Principales propiedades inmunomoduladoras y antinflamatorias de la ficobiliproteína C-ficocianina / Main immunomodulatory and anti-inflamatory properties of phycobiliproteins C-phycocyanin

Las ficobiliproteínas son proteínas solubles en agua, que funcionan como pigmentos fotosintéticos accesorios en diferentes organismos tales como las cianobacterias, las algas rojas y las criptomonadas. En el alga verdeazul Spirulina platensis, una de las ficobiliproteínas más abundantes es la C-ficocianina, la cual tiene unido tres cromóforos ficocianobilina mediante un enlace tioéter a cisteínas específicas. La ficocianobilina es un tetrapirrol lineal asociado a la captación de energía solar en estos organismos. La C-ficocianina ha sido empleada en diferentes investigaciones biomédicas como biomarcador, por sus propiedades fluorescentes, y como posible agente terapéutico para el tratamiento de enfermedades asociadas al estrés oxidativo, por sus propiedades antioxidantes, inmunomoduladoras y antinflamatorias. Se ha demostrado que esta proteína aumenta la liberación de interferón gamma en células mononucleares de sangre periférica y modula la producción de citocinas inflamatorias como el factor de necrosis tumoral alfa, entre otras. Además, se ha encontrado que la C-ficocianina tiene efecto inmunomodulador de citocinas que potencian la activación de las células del sistema inmune, como la IL-6 y la IL-1ß, así como la regulación de aproximadamente 190 genes implicados en la inmunidad(AU)

Phycobiliproteins are water-soluble proteins that function as accessory photosynthetic pigments in different organisms such as cyanobacteria, red algae and cryptomonads. In the blue-green algae Spirulina platensis one of the most abundant phycobiliproteins is the C-phycocyanin, which has three phycocyanobilin chromophores linked through a thioether bond to specific cysteine. The phycocyanobilin is a linear tetrapyrrole associated with solar energy absorption in these organisms. The C-phycocyanin has been used in several biomedical researches as a biomarker, for their fluorescence properties, and as a possible therapeutic agent for the treatment of diseases associated with oxidative stress for its antioxidant, anti-inflammatory and immunomodulatory properties. It has been shown that this protein increases the release of interferon gamma in peripheral blood mononuclear cells, and modulates the production of inflammatory cytokines such as tumor necrosis factor among others. Furthermore it has been found that the C-phycocyanin has immunomodulatory effect on cytokines that enhance the activation of immune cells, such as IL-6 and IL-1ß, and the regulation of about 190 genes involved in immunity(AU)

Inhibition of Fibrotic Contraction by C-Phycocyanin through Modulation of Connective Tissue Growth Factor and α-Smooth Muscle Actin Expression

The effects of C-phycocyanin (C-pc), a phycobiliprotein, on the expression of pro-fibrotic mediators in hyper-tropic scarring such as connective tissue growth factor (CTGF) and α-smooth muscle actins (α-SMA) were investigated in relation to trans-differentiation of fibroblast to myo-fibroblast, an icon of scar formation. C-pc was isolated from Spirulina Platensis extract using sonication method and C-pc concentration was determined by Bennet and Bogorad equation. α-SMA and CTGF levels in wounded primary human dermal fibroblasts were determined by western blot analysis and immuno-fluorescence confocal microscope was employed. Fibroblast contractility was examined by three-dimensional collagen lattice contraction assay. There was an elevation of α-SMA (121%) and CTGF (143%) levels in wound cells as compared with non-wound cells. The does-response profiles of down regulation demonstrated that the maximum inhibitions of α-SMA by 63% (p<0.05) and CTGF by 50% (p<0.1) were achieved by C-pc (6 nM) treated cells. In confocal assay, non-wound fibroblasts exhibited basal level of α-SMA staining, while wounded cells without C-pc treatment showed strong up-regulation of α-SMA by 147% (p<0.05). C-pc (6 nM) inhibited α-SMA expression by 70% (p<0.05) and reduced collagen contraction by 29% (p<0.05). C-pc seemed to lessen the over expression of CTGF, α-SMA, subsequently alleviating the fibrotic contracture. This study suggests the potential application of C-pc to regulation of the expression of pro-fibrotic mediators in scarring process and its potential usage as an efficient means for anti-fibrosis therapy.

