Identification of cytotoxic constituents of Narthecium ossifragum using bioassay-guided fractionation     

Uhlig S  Wisløff H  Petersen D 《Journal of agricultural and food chemistry》2007,55(15):6018-6026

Narthecium ossifragum, a member of the Liliaceae family, contains phytochemicals that have hepatotoxic and nephrotoxic activity in several ruminant species. 3-Methoxyfuran-2(5H)-one has previously been isolated as the principal nephrotoxin, and its toxicity has been confirmed in vivo. However, previous investigations into the nephrotoxicity of N. ossifragum both in vivo and in vitro indicate that other phytochemical factors might contribute to the nephrotoxicity of the plant. In this study, the cytotoxicity in renal tubular cells (LLC-PK1) was measured using an aqueous extract from the plant and fractions from chromatographic separation to identify the cytotoxic constituents of the extract. In an iterative process two different groups of compounds were identified as the major cytotoxic principles in LLC-PK1 cells: steroidal saponins (primarily di- and trisaccharides of sarsasapogenin) and 5-hydroxy-4-methoxyfuran-2(5H)-one. Up to a concentration of 880 microg/mL (7.7 M) 3-methoxyfuran-2(5H)-one was not cytotoxic. The cytotoxicity of the saponins was abolished upon hydrolysis, indicating that the carbohydrate moiety of the molecule is a prerequisite for toxicity on the cellular level. The results of the present study have two important implications: first, the results question the direct involvement of 3-methoxyfuran-2(5H)-one in the nephrotoxicity of N. ossifragum; second, the findings should induce future investigations into the possible role of saponins in N. ossifragum-related nephrotoxicosis observed in ruminants that graze on this plant.  相似文献   

Soil resistance to interrill erosion: Model parameterization and sensitivity   总被引：1，自引：0，他引：1  

Silvio Jos Gumiere  Yves Le Bissonnais  Damien Raclot 《CATENA》2009,77(3):274-284

Interrill erosion, which is less visible in the landscape than rill and gully erosion, may cause major sediment deposits in the lower part of cultivated fields. It is often associated with runoff resulting from sealing and crusting, and soil properties such as soil detachability or soil aggregate stability have been used to express soil resistance to interrill erosion processes, i.e., interrill erodibility. From a literature review including more than fifteen erosion models, we have identified three main methods used to measure these properties: aggregate stability and splash cup detachability, methods performed in the laboratory using only a few grams of soil, and standard plot methods that are based on field plot measurements. This difference makes the parameters involved in assessing interrill erodibility dependent upon the scale and the hydrological processes involved and difficult to compare. According to the literature, the sensitivity of actual erosion models to interrill erodibility is lower than the sensitivity to hydrological properties and rill erodibility parameters. This numerical study shows that erodibility measurements from the three major assessment methods give different results regarding the contribution of interrill erosion and show that the sensitivity of erosion modeling to interrill erodibility may in fact be greater than shown in the literature on global sensitivity analysis.  相似文献   

Genetic variability of Meloidogyne paranaensis populations and their aggressiveness to susceptible coffee genotypes          下载免费PDF全文

M. F. A. Santos  V. R. Correa  J. R. Peixoto  V. S. Mattos  J. G. P. Silva  A. W. Moita  S. M. L. Salgado  P. Castagnone‐Sereno  R. M. D. G. Carneiro 《Plant pathology》2018,67(1):193-201

Meloidogyne paranaensis is one of the most destructive root‐knot nematode (RKN) species parasitizing coffee in Brazil and in the Americas generally. The objectives of this study were to assess the genetic variability, aggressiveness and virulence of seven different M. paranaensis populations on susceptible and resistant Coffea spp. All seven RKN populations were identified by biochemical and molecular methods. Coffee seedlings were inoculated in the greenhouse, and the nematode reproduction factor was used to infer their reproduction on coffee genotypes. Phylogenetic studies showed a low genetic variability in M. paranaensis populations, regardless of the existence of three esterase phenotypes (Est P1, P2 and P2a), except for the population Est P2a from Guatemala, which is genetically different from other M. paranaensis populations from Brazil. The Est P2a and Est P2 (Herculândia, SP, Brazil) populations were the most aggressive on two susceptible C. arabica cultivars under greenhouse conditions. None of the M. paranaensis populations were virulent on resistant coffee genotypes, confirming their resistance to the seven M. paranaensis populations tested. The resistant coffee cultivars, namely Clone 14 INCAPER, Catuaí Vermelho × Amphillo MR2161 (E1 16‐5 III), Apoatã IAC 2258, Timor Hybrid UFV 408‐01 (E1 6‐6 II) and IPR 100, exhibited segregation for resistance in the ratio of 0%, 2.4%, 12%, 26% and 29%, respectively. These are promising results, because they validate resistance against several M. paranaensis populations in different Coffea spp. genetic resources, which can be used in breeding programmes or as rootstocks, such as Apoatã IAC 2258 and Clone 14 INCAPER.  相似文献   

