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PubMed1996

Dietary marine algae promotes efficient deposition of n-3 fatty acids for the production of enriched shell eggs.

Two experiments were conducted to investigate the usefulness of a natural golden marine algae (MA) as a poultry ration supplement for the production of shell eggs rich in n-3 fatty acids (n-3 FA). This MA is unique due to a high concentration of docosahexaenoic acid (DHA; C22:6n-3) and the absence of other n-3 FA normally present in marine oils such as menhaden oil (MO). In the first experiment, 60 24-wk-old Single Comb White Leghorn (SCWL) hens were divided among four dietary treatments, including a typical corn-soybean control (CON); 1.5% MO, supplying 233 mg eicosapentaenoic acid (EPA) and 155 mg DHA per d; 2.4% MA, supplying 200 mg DHA/d; and 4.8% MA, supplying 400 mg DHA/d. A second experiment using 96 56-wk-old SCWL was conducted using the same diets. In both experiments, eggs were collected weekly for 4 wk for determination of egg production parameters and yolk FA content. Each week, yolk samples were extracted, methyl estered, and quantified using gas chromatography. Transient depression in egg and yolk weights were noted early in Experiment 1 in response to dietary 4.8% MA. Although egg and yolk weights were not affected in Experiment 2, egg production was significantly reduced in the 4.8% MA treatment. Egg production was unaffected due to diet or week in Experiment 1. In both experiments, yolk polyunsaturated profiles were significantly influenced by diet. Dietary n-3 FA supplementation significantly increased yolk total N-3 FA with concomitant reductions in yolk n-6 FA. Although hens fed MO were supplied predominantly EPA, the principal yolk FA deposited was DHA. Marine algae also promoted efficient yolk DHA deposition with the highest yolk DHA concentrations attained in eggs from hens fed 4.8% MA. These data indicate that utilization of MA as a direct source of dietary n-3 FA may provide an efficient alternative to current sources of n-3 FA available for the production of poultry products rich in n-3 FA.

Animal Feed↗

PubMed2004

Inhibitory action of marine algae extracts on the Trypanosoma cruzi dihydroorotate dehydrogenase activity and on the protozoan growth in mammalian cells.

Trypanosoma cruzi, the causative agent of Chagas' disease, replicates in mammalian cells and relies on the de novo pyrimidine biosynthetic pathway that supplies essential precursors for nucleic acid synthesis. The protozoan dihydroorotate dehydrogenase (DHOD), the fourth enzyme of the pathway catalyzing production of orotate from dihydroorotate, markedly differs from the human enzyme. This study was thus aimed to search for potent inhibitors against T. cruzi DHOD activity, and a number of methanol extracts prepared from green, brown, and red algae were assayed. The extracts from two brown algae, Fucus evanescens and Pelvetia babingtonii, yielded 59 and 58% decrease in the recombinant DHOD activity, respectively, at the concentration of 50 microg/ml. Inhibition by these extracts was noncompetitive with respect to dihydroorotate, with apparent Ki values of 35.3+/-5.9 and 10.3+/-4.4 microg/ml, respectively. Further, in an in vitro T. cruzi-HeLa cell infection system, ethanol-reconstituted F. evanescens and P. babingtonii extracts at the concentration of 1 microg/ml, respectively, decreased significantly the infection rate of host cells and the average parasite number per infected cell. These results imply that F. evanescens and P. babingtonii contain inhibitor(s) against the T. cruzi DHOD activity and against the protozoan infection and proliferation in mammalian cells. Identification of inhibitor(s) in these two brown algae and further screening of other marine algae may facilitate the discovery of new, anti-trypanosomal lead compounds.

Animals↗

PubMed1999

Determination of the individual electrical and transport properties of the plasmalemma and the tonoplast of the giant marine alga Ventricaria ventricosa by means of the integrated perfusion/charge-pulse technique: evidence for a multifolded tonoplast.

