Screening and preliminary characterization of hemagglutinins in Vietnamese marine algae

Extracts from 44 species of Vietnamese marine algae, including 15 Chlorophyta, 18 Rhodophyta and 11 Phaeophyta species, were examined for hemagglutination activity with a variety of different animal and human erythrocytes that were untreated or treated with enzymes. Almost all extracts showed activity toward at least one type of erythrocytes, although those from three Chlorophyta and two Rhodophyta species showed no hemagglutination with any type of erythrocytes examined. Strong activity was detected in extracts from two Chlorophyta (Anadyomene plicata and Avrainvillea erecta) and four Rhodophyta species (Gracilaria eucheumatoides, Gracilaria salicornia, Kappaphycus alvarezii, and Kappaphycus striatum) with enzyme-treated rabbit and sheep erythrocytes. The hemagglutinins of seven Chlorophyta and eight Rhodophyta species were examined for sugar-binding specificity, pH- and temperature-stability, and divalent cation-independency of hemagglutination using ammonium sulfate-precipitates prepared from their extracts. In a hemagglutination-inhibition test with various monosaccharides and glycoproteins, none of the hemagglutinins had affinity for monosaccharides, except the Codium arabicum and Gracilaria euchematoides hemagglutinins, whose activities were inhibited by both N-acetyl-d-galactosamine and N-acetyl-d-glucosamine. On the other hand, all of the hemagglutinins activities were inhibited by some glycoproteins. The inhibition profiles with glycoproteins were different depending on hemagglutinin species, and suggest the presence of lectins specific for high mannose N-glycans, complex N-glycans, or O-glycans. The activities of these algal hemagglutinins were stable over a wide range of pH and temperature, and independent of the presence of divalent cations. These results indicate that Vietnamese marine algae are a good source of novel and useful lectins.     

A new screening for hemagglutinins from Vietnamese marine macroalgae

Aqueous extracts from 42 species of Vietnamese marine macroalgae, including 17 Chlorophyta, 22 Rhodophyta, and three Phaeophyta species, were examined for hemagglutination activity using native and enzyme-treated different animal and human erythrocytes. All extracts agglutinated at least one type of erythrocytes tested. Strong activity was detected in extracts from four Chlorophyta (Caulerpa serulata var. boryana, Caulerpa sertularioides f. longipes, Halimeda velasquezii, and Halimeda discoidea) and two Rhodophyta species (Gelidiella acerosa and Titanophora pulchra) with enzyme-treated rabbit and horse erythrocytes. The hemagglutinins of some active species were examined for sugar-binding specificity, pH, temperature stability, and divalent cation independency using ammonium sulfate precipitates prepared from their extracts. In a hemagglutination–inhibition test with various monosaccharides and glycoproteins, none of the hemagglutinins had affinity for monosaccharides. The activity of the hemagglutinins was inhibited by some glycoproteins tested. The inhibition profiles with glycoproteins were different depending on hemagglutinin species, suggesting the presence of lectins specific for complex N-glycans, high mannose N-glycans or O-glycans. On the other hand, the activities of almost all algal hemagglutinins were stable over a wide range of pH and temperature, and independent of the presence of divalent cations, except Gelidiopsis scoparia hemagglutinin, its activity was dependent on the presence of divalent cations. These results suggest that Vietnamese marine macroalgae may be good sources of useful lectins for many biological applications.     

Lectin activity in pollen from plants representative of thirty orders of spermatophyta