The role of silvicultural systems and forest types in preventing soil erosion processes in mountain forests: a methodological approach using cesium-137 measurements     

Valeria Altieri  Silvio De Franco  Fabio Lombardi  Pasquale Antonio Marziliano  Giuliano Menguzzato  Paolo Porto 《Journal of Soils and Sediments》2018,18(12):3378-3387

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Morphofunctional evaluation of the testicle and the spermatogenic process of adult white-eyed parakeets (Aratinga leucophthalma MULLER, 1776) during the different seasons of the year     

Peixoto JV  Paula TA  Balarini MK  Matta SL  Santos JA  Lima CB  Peixoto GV 《Anatomia, histologia, embryologia》2012,41(4):248-255

In this experiment, testicle fragments of 14 adult White-eyed Parakeets (Aratinga leucophthalma) were evaluated as for their seasonal reproductive activities using the following quantitative parameters: average thickness of the testicular tunica albuginea, volumetric proportion of tubular and extratubular compartments, average diameter of the seminiferous tubules and corporal weight. Parameters were created for qualitative evaluations of the degree of spermatogenic development. In this experiment, all the animals were distributed into four groups, and their testicular fragments were collected during the middle of summer, fall, winter and spring. The animals were submitted to volatile general anaesthesia, and a biopsy was made by celioscopy. The fragments collected were processed histologically. The slides were prepared and later evaluated by using an optical microscope. The average seasonal values of the corporal weight increased, starting in the winter and reaching the peak during the spring. A seasonal testicle cycle was observed, because, in the spring, the testicles showed values for the quantitative and qualitative parameters of spermatic production compatible with the period of greater activity, while the opposite thing happened during the fall. Our data indicate that the parameters of sperm production may be correlated with daily light rather than with air humidity.  相似文献   

Ultrastructural and cell wall modifications during infection of <Emphasis Type="Italic">Eucalyptus viminalis</Emphasis> roots by a pathogenic <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> strain     

Maria-Isabel?Salerno  Silvio?Gianinazzi  Christine?Arnould  Vivienne?Gianinazzi-PearsonEmail author 《Journal of General Plant Pathology》2004,70(3):145-152

Fusarium species are soil-borne fungal pathogens that produce a variety of disease symptoms when attacking crop plants. The mode of root colonization of Eucalyptus viminalis seedlings by a pathogenic F. oxyporum strain (Foeu1) at the ultrastructural level and changes in cell wall pectin during host pathogen interactions are described. Root systems of E. viminalis plants were inoculated with F. oxysporum in an in vitro model system. Hyphae of F. oxysporum adhered to the outer epidermal cell walls through fibrillar material, and after penetration they spread into the internal tissues. They developed intercellularly and intracellularly in the root cortex and invaded vascular tissues. Papillae were induced, and the host plasma membrane ruptured in colonized cells, causing rapid host tissue and cell damage. Changes in distribution and occurrence of nonesterified and methyl-esterified pectins were evaluated after root colonization by F. oxysporum using two monoclonal antibodies, JIM 5 and JIM 7, respectively. Nonesterified pectin in control roots was mainly localized in the epidermal cell walls and middle lamellae in parenchymal cortex, whereas methyl-esterified pectin accumulated more in primary cell walls of the cortex and phloem. Decreases in immunodetected nonesterified and methyl-esterified pectins were associated with extensive plant tissue degradation after root colonization by the pathogenic fungus.  相似文献   

Brucella abortus INTA2, a novel strain 19 (Delta)bp26::luc (Delta)bmp18 double mutant lacking drug resistance markers   总被引：2，自引：0，他引：2  

Campos E  Cravero SL  Delgui L  Mora I  Kahn N  Arese AI  Rossetti OL 《Veterinary microbiology》2002,87(1):1-13

Brucella abortus INTA2, a novel mutant strain, was constructed by inactivation of two B. abortus S19 genes: bp26 and bmp18, with the objective of obtaining a mutant strain that could be compatible with a diagnostic test and have less residual virulence than strain 19. The double mutant was constructed by replacing a large section of the bp26 coding region with the luciferase (luc) coding gene, resulting in mutant strain B. abortus M1luc, followed by partial deletion of bmp18 coding sequence. Both genes were inactivated by allelic replacement assisted by sacB counter-selection. Luciferase expression was evaluated and confirmed that it is a valid marker in the construction of mutant strains. When B. abortus INTA2 was inoculated in BALB/c mice, significantly fewer colony forming units (CFUs) were recovered from mice spleens during initial phase of infection. No splenomegaly was observed in strain INTA2-immunized mice at any time suggesting that strain INTA2 has lost some residual virulence of the parental strain. Nevertheless, similar protection levels against virulent challenge were observed in mice immunized with strains INTA2 or S19. Although strain INTA2 would still induce O-side antibodies, it does not express BP26. This would allow differentiation of INTA2-vaccinated animals from animals infected with field strains by measuring anti-BP26 antibodies, either by an agglutination test or ELISA using BP26 as antigen. Altogether these results indicate that B. abortus INTA2 might be a promising vaccine strain against brucellosis.  相似文献   

