RESUMO
KEY MESSAGE: Vanadium compounds increased the content and release of distinct isoflavones in a Trifolium pratense suspension culture. Regarding transport-mechanism inhibitors, the process was mostly facilitated by ABC proteins and vesicular transport. The transport of isoflavones and other secondary metabolites is an important part of metabolism within plants and cultures in vitro regarding their role in defence against various abiotic and biotic stressors. This research focuses on the way how to increase production and exudation of isoflavones by application of chemical elicitor and the basic identification of their transport mechanisms across cell membranes. The release of five isoflavones (genistin, genistein, biochanin A, daidzein, and formononetin) into a nutrient medium was determined in a Trifolium pratense var. DO-8 suspension culture after two vanadium compound treatments and cultivation for 24 and 48 h. The NH4VO3 solution caused a higher concentration of isoflavones in the medium after 24 h. This increased content of secondary metabolites was subsequently suppressed by distinct transport-mechanism inhibitors. The transport of isoflavones in T. pratense was mostly affected by ABC inhibitors from the multidrug-resistance-associated protein subfamily, but the genistein concentration in the medium was lower after treatment with multidrug-resistance protein subfamily inhibitors. Brefeldin A, which blocks vesicular transport, also decreased the concentration of some isoflavones in the nutrient medium.
Assuntos
Isoflavonas/metabolismo , Trifolium/metabolismo , Vanádio/farmacologia , Transporte Biológico/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Trifolium/efeitos dos fármacosRESUMO
The family Fabaceae traditionally serves as a food and herbal remedies source. Certain plants serve for treatment of menopausal symptoms based on a presence of typical secondary metabolites, isoflavones. Beside soybean and clovers, other plants or cultures in vitro can produce these molecules. A cultivation in vitro can be enhanced by elicitation that stimulates metabolites biosynthesis via stress reaction. Vanadium compounds have been already described as potential elicitors, and the aim of this study was to determine the impact of NH4VO3 and VOSO4 solutions on isoflavones production in Genista tinctoria L. cell cultures. The significant increase of isoflavones content, such as genistin, genistein, or formononetin, was measured in a nutrient medium or dry mass after NH4VO3 treatment for 24 or 48 h. The possible transport mechanism of isoflavones release as a result of elicitation was further evaluated. An incubation with different transport inhibitors prior to elicitation took effect on isoflavones content in the medium. However, there was a non-ended result for particular metabolites such as genistein and daidzein, where ATP-binding cassette (ABC) or, alternatively, multidrug and toxin extrusion (MATE) proteins can participate. Possible elicitation by some inhibitors was discussed as a result of their pleiotropic effect. Despite this outcome, the determination of the transport mechanism is an important step for identification of the specific transporter.
Assuntos
Técnicas de Cultura de Células/métodos , Genista/citologia , Isoflavonas/química , Compostos de Vanádio/farmacologia , Genista/química , Genista/efeitos dos fármacos , Metabolismo Secundário/efeitos dos fármacos , Vanadatos/farmacologiaRESUMO
Mesocestoides vogae larvae represent a suitable model for evaluating the larvicidal potential of various compounds. In this study we investigated the in vitro effects of three natural flavonolignans-silybin (SB), 2,3-dehydrosilybin (DHSB) and silychristin (SCH)-on M. vogae larvae at concentrations of 5 and 50 µM under aerobic and hypoxic conditions for 72 h. With both kinds of treatment, the viability and motility of larvae remained unchanged, metabolic activity, neutral red uptake and concentrations of neutral lipids were reduced, in contrast with a significantly elevated glucose content. Incubation conditions modified the effects of individual FLs depending on their concentration. Under both sets of conditions, SB and SCH suppressed metabolic activity, the concentration of glucose, lipids and partially motility more at 50 µM, but neutral red uptake was elevated. DHSB exerted larvicidal activity and affected motility and neutral lipid concentrations differently depending on the cultivation conditions, whereas it decreased glucose concentration. DHSB at the 50 µM concentration caused irreversible morphological alterations along with damage to the microvillus surface of larvae, which was accompanied by unregulated neutral red uptake. In conclusion, SB and SCH suppressed mitochondrial functions and energy stores, inducing a physiological misbalance, whereas DHSB exhibited a direct larvicidal effect due to damage to the tegument and complete disruption of larval physiology and metabolism.
