-15%) on rheological behaviour and parameters were evaluated. Algal suspensions behaved as non-Newtonian fluids obeying either a Bingham plastic linear relationship or an Ostwald-de Waele power law corresponding to a pseudoplastic fluid. Characteristic dynamic viscosity of Bingham plastic fluids were in the range 0.045-0.115 Pa�s for C. virgatum suspensions and 0.021-0.114 Pa�s for C. vagabunda ones, whereas apparent viscosity varied from 0.138 Pa�s to 43.551 Pa�s for C. virgatum and from 0.181 Pa�s to 45.417 Pa�s for C. vagabunda. Data obtained in 8 rheological tests corresponding to a Bingham plastic behaviour of C. vagabunda suspensions, which were processed according to a 23 factorial experiment, emphasized an increase in suspension viscosity with all process factors. The results could be useful for optimization of enzymatic hydrolysis process in order to develop efficient and cost effective saccharification and fermentation strategies.

Enemy release an unlikely explanation for the invasive potential of the brown alga Sargassum muticum: experimental results, literature review and meta-analysis

The enemy release hypothesis predicts that non-indigenous species (NIS) are released from natural enemies (e.g. grazers etc.) in their new environment, thus facilitating invasion. Sargassum muticum is a conspicuous and successful invasive brown alga and several studies have investigated whether native herbivores feed less on S. muticum relative to native algae within the invaded range. Some of these studies have concluded that S. muticum is avoided by native herbivores, but this conclusion may be premature as the results are rather inconclusive and seem to depend partly on the type of algae included in the comparison. We conducted therefore a series of feeding experiments to test if Danish S. muticum is grazed less upon than a range of native algae by the sea urchin Psammechinus miliaris and complemented the experiments with a meta-analysis based on published data. In no-choice trials, P. miliaris consumed S. muticum faster than it consumed slow-growing Fucus vesiculosus and Halidrys siliquosa, whereas Saccharina latissima, Ceramium virgatum and Ulva intestinalis were grazed upon at higher or the same rates as S. muticum. More or less identical patterns were seen in the two- and multiple-choice experiments, where S. muticum was generally consumed faster than F. vesiculosus and H. siliquosa, but slower than S. latissima and the two most fast-growing algal species (U. intestinalis and C. virgatum). We screened the literature for comparable data and found 26 experiments with 27 species of algae and 14 species of invertebrate grazers. Meta-analysis on these data showed the same overall trend as observed in our experiments; S. muticum is generally consumed at the same rate or faster than other thick, leathery and canopy-forming algae, which are assumed to constitute the major competitors to S. muticum, but slower than more fast-growing sub-canopy species and more opportunistic algae. We question therefore that enemy release can explain the invasion success of S. muticum.

Rapid assessment survey of fouling and introduced seaweeds from southern Maine to Rhode Island

Abstract Rapid assessment surveys (RASs) of fouling and introduced seaweeds were conducted during late July, 2010 and early August, 2013 at multiple marina/harbor sites ranging from southern Maine to Rhode Island. Twenty sites were evaluated during 2010, and 19 in 2013 including 13 of the 2010 sites resurveyed. Based upon a composite of 19 study sites, 99 benthic algal taxa were recorded, including 24 Chlorophyceae, 23 Phaeophyceae, 45 Rhodophyceae, four macroscopic colonial diatoms (Bacillariophyceae), one Xanthophyceae, and two Cyanophyceae or Cyanobacteria. Twenty-seven species (27.3%) were limited to a single site, whereas only three taxa occurred at > 70% of the sites, including Ulva lactuca, Ceramium virgatum, and “Neosiphonia japonica.” Twelve introduced seaweeds were recorded, including one green, two brown, and nine red algae; their probable origins were the Australasia area, Europe, and the northwest and northeast Pacific. “Neosiphonia japonica,” which has recently been delineated within the NW ...