The charge-pulse relaxation spectrum of nonperfused and perfused (turgescent) cells of the giant marine alga Ventricaria ventricosa showed two main exponential decays with time constants of approximately 0.1 msec and 10 msec, respectively, when the cells were bathed in artificial sea water (pH 8). Variation of the external pH did not change the relaxation pattern (in contrast to other giant marine algae). Addition of nystatin (a membrane-impermeable and pore-forming antibiotic) to the vacuolar perfusion solution resulted in the disappearance of the slow exponential, whereas external nystatin decreased dramatically the time constant of the fast one. This indicated (by analogy to corresponding experiments with Valonia utricularis, J. Wang, I. Spiess, C. Ryser, U. Zimmermann, J. Membrane Biol. 157: 311-321, 1997) that the fast relaxation must be assigned to the RC-properties of the plasmalemma and the slow one to those of the tonoplast. Consistent with this, external variation of [K+]o or of [Cl-]o as well as external addition of K+- or Cl--channel/carrier inhibitors (TEA, Ba2+, DIDS) affected only the fast relaxation, but not the slow one. In contrast, addition of these inhibitors to the vacuolar perfusion solution had no measurable effect on the charge-pulse relaxation spectrum. The analysis of the data in terms of the "two membrane model" showed that K+- and (to a smaller extent) Cl--conducting elements dominated the plasmalemma conductance. The analysis of the charge-pulse relaxation spectra also yielded the following area-specific data for the capacitance and the conductance for the plasmalemma and tonoplast (by assuming that both membranes have a planar surface): (plasmalemma) Cp = 0.82 * 10(-2) F m-2, Rp = 1.69 * 10(-2) Omega m2, Gp = 5.9 * 10(4) mS m-2, (tonoplast) Ct = 7. 1 * 10(-2) F m-2, Rt = 14.9 * 10(-2) Omega m2 and Gt = 0.67 * 10(4) mS m-2. The electrical data for the tonoplast show that (in contrast to the literature) the area-specific membrane resistance of the tonoplast of these marine giant algal cells is apparently very high as reported already for V. utricularis. The exceptionally high value of the area-specific capacitance could be explained - among other interpretations - by assuming a 9-fold enlargement of the tonoplast surface. The hypothesis of a multifolded tonoplast was supported by transmission electronmicroscopy of cells fixed under maintenance of turgor pressure and of the electrical parameters of the membranes. This finding indicates that the tonoplast of this species exhibited a sponge-like appearance. Taking this result into account, it can be easily shown that the tonoplast exhibits a high-resistance (1.1 Omega m2). Vacuolar membrane potential measurements (performed in parallel with charge-pulse relaxation studies) showed that the potential difference across the plasmalemma was mainly controlled by the external K+-concentration which suggested that the resting membrane potential of the plasmalemma is largely a K+-diffusion potential. After permeabilization of the tonoplast with nystatin the potential of the intact membrane barrier dropped from about slightly negative or positive (-5.1 to +18 mV, n = 13) to negative values (-15 up to -68 mV; n = 8). This indicated that the cytoplasm of V. ventricosa was apparently negatively charged relative to the external medium. Permeabilization of the plasmalemma by addition of external nystatin resulted generally in an increase in the potential to slightly more positive values (-0.8 to +4.3 mV; n = 5), indicating that the vacuole is positively charged relative to the cytoplasm. These findings apparently end the long-term debate about the electrical properties of V. ventricosa. The results presented here support the findings of Davis (Plant Physiol. 67: 825-831, 1981), but are contrary to the results of Lainson and Field (J. Membrane Biol. 29: 81-94, 1976).

Action Potentials↗

PubMedDate not supplied

[The prospects for using marine algae].

Different aspects of utilization of the products of marine algae processing are discussed: phycocolloids, sterins, isoprenoids, etc. The natural resources of algae are decreased due to their intensive exploitation. Hence, the development of algal mariculture becomes very urgent.

Agar↗

PubMed2003

Gating of Cl- currents in protoplasts from the marine alga Valonia utricularis depends on the transmembrane Cl- gradient and is affected by enzymatic cell wall degradation.