Assuntos
Hipóxia , Larva/efeitos dos fármacos , Mesocestoides/efeitos dos fármacos , Silibina/farmacologia , Silimarina/farmacologia , Animais , Antioxidantes/farmacologia , Técnicas In Vitro , Larva/fisiologia , Mesocestoides/fisiologia , Substâncias Protetoras/farmacologiaRESUMO
Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) has become a frequently deadly infection due to increasing antimicrobial resistance. This serious issue has driven efforts worldwide to discover new drugs effective against Mtb. One research area is the synthesis and evaluation of pyrazinamide derivatives as potential anti-TB drugs. In this paper we report the synthesis and biological evaluations of a series of ureidopyrazines. Compounds were synthesized by reacting alkyl/aryl isocyanates with aminopyrazine or with propyl 5-aminopyrazine-2-carboxylate. Reactions were performed in pressurized vials using a CEM Discover microwave reactor with a focused field. Purity and chemical structures of products were assessed, and the final compounds were tested in vitro for their antimycobacterial, antibacterial, and antifungal activities. Propyl 5-(3-phenylureido)pyrazine-2-carboxylate (compound 4, MICMtb = 1.56 µg/mL, 5.19 µM) and propyl 5-(3-(4-methoxyphenyl)ureido)pyrazine-2-carboxylate (compound 6, MICMtb = 6.25 µg/mL, 18.91 µM) had high antimycobacterial activity against Mtb H37Rv with no in vitro cytotoxicity on HepG2 cell line. Therefore 4 and 6 are suitable for further structural modifications that might improve their biological activity and physicochemical properties. Based on the structural similarity to 1-(2-chloropyridin-4-yl)-3-phenylurea, a known plant growth regulator, two selected compounds were evaluated for similar activity as abiotic elicitors.
Assuntos
Antituberculosos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Pirazinas/farmacologia , Antituberculosos/síntese química , Antituberculosos/química , Proliferação de Células/efeitos dos fármacos , Fagopyrum/química , Células Hep G2 , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Reguladores de Crescimento de Plantas/síntese química , Reguladores de Crescimento de Plantas/química , Reguladores de Crescimento de Plantas/farmacologia , Pirazinamida/química , Pirazinamida/farmacologia , Pirazinas/síntese química , Pirazinas/química , Estresse Fisiológico/efeitos dos fármacosRESUMO
The domestic chinchilla (Chinchilla lanigera) is kept as a pet and previous studies suggest that it may play an important role as a source of zoonotic parasites, including Giardia intestinalis, Cryptosporidium spp. and microsporidia. In this study, we examined the occurrence and genetic diversity of above mentioned parasites in pet chinchillas in the Czech Republic by PCR/sequencing of the 18S rRNA, TPI, and ITS genes. Of 149 chinchillas from 24 breeders, 91.3â¯% were positive for G. intestinalis, 8.1â¯% for Cryptosporidium spp., 2.0â¯% for Encephalitozoon spp., and 5.4â¯% for E. bieneusi. Molecular analyses revealed presence of G. intestinalis assemblage B, C. ubiquitum (XIIa family), E. bieneusi genotypes D, SCF2, and, CHN-F1, and E. intestinalis. The infection intensity of G. intestinalis determined by qRT-PCR reached up to 53,978 CPG, C. ubiquitum up to 1409 OPG, E. intestinalis up to 1124 SPG, and E. bieneusi up to 1373 SPG. Only two chinchillas with C. ubiquitum and five with G. intestinalis had diarrhoea at the time of the screening. Three chinchillas in the long-term study were consistently positive for G. intestinalis, with intermittent excretion of C. ubiquitum, E. intestinalis, and E. bieneusi over 25 weeks. The findings indicate that chinchillas are frequently infected with zoonotic parasitic protists, but that these infections rarely show clinical signs. The lack of visible signs could reduce the vigilance of pet owners when handling their chinchillas, increasing the risk of transmission within breeding groups and possibly to humans.