Ceramium cornutum and Ceramium pallidum (Rhodophyta: Ceramiales) two new records for Morocco: morphology and reproductive structures

Two macroalgal taxa are reported for the first time from Morocco: Ceramium cornutum and Ceramium pallidum (Ceramiaceae: Ceramiales). The last species is also reported for the first time from Africa. Specimens of both taxa were collected in the lower intertidal to subtidal zones from different localities in northwest Morocco. These new records, are examined in detail and compared with congeners such as Ceramium cimbricum, Ceramium diaphanum, Ceramium tenerrimum and Ceramium virgatum. Both morphological features and reproductive structures are given; illustrations, habitat, geographic distribution and taxonomic remarks for each species are also provided. In this paper new data are provided for C. cornutum, especially number of periaxial cells and type of rhizoids.

Benthic algal vegetation in Isfjorden, Svalbard

Benthic algal vegetation was investigated at 10 sites in Isfjorden, Svalbard. Five sites were visited during summer 2010 and five during summer 2012. Both the littoral and sublittoral vegetation were sampled, the littoral by hand-picking and use of a throwable rake and the sublittoral using a triangular dredge. A total of 88 different taxa were registered, comprising 17 Chlorophyta, 40 Ochrophyta, 30 Rhodophyta and the Xantophyceae Vaucheria sp. The green algae Ulvaria splendens (Ruprecht) Vinogradova was recorded in Svalbard for the first time. Most of the sites consisted of hard bottom substrate, but one site, Kapp Wijk, consisted of loose-lying calcareous red algae (rhodoliths) and had species not recorded elsewhere. The sublittoral at the other sites was dominated by kelp. Molecular analysis confirmed the presence of the red alga Ceramium virgatum and a dwarf form of the brown alga Fucus vesiculosus . This study provides a baseline for future studies investigating changes in the vegetation due to environmental changes. Keywords: Arctic; Svalbard; Isfjorden; benthic algal diversity. (Published: 11 August 2015) To access the supplementary material for this article, please see supplementary files in the column to the right (under Article Tools). Citation: Polar Research 2015, 34 , 25994, http://dx.doi.org/10.3402/polar.v34.25994

Abundance and Size Distribution of the Sacoglossan Elysia viridis on Co-Occurring Algal Hosts on the Swedish West Coast

Sacoglossans are specialized marine herbivores that tend to have a close evolutionary relationship with their macroalgal hosts, but the widely distributed species Elysia viridis can associate with several algal species. However, most previous investigations on the field abundance and size distribution of E. viridis have focussed on Codium spp. in the British Isles, and algae from this genus are considered superior hosts for E. viridis. In the present study, we investigated the abundance and size distribution of E. viridis on 6 potential host algae with differing morphologies (the septate species Cladophora sericea, Cladophora rupestris, Chaetomorpha melagonium, and Ceramium virgatum, as well as the siphonaceous species Codium fragile and Bryopsis sp.) at 2 sites on the Swedish west coast over the course of a year. In spring, slugs were almost absent from all algal hosts. In summer and autumn, E. viridis consistently occurred on several of the algal species at both sites. The highest number of small E. viridis were found on C. sericea, intermediate numbers of significantly larger E. viridis were found on C. rupestris, while fewer, intermediate sized animals were found on C. fragile. Throughout the study period, only a few E. viridis individuals were found on C. melagonium, Bryopsis sp., and C. virgatum. Our results indicate that E. viridis is an annual species in Sweden, capable of exploiting co-occurring congeneric and intergeneric algal hosts with differing morphologies. These results corroborate previous findings that E. viridis can exploit several different algal species, but does not indicate that C. fragile is a superior host.