Summary Pollen extracts from a variety of species representative of thirty orders of spermatophyta, including gymnosperms, dicotyledons and monocotyledons, were examined for the presence of lectin activity by means of a hemagglutination assay. Hemagglutinating activity (HA) was detected in the pollen extracts of all the species examined, indicating that lectins are generally present in the pollen of spermatophyta. The response of this pollen hemagglutinating activity to the sugars and glycoproteins tested as potential inhibitors was identical in all species examined. Moreover, the hemagglutinating activity of pollen extracts from eight species which had been selected as representative of the gymnosperms and both subclasses of angiosperms exhibited similar properties (e.g. distribution by differential centrifugation, stability to heat, response to bivalent ions). The bulk of the hemagglutinating activity was always recovered in the pellet after centrifugation at 1000 g for 5 min. Although sequential treatments with 1% Triton X-100 and 1 M KCl were ineffective, subsequent incubation of the pellet with saline phosphate buffer released hemagglutinating activity. The solubilized hemagglutinating activity was destroyed by protease treatment, indicating that the substance(s) responsible for the activity is (are) protein in nature and, consequently, might be considered to be a lectin. The sugar specifity of the pollen lectin activity from wheat, potato and bean was compared with that of wheat germ agglutinin (WGA), potato agglutinin and bean agglutinin — the lectins present in sporophytic tissues of these plants. For all three plants, the response of the pollen lectin activity to sugars and glycoproteins was different from that shown by the lectin from sporophytic tissues.Abbreviations HA Hemagglutinating activity - PBS 150 mM Na-phosphate buffer (pH 7.2) containing 0.9% NaCl - PHA Phaseolus vulgaris agglutinin - STA Solanum tuberosum agglutinin - WGA wheat germ agglutinin     

CHARACTERIZATION OF POLLEN ANTIGENS FROM AMBROSIA L. (COMPOSITAE) AND RELATED TAXA BY IMMUNOELECTROPHORESIS AND RADIAL IMMUNODIFFUSION

The pollen antigens of various Ambrosia and related species were studied to learn whether substances closely related to antigen E (the major allergen of Ambrosia artemisiifolia) were present. After conventional immunoelectrophoresis, pollen extracts from six Ambrosia species each produced at least one pronounced precipitin line with antiserum for purified antigen E. Electrophoretic mobility was the same for several species (A. artemisiifolia, A. bidentata, A. psilostachya, and A. trifida) but was relatively lower for A. acanthicarpa and A. ambrosioides. Precipitin rings were also produced when pollen extracts of the various Ambrosia species were subjected to radial immunodiffusion in agarose which contained antiserum for purified antigen E. There was great variation among the Ambrosia species with respect to precipitin ring diameters. The variation may be due to differences among species in content of the antigen E-like substances or to altered interaction with the immobilized antibody. Crossed (2-dimensional) immunoelectrophoresis was shown to be useful for characterizing Ambrosia pollen antigens. Pollen extracts from A. artemisiifolia produced eight pronounced precipitin bands and at least eight faint, relatively fast-moving bands after crossed immunoelectrophoresis with antiserum against a whole pollen extract from the same species. One of the pronounced bands contained antigen E.     

Agglutinins from marine macroalgae of the southeastern United States

Protein extracts from 22 species of marine macroalgae from Florida and North Carolina were compared for their abilities to agglutinate sheep and rabbit erythrocytes. Protein extracts from 21 algal species agglutinated rabbit erythrocytes compared to 19 for sheep erythrocytes. However, agglutination by brown algal extracts was variable. The agglutination produced by protein extracts from Dictyota dichotoma could be blocked by addition of polyvinylpyrrolidone. Protein extracts from North Carolina macroalgae were also tested against five bacterial species. Three of these agglutinated bacterial cells. Ulva curvata and Bryopsis plumosa agglutinated all five species. Protein extracts from five species of Florida algae were tested for their effects on mitogenesis in mouse splenocytes and human lymphocytes. Gracilaria tikvahiae HBOI Strain G-5, Ulva rigida and Gracilaria verrucosa HBOI Strain G-16S stimulated mitogenesis in mouse splenocytes, while Gracilaria tikvahiae HBOI Strain G-16stimulated mitogenesis in human lymphocytes.     