RESUMO
Carotenoids are the most abundant lipid-soluble phytochemicals and are used as dietary supplements to protect against diseases caused by oxidative stress. Astaxanthin, a xanthophyll carotenoid, is a very potent antioxidant with numerous beneficial effects on cellular functions and signaling pathways. In this study, using spleen cells from healthy Balb/c mice, we report the bio-functional effects of an astaxanthin-rich extract (EXT) prepared from the microalga Haematococcus pluvialis and its astaxanthin monoesters-rich fraction (ME) and astaxanthin diesters-rich fraction (DE) obtained by fractionation of EXT using countercurrent chromatography (CCC). After incubation under standard culture conditions (humidity, 37 °C, 5% CO2, atmospheric oxygen), the viability of untreated splenocytes, as determined by the trypan blue exclusion assay, the MTT assay, and the neutral red assay, decreases to approximately 75% after 24 h compared with naïve splenocytes. This effect correlated with the decrease in mitochondrial membrane potential and the transition of ~59% of cells to the early stage of apoptosis, as well as with the decreased ROS production, indicating that hyperoxia in cell-culture deteriorates cell functions. They are restored or stimulated by co-cultivation with EXT, ME, and DE up to 10 µg/mL in the order EXT > DE > ME, suggesting that esterification increases bioavailability to cells in vitro. ROS and H2O2 concentrations reflect mRNA transcriptional activity of Nrf2, superoxide dismutase 1 (SOD1), catalase, and glutathione peroxidase 1, as well as SOD-mediated ROS conversion, whereas they inversely correlate with iNOS-mediated NO production. The highest-tested concentration of EXT, ME, and DE (40 µg/mL) is detrimental to cells, probably because of the overwhelming scavenging activity of astaxanthin and its esters for the reactive oxygen/nitrogen species required for cellular functions and signal transduction at low physiological concentrations. In this study, we demonstrate that differential activities of ME and DE contribute to the final antioxidant and cytoprotective effects of astaxanthin extract, which is beneficial in preventing a wide range of ROS-induced adverse effects, with DE being more effective. In addition, the selection of physioxia-like conditions for pharmacological research is highlighted.
RESUMO
BACKGROUND: Cryptosporidium spp. are globally distributed parasites that infect epithelial cells in the microvillus border of the gastrointestinal tract of all classes of vertebrates. Cryptosporidium chipmunk genotype I is a common parasite in North American tree squirrels. It was introduced into Europe with eastern gray squirrels and poses an infection risk to native European squirrel species, for which infection is fatal. In this study, the biology and genetic variability of different isolates of chipmunk genotype I were investigated. METHODS: The genetic diversity of Cryptosporidium chipmunk genotype I was analyzed by PCR/sequencing of the SSU rRNA, actin, HSP70, COWP, TRAP-C1 and gp60 genes. The biology of chipmunk genotype I, including oocyst size, localization of the life cycle stages and pathology, was examined by light and electron microscopy and histology. Infectivity to Eurasian red squirrels and eastern gray squirrels was verified experimentally. RESULTS: Phylogenic analyses at studied genes revealed that chipmunk genotype I is genetically distinct from other Cryptosporidium spp. No detectable infection occurred in chickens and guinea pigs experimentally inoculated with chipmunk genotype I, while in laboratory mice, ferrets, gerbils, Eurasian red squirrels and eastern gray squirrels, oocyst shedding began between 4 and 11 days post infection. While infection in mice, gerbils, ferrets and eastern gray squirrels was asymptomatic or had mild clinical signs, Eurasian red squirrels developed severe cryptosporidiosis that resulted in host death. The rapid onset of clinical signs characterized by severe diarrhea, apathy, loss of appetite and subsequent death of the individual may explain the sporadic occurrence of this Cryptosporidium in field studies and its concurrent spread in the population of native European squirrels. Oocysts obtained from a naturally infected human, the original inoculum, were 5.64 × 5.37 µm and did not differ in size from oocysts obtained from experimentally infected hosts. Cryptosporidium chipmunk genotype I infection was localized exclusively in the cecum and anterior part of the colon. CONCLUSIONS: Based on these differences in genetics, host specificity and pathogenicity, we propose the name Cryptosporidium mortiferum n. sp. for this parasite previously known as Cryptosporidium chipmunk genotype I.
