Phytoremediation of Cu-contaminated vineyard soils in Brazil: A compendium of Brazilian pot studies

Vineyard soils can be contaminated by copper (Cu) due to successive applications of fungicides and organic fertilizers. Soil remediation can be addressed by altering soil properties or selecting efficient Cu-extracting cover crops tolerant to Cu toxicity. Our objectives were to synthesize the Cu-extracting efficiency by plant species tested in Brazil, classify them according to Cu resistance to toxicity, and assess the effect of soil properties on attenuating Cu toxicity. We retrieved results from 41 species and cultivars, totaling 565 observations. Freshly added Cu varied between 50 and 600 mg Cu kg-1 of soil across studies. The partition of Cu removal between the above- and below-ground portions was scaled as a logistic variable to facilitate data synthesis. The data were analyzed using the Adaboost machine learning model. Model accuracy (predicted vs. actual values) reached R2  = 0.862 after relating species, cultivar, Cu addition, clay, SOM, pH, soil test P, and Cu as features to predict the logistic target variable. Tissue Cu concentration varied between 7 and 105 mg Cu kg-1 in the shoot and between 73 and 1340 mg Cu kg-1 in the roots. Among soil properties, organic matter and soil test Cu most influenced the accuracy of the model. Phaseolus vulgaris, Brassica juncea, Ricinus communis, Hordeum vulgare, Sorghum vulgare, Cajanus cajan, Solanum lycopersicum, and Crotolaria spectabilis were the most efficient Cu-extracting cover crops, as shown by positive values of the logistic variable (shoot removal > root removal). Those Cu-tolerant plants showed differential capacity to extract Cu in the long run.

In vitro germination and reserve mobilization of Vriesea friburgensis Mez

Studies on the germination and establishment of plants are key pieces to understanding the reproductive success of plants. This work aimed to describe in vitro germination and reserve mobilization in the bromeliad Vriesea friburgensis through morphological, histochemical, and biochemical analysis. The conditions used in this study for the in vitro germination are adequate. From the third day of in vitro inoculation, a uniform germination of 98% was obtained, exhibiting a high physiological quality of the seeds and a high potential to produce seedlings (94%). There is early reserve mobilization, which began in the imbibition phase. The accumulated reserves in the endosperm cytoplasm are degraded by hydrolytic enzymes provided by the aleurone layer. It is possible that compounds in the cell walls of the endosperm contribute to a lesser extent in mobilization. Additionally, it was observed that starch accumulation in the cotyledon increases when the seedling has formed. Results from this study provide insights for future studies on ecology, seed technology, and conservation in this species. This study contributes to the limited knowledge of the dynamics of reserves during germination and seedling establishment in Bromeliaceae. To the best of our knowledge, this is the first study with this approach in the genus Vriesea.

Anatomical and histochemical characterization of seeds of Cattleya intermedia subjected to different storage conditions

Abstract Studies involving morphological and anatomical changes resulting from seed storage are rare, but relevant to ensure information related to the quality of seeds and seedlings originated from these seeds. The objectives of this work as to carry out the anatomical and histochemical characterization of seeds from the Cattleya intermedia orchid, verifying the occurrence of possible alterations coming from different temperatures and storage periods. The treatments consisted of temperatures of: 25 (± 2 °C) (room), -20 °C (freezer), -80 °C (ultra freezer) and - 196 °C (cryopreservation); and storage periods: two, four and six months. For the anatomical and histochemical analyses, scanning electron microscopy and light microscopy were performed. The following stains were employed: toluidine blue (TBO), Coomassie brilliant blue (CBB), Sudan IV and periodic acid-Schiff (PAS). The dehydration observed in the seeds was considered the main damage resulting from storage. Changes in the internal structures of the seeds were also noted, such as degeneration, mainly in seeds kept at room temperature 25 (± 2 °C), which caused a reduction in the main components of reserves. The -80 °C (ultra freezer) temperature during the two and four months period was efficient in the conservation seed of the tissues and cells, confirming the possibility of using this condition for better conservation of the seeds of this species.

Identification and characterization of SSR markers of Guadua chacoensis (Rojas) Londoño & P.M. Peterson and transferability to other bamboo species

The aim of this study was to develop simple sequence repeat (SSR) markers for genetic studies on G. chacoensis, as well as to evaluate their transferability to other bamboo species. Genomic DNA was isolated from G. chacoensis and its partial sequencing was used to find SSR loci. The obtained sequencing data were de novo assembled using the software CLC Genomics Workbench^® 8.0v. The SSR loci primers were identified and designed with the software SSRLocator. The selected markers were validated using 56 plants sampled in seven populations from southern Brazil. The markers with potential polymorphism were selected and fluorescently labeled for characterization by capillary electrophoresis. In total, 92 SSR loci were found in G. chacoensis contigs. Suitable primers were designed for 70 SSR loci, and the remaining 22 SSR loci did not have sequences for primer development. Out of 35 selected SSR markers, after PCR optimization, 10 with high polymorphism potential were characterized. These loci can be used in genetic analyses of G. chacoensis and all of them were successfully transferred to other bamboo species. Non-polymorphic loci require further tests with additional plants, from different populations, to identify possibilities of their use.