Cell death induction and nitric oxide biosynthesis in white poplar (Populus alba) suspension cultures exposed to alfalfa saponins

The present work reports on the biological activity of alfalfa (Medicago sativa) saponins on white poplar (Populus alba, cultivar ‘Villafranca’) cell suspension cultures. The extracts from alfalfa roots, aerial parts and seeds were characterized for their saponin content by means of thin layer chromatography (TLC) and electrospray ionisation coupled to mass spectrometry. The quantitative saponin composition from the different plant extracts was determined considering the aglycone moieties and determined by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) analyses. Only soyasapogenin I was detected in the seed extract while several other saponins were found in the root and leaf extracts. Actively proliferating white poplar cell cultures were challenged with the different saponin extracts. Only alfalfa root saponins, at 50 µg ml^?1, induced significant cell death rates (75.00 ± 4.90%). Different cell subpopulations with peculiar cell death morphologies were observed and the programmed cell death (PCD)/necrosis ratio was reduced at increasing saponin concentrations. Enhancement of nitric oxide (NO) production was observed in white poplar cells treated with root saponins (RSs) at 50 µg ml^?1 and release of reactive oxygen species (ROS) in the culture medium was also demonstrated. Saponin‐induced NO production was sensitive to sodium azide and N^G‐monomethyl‐l ‐arginine, two specific inhibitors of distinct pathways for NO biosynthesis in plant cells.     

Analysis of the agglutinating activity from unicellular algae

Agglutinating activity often varies both between and within the algal species assayed. However, it is difficulty to interpret such variation without further analysis. We report a statistical analysis of agglutinating activities against human, cow, sheep, and pig erythrocytes, using cell extracts from 43 taxa (strains) of freshwater microalgae. Most of the extracts agglutinated erythrocytes from at least one of the sources, but pig erythrocytes appeared to be most suitable for the detection of agglutination reactions. Chlorella cell extracts preferentially agglutinated human erythrocytes, whereas extracts of other taxa were less active against mammalian erythrocytes. Cluster analysis generated four distinct subclusters of taxa, characterized by different specificities for antigens or carbohydrate receptors on the erythrocytes. Principal component analysis further separated the agglutination characteristics of Chlamydomonas from Chlorella on the first two components. Specificity for pig erythrocytes accounted for most of the clustering or grouping of algal taxa in multivariate analysis. However, clustering or grouping patterns of Chlorella species on haemagglutinating activity resembled that based on DNA sequences, revealing a possible genetic connection of agglutinins and their biochemical characteristics in algal cells. Variability of agglutination reactions among the algae investigated is simplified and interpreted most easily using multivariate analysis.     

Saponins of Chlorophytum Species

The genus Chlorophytum (Liliaceae) owing to the presence of pharmacologically important saponins has attracted interest of the scientific community to investigate the chemistry of the saponins and study their cytotoxicity. Chloromaloside-A having cytotoxicity against cancer cell lines has been isolated from C. malayense, while saponins from C. borivilianum are gaining popularity as substitute for viagra. The paper presents a review of different saponins isolated from the Chlorophytum species and their pharmacological importance.     

Biochemical and immunochemical characterization of hop-hornbeam (Ostrya Carpinifolia Scop.) pollen

In the last few years Ostrya carpinifolia pollen is consideredas an important cause of respiratoryallergy in Mediterranean areas. The concentration ofthe pollen was measured over a period of fifteen yearsfrom 1981 to 1996 in an area around Genoa; the resultsof this study have clearly indicated an increasingtrend that correlate with persons sensitization.In this study we sought to define the immunochemical andbiochemical properties of hop-hornbean pollen. Soluble proteins extracted from Ostryacarpinifolia pollen and from the taxonomicallyrelated species Corylus Avellana, were analyzedby polyacrylamide gel electrophoresis (SDS-PAGE), byhorizontal isoelectrofocusing (IEF) and by twodimensions electrophoresis (2D-PAGE). Allergenicproteins were identified with sera of sensibilizedpatients and cross-reactivity was evaluated byimmunoblotting techniques. The electrophoreticanalysis showed a partial identity between theproteins from Ostrya and Corylus extracts. The immunoblotting assay, developed withhuman IgE from subjects allergic to hop-hornbeampollen, displayed the major IgE reactivity for acomponent with a molecular weight of 17 kDa expressedin both Ostrya and Corylus extracts. This reactivity is consistent with the presence ofBet v 1 that is described as the major pollen allergenin the Betulaceae and Corylaceae families. Sera fromsubjects allergic to Ostrya were then preadsorbed with recombinant Bet v 1 immobilized in the Pharmacia CAP System; a significant reduction ofthe IgE binding activity was observed after thetreatment. We therefore suggest that Bet v 1 couldbe one of the allergenic proteins present in theOstrya pollen possibly being responsible forcross-reactivity with other members of taxonomicallyrelated families.     