Utilization of the invasive alga Gracilaria vermiculophylla (Ohmi) Papenfuss by the native mud snail Ilyanassa obsoleta (Say)

The recent invasions of the red alga, Gracilaria vermiculophylla, to the Atlantic and Eastern Pacific Oceans have the potential to significantly alter intertidal and subtidal soft sediment communities. In particular, G. vermiculophylla increases habitat complexity and provides a novel hard substrate in an otherwise two dimensional habitat. Following our observations that the native omnivorous mud snail Ilyanassa obsoleta utilizes G. vermiculophylla for egg capsule deposition, our field surveys demonstrated that the in situ abundance of egg capsules on G. vermiculophylla matched abundances on a native alga Ceramium virgatum and were at least 11–50 times greater than on all other co-occurring macrophytes. Additionally, through mesocosm experiments, we showed that I. obsoleta preferentially deposits eggs on the invasive G. vermiculophylla over native substrates. However, despite the thick layer of egg capsules found on G. vermiculophylla, no detrimental effects were seen on thalli growth. In contrast, growth of the native red alga Ceramium virgatum was significantly reduced when egg capsules were present, suggesting G. vermiculophylla can out-compete native macrophytes in areas of I. obsoleta abundance, while facilitating reproduction of the native mud snail. This novel interaction has the potential to significantly alter biological interactions in soft sediment communities through a variety of different mechanisms, including the alteration of trophic cascades via the increase in mud snail abundance. Furthermore, facilitation of the reproductive success of I. obsoleta may lead to increases in the occurrence of cercarial dermatitis, as I. obsoleta is a known intermediate host organism.

Extraction and characterization of volatile compounds and fatty acids from red and green macroalgae from the Romanian Black Sea in order to obtain valuable bioadditives and biopreservatives

Three species of macroalgae, Ceramium virgatum (Rhodophyta), Ulva intestinalis, and Cladophora vagabunda (Chlorophyta), harvested from the Romanian Black Sea coast, were studied as sources of valuable compounds that could be used as additives and biopreservatives. Volatile compounds including hexanal (11.2 %), octane (9.8 %), nonanal (7.0 %), octanal (6.7 %), 2,5,5-trimethyl-2-hexene (4.7 %), 3-hexen-2-one (4 %), and o-cymene (3.6 %) were identified as the major components in the biomass extract of C. vagabunda. In C. virgatum, the major volatile components were 3-hexen-2-one (27.9 %), acetone (12.4 %), hexanal (3.4 %), and o-cymene (2.7 %). The major volatile compounds of U. intestinalis were hexanal (14.6 %), trichloromethane (7.3 %), nonanal (5.6 %), 3-hexen-2-one (5.3 %), and octanal (3.1 %). Some of these compounds have industrial applications as additives in the food, pharmaceutical, or cosmetics industries. The U. intestinalis extract had a greater content of mono- and polyunsaturated fatty acids around 46.0 % as compared with 42.0 % for C. vagabunda and 31.9 % for C. virgatum. The most abundant fatty acids were palmitic acid (C16:0), arachidonic acid (C20:4n-6), and oleic acid (C18:1ω-9cis). The antimicrobial effect of fatty acid extracts was tested against four pathogenic bacteria. The minimum inhibitory concentrations of C. vagabunda, C. virgatum, and U. intestinalis fatty acids extracts were 1.8, 3.8, and 3.8 mg mL−1, respectively, for all bacterial strains. This study can help the efforts of finding new, value-added uses for natural marine resources.

Grazer avoidance may explain the invasiveness of the red alga Gracilaria vermiculophylla in Scandinavian waters

The invasive red alga Gracilaria vermiculophylla has quickly spread across Europe, but it is unclear whether its success is based on a high tolerance to variations in environmental conditions or to the absence of native grazers that feed on this alga. We tested whether native invertebrate grazers prefer native algae to G. vermiculophylla. Feeding preferences of three common herbivores were quantified when offered G. vermiculophylla and native Fucus vesiculosus, Ceramium virgatum, and Ulva intestinalis in no-, two- and multiple-choice trials. Herbivore growth was measured when fed each of the algae separately. Grazers consumed G. vermiculophylla in no-choice trials, but avoided generally this alga when having a choice. U. intestinalis was always preferred over G. vermiculophylla, and grazers fed with U. intestinalis grew faster than those fed with G. vermiculophylla. We conclude that grazers avoid G. vermiculophylla to most native algae, which may benefit G. vermiculophylla in northern European estuaries.