The electrical properties of protoplasts of the turgor pressure-regulating giant marine alga Valonia utricularis were investigated by using the patch-clamp technique. In the whole-cell configuration, large inward currents were elicited by negative-going voltage pulses. The time-dependent component was predominantly carried by Cl-, as revealed by 'tail current' analysis. When experiments were performed on protoplasts directly after mechanical release from the 'mother cell', small outward currents were additionally observed at membrane voltages more positive than ECl-. These outward currents disappeared to a large extent after treatment of the protoplasts with a mixture of cell wall-degrading enzymes. Plots of the chord conductance versus the clamped membrane voltage revealed that enzymatic treatment affected the gating properties. By fitting Boltzmann distributions to the data, a midpoint potential of + 5 +/- 5 mV (n = 7) was obtained in symmetrical Cl- solutions for mechanically released protoplasts. In contrast, protoplasts treated additionally with enzymes exhibited a midpoint potential of -13 +/- 5 mV (n = 8). By varying the external and internal Cl- concentration, gating was also shown to depend on the Cl- gradient across the plasmalemma both in enzymatically treated and untreated protoplasts. Plotting of the midpoint potential against the Nernst potential of Cl- rendered a slope less than 1 (0.70 and 0.64, respectively) indicating that gating did not strictly depend on the electrochemical Cl- gradient. The voltage- and Cl--dependence as well as inhibition experiments with 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) suggested that the Cl- conductance of the membrane is dominated by the Valonia Anion Channel 1 (VAC1) described by Heidecker, M., Wegner, L.H., Zimmermann, U. 1999: A patch-clamp study of ion channels in proto-plasts prepared from the marine alga Valonia utricularis. J. Membrane Biol. 172:235-247. The relevance of the findings for membrane potential control and turgor regulation in V. utricularis as well as the general implications of the data for electrophysiological work on protoplasts (that are usually obtained by enzymatic digestion of plant tissue) are discussed.

Cells, Cultured↗

PubMed1975

Antimicrobial agents from marine algae.

The antimicrobial activity of five compounds extracted from marine algae was tested against Staphylococcus aureus, Salmonella choleraesuis, Mycobacterium smegmatis, Candida albicans, and Escherichia coli. Three of the compounds, cycloeudesmol, laurinterol, and debromolaurinterol, exhibited activity at concentrations approaching that of streptomycin. None of the compounds inhibited all of the organisms tested. There appeared to be selectivity for gram-positive microbes.

Anti-Bacterial Agents↗

PubMedDate not supplied

Antiherpes virus effect of the red marine alga Polysiphonia denudata.

The water extract from the red marine alga Polysiphonia denudata (Dillwyn) Kutz. from the Bulgarian Black Sea coast selectively inhibited the reproduction of herpes virus type 1 and type 2 in cell cultures (EC50=8.7 to 47.7 mg/ml) as shown by the reduction of virus-induced cytopathic effect and viral infectivity. The virus-inhibitory effect was dose-related, strain-specific and depended on virus inoculum. The inhibition affected adsorption as well as the intracellular stages of viral replication. The presence of the extract throughout the whole replicative cycle was necessary for the full expression of the antiviral effect. In higher concentrations (MIC90=6.5 mg/ml) the extract exhibited strong extracellular virus inactivating activity.

Animals↗

PubMed2004

Red marine alga Bryothamnion triquetrum lectin induces endothelium-dependent relaxation of the rat aorta via release of nitric oxide.

We have investigated the vascular relaxant effects of the lectin from a red marine alga Bryothamnion triquetrum (BTL), in particular, the endothelial-dependency and the participation of a specific glycoprotein-binding site. BTL (1-100 microg mL(-1)) was applied to rat isolated aortic rings, with or without endothelium, tonically precontracted with phenylephrine (0.1 microM). Endothelium-dependent relaxation was assessed in the presence of indometacin (10 microM), L-nitro arginine methyl ester (L-NAME, 100 microM) and tetraethylammonium (TEA, 500 microM). For the involvement of the glycoprotein-binding site, BTL was assayed in presence of mucin (300 microg mL(-1)) or N-acetyl D-glucosamine (GlcNAc; 300 microg mL(-1)), a specific and non-specific lectin-binding sugar, respectively. BTL fully and concentration dependently relaxed preparations that possessed an intact endothelium (IC50 (concn producing 50% contraction) = 12.1 +/- 1.6 microg mL(-1)), whereas no significant relaxation was observed in endothelial-denuded tissue. L-NAME, but not indometacin or TEA, completely inhibited the lectin relaxation, suggesting the involvement of nitric oxide (NO). The lectin in association with mucin, but not with GlcNAc, inhibited BTL-induced relaxation, implicating the involvement of the lectin binding site. Our data suggest that the relaxant effect of the red marine alga Bryothamnion triquetrumlectin on isolated aorta occurs via interaction with a specific lectin-binding site on the endothelium, resulting in a release of NO.