Saponins in Tribulus terrestris – Chemistry and Bioactivity

Tribulus terrestris is a valuable herb known for its application in the folk medicine in many parts of the world. Furostanol and spirostanol saponins of tigogenin, neotigogenin, gitogenin, neogitogenin, hecogenin, neohecogenin, diosgenin, chlorogenin, ruscogenin and sarsasapogenin type are frequently found in this plant. Four sulphated saponins of tigogenin and diosgenin type are also isolated. Extracts and steroidal saponins have been found to possess various pharmacological activities. Preparations based on the saponin fraction of T. terrestris are used for treatment of infertility and libido disorders in men and women, as well as for treatment of cardiac diseases. Food supplements containing T. terrestris extracts are on sale in USA and Europe with claim of a general stimulating action. In this review the steroidal saponins found in T. terrestris are presented, covering the literature up to 2004. The data reveal clear difference in the saponin composition of samples from this plant species collected from different geographical regions. A comprehensive account on the biological activity of extracts and individual saponins is also included.     

Effects of auxins and different culture systems on the adventitious root development of Passiflora pohlii Mast. and their ability to produce antioxidant compounds

Passiflora pohlii Mast. is a wild species native to Brazil, with potential agronomic interest. Although there are few studies on this particular species, recent works described several biological activities in other species of the genus. The goal of this work was to establish adventitious roots cultures from stem and root segments excised from in vitro-grown plants of P. pohlii, as well as to perform phytochemical analyses and evaluate the antioxidant potential of extracts obtained from the in vitro materials, in comparison with in vivo-grown plants. The influence of different parameters (type of explant, culture systems, light, and type and concentrations of auxins) on the induction of adventitious roots was evaluated. Internodal segments showed the best rhizogenesis induction on solidified medium supplemented with 2.7 µM NAA, whereas root segments showed the highest proliferation rate on liquid medium supplemented with 2.85 µM IAA, both in the absence of light. TLC analysis indicated the presence of saponins in extracts from all in vivo and in vitro-derived materials. The antioxidant potential was determined by DPPH and TLC-DPPH assays. The highest antioxidant activities were observed in extracts from primary and secondary roots of in vivo-grown plants. The characterization of the phytochemical profile of the in vitro and in vivo materials, as well as their pharmacological potential are reported for the first time for this species.

     

Identification of superoxide dismutase isoenzymes in tobacco pollen

We investigated the possible existence of superoxide dismutase (SOD; EC 1.15.1.1) isoenzymes in the pollen of Nicotiana tabacum (Petit Havana SR-1 cultivar). To detect SOD activity, crude extracts from tobacco pollen were subjected to native polyacrylamide gel electrophoresis followed by staining with nitroblue tetrazolium (NBT). The presence of six SOD isoenzymes was detected in tobacco pollen. Treatment with SOD inhibitors indicated the presence of one manganese SOD (Mn SOD), five copper-zinc SOD (Cu/Zn SOD) isoenzymes, and the absence of iron SOD (Fe SOD).     

Agglutination of human and animal erythrocytes in marine unicellular algae

Ethanol extracts of 12 marine unicellular algae were assayed for agglutinating activity against native and enzyme-treated human and animal erythrocytes. All of the algae assayed agglutinated at least one group of normal erythrocytes from humans. Notably, all algal extracts agglutinated erythrocytes of hemophilia patients arising from coagulation disorders. Meanwhile, all algae had a strong reaction with monkey erythrocytes, but to a lesser extent or not at all with sheep erythrocytes. Both trypsin and pronase improved the detection of most algal agglutinins and caused a drastic increase in hemagglutinating activity after treatment for 2 h or more. However, hemagglutinating activity decreased or disappeared completely when two extracts of different algal species were combined. Journal of Industrial Microbiology & Biotechnology (2000) 24, 262–266. Received 24 September 1999/ Accepted in revised form 06 January 2000     