Cultivos discontinuos alimentados con urea de la cianobacteria Phormidium sp. en función de la salinidad y edad del cultivo / Urea fed-batch cultures of the cyanobacterium Phormidium sp. as a function of the salinity and age of cultures

Se comparó la eficiencia de sistemas de cultivos discontinuos alimentados versus cultivos discontinuos convencionales, en cuanto a concentración de nitrógeno, adicionando 0,2 mM de urea cada tres días al final de la fase exponencial, durante 21 días. Se realizaron cultivos con un volumen de 1500 mL a 15 y 35 UPS de salinidad, enriquecidos con medio ALGAL 8mM NaNO3, a 238 µmol q m-2 s-1, aireación constante, fotoperiodo 12:12 horas y temperatura de 29 ±3°C. Phormidium sp. posee la capacidad de hidrolizar la urea; mostrando una asimilación de 65±7,07% de la misma, con la mayor producción (p<0,05) de clorofila a, ficocianina y proteínas de 20,26±1,24; 203,47±12,83 y 707,87±28,47 µg mL-1en los cultivos alimentados. La producción de pigmentos vario en el tiempo, independientemente a la salinidad y sistema de cultivo, mientras que la producción de proteínas y carbohidratos totales fue directamente proporcional a la edad del cultivo, con valores máximos de 612,74 ± 5,41 µg mL-1 y 8,96±0,08 mg mL-1 respectivamente a los 31 días. La síntesis de lípidos y EPS fueron influenciadas (p<0,05) por la salinidad, presentando los máximos de lípidos a 15 UPS con 12,22±2,91µg mL-1, y los EPS se incrementaron a 35 UPS con 2,00 ± 0,26 y 2,03 ± 0,15 mg mL-1. Estos resultados determinan que los cultivos de Phormidium sp. alimentados con urea y a salinidades de 15 y 35 UPS, representan una alternativa económica para la producción de clorofila a, ficocianina y proteínas, incrementándose un 31,04; 40,72 y 31,94 % respectivamente en comparación con cultivos no alimentados.

Fed-batch system efficiency versus batch cultures was compared in relation to nitrogen concentration, adding 0,2mM urea at the end of the exponential phase, during 21 days. Cultures were carried out in 1500 mL to 1.5 and 3.5 UPS of salinity, enriched with Algal medium 8mM NaNO3, 238 mol q m-2 s-1, constant aeration, photoperiod 12:12 h. and 29 ±3°C. Phormidium sp. is able to hydrolyze urea; showing a total assimilation of 65±7.07%, with the highest (p< 0.05) chlorophyll a, phycocyanin and protein production of 20.26 ± 1.24, 203.47 ± 12.83 and 707.87 ± 28.47 µg mL-1 in the fed-batch cultures. On the other hand, pigment production varies in time, regardless salinity and culture system. Proteins and total carbohydrate production were directly proportional to the age of cultures, with maximum values of 612.74 ± 5.41 µg mL-1 and 8.96 ± 0.08 mg mL-1, respectively. Lipid and EPS were influenced (p< 0.05) by salinity, showing maximum of lipids at 15 UPS with 12.22±2.91 µg mL-1, and EPS at 15 and 35 UPS with 2.00 ± 0.26 and 2.03 ± 0.15 mg mL-1. These results determine that Phormidium sp. cultures fed with urea, to salinities of 15-35 UPS, represent an economic alternative for chlorophyll a, phycocyanin and protein production, with an increase of 31.04, 40.72 and 31.94% respectively in comparison with non-fed cultures.