Male sterility in Bambusa tuldoides Munro

Despite their great economic importance, relatively little is known about bamboo sexual reproduction because they usually spread through rhizomes and have long intervals between flowering periods. Bambusa tuldoides is no exception; the intervals between flowering periods are about 23 years and often do not result in successful caryopsis production. The aim of the present work was to characterize Bambusa tuldoides sexual reproduction at three stages of flower development and investigate possible male sterility. Pollen was cultured onto several types of culture medium in order to encourage germination, but not a single of the thousands of observed pollen germinated under any condition. Anthers and microspores were analyzed by scanning electron microscopy, transmission electron microscopy, and optical microscopy techniques. Anther dehiscence appeared to be normal when compared to other species. In contrast, microspores began to develop abnormally starting as early as the first flower development stage: retraction of the cytoplasm and rupture of the nuclear and mitochondria membrane. As the interior machinery of the microspores degenerated, starch accumulated within numerous amyloplasts during stages two to four of flower development. The sporoderms of these microspores were similarly incomplete: though they possessed an exine, they lacked an intine. The results here obtained suggest that the non-viability of these abnormal pollen grains prevents the development of Bambusa tuldoides caryopses.

In vitro culture and acclimatization of Cattleya xanthina (Orchidaceae), an endangered orchid of the Brazilian Atlantic Rainforest

Abstract Cattleya xanthina is a Neotropical orchid endemic to the Brazilian Atlantic Rainforest, at high risk of extinction. In this paper, we investigated the effects of different culture media on C. xanthina as well as on their endogenous nitrogen status. Culture media studied: Knudson C (KC), Vacin and Went (VW), and Murashige and Skoog (MS), the latter used at two different concentration (full and half-strength; MS/2). After 180 days, plants were transferred to MS medium with different NAA and BA concentrations. In each treatment, biometric parameters were measured and the endogenous levels of photosynthetic pigments, total protein, nitrate and ammonium ions were quantified. Plants grown on KC medium had the lowest concentration of nitrogen but exhibited the greatest shoot development, production of photosynthetic pigments and total protein. Results of growth regulators showed that the highest concentration of auxin stimulated root development and the production of photosynthetic pigments, and that a higher concentration of cytokinin promoted protein synthesis and the development of shoots. Most successful acclimatization was obtained when a mixture of Sphagnum and Pinus bark was used as the substrate.

Fertilidade e análise de reservas em gemas das videiras ‘Greco di Tufo’, ‘Coda di Volpe’ e ‘Viognier’ cultivadas em São Joaquim – Santa Catarina

Resumo: Avaliaram-se fertilidade, teores de carboidratos solúveis totais e amido em gemas dormentes das viníferas ‘Greco di Tufo’, ‘Coda di Volpe’ e ‘Viognier’ em vinhedo localizado no município de São Joaquim, SC, no ano de 2013. A partir de ramos de ano em dormência profunda, as gemas foram observadas em três posições: gemas basais (1a à 3a gema), gemas medianas (4a à 6a gema) e gemas apicais (7a à 10a gema). A presença ou ausência de inflorescência foi avaliada pela brotação das gemas em câmara do tipo BOD. Em campo, as variedades foram avaliadas quanto aos sistemas de poda, em poda curta sob cordão esporonado e poda mista em guyot. As variedades Greco di Tufo e Coda di Volpe exibiram maior número de gemas férteis nos ramos em posições medianas e apicais. Foram observadas em BOD 79,2% e 75,0% de gemas férteis na posição apical dos ramos para as variedades Greco di Tufo e Coda di Volpe respectivamente. Os maiores teores de carboidratos solúveis totais foram encontrados para as três variedades nas gemas basais. Foram observadas variações entre variedades quanto ao teor de amido nas gemas em diferentes posições nos ramos.  