Animals↗

PubMed1998

Cross-species induction and enhancement of antimicrobial activity produced by epibiotic bacteria from marine algae and invertebrates, after exposure to terrestrial bacteria.

Antibiotic producing marine bacteria isolated from surfaces of the marine alga Fucus vesiculosus and the nudibranch Archidoris pseudoargus were exposed to live cells of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and heat-killed cells of Staph. aureus. Twelve out of the 16 marine strains tested showed enhanced antimicrobial activity towards Staph. aureus, E. coli and Ps. aeruginosa following this exposure. Three out of seven strains tested showed enhanced antimicrobial activity when exposed to Ps. aeruginosa and three out of seven strains showed enhanced antimicrobial activity when exposed to E. coli. These results suggest that production of antimicrobial compounds by marine bacteria can be induced by the presence of terrestrial bacteria. This appears to be the first example of cross-species induction and enhancement of antimicrobial activity in marine bacteria and has important implications for the design of antibiotic screening assays and for an understanding of microbial competition in the environment.

Animals↗

PubMed2006

Ulva conglobata, a marine algae, has neuroprotective and anti-inflammatory effects in murine hippocampal and microglial cells.

It has been reported that inflammatory processes are associated with the pathophysiology of Alzheimer's disease (AD), and the treatment of AD using anti-inflammatory agents slows the progress of AD. Marine algae have been utilized in food products as well as in medicine products for a variety of purposes. In this study, we investigated the neuroprotective effects of methanol extracts of Ulva conglobata (U. conglobata), a marine algae, on glutamate-induced neurotoxicity in the murine hippocampal HT22 cell line and the anti-inflammatory effects on interferon gamma (IFN-gamma)-induced microglial activation in BV2 cells. U. conglobata methanol extracts significantly attenuated the neurotoxicity induced by glutamate in HT22 cells and inhibited nitric oxide production induced by IFN-gamma in BV2 cells. U. conglobata methanol extract treatments were also examined and it was found that they almost completely suppressed the expression of the proinflammatory enzyme cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS). These results suggest that U. conglobata possesses therapeutic potential for combating neurodegenerative diseases associated with neuroinflammation.

Animals↗

PubMed2005

[Chemical constituents from marine alga Chaetomorpha basiretorsa].

OBJECTIVE: To investigate the chemical constituents of marine alga Chaetomorpha basiretorsa. METHOD: Compounds were isolated by normal phase silica gel and Sephadex LH-20 gel colum chromatography, reverse phase MPLC, reverse phase HPLC and recrystallization. Their structures were elucidated by spectroscopic methods including MS, IR, NMR, and X-ray crystalography. Cytotoxicity of the compounds were screened by using standard MTT method. RESULT: Nine compounds were isolated from C. basiretorsa and their structures were identified as N-phenyl-2-naphthalenamine( I ), dibutyl phthalate( II ), diisobutyl phthalate( III ), 1-phenyl-ethane-1, 2-diol( IV ), 2-hydrox-gamma-benzaldehyde( V ), diethyleneglycol monobenzoate( VI ), uracil( VII ), thymine( VIII ) and thymidine( IX ). CONCLUSION: All these compounds were obtained from this genus for the first time, N-phenyl-2-naphthalenamine and diethyleneglycol monobenzoate were first reported from the marine organisms. Compound I and VII showed moderate activity against KB cell(IC50 10.15 microg x mL(-1) for I and 3.79 microg x mL(-1) for VII ) and MCF-7 cell(IC50 3.24 microg x mL(-1) for VII).