A study of chlorophyll-like and phycobilin pigments in the C endosymbiont of the apple- snail Pomacea canaliculata

Pigments present in the brown-greenish C morph of an intracellular endosymbiont of Pomacea canaliculata were investigated. Acetone extracts of the endosymbiotic corpuscles showed an absorption spectrum similar to that of chlorophylls. Three fractions obtained from silica gel column chromatography of the acetone extracts (C I, C II and C III), were studied by positive ion fast atom bombardment-mass spectrometry (FAB-MS) and hydrogen-nuclear magnetic resonance (H-NMR). Results indicated the presence of (1) a sterol in the yellow colored C I fraction; (2) a mixture of pheophorbides a and b in the major green fraction, C II; and (3) a modified pheophorbide a in the smaller green fraction, C III. Aqueous extracts of the C endosymbiont did not show evidence of the occurrence of C-phycocyanin, allophycocyanin or phycoerithrin (light absorption, fluorescence emission, and electrophoresis of the protein moieties) while cyanobacterial cells (Nostoc sp.) showed evidence of C-phycocyanin and allophycocyanin. The possible phylogenetic and functional significance of the pigments present in the C endosymbiont is discussed.

Statistical evaluation of nutritional components impacting phycocyanin production in Synechocystis SP

Alkaliphilic cyanobacterial cultures were isolated from Lonar lake (MS, India). Among the set of cultures, Synechocystis sp, was studied for phycocyanin production. A maximum yield was obtained in BG-11 medium at optimized conditions (pH 10 and 16 h light). In order to increase the phycocyanin yield media optimization based on the eight media components a Plackett-Burman design of the 12 experimental trials was used. As per the analysis CaCl2.2H2O and Na2CO3 have been found to be the most influencing media components at 95% significance. Further the optimum concentrations of these components were estimated following a Box Wilson Central Composite Design (CCD) with four star points and five replicates at the center points for each of two factors was adopted for optimization of these two media components. The results indicated that there was an interlinked influence of CaCl2.2H2O and Na2CO3 on 98% significance. The maximum yield of phycocyanin (12% of dry wt) could be obtained at 0.058 g/l and 0.115 g/l of CaCl2.2H2O and Na2CO3, respectively.

Experimental study on the therapeutic effect of C-phycocyanin against pulmonary fibrosis induced by paraquat in rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the therapeutic effect of C-phycocyanin (C-PC) from Spirulina platensis on paraquat (PQ)-induced pulmonary fibrosis in rats.</p><p><b>METHODS</b>A total of 90 healthy Wistar rats were randomly and equally divided into normal control group, model group (PQ group), and C-PC treatment group (C-PC group). Each rat in the PQ group and C-PC group were orally administered with a single dose of PQ (50 mg/kg) to establish a rat model of PQ poisoning. Then, the rats in the normal control group and PQ group were orally given saline solution (1 ml/100 g) every day, and the rats in the C-PC group were orally given C-PC (50 mg/kg) every day. Six rats were randomly selected from each group on days 1, 3, 7, 14, and 28. The inferior lobe of each rat's right lung was homogenized for the measurement of hydroxyproline (HYP) and maleic dialdehyde (MDA) levels and superoxide dismutase (SOD) activity. Parts of each rat's left lung were subject to HE staining and Masson staining for pathological observation, and the expression of transforming growth factor-β(1) (TGF-β(1)), nuclear factor-kappa B p65 (NF-κB p65), and tumor necrosis factor-α (TNF-α) in lung tissue was measured by immunohistochemistry.</p><p><b>RESULTS</b>The HYP levels on days 1, 3, 7, 14, and 28 and MDA levels on days 14 and 28 were significantly lower in the C-PC group than in the PQ group (P < 0.05, P < 0.01). The SOD activity was significantly higher in the C-PC group than in the PQ group on days 1, 7, 14, and 28 (P < 0.05, P < 0.01). The protein content of TGF-β(1) and the activities of NF-κB p65 and TNF-α in the PQ group and C-PC group were significantly higher than those in the normal control group, while the indices in the C-PC group were significantly lower than those in the PQ group (P < 0.05, P < 0.01). The pathological observation showed that C-PC could alleviate pulmonary alveolitis and fibrosis in rats with PQ poisoning.</p><p><b>CONCLUSION</b>C-PC can significantly inhibit PQ-induced pulmonary alveolitis and fibrosis in rats.</p>

Protective Effect of C-phycocyanin against Inflammation and Interstitial Fibrosis in an Obstructive Nephropathy Model / 대한신장학회지

No abstract available.