Histodifferentiation and ultrastructure of nodular cultures from seeds of Vriesea friburgensis Mez var. paludosa (L.B. Smith) L.B. Smith and leaf explants of Vriesea reitzii Leme & A. Costa (Bromeliaceae)

Micropropagation via induction, multiplication and development of nodular cultures (NCs) is an efficient regeneration system for Bromeliaceae, a family of endangered monocot plants with ornamental value. Therefore, the present work aimed to induce NCs from seeds and leaf explants of Vriesea in order to characterize the morphological and histochemical aspects of induction and formation of these cultures. Seeds of Vriesea friburgensis var. paludosa were sterilized and inoculated into liquid culture media supplemented with different concentrations and combinations of growth regulators. Leaf explants of Vriesea reitzii were inoculated into medium supplemented with 4 μM α-naphthalene acetic acid (NAA) and 2 μM 6-benzylaminopurine (BAP). The addition of NAA (4 μM) in the culture medium used for seeds led to an induction rate of 72% in NCs. First, the embryo began to germinate, and afterwards, nodular structures started to form. While NCs formed from seeds is associated with root and shoot meristems, the formation of NCs from leaf explants involves the intercalary meristem. Meristematic cells generate an appropriate response in the induction medium, producing NCs by the proliferation of small cells with meristematic characteristics and large vacuolated cells. These results provide a better understanding of morphogenetic responses in bromeliads and, hence, the opportunity to develop optimized micropropagation protocols.

Abbreviations: BAP, 6-benzylaminopurine; 2-iP, N6 (2-isopentyl) adenine; CBB, Coomassie Brilliant Blue; CLSM, confocal laser scanning microscopy; MSB, MS basal medium; NAA, α-Naphthalene acetic acid; NCs, nodular cultures; PAS, Periodic Acid-Schiff; SEM, scanning electron microscopy; TDZ, N-phenyl-N’-1,2,3-thidiazol-5-ylurea; TB-O, Toluidine Blue O; TEM, Transmission electron microscopy.

Seasonality and hydrodistillation time effects on the yield and chemical composition of leaves essential oil of Piper mikanianum (Kunth) Steudel

Piper mikanianum from Santa Catarina, southern Brazil, is a well known source of safrole, an arylpropanoid precursor of several bioactive molecules. This work determined the seasonal and hydrodistillation time influence on the essential oil (EO) yield and composition. Dehydrated leaves were hydrodistilled with and without fractioning during a total period of 240 min. The EO yields varied from 0.66-0.84% with the highest values been observed during spring and summer seasons. The highest concentration of safrole was found in the winter oil (81%). In the fractioning experiments the concentration of safrole varied from 75-80% in F1 (oil distilled during 60 min) and 42-64% in F2 (oil distilled between 60-240 min).

Micropropagation systems of Feijoa (Acca sellowiana (O. Berg) Burret)

Acca sellowiana (O. Berg) Burret sin. Feijoa sellowiana (Myrtaceae) is a semiwoody fruit species native to South Brazil, Uruguay, and Argentina; edible fruits are tasty. The naturally occurring populations in Santa Catarina State show high variability in fruit size, color, and other features. A breeding program launched in 1990 resulted in the release of four Brazilian commercial varieties. The conventional clonal propagation methods of this species, such as cutting and grafting, have shown low efficiency. Therefore, tissue culture techniques were developed for mass propagation. This chapter describes several protocols based on organogenesis and somatic embryogenesis. Additional techniques including synthetic seed technology and temporary immersion system are also described.

5-Azacytidine combined with 2,4-D improves somatic embryogenesis of Acca sellowiana (O. Berg) Burret by means of changes in global DNA methylation levels

DNA methylation is an epigenetic regulatory mechanism of gene expression which can be associated with developmental phases and in vitro morphogenetic competence in plants. The present work evaluated the effects of 5-azacytidine (AzaC) and 2,4-dichlorophenoxyacetic acid (2,4-D) on Acca sellowiana somatic embryogenesis (SE) and global DNA methylation levels by high-performance liquid chromatography mass spectrometry (HPLC/MS/MS). 2,4-D-free treatments revealed no somatic embryo formation in both accessions tested. Treatments supplemented with 2,4-D pulse plus AzaC in the culture medium resulted in increased embryo formation. In AzaC-free treatment, HPLC/MS/MS analysis showed a gradual increase in methylation levels in cultures of both accessions tested during SE induction. Treatment with AzaC and 2,4-D-free resulted in a marked decrease in methylation for both accessions, ranging from 37.6 to 20.8 %. In treatment with 2,4-D and AzaC combined, the 85 accession showed increasing global methylation levels. Otherwise, the 101X458 accession, in the same treatment, showed a decrease between 10 and 20 days, followed by an increase after 30 days (39.5, 36.2 and 41.6 %). These results indicate that 2,4-D pulse combined with AzaC improves SE induction. However, the conversion phase showed that although positively influencing SE induction, AzaC had a dysregulatory effect on the stage of autotrophic plant formation, resulting in significantly lower conversion rates. The results suggest that DNA methylation dramatically influences SE in Acca sellowiana, and global DNA methylation dynamics are related to morphogenetic response.

KEY MESSAGE

5-Azacytidine combined with 2,4-D increases the number of Acca sellowiana somatic embryos. Global DNA methylation is directly affected by these compounds.