Assuntos
Cryptosporidiidae , Criptosporidiose , Cryptosporidium , Humanos , Animais , Camundongos , Cobaias , Criptosporidiose/parasitologia , Gerbillinae , Furões , Fezes/parasitologia , Galinhas , Sciuridae/parasitologia , Genótipo , Oocistos , FilogeniaRESUMO
Bergenia, a genus included in the family Saxifragaceae, is a valuable source of healing matters. About 30 Bergenia species are known all over the world. Scientific research is focused on five species mainly distributed in the mountains of Central and East Asia: Bergenia ciliata (Haw.) Sternb., Bergenia stracheyi Engl., Bergenia crassifolia (L.) Fritsch, Bergenia ligulata (Wall.) Engl. and Bergenia himalaica Boriss. These taxons belong to the widely used medicinal herbs in the traditional Chinese, Nepalese and Indian medicine, for therapy of cough and pulmonary diseases, to stop bleeding, to increase immunity and to dissolve kidney or bladder stones. Bergenia consists of many different active compounds including bergenin, norbergenin, catechin, gallic acid, arbutin and other polyphenols. In the Czech Republic this species is commonly grown but it is not used for medical therapy. Individual parts of this plant demonstrate an interesting biological activity, and antibacterial, antiviral, cytoprotective and antioxidant effects.
Assuntos
Extratos Vegetais/farmacologia , Plantas Medicinais/química , Saxifragaceae/químicaRESUMO
The effect of new synthetic pyrazinecarboxamide derivatives as potential elicitors of flavonolignan and flavonoid production in Silybum marianum and Ononis arvensis cultures in vitro was investigated. Both tested elicitors increased the production of flavonolignans in S. marianum callus and suspension cultures and flavonoids in O. arvensis callus and suspension cultures. Compound I, 5-(2-hydroxybenzoyl)-pyrazine-2-carboxamide, has shown to be an effective elicitor of flavonolignans and taxifoline production in Silybum marianum culture in vitro. The maximum content of silydianin (0.11%) in S. marianum suspension culture was induced by 24 h elicitor application in concentration of 1.159 × 10⻳ mol/L. The maximum content of silymarin complex (0.08%) in callus culture of S. marianum was induced by 168 h elicitor application of a concentration 1.159 × 10â»4 mol/L, which represents contents of silydianin (0.03%), silychristin (0.01%) and isosilybin A (0.04%) compared with control. All three tested concentrations of compound II, N-(2-bromo-3-methylphenyl)-5-tert-butylpyrazin-2-carboxamide increased the flavonoid production in callus culture of O. arvensis in a statistically significant way. The best elicitation effect of all elicitor concentrations had the weakest c3 concentration (8.36 × 10â»6 mol/L) after 168 h time of duration. The maximum content of flavonoids (about 5,900%) in suspension culture of O. arvensis was induced by 48 h application of c3 concentration (8.36 × 10â»6 mol/L).
Assuntos
Amidas , Fabaceae/química , Flavonoides/biossíntese , Flavonolignanos/biossíntese , Pirazinas , Silybum marianum/química , Amidas/química , Amidas/farmacologia , Células Cultivadas , Fabaceae/citologia , Fabaceae/metabolismo , Flavonoides/química , Flavonolignanos/química , Humanos , Silybum marianum/citologia , Silybum marianum/metabolismo , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Pirazinas/química , Pirazinas/farmacologiaRESUMO
The paper aims to specify all important active principles in the herb Genista tinctoria which exert different biological activities. It also mentions the methods of chemical evaluation of these substances.