C-phycocyanin Attenuates Renal Inflammation and Fibrosis in UUO Mice / 대한신장학회지

PURPOSE: It has been reported that Spirulina, a blue-green algae with potent antioxidant properties, affords significant protection against inflammation and fibrosis in the liver in vivo. The aim of the present study was to establish the possible protective role of C-phycocyanin, one of the active ingredients of Spirulina, in an experimental model of fibrosis in the kidney. METHODS: The study was carried out using male C57BL6 mice. Mice were divided into the following four groups: sham-operated group; C-phycocyanin (PC)-treated sham group; unilateral ureteral obstruction (UUO) group; and PC with UUO group. We evaluated renal TGF-beta mRNA, MCP-1, and osteopontin using real-time RT PCR. We evaluated renal TGF-beta, alpha-SMA, and CD68 by immunohistochemistry. We recorded light microscopic findings of kidney specimens. RESULTS: PC significantly decreased the expression of MCP-1 and alpha-SMA mRNA. Renal gene levels of expression of TGF-beta, MCP-1, and osteopontin in the UUO group were significantly higher than the sham-operated group (p<0.01). The levels of expression of TGF-beta, MCP-1, and osteopontin mRNA of kidneys in the PC-treated UUO group were significantly lower than the untreated UUO group (p< 0.05). The magnitude of expression of TGF-beta and alpha-SMA protein in the kidneys of the PC-treated UUO group was significantly less than the untreated UUO control group (p<0.05). CONCLUSION: The results of the present study suggest that PC has anti-inflammatory and anti-fibrotic effects in an experimental UUO murine model.

Preparation of phycocyanin subunits liposomes and the photodynamic experiment on cancer cells / 药学学报

Phycocyanin subunits liposomes (PCS-lip) were prepared and its cellular uptake and photodynamic therapy (PDT) effect on cancer cells were studied. In the experiment, film dispersion method was used to prepare phycocyanin subunits liposomes; particle size and distribution were detected by zetasizer and transmission electric microscope; the effects of liposome as carrier on cell uptake in vitro were evaluated in S180 by using fluorescence microscope; and photodynamic therapy effect was assessed with MTT method. As shown in the results, the particle size mainly ranged from 80 nm to 160 nm, and average encapsulation rate was 42.3%. In the concentration of 100 microg x mL(-1), transfection rate reached (18.5 +/- 0.8)% at 2 h, (23.1 +/- 0.9)% at 4 h, keeping a balance in 5-6 h, and its photodynamic therapy effect in vitro improved with the increasing of concentration of phycocyanin subunits liposomes. In the concentration of 200 micro x mL(-1) cell survival rate of BGC-823 and S180 reached (45 +/- 5.2)% and (36 +/- 5.5)%, respectively, and the cell survival rate differentiation between PCS-PDT group and PCS-lip-PDT group reached 7%-11% (P < 0.05). In this study film dispersion method could keep the biological activity of phycocyanin subunits very well. Phycocyanin subunits liposomes will transfect cells more quickly than phycocyanin subunits in the same concentration, and in the same conditions, phycocyanin subunits liposomes have the better PDT effect on cancer cells as they were incubated with cells for 4 h.

Antioxidant properties of Spirulina (Arthospira) platensis cultivated under different temperatures and nitrogen regimes

The main aim of this work was to investigate the effects of temperature and nitrogen concentration on the antioxidant potential of extracts from Spirulina (Arthospira) platensis biomass. S. platensis biomass obtained at 35°C and with 1.875 g.L-1 or 2.5 g.L-1 of sodium nitrate in the culture medium presented higher concentrations of phenolic compounds. The antioxidant potential of methanol extracts of biomass on the enzymatic browning caused by peroxidase were 29 and 35 percent, respectively, being the reduction related to the amount of phenolic compounds present in this extract.