Toxicological effects of oxyfluorfen on oxidative stress enzymes in tilapia Oreochromis niloticus     

F. Peixoto  D. Alves-Fernandes  A. Fontaínhas-Fernandes 《Pesticide biochemistry and physiology》2006,85(2):91-96

Several environmental pollutants enhance the intracellular formation of reactive oxygen species, and can lead to the damage of macromolecules and a decrease in oxidant defences levels in fish. The effects of the herbicide oxyfluorfen on the activities of antioxidant enzymes such as catalase, superoxide dismutase, glutathione reductase, and glutathione S-transferase were evaluated in freshwater fish Oreochromis niloticus. These were determined in tilapia liver exposed to sublethal concentrations (0.3 and 0.6 mg/L at 7, 14, and 21 days of exposure. This study also analyzed the effects of oxyfluorfen on the total fatty acid profile. The results showed that CAT activity was higher in tilapia exposed to oxyfluorfen at the sampling days, except at the highest concentration after 21 days. Similarly, the enhancing effect of the herbicide was observed on the GR activity. However, its effect was moderate at the highest dose. On the contrary, fish treated with oxyfluorfen at both doses displayed a decrease in the SOD activity. After 7 days of treatment at both concentrations tilapia showed a significant increase in GST levels, although the enzymatic activity decreased at 14 and 21 days of exposition when compared with the control. The major saturated fatty acids measured in tilapia liver were the palmitic acid (C16:0; 17.9%) and stearic acid (C18:0; 8.7%). The exposure to oxyfluorfen caused a significant increase of the oleic acid (C18:1), whereas the amount of nervonic acid (C24:1) increased at all sampling data. The results of the present study should be taken in account when using tilapia as an environmental indicator species in studies of xenobiotic biotransformation and biomarker response, as well as in monitoring programmes.  相似文献   

Effects of gender and temperature on oxidative stress enzymes in Nile tilapia Oreochromis niloticus exposed to paraquat     

A. Figueiredo-Fernandes  F. Peixoto  E. Rocha  M.A. Reis-Henriques 《Pesticide biochemistry and physiology》2006,85(2):97-103

Many classes of environmental pollutants can enhance the intracellular formation of reactive oxygen species, which can conduce to the damage of macromolecules and changes in oxidant defences levels in fish. In the present study it was analysed the hepatic levels of superoxide dismutase (SOD), glutathione reductase (GR), and glutathione S-transferase (GST) in males and females of Nile tilapia Oreochromis niloticus exposed to paraquat (PQ), at 17 and 27 °C. Tilapia were exposed to a sublethal concentration of PQ (0.5 mg L⁻¹) during 45 days. Condition factor and hepatosomatic index of males and females exposed to PQ were significantly higher when compared with the control group, except in females at 17 °C. SOD and GST activities were higher in males and females exposed to PQ than in the control group at 17 and 27 °C. The levels of both enzyme activities revealed that they are sex-dependent with males exposed to PQ showing higher SOD activity (5.05 ± 0.13 and 4.84 ± 0.23 U/g protein, respectively at 17 and 27 °C) than females (4.21 ± 0.07 and 3.87 ± 0.27 U/g protein, respectively at the same temperature). Similar results were observed in GST activity. A GR activity significantly higher (9.09 ± 0.44 and 7.97 ± 1.08 U/g protein at 17 and 27 °C, respectively) was observed in PQ-exposed females, but not in exposed males. Fish exposed to PQ showed higher values of SOD and GST activities than the control group at both temperatures. These results are gender-dependent, while GR activity was higher only in PQ-exposed females. No significant differences were found for SOD, GST and GR activities between fish exposed to 17 and 27 °C, although males and females showed higher values at 17 °C. In short, this work advanced new knowledge on influence of gender in same biochemical parameters in tilapia exposed to PQ and demonstrated that their effects could be observed at different temperatures.  相似文献   

Tissue composition and allometric growth of carcass of lambs Santa Inês and crossbreed with breed Dorper     

de Sousa  Marco Antonio Paula  Lima  Alyne Cristina Sodré  Araújo  Jonas Carneiro  Guimarães  Célia Maria Costa  Joele  Maria Regina Sarkis Peixoto  Borges  Iran  Daher  Luciara Celi Chaves  Silva  André Guimarães Maciel e 《Tropical animal health and production》2019,51(7):1903-1908

Tropical Animal Health and Production - This study aimed to assess the tissue composition and allometric growth of carcasses of Santa Inês and crossbred Dorper x Santa Inês lambs confined...  相似文献