Dark-induced hormone changes coincide with the resumption of light-inhibited shoot growth in Catasetum fimbriatum (Orchidaceae)

Catasetum fimbriatum plants cultivated in the absence of light exhibit continuous shoot growth leading to the formation of nodes and internodes. On the other hand, when these plants are incubated in the presence of light, shoot longitudinal growth is inhibited and pseudobulbs develop just below the shoot apical meristem. These facts provide evidence of a possible influence of light on mitotic cell division in the shoot apex as well as on pseudobulb initiation. The effects of light and dark on the interruption and/or maintenance of shoot apex mitotic activity and the subsequent formation of pseudobulbs in the sub-meristematic regions were investigated by means of histological and hormonal studies. The interruption of shoot apex development occurred around the 150th d of light incubation and seems to have resulted from the establishment of a strong storage sink in the region of the future pseudobulb, in detriment to the continuous activity of the shoot apical meristem. The reduced total cytokinins/IAA ratio in the apex, mainly due to high levels of IAA, could be a key factor in the interruption of cell divisions. Transfer to the dark brings about the resumption of shoot apex development of plants through the re-entrance of cells in the cell cycle which coincides with a significant increase in the total cytokinins/IAA ratio.

The role of γ -aminobutyric acid (Gaba) in somatic embryogenesis of Acca sellowiana Berg. (Myrtaceae)

The γ-aminobutyric acid (Gaba) is a non-protein amino acid found in prokaryotes and eukaryotes. Its role in plant development has not been fully established. This study reports a quantification of the levels of endogenous Gaba, as well as investigation of its role in different stages of somatic embryogenesis in Acca sellowiana Berg. (Myrtaceae). Zygotic embryos were used as explants and they were inoculated into the culture medium contained different concentrations of Gaba (0,2, 4, 6, 8 and 10 µM). The highest concentrations of endogenous Gaba were detected between the third and nine days after inoculation, reaching the value of 12.77 µmol.g-1FW. High frequency of somatic embryogenesis was observed in response to 10 µM Gaba. This treatment also resulted in a large number of normal embryos, and the lowest percentage of formation of fused somatic embryos, phenotypic characteristic of most deformed embryos in all treatments. Also, all treatments promoted the formation of the somatic embryos with positive characteristics of development resumption, which however did not originate the seedlings.

The effect of arbuscular mycorrhizal fungal isolates on the development and oleoresin production of micropropagated Zingiber officinale

We have investigated the effects of phosphate fertilization and inoculation with isolates of arbuscular mycorrhizal fungi Scutellospora heterogama SCT120E, Gigaspora decipiens SCT304A, Acaulospora koskei SCT400A, Entrophospora colombiana SCT115, and an assemblage (Mix) of all four isolates on growth, development and oleoresin production of micropropagated Zingiber officinale. After 120 and 210 d of growth, the Mix and phosphorus addition significantly increased shoot height relative to control plants. Phosphorus addition was the only treatment resulting in significantly large shoot dry biomass relative to control after 120 d. No statistical differences were observed between treatments for shoot dry biomass after 210 d and for fine and coarse root biomass at both harvests. Inoculation with S. herogama and G. decipiens resulted in larger yields of oleoresin, corresponding to 3.48% and 1.58% of rhizome fresh biomass respectively. Based on retention index and mass spectrometry, we have characterized the following constituents present in ginger rhizomes: ar-curcumene, zingiberene, γ-cadinene, bisabolene, δ- or α-cadinene and farnesol. Two other constituents were characterized as possible members of the gingerol class. Results suggest that the screening and inoculation of arbuscular mycorrhizal fungi in ginger plants is a feasible procedure to increase the oleoresin production of Z. officinale and consequently increase the aggregate value of ginger rhizome production.

Thidiazuron influences the endogenous levels of cytokinins and IAA during the flowering of isolated shoots of Dendrobium

This study reports the effects of thidiazuron (TDZ) on the endogenous levels of indoleacetic acid (IAA), zeatin, zeatin riboside ([9R]Z), isopentenyladenine and isopentenyladenosine ([9R]iP) as well as structural changes in the apical meristem of Dendrobium Second Love shoots during flower induction and initial development in vitro. The results revealed that the presence of 1.8microM TDZ had a profound effect on the endogenous cytokinins (CKs) and IAA levels of the explants, when compared to those grown on a TDZ-free medium. A significant increase in CKs (especially [9R]iP and [9R]Z) and IAA in the first samples (taken at day 5) grown on TDZ-enriched medium was associated with flower induction, while a second increase in the level of these hormones after 25d of culture was related to flower development. The histological changes detected in the shoot apical meristem of explants grown in the presence of 1.8microM TDZ during 30d of culture are also described. Based on these findings, it is suggested that both auxin and CKs seem to be involved with the floral transition of Dendrobium Second Love in vitro. However, a possible direct effect of TDZ on flower formation is not discarded.