A cianobactéria Spirulina tem sido comercializada e estudada devido as suas propriedades nutricionais e terapêuticas no tratamento de doenças como o câncer, a hipercolesterolemia e a aterosclerose. Determinados compostos presentes na Spirulina, como os compostos fenólicos, a ficocianina e o tocoferol, podem apresentar atividade antioxidante. O principal objetivo deste trabalho foi avaliar o efeito da temperatura de cultivo e da concentração de nitrogênio no meio de cultivo, sobre o potencial antioxidante da microalga Spirulina (Arthospira) platensis. Quando a microalga foi cultivada a 35°C e concentrações de nitrato de sódio de 1,875 g.L-1 ou 2,5 g.L-1, o potencial antioxidante dos extratos obtidos a partir da biomassa, sobre o escurecimento enzimático causado pela peroxidase, foi de 29 por cento e 35 por cento, respectivamente, sendo a redução no escurecimento relacionada com as quantidades de compostos fenólicos presentes nos extratos.

Antioxidant potential of C-phycocyanin isolated from cyanobacterial species Lyngbya, Phormidium and Spirulina spp.

The antioxidant activity of C-Phycocyanin (C-PC) isolated from three cyanobacterial species Lyngbya (marine), Phormidium (marine) and Spirulina (fresh water) was studied in vitro. The results demonstrate that C-PCs from Lyngbya, Phormidium and Spirulina spp. are able to scavenge peroxyl radicals (determined by crocin bleaching assay) with relative rate constant ratio of 3.13, 1.89 and 1.8, respectively. C-PCs also scavenge hydroxyl radicals (determined by deoxyribose degradation assay) with second order rate constant values of 7.87 x 10(10), 9.58 x 10(10) and 6.42 x 10(10), respectively. Interestingly, Lyngbya C-PC is found to be an effective inhibitor of peroxyl radicals (IC50 6.63 microM), as compared to Spirulina (IC50 12.15 microM) and Phormidium C-PC (IC50 12.74 microM) and is close to uric acid (IC50 2.15 microM). Further, the studies suggest that the covalently-linked tetrapyrrole chromophore phycocyanobilin is involved in the radical scavenging activity of C-PC. The electron spin resonance (ESR) spectra of C-PCs indicate the presence of free radical active sites, which may play an important role in its radical scavenging property. This is the first report on the ESR activity of native C-PCs without perturbations that can cause radical formation.

Effects of integrin beta1 on phycocyanin inhibiting proliferation of K562 cells / 中国实验血液学杂志

This study was purposed to investigate the effect of phycocyanin at different concentration on proliferation of K562 cells, to detect the changes of integrin beta1 expression and intracellular focal adhesion kinase (FAK) gene expression on the surface K562 cells treated with phycocyanin, and to explore the possible mechanism of integrin beta1 effect on phycocyanin inhibiting proliferation of K562 cells. The expression level of integrin beta1 on the surface of K562 cells was evaluated by flow cytometry (FCM); the growth of K562 cells treated with phycocyanin was measured by MTT assay; the expression level of FAK mRNA was analyzed by relatively quantitative RT-PCR after four-day culture of K562 cells with phycocyanin of 40 microg/ml, 80 microg/ml and 160 microg/ml, respectively. The results showed that integrin beta1 expression on the surface of K562 cells was significantly higher than that in bone marrow mononuclear cells (BMMNC) from normal subjects. Phycocyanin could not change the level of integrin beta1 expression. Phycocyanin could increase the expression of FAK gene on K562 cells and inhibit the proliferation of K562 cells. It is concluded that phycocyanin can inhibit the proliferation of K562 cells through enhancing the conjunction of cell stroma with integrin beta1 on K562 cell surface, up-regulating the expression level of FAK gene in K562 cells, restoring the signaling pathway of proliferation inhibition mediated by integrin beta1. The possible mechanism of phycocyanin in the proliferation inhibition of K562 cells is to increase the expression of FAK gene. The phycocyanin may be considered as a potential agent for inhibition of cancer cell proliferation.