Compartmentation and localization of bioactive metabolites in different organs of Allium roylei

To investigate the involvement of Allium roylei metabolites in the plant’s defenses, a comprehensive analysis of the content of cysteine sulfoxides, flavonols, polyphenols, ascorbic acid, and saponins was carried out in the various organs of this species. Metabolomics high performance liquid chromatography (HPLC), spectral-based analysis, and histochemcial studies have given important insight to the validity of saponins as a key component involved in plant protection. The root-basal stem, bulb, and leaf extracts exhibited 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity with inhibition concentration (IC₅₀) ranging from 0.649 to 0.757?mg/mL. The antimicrobial properties of the saponin and flavonoid crude extracts were evaluated. The saponin extracts demonstrated significant antifungal activity depending on the applied concentration, and the growth inhibition rate of the tested fungal pathogens ranged from 1.07 to 47.76%. No appreciable antibacterial activity was recorded in the same sample.     

Isolation of antifungal compounds from someZygophyllum species and their bioassay against two soil-borne plant pathogens

Roots and aerial shoots ofZygophyllum coccineum L.,Z. album L. andZ. dumosum Boiss were extracted with solvents of increasing polarity and tested against spore germination ofVerticellium albo-atrum andFusarium oxysporum f.sp.lycopersici. The effectiveness of each extract depends on the solvent, plant species, organ and test fungus. Petroleum ether extracts were ineffective as fungistatics while the methanol extracts possessed a high inhibitory effect toward spore germination suppression, depending on the fungus and plant species. Water or ethyl acetate root extracts ofZ. album caused a marked suppression of spore germination of the test fungi. Six saponins were isolated from the effective extracts on silica gel and Sephadex columns. They were identified by acid hydrolysis, alkaline saponification, IR and FAB MS. Quinovic acid was the dominant aglycone. Kaempferol was isolated from the flavonoid fraction ofZ. dumosum for the first time. Some of the isolated saponins and kaempferol provided successful control against the test plant pathogens under greenhouse experiment when used as seed treatment.     

In vitro allelopathic effects of pollen from three Hieracium species (Asteraceae) and pollen transfer to sympatric Fabaceae

Pollen allelopathy occurs when pollen toxins inhibit sexual reproduction in heterospecifics. To quantify pollen allelopathic effects in vitro, pollen of Hieracium aurantiacum, H. floribundum, and H. pratense was extracted with double distilled water into concentrations of 0 (control), 0.1, 1, 3, 5, 10, and 25 pollen grains/μl. A subset of these extracts was partitioned by ion-exchange chromatography into acidic, basic, and neutral fractions. Pollen from six sympatric species of Fabaceae (Lotus corniculatus, Medicago sativa, Trifolium hybridum, T. pratense, T. repens, Vicia cracca) and the species of Hieracium was germinated on agar media containing different extract concentrations. As extract concentrations from intact pollen or from acidic fractions increased, mean percent germination of pollen of all Fabaceae decreased nonlinearly. Extract concentrations of 0.1 grains/μl and above inhibited pollen germination in the Fabaceae. In no case was any Hieracium species affected, i.e., there was no autotoxicity. Similar results were obtained using plants from nine populations of H. floribundum and H. pratense across eastern Canada. Observation of floral visitors indicated that there were relatively few movements between Hieracium and the Fabaceae (about 15% of total visits). Hence there is limited opportunity for heterospecific pollen transfer. This was consistent with censuses of stigma, i.e., few pollen grains of Hieracium were found on stigma of the Fabaceae. Thus, pollen allelopathy in Hieracium is unlikely to affect reproductive success in these six species of Fabaceae.     