Antithrombin activity of an algal polysaccharide

In an effort to reduce the risks of a possible iatrogenic transmission of bovine spongiform encephalitis (BSE) through the use of bovine-derived medicinal products, we patented in the USA in 1999 a polysaccharide from brown algae, endowed with interesting pharmacological activities: (a) concentration-dependent inhibition of thromboplastin or cephalin-kaolin-induced thrombin generation from platelets, (b) concentration-dependent inhibition of thrombin-induced platelet aggregation, (c) thrombin has hypotensive effect, which was blunted and zeroed by our fucansulfate in a dose-dependent way, (d) when aortae are stimulated with thrombin, they become stickier for polymorphonucleated leukocytes (PMNs); our fucansulfate decreased concentration-dependently, PMNs sticking to autologous rabbit aortae, (e) dose-dependent inhibition of thrombin-induced thrombosis. All the above data suggest that our fucansulfate could be a heparin substitute endowed with antithrombotic and anti-inflammatory activities, devoid or the problems caused to heparin by its animal origin, i.e., possible prion protein contamination.

Defibrotide normalizes cardiovascular function hampered by established atherosclerosis in the rabbit

In a previous paper we gave evidence that chronic oral defibrotide antagonizes the noxious effect of developing atherosclerosis in the cardiovascular system. In the present paper we give evidence that defibrotide is still capable of exerting beneficial effects on cardiovascular function once atherosclerosis is established. In fact, there was statistically significant amelioration by defibrotide infusion in the following, all of which were hampered by established atherosclerosis: in rabbit aorta relaxation to acetylcholine, prostaglandin E2, and 6-keto-prostaglandin F1alpha generation from rabbit aortas, rabbit heart left ventricular end-diastolic pressure, coronary perfusion pressure, and left ventricular developed pressure, vasopressor activity of acetylcholine and endothelin-1 on coronary perfusion pressure, and 6-keto-prostaglandin F1alpha generation from the rabbit heart. Since prostacyclin takes part in NO generation, is cellular protective, and inhibits 5-lipoxygenase product synthesis, its increase, caused by defibrotide, could explain defibrotide cardioprotective activity. Prostacyclin activity could be backed by prostaglandin E2, another cardioprotective prostaglandin.

Chronic oral defibrotide counteracts hypercholesterolemia noxious effects on cardiovascular function in the rabbit

The aim of the present work was to assess if the cardioprotective drug defibrotide could counteract the hypercholesterolemia noxious effects on cardiovascular function. Aortas and hearts from normal- or cholesterol-fed rabbits, treated or not with chronic oral defibrotide (100 mg/kg/day) for 45 days, were used in in vitro tests throughout the experiment. Hypercholesterolemia worsened: aorta stickiness toward polymorphonuclear leukocytes, aorta relaxation to acetylcholine, heart left ventricular end-diastolic pressure and coronary perfusion pressure, heart left ventricular diastolic pressure, acetylcholine and endothelin-1 activity on coronary perfusion pressure, and heart generation of 6-Keto-prostaglandin F1alpha. Oral defibrotide counteracted and/or obliterated the above hypercholesterolemia noxious effects. Particularly, oral defibrotide counteracted the parameters associated with early endothelial cell disfunction: that is, increased adherence of leukocytes to endothelium and endothelial vasorelaxation induced by acetylcholine, which acts through the release of endothelium-derived relaxing factor. These activities of defibrotide are probably exerted through the increased generation of prostacyclin. The fact that acetylcholine induced vasorelaxation is partially protected by oral defibrotide points to a partial rescue of endothelial ability to generate endothelium-derived relaxing factor, as acethylcoline acts through the release of endothelium-derived relaxing factor, by defibrotide itself. Defibrotide's endothelial protection could, in turn, explains why defibrotide protected cardiovascular function. This is not surprising as, in a few cases, endothelial dysfunction, observed in hypercholesterolemia, was found to be prevented or reversed, pharmacologically, by PN-2001-10, a calcium channel blocker, dipyridamole, and lovastatin.

Pharmacokinetics, absorption, distribution and disposition of [125I]-oligotide following intravenous or oral administration in the rat

Oligotide (O) was labelled with 125I. The radiolabelled compound ([125I]-Oligotide ([125I]-O)) retained the biological activity of parent O. Following single intravenous administration the half lives of radioactivity associated with O and/or O related components in plasma were 9-10 min and 9-10 h for alpha and beta phases respectively. Following single oral administration the half life of radioactivity associated with O and/or O related components in plasma was 11.45-12.76 h for beta fase. Following multiple oral administration once daily for 7 days, the half life of radioactivity associated with O and/or O related components following the 7th dose was 10-12 h for beta phase. The areas under plasma total radioactivity versus time curves were dose-dependent. Following single intravenous administration the major proportion of the administered dose was excreted via urine, while following single oral administration excretion via urine and faeces accounted for similar proportions of the administered dose. Following both single and oral administration the levels of radioactive components derived from [125I]-O in organs examined were generally highest in highly perfused organs.