1-Naphthylamine↗

PubMed1998

Vasoconstriction induced by zooxanthellatoxin-B, a polyoxygenated long-chain product from a marine alga.

We found that zooxanthellatoxin-B from a symbiotic marine alga, Symbiodinium sp., caused a concentration-dependent contraction of the rabbit isolated aorta at concentrations of 10(-7)-10(-5) M. Verapamil (10(-6) M) and mefenamic acid (10(-5) M) significantly attenuated the contractile response to zooxanthellatoxin-B at lower concentrations (10(-7)-10(-6) M) but not at higher concentrations (3 X 10(-6)-10(-5) M). The response to zooxanthellatoxin-B was partly inhibited by phentolamine (10(-6) M), whereas it was potentiated by ouabain (10(-5) M). Tetrodotoxin (10(-6) M), methysergide (10(-6) M), chlorpheniramine (10(-6) M) or indomethacin (3 X 10(-6) M), however, did not affect it. The zooxanthellatoxin-B-induced contraction was abolished by incubation in Ca2+-free solution. The contractile response increased in a concentration-dependent fashion with Ca2+ (0.03 and 10 mM) or Sr2 + (0.10 and 10 mM). After treatment with verapamil (10(-6) or 5 X 10(-6) M), the concentration-contractile response curves for Ca2+ and Sr2+ in the presence of zooxanthellatoxin-B were shifted to the right in parallel. MgCl2 (10 mM) shifted the concentration-response curve for Ca2+ more markedly than did verapamil. Zooxanthellatoxin-B increased tissue Na+ and reduced tissue K+ contents in the aorta, suggesting that zooxanthellatoxin-B increases Na+ and K+ permeability across the plasma membrane. These results suggest that the zooxanthellatoxin-B-induced contraction of the aorta is caused mainly by a direct action on smooth muscle, i.e., an increase in Ca2+ permeability that occurs at least partly through voltage-sensitive Ca2+ channels as well as through nonselective cation channels in the cell membrane of smooth muscle.

Animals↗

PubMed1993

Activation of murine macrophages by polysaccharide fractions from marine algae (Porphyra yezoensis).

Two discrete immunomodulating fractions were obtained from marine algae (Porphyra yezoensis): one was the Porphyra water-soluble fraction (PWSF) which was extracted with hot water from the whole body of algae, and the other was the Porphyra acid-soluble fraction (PASF) which was extracted with acid from the residue. The major constituent in both PWSF and PASF was a polysaccharide, the total sugar concentration in PWSF (56.4%) being lower than that in PASF (82.2%). The high contents of 3,6-anhydrogalactose and sulfate indicated the porphyran structure in PWSF and PASF. The results of an in vitro culture assay with proteose peptone-induced macrophages from mice revealed the PWSF and PASF both enhanced glucose consumption, as well as the production of nitrite and tumor necrosis factor (TNF), but that these were increased more by PWSF than by PASF. PWSF augmented IL-I secretion from these macrophages, while PASF did not. On the other hand, the carbon clearance activity of phagocytes from mice injected intraperitoneally with PASF was higher than that from PWSF-injected mice. The injection of PASF into mice also enhanced the carbon clearance activity in a dose-dependent manner. These results suggest that the two individual fractions possessed the ability to activate macrophages in vitro and in vivo in different ways.

Animals↗

PubMed1998

Inhibition of icosanoid production in MC/9 mouse mast cells by n-3 polyunsaturated fatty acids isolated from edible marine algae.

The effects of two polyunsaturated fatty acids, 18:4n-3 and 16:4n-3 purified from the marine algae, Undaria pinnatifida and Ulva pertusa, on icosanoid production in MC/9 mouse mast cells were assessed. Both fatty acids suppressed the production of leukotriene B4 (LTB4), leukotriene C4 (LTC4), and 5-hydroxyeicosatetraenoic acid (5-HETE). The order of the suppressive activity for the two marine algae-derived fatty acids and three other common polyunsaturated fatty acids was as follows; 22:6n-3 = 18:4n-3 = 18:3n-3 > 20:5n-3 = 16:4n-3 for LTB4; 22:6n-3 = 18:4n-3 = 18:3n-3 > 16:4n-3 > 20:5n-3 (no suppression) for LTC4; 22:6n-3 = 18:4n-3 > 18:3n-3 > 20:5n-3 = 16:4n-3 for 5-HETE.