The upstream sequence of the phycocyanin b subunit gene from Arthrospira platensis regulates expression of gfp gene in response to light intensity

In cyanobacteria, few details are known of the mechanisms through which the expression of the light-harvesting pigment c-phycocyanin is regulated. In the present study, a 419 bp upstream sequence of the phycocyanin b subunit (cpcB) gene from Arthrospira platensis FACHB341 was fused with green fluorescent protein (gfp) gene, and a heterologous reporting system was built up to investigate the influence of light intensity on the expression of gfp gene, and the regulation function of different region of the upstream sequence of cpcB gene. Results showed that the upstream sequence of cpcB gene could drive the expression of gfp gene in Synechococcus sp. strain PCC7942, and the expression was influenced by light intensity, the lower the light intensity, the higher the GFP level. Deletion analysis revealed that a light-responsive element was located in the region -276 to-218, a promoter sequence was in the region -85 to -1, and two positive cis elements were in the -419 to -276 and the -218 to -130 regions, respectively.

A simple method for efficient extraction and purification of C-phycocyanin from Spirulina platensis Geitler.

Phycocyanin is a major light harvesting accessory pigment of red algae and cyanobacteria. In the light of its many commercial applications in food and pharmaceutical industry, purity of the pigment plays a major role. Pharmaceutical industry demands a highly pure phycocyanin with A620/280 ratio of 4 and food industry a ratio of 2. In the present study phycocyanin was extracted in sodium phosphate buffer (pH 7) after macerating in liquid nitrogen. The crude phycocyanin thus extracted was precipitated with 50% ammonium sulphate, purified by dialysis and finally by gel filtration chromatography. Pure phycocyanin was finally obtained with an A620/A280 value of 4.98.

Pigment analysis and ammonia excretion in herbicide tolerant cyanobacteria.

Isolation of cyanobacteria was attempted from herbicide applied rice soils. The predominant genera were Westiellopsis followed by Anabaena, Nostoc and Oscillatoria. The herbicide tolerance was further tested by growing the cyanobacterial cultures in BG-11 medium supplemented with varying concentrations of the commonly used rice herbicide, viz butachlor under in vitro condition. The chlorophyll-a, phycobiliproteins and ammonia excretion were assessed at periodic intervals. Westiellopsis showed the maximum tolerance followed by Anabaena, Nostoc and Oscillatoria.

Crecimiento, producción de pigmentos y exopolisacáridos de la cianobacteria anabaena sp. PCC 7120 en función del pH y CO2 / Effect of pH and CO2 on growth, pigments and exopolysaccharides production from cianobacteria anaebaena sp. PCC 7120

El crecimiento producción de clorofila a, ficocianina, carotenoides y exopolisacáridos (EPS) de la cianobacteria filamentosa Anabaena sp. PCC 7120 fueron analizados en función del pH (5,5-10,5) con o sin soluciones amortiguadoras en cultivos discontinuos y en función del CO2 (0,03 y 5,0 por ciento) en cultivos semicontinuos a una tasa de renovación del 10 por ciento. El crecimiento de la cianobacteria se analizó por turbidez a 750nm y recuento celular, y la actividad fotosintética mediante uso de un electrodo de O2. Los cultivos, por triplicado, se mantuvieron con aireación constante, a 28 ñ 2ºC y con iluminación continua o fotoperíodo según el experimento. El pH y tampón utilizado influyeron en el crecimiento. El mayor crecimiento y contenido de EPS se alcanzaron, respectivamente, a pH 8,0-9,0 y 10,0. Sin embargo, los cultivos no tamponados resultaron con mayor contenido de clorofila a y ficocianina. El crecimiento, la actividad fotosintética y los carotenoides no variaron con la adición de CO2. Los cultivos semicontinuos con bajo CO2 produjeron los valores más elevados de clorofila a, ficocianina y exopolisacáridos, con 25,9 ñ 1,69, 2010 ñ 22,61 y 2286,0 ñ 42,76 µg.ml-1, respectivamente. El contenido de ficocianina y de EPS fue de 2,7 y 4 veces superior al obtenido a altos niveles de CO2. El pH y el sistema semicontinuo constituyen herramientas importantes para modular el crecimiento y contenido de pigmentos y de EPS de Anabaena sp. PCC 7120

Actividad antioxidante de la ficocianina frente a radicales peroxílicos y la peroxidación lipídica microsomal / Antioxidant activity of phycocyaning againts peroxyl radicals and microsomal lipid peroxidation