Assuntos
Genista/química , Plantas Medicinais/química , Alcaloides/análise , Alcaloides/farmacologia , Isoflavonas/análise , Isoflavonas/farmacologiaRESUMO
In this paper we assessed: (i) the change in nitric oxide synthase (NOS) isoforms' expression and intracellular localization and in NOS mRNA in porcine oocytes during meiotic maturation; (ii) the effect of NOS inhibition by N(omega)-nitro-l-arginine methyl ester (l-NAME) and aminoguanidine (AG) on meiotic maturation of cumulus-oocyte complexes (COC) as well as denuded oocytes (DO); and (iii) nitric oxide (NO) formation in COC. All three NOS isoforms (eNOS, iNOS and nNOS) and NOS mRNA (eNOS mRNA, iNOS mRNA and nNOS mRNA) were found in both porcine oocytes and their cumulus cells except for nNOS mRNA, which was not detected in the cumulus cells. NOS isoforms differed in their intracellular localization in the oocyte: while iNOS protein was dispersed in the oocyte cytoplasm, nNOS was localized in the oocyte cytoplasm and in germinal vesicles (GV) and eNOS was present in dots in the cytoplasm, GV and was associated with meiotic spindles. l-NAME inhibitor significantly suppressed metaphase (M)I to MII transition (5.0 mM experimental group: 34.9% MI, control group: 9.5% MI) and at the highest concentration (10.0 mM) also affected GV breakdown (GVBD); in contrast also AG inhibited primarily GVBD. The majority of the oocytes (10.0 mM experimental group: 60.8%, control group: 1.2%) was not able to resume meiosis. AG significantly inhibited GVBD in DO, but l-NAME had no significant effect on the GVBD of these cells. During meiotic maturation, NO is formed in COC and the NO formed by cumulus cells is necessary for the process of GVBD.
Assuntos
Meiose , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/metabolismo , Oócitos/enzimologia , Animais , Células do Cúmulo/enzimologia , Feminino , Microscopia Confocal , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/genética , Oócitos/efeitos dos fármacos , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Mensageiro/metabolismoRESUMO
Substituted pyrazinecarboxamides markedly influenced production of flavonolignans in Silybum marianum callus and suspension cultures. In this study the effect of two compounds, N-(3-iodo-4-methylphenyl)pyrazine-2-carboxamide (1) and N-(3-iodo-4-methylphenyl)-5-tert-butyl-pyrazine-2-carboxamide (2), as abiotic elicitors on flavono-lignan production in callus culture of S. marianum was investigated. Silymarin complex compounds have hepatoprotective, anticancer and also hypocholesterolemic activity. In vitro flavonolignan concentration in cells is very low and the elicitation is one of the methods to increase production. Elicitors were tested at three concentrations and at different culture times. In the case of elicitation with 1, the greatest increase of flavonolignan and taxifoline production was observed at concentration c(1a) after 6-hours of elicitation and after 24 and 72-hours at concentration c(1b). However, increased production of silychristin, one of the compounds in the silymarin complex, was achieved after only 6-hours elicitation with c(1a) (2.95 x 10(-4) mol/L). The content of silychristin was 2-times higher compared to the control sample. An increased production of silychristin was reached with compound 2 at the concentration c(2) (2.53 x 10(-3) mol/L) after 72 h of elicitation. The production of silychristin in this case was increased 12-times compared to control.
Assuntos
Flavonolignanos/biossíntese , Pirazinas/química , Pirazinas/farmacologia , Silybum marianum/efeitos dos fármacos , Silybum marianum/metabolismo , Técnicas de Cultura de Tecidos/métodos , Flavonolignanos/análise , Flavonolignanos/química , Quercetina/análogos & derivados , Quercetina/análise , Quercetina/químicaRESUMO
BACKGROUND: Avian cryptosporidiosis is a common parasitic disease that is caused by five species, which are well characterised at the molecular and biological level, and more than 18 genotypes for which we have limited information. In this study, we determined the occurrence and molecular characteristics of Cryptosporidium spp. in farmed ostriches in the Czech Republic. METHODS: The occurrence and genetic identity of Cryptosporidium spp. were analysed by microscopy and PCR/sequencing of the small subunit rRNA, actin, HSP70 and gp60 genes. Cryptosporidium avian genotype II was examined from naturally and experimentally infected hosts and measured using differential interference contrast. The localisation of the life-cycle stages was studied by electron microscopy and histologically. Infectivity of Cryptosporidium avian genotype II for cockatiels (Nymphicus hollandicus (Kerr)), chickens (Gallus gallus f. domestica (L.)), geese (Anser anser f. domestica (L.)), SCID and BALB/c mice (Mus musculus L.) was verified. RESULTS: A total of 204 individual faecal samples were examined for Cryptosporidium spp. using differential staining and PCR/sequencing. Phylogenetic analysis of small subunit rRNA, actin, HSP70 and gp60 gene sequences showed the presence of Cryptosporidium avian genotype II (n = 7) and C. ubiquitum Fayer, Santín & Macarisin, 2010 IXa (n = 5). Only ostriches infected with Cryptosporidium avian genotype II shed oocysts that were detectable by microscopy. Oocysts were purified from a pooled sample of four birds, characterised morphometrically and used in experimental infections to determine biological characteristics. Oocysts of Cryptosporidium avian genotype II measure on average 6.13 × 5.15 µm, and are indistinguishable by size from C. baileyi Current, Upton & Haynes, 1986 and C. avium Holubová, Sak, Horcicková, Hlásková, Kvetonová, Menchaca, McEvoy & Kvác, 2016. Cryptosporidium avian genotype II was experimentally infectious for geese, chickens and cockatiels, with a prepatent period of four, seven and eight days post-infection, respectively. The infection intensity ranged from 1000 to 16,000 oocysts per gram. None of the naturally or experimentally infected birds developed clinical signs in the present study. CONCLUSIONS: The molecular and biological characteristics of Cryptosporidium avian genotype II, described here, support the establishment of a new species, Cryptosporidium ornithophilus n. sp.
Assuntos
Cryptosporidium/classificação , Struthioniformes/parasitologia , Animais , Animais Domésticos/parasitologia , Doenças das Aves/parasitologia , Aves/parasitologia , Classificação , Criptosporidiose/parasitologia , Cryptosporidium/genética , Cryptosporidium/ultraestrutura , Código de Barras de DNA Taxonômico/veterinária , Genes de Protozoários/genética , Especificidade de Hospedeiro , Estágios do Ciclo de Vida , FilogeniaRESUMO
Cryptosporidium is a genus of apicomplexan parasites that inhabit the respiratory and gastrointestinal tracts of vertebrates. Research of these parasites is limited by a lack of model hosts. This study aimed to determine the extent to which infection at the embryo stage can enhance the propagation of Cryptosporidium oocysts in chickens. Nine-day-old chicken embryos and one-day-old chickens were experimentally infected with different doses of Cryptosporidium baileyi and Cryptosporidium parvum oocysts. Post hatching, all chickens had demonstrable infections, and the infection dose had no effect on the course of infection. Chickens infected as embryos shed oocysts immediately after hatching and shed significantly more oocysts over the course of the infection than chickens infected as one-day-olds. In chickens infected as embryos, C. baileyi was found in all organs except the brain whereas, C. parvum was only found in the gastrointestinal tract and trachea. In chickens infected as one-day-olds, C. baileyi was only found in the gastrointestinal tract and trachea. Chickens infected as embryos with C. baileyi died within 16 days of hatching. All other chickens cleared the infection. Infection of chickens as embryos could be used as an effective and simple model for the propagation of C. baileyi and C. parvum.
Assuntos
Cryptosporidium parvum/crescimento & desenvolvimento , Cryptosporidium/crescimento & desenvolvimento , Técnicas de Cultura , Oocistos/crescimento & desenvolvimento , Animais , Embrião de Galinha , Galinhas , Criptosporidiose/parasitologiaRESUMO
The contents of endogenous brassinosteroids (BRs) together with various aspects of plant morphology, water management, photosynthesis and protection against cell damage were assessed in two maize genotypes that differed in their drought sensitivity. The presence of 28-norbrassinolide in rather high quantities (1-2 pg mg-1 fresh mass) in the leaves of monocot plants is reported for the first time. The intraspecific variability in the presence/content of the individual BRs in drought-stressed plants is also described for the first time. The drought-resistant genotype was characterised by a significantly higher content of total endogenous BRs (particularly typhasterol and 28-norbrassinolide) compared with the drought-sensitive genotype. On the other hand, the drought-sensitive genotype showed higher levels of 28-norcastasterone. Both genotypes also differed in the drought-induced reduction/elevation of the levels of 28-norbrassinolide, 28-norcastasterone, 28-homocastasterone and 28-homodolichosterone. The differences observed between both genotypes in the endogenous BR content are probably correlated with their different degrees of drought sensitivity, which was demonstrated at various levels of plant morphology, physiology and biochemistry.