Epiphyte and herbivore interactions impact recruitment in a marine subtidal system

Marine assemblages are influenced by the rate and timing of species settlement and recruitment. Both abiotic factors and biotic interactions can impact recruitment rates of marine species in a variety of systems. However, the impacts of species which recruit at the same time upon each other are less well understood. We investigated the relationship between the recruitment of Lacuna vincta, a small (<6 mm shell diameter) marine snail, and two species of algal epiphytes, the native Ceramium virgatum and the invasive Neosiphonia harveyi, in the shallow subtidal zone of Narragansett Bay, Rhode Island. All three species exhibit peak recruitment densities during two months in the summer. We found that the presence of algal epiphytes facilitates the recruitment rate of L. vincta, regardless of the epiphyte species composition. We also found a positive relationship between the number of L. vincta present and epiphyte recruitment, which is disproportionately driven by higher recruitment of N. harveyi than C. virgatum. Understanding recruitment dynamics and interactions is vital to effectively mitigate the effects of and adaptations to changes due to the establishment of non-native species.

Antiprotozoal and cytotoxic potential of British and Irish red algae

Marine algae are a prolific source of diverse natural products, but their biomedical potential has barely been explored. As part of our continuing research on seaweeds [1], we have screened crude extracts of 23 marine red algae (Rhodophyta) collected from Britain and Ireland. Algal material was extracted with CHCl3: MeOH mixtures (3:1 and 1:1) at room temperature and evaporated to dryness in vacuo before use in bioassays. The clinically important blood-stage life forms of Trypanosoma brucei rhodesiense, T. cruzi and Leishmania donovani were used as test organisms in the in vitro assays. The selective toxicity of the extracts was determined towards mammalian skeletal myoblast (L6) cells. All algal extracts showed activity against T. brucei rhodesiense, with Corallina officinalis (Corallinaceae) and Ceramium virgatum (Ceramiaceae) being the most potent (IC50 values 4.8 and 5.4µg/ml, respectively), whilst none of the algal extracts inhibited the growth of T. cruzi. With the exception of a Porphyra leucosticta (Bangiaceae) extract, all seaweed extracts also displayed leishmanicidal activity with IC50 values ranging from 16.5 to 85.6µg/ml. Corallina officinalis was the only seaweed that showed some marginal cytotoxicity (IC50 value 88.6µg/ml), whereas all remaining extracts were non-toxic towards L6 cells at 90µg/ml concentration. To our knowledge, this is the first study reporting antiprotozoal activity of British and Irish red algae.

Antiprotozoal, antimycobacterial and cytotoxic potential of twenty‐three British and Irish red algae

As part of our continuing research on seaweeds, we have screened the crude extracts of 23 red marine algae collected from England and Ireland. The clinically important blood-stage life forms of Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani and Mycobacterium tuberculosis were used as test organisms in the in vitro assays. The selectivity of the extracts was determined by using mammalian skeletal myoblast (L6) cells. All algal extracts showed activity against T. brucei rhodesiense, with Corallina officinalis and Ceramium virgatum being the most potent (IC(50) values 4.8 and 5.4 microg/ml), whilst none of the algal extracts inhibited the growth of T. cruzi. Except for Porphyra leucosticta, extracts from all seaweeds also showed leishmanicidal activity with IC(50) values ranging from 16.5 to 85.6 microg/ml. Only the crude extract of Calliblepharis jubata showed some weak activity against Mycobacterium tuberculosis (MIC value 256 microg/ml), while the others were inactive at this concentration. Corallina officinalis was the only seaweed that displayed some marginal cytotoxicity (IC(50) value 88.6 microg/ml), and all remaining extracts were non-toxic towards L6 cells at 90 microg/ml concentration. To our knowledge, this is the first study reporting antiprotozoal and antimycobacterial activity of British and Irish red algae.