Study on pharmacokinetics of radioactive labelled defibrotide after oral or intravenous administration in rats

Defibrotide (D) was labelled with 125I or with 32P. The radiolabelled compounds ([125I]-Defibrotide ([125I]-D), [32P]-Defibrotide ([32P]-D) retained the same profibrinolytic activity, in vitro, as the parent drug, suggesting that the labelling procedures had not modified the pharmacological properties of D and hence that its chemical structure was not affected significantly. After single intravenous or oral administration of [125I]-D or [32P]-D the pharmacokinetic parameters for the two labels were generally in good agreement (75%). t 1/2 alpha was in the range of minutes while t 1/2 beta was in the range of hours. Bioavailability, following single oral administration of [125I]-D or [32P]-D, was in the range of 58-70%. These data suggest that D, in spite of its macromolecular nature, is absorbed, after oral administration, fairly well.

Is defibrotide's activity on leukocytes adenosine-receptor mediated? An "in vitro"--"ex vivo" appraisal

Defibrotide both "in vitro" and "ex vivo" decreases PMN adhesion to nylon columns. This activity is blunted by 8-phenyltheophylline, a known blocker of adenosine A1/A2 receptors, suggesting that Defibrotide acts on that kind of receptors. Indomethacin, a blocker of PGI2 synthesis, did not cancel DFT's activity, suggesting that PGI2 is not involved in DFT's activity, at least under our experimental conditions. Non-PMN leukocytes behaved differently "ex vivo" than PMNs. DFT's activity was not blunted by 8-phenyltheophylline, suggesting that DFT acts on this kind of cell through a different mechanism. The "in vitro" experiment did not confirm "ex vivo" studies suggesting that in the "in vitro" experiment "something" is missing that is present in "ex vivo" experiments.

Effect of chronic administration of hydrocortisone on the induction and evolution of acute pancreatitis induced by cerulein

The effects of chronic administration of hydrocortisone (10 mg/kg/day) on the development and evolution of acute pancreatitis induced by supramaximal stimulation with cerulein were examined in the rat. In these circumstances the potentially therapeutic effect of L-364,718, a CCK-receptor antagonist, was assayed. Administration of hydrocortisone over 7 days did not increase the severity of edematous acute pancreatitis induced by cerulein, since the reduction in pancreatic secretion, the hyperamylasemia and the increase in the levels of hematocrit and fluid in the pancreatic tissue were similar in rats with acute pancreatitis treated and untreated with hydrocortisone previously. When hydrocortisone was administered chronically, before administration of supramaximal doses of cerulein, a spontaneous regression of acute pancreatitis occurred. However, when hydrocortisone administration was continued after inducing pancreatitis, pancreatic recovery was prevented, observing a significantly depressed acinar secretion and elevated values of hematocrit and tissue fluid (edema). L-364,718 administration proved to be detrimental in the evolution of edematous acute pancreatitis when the rats had been treated chronically with hydrocortisone because the blockade exerted on secretion prevented the draining of enzymes stored in excess by hydrocortisone administration.

Effects of defibrotide on leukocytosis in rabbits with diet-induced atherosclerosis

The antithrombotic drug Defibrotide (DFT) (a polydeoxyribonucleotide with a mean MW of 20,000 Daltons) reduces the number of leukocytes and platelets in thrombi. Because leukocytes and platelets are of importance in the genesis of endothelial lesions leading to atherosclerosis, DFT was given to challenge leukocytosis in rabbits with diet-induced atherosclerosis (0.25% cholesterol for 16 weeks). After 9 weeks of cholesterol feeding and at the end of experiment, oral DFT (60 mg/Kg per day) had decreased the leukocyte count raised by the cholesterol diet. Leukocyte stickiness and leukocyte differential counts were not modified by either oral cholesterol or by oral cholesterol plus oral DFT. At the end of experiment, oral DFT had normalized the platelet count increased by cholesterol diet. The red blood cell count decreased by oral cholesterol at 9 weeks and at the end of experiment was normalized by DFT. The % of aortae endothelial surface involved in the atherosclerotic process was decreased by oral DFT. The frequencies of intimal thickening in blood vessels of kidneys and hearts and in cardiac valves were reduced by oral DFT by 47%, 29% and 17%, although these reductions were not statistically significant. It is suggested that DFT, by preventing the increase in the number of leukocytes and platelets and deactivating them, as demonstrated in papers already published, was able to counteract against the atherosclerotic process.