Assuntos
Brassinosteroides/farmacologia , Secas , Fotossíntese , Reguladores de Crescimento de Plantas/farmacologia , Folhas de Planta/genética , Estresse Fisiológico , Zea mays/genética , Genótipo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Zea mays/efeitos dos fármacos , Zea mays/crescimento & desenvolvimentoRESUMO
The condensation of substituted pyrazine-2-carboxylic acid chlorides with ring-substituted anilines yielded five substituted pyrazine-2-carboxylic acid amides. Thesynthesis, and analytical, lipophilicity and biological data of the newly synthesizedcompounds are presented in this paper. The photosynthesis inhibition, antialgal activityand the effect of a series of pyrazine derivatives as abiotic elicitors on the accumulation offlavonoids in a callus culture of Ononis arvensis (L.) were investigated. The most activeinhibitor of the oxygen evolution rate in spinach chloroplasts was 6-chloro-pyrazine-2-carboxylic acid (3-iodo-4-methylphenyl)-amide (2, IC(50) = 51.0 micromol.L(-1)). The highestreduction of chlorophyll content in Chlorella vulgaris was found for 5-tert-butyl-N-(4-chloro-3-methylphenyl)-pyrazine-2-carboxamide (3, IC(50) = 44.0 micromol.L(-1)). The maximalflavonoid production (about 900%) was reached after a twelve-hour elicitation processwith 6-chloropyrazine-2-carboxylic acid (3-iodo-4-methylphenyl)-amide (2).
Assuntos
Acetamidas/síntese química , Acetamidas/farmacologia , Herbicidas/síntese química , Herbicidas/farmacologia , Acetamidas/química , Chlorella vulgaris/efeitos dos fármacos , Clorofila/metabolismo , Cloroplastos/efeitos dos fármacos , Flavonoides/metabolismo , Herbicidas/química , OxigênioRESUMO
Plant tissue cultures are a potential source of secondary metabolites. However, their production, when compared with intact plants, is usually lower. Phenylalanine, a biogenetic precursor of podophyllotoxin, was used to stimulate podophyllotoxin production in callus and suspension cultures of Juniperus virginiana L. The best phenylalanine effect on podophyllotoxin production was manifested in three-years-old callus cultures after a 21-days application of a 10 mmol/L concentration. A podophyllotoxin content of 0.15 mg/g DW was determined, which was about 400% higher in comparison with the control. The maximum content (0.48 mg/g DW) in newly derived suspension cultures (the 4' passage) was induced by 14-days application of a I mmol/L concentration; this was about 243% higher than the control. In one-year-old suspension cultures the highest podophyllotoxin content (0.56 mg/g DW) was recorded also after 14-days application of a I mmol/L concentration; this was about 211% higher than in the control cultures.
Assuntos
Juniperus/metabolismo , Podofilotoxina/biossíntese , Técnicas de Cultura de Células , Juniperus/crescimento & desenvolvimento , Fenilalanina/farmacologia , Podofilotoxina/químicaRESUMO
The total arbutin content in the leaves of all the studied Bergenia plants (B. crassifolia, B. ciliata and B. x ornata) was determined. The highest values of the arbutin content have been established for B. crassifolia (58.9 ± 0.7 mg.g-¹ DW) and B. x ornata (51.0 ± 1.21 mg.g-¹ DW), and the lowest for B. ciliata (5.9 ± 0.6 mg.g-¹ DW). Arbutin concentration in the Bergenia leaves was the lowest in spring, in the autumn, on the contrary it increased. All the tested aqueous extracts caused a dose-dependent increase in diphenolase activity of fungal tyrosinase in a similar way as arbutin. On the other hand, all the ethanol extracts inhibited the diphenolase activity of tyrosinase.