Airborne pollen survey of central calcutta,india, in relation to allergy

A continuous aeropalynological survey at Central Calcutta for two consecutive years (1985–1987) was done by using a Burkard Seven Day Recording Volumetric Spore Trap. A total of 65 pollen taxa was identified of which pollen of Trema orientalis showed a maximum frequency (about 68%) followed by Poaceae and Cyperaceae. A pollen calendar was prepared and seasonal periodicities were recorded. Some entomophilous pollen types (e.g., Delonix regia, Bougainvillea spectabilis) were also observed. The presence of pollen of Pinus, Podocarpus, and Alnus in the air of Calcutta is probably due to long distance transport from Eastern Himalayas where these plants grow. Routine skin tests were performed by using the antigenic extracts of 22 pollen types where grass, Catharanthus roseus, Cocos nucifera, Azadirachta indica, Carica papaya, Albizia lebbek, Shorea robusta, Eucalyptus sp., Terminalia sp., were proved to be allergenically potent.     

Hemagglutinins (lectins) in fruit bodies of Japanese higher fungi

Extracts from fruit bodies of 110 species of Japanese fungi were examined with trypsinized human and rabbit erythrocytes. More than 80% of the extracts showed the hemagglutination activities, a higher proportion than reported previously. Over half of species that had been reported to be inactive exhibited hemagglutination. Among them, some extracts showed human blood group specific-hemagglutination; A-specific,Panellus serotinus, Psathyrella piluliformis, Cantharellus cibarius andStropharia rugosoannulata; B-, O-specific,Gyroporus castaneus andPanellus stypticus; and Ospecific,Linderia bicolumnata andPhallus impudicus. Twenty-one species were reactive toward only rabbit erythrocytes. Several species exhibited very high hemagglutination activity. The results suggested that some of these Japanese fungi would be promising sources of lectins.     

Pollen hosts of western palaearctic bees of the genus Colletes (Hymenoptera: Colletidae): the Asteraceae paradox

To assess the pollen hosts of 60 western palaearctic bee species of the genus Colletes (Colletidae), we microscopically analysed 1336 pollen loads of collected females. Twenty‐six species (43.3%) were found to be specialized at the level of plant family, subfamily or genus. Thirty‐four species (56.7%) proved to be pollen generalists to varying degrees, visiting the flowers of up to 15 different plant families. Flowers of the subfamily Asteroideae (Asteraceae) are by far the most important pollen source, contributing 23.6% to the pollen‐plant spectrum of the whole bee genus. The high significance of Asteroideae pollen is due to the large number of specialists: 14 Colletes species belonging to four different taxonomic groups harvest pollen exclusively or predominantly on flowers of the Asteroideae. By striking contrast, Asteroideae pollen plays only a marginal role in the diets of the pollen generalists: it was recorded in only 2.7% of the pollen loads and in seven out of the 34 pollen generalists. Among the few generalists exploiting Asteroideae for pollen, three closely related species have ancestors which were possibly specialized on Asteraceae. The pattern of use of Asteroideae pollen by the Colletes bees supports recent findings that this pollen possesses unfavourable or protective properties, which render its digestion difficult, and suggests that bees need physiological adaptations to successfully utilize it. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 719–733.     

TOXICITY OF SUBTROPICAL MARINE ALGAE USING FISH MORTALITY AND RED BLOOD CELL HEMOLYSIS FOR BIOASSAYS1

Two bioassays (fish mortality and fish erythrocyte hemolysis) were used to survey for the presence of toxic principles in aqueous extracts of 19 species of marine macro-algae found in south Florida coastal waters. Extracts from six species (Chlorophyta—Anadyomene stellata (Wulfen) C. Ag., Caulerpa prolifera (Forsskål) Lamour., Penicillus capitatus Lamarck: Rhodophyta—Centroceras clavulatum (C. Ag.) Montague, Laurencia papillosa (Forsskål) Grev., L. poitel (Lamour.) Howe) showed lethal toxicity to the spotfin mojarra, Euconistomus argenteus Baird & Girard. Extracts from three species (Chlorophyta—A. stellata: Phaeophyta—Dictyota dichotoma (Hudson) Lamour.: Rhodophyta—Wrangelia penicillata C. Ag.) lysed erythrocytes of sea bream, Archosargus rhomboidalis (L.).