Oligotide, a new single-stranded oligodeoxyribonucleotide, preserves postsynaptic beta-adrenergic and cholinergic receptor functions in rabbit hearts after acute infarction

Acute myocardial infarction was induced in New Zealand male albino rabbits. 3 days after surgery, the mortality rate and plasma CPK activity were reduced by 64% and 66% respectively by intravenous infusion of Oligotide (32 mg/kg/h for 6h), a single-stranded oligodeoxyribonucleotide of mammalian origin. Perfused hearts, obtained from Oligotide-treated rabbits 3 days after surgery, showed a strength of contraction in the range of that of hearts of sham-operated animals and an ameliorated postsynaptic beta-adrenergic and cholinergic receptor function. In addition, in these hearts, "ex vivo" treatment with Oligotide resulted in almost complete preservation of both adrenergic and cholinergic responses to their specific agonists. These data suggest that Oligotide by protecting the hearts from the ischemic damage and possibly by restricting left ventricular tissue necrosis may have normalized the biological responses of this organ to isoproterenol and preserved the integrity of coronary endothelial-dependent relaxant function.

Action of CCK on CDE diet-induced acute pancreatitis in rats treated with hydrocortisone

The present work studies the effect of previous hydrocortisone administration (10 mg/kg/day) over 7 days on the later development of diet-induced acute pancreatitis in the rat. Acute pancreatitis was induced by feeding a diet deficient in choline and supplemented with 0.5% ethionine (CDE diet) over 10 days. Hydrocortisone pretreatment exacerbated CDE-induced acute pancreatitis. There was a significant increase in serum amylase, pancreatic edema, and haematocrit levels and an insignificant decrease in pancreatic mass in rats pretreated with hydrocortisone. Pancreatic enzyme secretion was strongly reduced in the rats subjected to acute pancreatitis, and although the drop in enzyme levels did not reach statistical significance, the values of secretion were even further reduced in the animals treated with hydrocortisone, pointing to the absence of pancreatic functionality. This effect can be attributed to enzyme storage elicited by previous hydrocortisone administration; activated intracellularly, these enzymes could aggravate the pathology. Administration of the cholecystokinin octapeptide (CCK-8) (10 micrograms/kg/day) during the development of acute pancreatitis in animals pretreated with hydrocortisone substantially improved the general state of the animals' pancreases. There was a significant decrease in serum amylase, pancreatic edema and haematocrit levels in rats injected with CCK, which was accompanied by an increase in pancreatic functionality. Conversely, the administration of L-364,718 (0.1 mg/kg/day), a CCK antagonist, did not improve pancreatic functionality and did not appreciably affect the general state of the organ. It is concluded that in rats with storage levels increased by hydrocortisone administration that are subjected to acute pancreatitis, the secretagogue effect of CCK is more beneficial than the repose of the gland induced by L-364,718.(ABSTRACT TRUNCATED AT 250 WORDS)

Defibrotide's activity on leukocytes and platelets in rabbits with diet-induced atherosclerosis

Oral Defibrotide decreased leukocyte and platelet counts, raised by cholesterol diet, and the area (%) of aorta endothelial surface involved in atherosclerosis. Frequency of intimal thickening in blood vessels of kidneys and hearts and in cardiac valves was reduced by oral Defibrotide by 47%, 29% and 17%. It is suggested that oral Defibrotide reduced the involvement of the aorta in the atherosclerotic process by acting on leukocytes and platelets, to both reduce their number and deactivate them.

Human pharmacokinetics of glycosaminoglycans using deuterium-labeled and unlabeled substances: evidence for oral absorption

In the present study, the pharmacokinetics of extractive GAGs used as therapeutic agents have been studied after intravenous and oral administration on volunteers. The use of native or deuterium-labeled compounds, followed by HPLC/MS detection, allowed the quantitation of exogenous heparin and DS as major disaccharide fragments, obtained either by enzymatic or chemical depolymerization. In particular the high level of labeling reached in DS allowed its differentiation from structurally related endogenous species. The estimated plasmatic bioavailability was about 18% for DS. Notwithstanding the impossibility of evaluating the same parameters for heparin species, due to the interferences of endogenous GAGs, the results obtained provided clear evidence of oral availability of heparin and DS through detection and quantitation of structures specifically related to these GAGs. Due to the selectivity of the lyases used, the enzymatic degradation specifically allowed the detection of both DS and heparin species still retaining the original sulfation pattern. Additionally, the chemical degradation could detect the main metabolites of the drugs, consisting of partially to totally desulfated GAGs showing a more or less marked reduction in their molecular weight.

Comparable beneficial effects of defibrotide and nifedipine in calcium induced atherosclerosis

The present study demonstrates the antiatherosclerotic property of Defibrotide (DFT) in an experimental model in which the pathology is secondary to calcium deposition in the vessel wall and various organs. Rats were treated by gavage for 21 consecutive days with Vitamin D3 and/or, twice a day, with DFT or Nifedipine (N). The calcium contents of aorta, heart and kidney were determined by atomic absorption spectrometry. Specimens of these tissues were examined histologically. DFT or N administered alone did not modify the calcium contents of aorta, heart or kidney. On the contrary, Vitamin D3 caused a huge increase in the calcium concentration in the aorta and in the kidney, whereas the heart content was only double that of control animals. In rats treated with Vitamin D3, contemporaneous administration of DFT or N sharply and highly significantly reduced the aorta calcium concentration and there were less striking, although still significant, reductions in the other two tissues. Histological examination paralleled these data; the effect of DFT or N in reducing the mineralization of aorta and heart was very evident, and more pronounced for DFT. These results confirm that DFT, even though not belonging to the class of the calcium antagonists, has comparable antiatherosclerotic properties, possibly due to its endothelial protective efficacy, as evidenced by the lesser amount of calcium in the aortic tissue.