Assuntos
Arbutina/análise , Monofenol Mono-Oxigenase/análise , Extratos Vegetais/análise , Saxifragaceae/química , Folhas de Planta/química , Saxifragaceae/enzimologia , Estações do AnoRESUMO
BACKGROUND: Azorella compacta is traditionally used in the form of tea (infusion), in the Andean region of South America, to treat various chronic diseases. However, the health-promoting properties of this herbal tea have not yet been extensively explored. MATERIALS AND METHODS: The free radical scavenging activity of A. compacta infusion (ACI) was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and superoxide anion radical assays. The activation of immune cells by ACI, as determined by cell surface cluster of differentiation 69 expression, was measured by flow cytometry. The qualitative polyphenolic composition of ACI was investigated by HPLC/PDA/ESI-MS, (High-performance liquid chromatography coupled with photodiode array detection and electrospray ionization - mass spectrometry) and the total content of polyphenols was estimated by spectrophotometric methods. RESULTS: Eight polyphenols including chlorogenic acid, 6,8-di-C-hexosyl apigenin, isoorientin, orientin, dicaffeoylquinic acid, biochanin A-O-glucoside, biochanin A-O-(malonyl)-glucoside, and licoisoflavone A were tentatively identified in ACI. The total contents of phenols, flavonoids, and tannins in lyophilized ACI were 5.40 mg/100 mg ACI, 1.79 mg/100 mg ACI, and 1.76 mg/100 mg ACI, respectively. ACI, within the range of 25-400 µg/mL, scavenged DPPH and O2.- by 15-90% and 20-88%, respectively. The human natural killer (NK) cells were substantially activated by ACI, whereas T cells and granulocytes were slightly stimulated. CONCLUSION: Overall, the results demonstrate the free radical scavenging and immune-stimulating properties of ACI, and support, at least in part, its potential utilization as a functional herbal tea. for preventing chronic diseases and as a nonspecific immune stimulator during human immunosenescence. SUMMARY: The total contents of phenols, flavonoids, and tannins in Azorella compacta infusion (ACI) were 5.40 mg/100 mg ACI, 1.79 mg/100 mg ACI, and 1.76 mg/100 mg ACI, respectively.Eight polyphenols including chlorogenic acid, 6,8-di-C-hexosyl apigenin, isoorientin, orientin, dicaffeoylquinic acid, biochanin A-O-glucoside, biochanin A-O-(malonyl)-glucoside, and licoisoflavone A were tentatively identified in ACI by HPLC/PDA/ESI-MS.ACI, within the range of 25-400 µg/ml, scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH) and O2. by 15-90% and 20-88%, respectively.The human natural killer (NK) cells were substantially activated by ACI, whereas T cells and granulocytes were slightly stimulated. Abbreviations used: ESI: electrospray ionization, HPLC: high performance liquid chromatography, PDA: photodiode array detector, MS: mass spectrometry, MS/MS: tandem mass spectrometry, MW: molecular weight, m/z: mass-to-charge ratio, FITC: fluorescent isothiocyanate, PE: phycoerythrin.
RESUMO
A comparative analysis of various parameters that characterize plant morphology, growth, water status, photosynthesis, cell damage, and antioxidative and osmoprotective systems together with an iTRAQ analysis of the leaf proteome was performed in two inbred lines of maize (Zea mays L.) differing in drought susceptibility and their reciprocal F1 hybrids. The aim of this study was to dissect the parent-hybrid relationships to better understand the mechanisms of the heterotic effect and its potential association with the stress response. The results clearly showed that the four examined genotypes have completely different strategies for coping with limited water availability and that the inherent properties of the F1 hybrids, i.e. positive heterosis in morphological parameters (or, more generally, a larger plant body) becomes a distinct disadvantage when the water supply is limited. However, although a greater loss of photosynthetic efficiency was an inherent disadvantage, the precise causes and consequences of the original predisposition towards faster growth and biomass accumulation differed even between reciprocal hybrids. Both maternal and paternal parents could be imitated by their progeny in some aspects of the drought response (e.g., the absence of general protein down-regulation, changes in the levels of some carbon fixation or other photosynthetic proteins). Nevertheless, other features (e.g., dehydrin or light-harvesting protein contents, reduced chloroplast proteosynthesis) were quite unique to a particular hybrid. Our study also confirmed that the strategy for leaving stomata open even when the water supply is limited (coupled to a smaller body size and some other physiological properties), observed in one of our inbred lines, is associated with drought-resistance not only during mild drought (as we showed previously) but also during more severe drought conditions.