Animals↗

PubMed1995

Discrete subcellular localization of membrane-bound ATPase activity in marine angiosperms and marine algae.

The subcellular distribution of membrane-bound ATPases was compared among terrestrial plants, seagrasses and marine algae by cytochemical techniques. High ATPase activity was detected in the copiously invaginated plsma membrane that was characteristic of transfer cells but not in the tonoplast of epidermal cells in mature leaves of seagrasses. Magnesium- or Ca(2+)-dependent ATPase activity was induced together with the characteristics of transfer cells during the development of leaf tissues able to resist seawater. Northern hybridization revealed the effective induction of the synthesis of mRNA for plasma-membrane H(+)-ATPase during the development of leaves. Such high ATPase activity was not detected in the smooth plasma membranes of marine macro-algae but was found in the membranes of some cytoplasmic vesicles or microvacuoles, providing evidence of the excretion of salts by exocytosis. It appears, therefore, that two essentially different methods for excreting excess salts have developed separately in these two classes of marine plants. The evolution of mechanisms of salt tolerance in the plant kingdom is discussed in terms of the differential subcellular distribution of ATPase activity.

Adenosine Triphosphatases↗

PubMed2006

H+ -pumping rhodopsin from the marine alga Acetabularia.

An opsin-encoding cDNA was cloned from the marine alga Acetabularia acetabulum. The cDNA was expressed in Xenopus oocytes into functional Acetabularia rhodopsin (AR) mediating H+ carried outward photocurrents of up to 1.2 microA with an action spectrum maximum at 518 nm (AR518). AR is the first ion-pumping rhodopsin found in a plant organism. Steady-state photocurrents of AR are always positive and rise sigmoidally from negative to positive transmembrane voltages. Numerous kinetic details (amplitudes and time constants), including voltage-dependent recovery of the dark state after light-off, are documented with respect to their sensitivities to light, internal and external pH, and the transmembrane voltage. The results are analyzed by enzyme kinetic formalisms using a simplified version of the known photocycle of bacteriorhodopsin (BR). Blue-light causes a shunt of the photocycle under H+ reuptake from the extracellular side. Similarities and differences of AR with BR are pointed out. This detailed electrophysiological characterization highlights voltage dependencies in catalytic membrane processes of this eukaryotic, H+ -pumping rhodopsin and of microbial-type rhodopsins in general.

Acetabularia↗

PubMed2001

Molecular cloning of Na(+)-ATPase cDNA from a marine alga, Heterosigma akashiwo.

We cloned novel Na(+)-ATPase (HANA) cDNA from marine alga Heterosigma akashiwo. The full-length HANA cDNA was 4467 bp long and coded for a 1330 amino acid protein with a molecular weight of 146,306. The deduced product exhibited around 40% identity in amino acids with Na(+)/K(+)-ATPase alpha-subunits. A hydrophilic sequence of 285 amino acid residues that showed no homology with any sequence listed in databases existed in the M7--M8 junction of HANA. This is the first report on the primary structure of putative Na(+)-transporting ATPase from plant cells.

Adenosine Triphosphatases↗

PubMedDate not supplied

[Nature of the afterglow of marine algae].

Excitation spectra and light curves were studied in three species of marine algae at monochromatic light excitation of the second-range afterglow. It was shown that light curves were satisfactorily described by an equation similar to the equation of enzyme catalysis with low light intensity of half-saturation (about 0.5 W X m-2). Shapes of the excitation spectra and spectral curves of quantum yield of the second-range afterglow was analysed considering the early non-linearity of its light curves. It was found that the results obtained and the literature data on a relatively high quantum yield of the second-range afterglow in the region of absorption of long-wave pigment system (above 680 nm) can be explained by the non-linearity mentioned above, not suggesting a participation of PSI in the generation of this afterglow.

Chlorophyta↗