La ficocianina es una biliproteína que se extrae de las algas verdeazules como la Spirulina (Arthospira) máxima. Esta proteína porta 3 grupos cromogénicos (tetrapirroles lineales) por unidad monométrica, que poseen una estructura muy similar a la de la bilirrubina, que es un reconocido antioxidante endógeno. Por otra parte se conoce que otros derivados de las porfirinas, como la clorofila alfa, presentan propiedades antioxidantes. Teniendo en cuenta estos antecedentes, en este trabajo el propósito fue evaluar si la ficocianina presentaba propiedades antioxidantes frente a radicales peroxílicos en diferentes condiciones experimentales como fueron: 1. disminución de la banda de absorción a 620 nm, asociada con la integridad del cromógeno, al reaccionar con radicales peroxílicos; 2. protección de hematíes humanos de la lisis inducida por radicales peroxílicos; 3. inhibición de la peroxidación lipídica microsomal inducida por Fe+2 -ascórbico. Los resultados indicaron que los grupos cromóforos de la ficocianina reaccionaban rápidamente con los radicales peroxílicos, mecanismo por el cual la biliproteína era capaz de proteger los hematíes de la lisis celular y de inhibir la peroxidación lipídica microsomal

Comparison between R-phycocyanin-labeled and R-phycoerythrin-labeled monoclonal antibody (Mab) probes for the detection of Entamoeba histolytica trophozoites.

A comparison between R-phycocyanin (R-PC)-labeled monoclonal antibody (MAb) probe and R-phycoerythrin (R-PE)-labeled MAb probe for the detection of the three standard reference strains of the cultured-derived Entamoeba histolytica trophozoites, namely HK-9, HM-1:IMSS, and HTH-56:MUTM were evaluated by using direct immunofluorescence antibody (DIFA) assay five times for each strain. Under the blue irradiation of the fluorescent microscope, both R-PC-labeled and R-PE-labeled MAb probes showed consistently greenish-yellow trophozoites and golden-orange trophozoites, respectively. The R-PE-labeled MAb probe stained the trophozoites more brightly and clearly than those stained by the R-PC-labeled MAb probe of the same Eh208C2-2MAb. When observed under the green irradiation, both probes showed the same intensity of brightly red color at the trophozoites of all three strains of E. histolytica. The sensitivity of both tests was 100%. Since this Eh208C2-2MAb could recognize specifically E. histolytica pyruvate:ferredoxin oxidoreductase (PFOR) enzyme, therefore, our two antibody probes would be valuable for use as a rapid, easy and sensitive test for diagnosis of invasive amebiasis. Further applications of these two probes directly onto the fecal sample spots and to more culture-derived strains of E. histolytica/E. dispar of known zymodemes in collaboration with the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDRB), Dhaka, Bangladesh, are under investigation.

Photodynamic DNA damage induced by phycocyanin and its repair in Saccharomyces cerevisiae

In the present study, we analyzed DNA damage induced by phycocyanin (PHY) in the presence of visible light (VL) using a set of repair endonucleases purified from Escherichia coli. We demonstrated that the profile of DNA damage induced by PHY is clearly different from that induced by molecules that exert deleterious effects on DNA involving solely singlet oxygen as reactive species. Most of PHY-induced lesions are single strand breaks and, to a lesser extent, base oxidized sites, which are recognized by Nth, Nfo and Fpg enzymes. High pressure liquid chromatography coupled to electrochemical detection revealed that PHY photosensitization did not induce 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) at detectable levels. DNA repair after PHY photosensitization was also investigated. Plasmid DNA damaged by PHY photosensitization was used to transform a series of Saccharomyces cerevisiae DNA repair mutants. The results revealed that plasmid survival was greatly reduced in rad14 mutants, while the ogg1 mutation did not modify the plasmid survival when compared to that in the wild type. Furthermore, plasmid survival in the ogg1 rad14 double mutant was not different from that in the rad14 single mutant. The results reported here indicate that lethal lesions induced by PHY plus VL are repaired differently by prokaryotic and eukaryotic cells. Morever, nucleotide excision repair seems to play a major role in the recognition and repair of these lesions in Saccharomyces cerevisiae