Pharmacokinetics, absorption, distribution and disposition of [125I]-defibrotide following intravenous or oral administration in the rat

Defibrotide (D) was labelled with 125I. The radiolabelled compound ([125I]-Defibrotide ([125I]-D)) retained the same profibrinolytic activity as the parent drug. Following single intravenous administration of [125I]-D the half lives of radioactivity associated with D components in plasma were 9.45 min and 11.27 h for alpha and beta phases respectively. Following single oral administration of [125I]-D the half life of radioactivity associated with D components in plasma was 12.83 h for the elimination phase. Bioavailability was apparently 58%. The areas under plasma total radioactivity versus time curves were dose-dependent following both intravenous and oral administration. No significant accumulation of total radioactivity in plasma was observed following multiple oral administration of [125I]-D. Following single intravenous administration of [125I]-D a larger proportion of administered radioactivity was excreted via urine than faeces while following single oral administration excretion via urine and faeces accounted for similar proportions of administered radioactivity. Following both single and oral administration the levels of total radioactivity in tissues and organs examined were generally highest in highly perfused organs and were very high in the thyroid despite pretreatment with non-radiolabelled potassium iodide. Radioactivity was also found to be associated with the aorta wall.

High-performance liquid chromatography determination of polydeoxyribonucleotides in plasma: its application to the determination of defibrotide's pharmacokinetics in the rabbit

We describe an HPLC method for the determination of whole polydeoxyribonucleotides in animal plasma. This method was compared to a colorimetric method, which evaluates the sugar moiety of polydeoxyribonucleotides, and to an agarose gel electrophoresis method, which evaluates the whole polydeoxyribonucleotides as does the HPLC method, and was found to give results very close to those obtained with these two other methods. A pharmacokinetic study of the antithrombotic, profibrinolytic, polydeoxyribonucleotidic drug defibrotide was carried out by evaluating the plasma drug levels by these three methods. The pharmacokinetic parameters calculated from the data are very similar.

A novel insight into the mechanism of the antithrombotic action of defibrotide

Defibrotide is a polydeoxyribonucleotide sodium salt with antithrombotic properties. These properties have been attributed to its profibrinolytic activity [increase of tissue plasminogen activator (t-PA) activity, concomitant decrease of that of plasminogen activator inhibitor (PAI)], but there could conceivably be other factor(s). To look for these, we studied Defibrotide in a thrombosis model (pulmonary thromboembolism in mice) in which free radicals play a pivotal role. Defibrotide was found to be active after both intravenous and oral administration. Defibrotide behaved in vitro like a scavenger of H2O2 but not of O2.- in cell-free systems. Defibrotide added in vitro to cellular systems decreased the stimulated release of beta-glucuronidase from polymorphonuclear cells (PMNs), the luminol chemiluminescence induced by oxygen species generated by stimulated PMNs and the generation of O2.- from stimulated macrophages. We think that the antithrombotic activity of Defibrotide is based on other factor(s) in addition to profibrinolytic activity, i.e., some scavenger activity and desensitization of cells involved in thrombus formation must also be taken into account.

Novel beneficial mechanisms of defibrotide, a prostacyclin enhancing agent in splanchnic artery occlusion and reperfusion in rats

To further clarify the protective mechanism(s) of defibrotide in splanchnic artery occlusion (SAO) shock, we observed the effect of defibrotide on polymorphonuclear leukocyte (PMN) accumulation in the intestinal tissue, gastric lysosomal hydrolases and endothelial function of the ischemia-reperfused superior mesenteric artery (SMA). Pentobarbital anesthetized rats were subjected to occlusion of both the celiac and superior mesenteric arteries for 90 min followed by 2 h reperfusion. The rats receiving only the vehicle for defibrotide exhibited a marked increase in intestinal myeloperoxidase (MPO) activity and a significant endothelial dysfunction manifested by the loss of endothelium-dependent vasorelaxation. Only 2 of 6 rats (33%) survived 2 h of reperfusion. In contrast, those rats treated with defibrotide exhibited significantly attenuated PMN accumulation in intestinal tissue, enhanced endothelium-dependent vasorelaxation in SMA rings, prolonged survival time and increased survival rate to 6 of 7 (i.e., 86%). However, addition of defibrotide in vitro had no direct effect on LTB4 activated PMN adherence to vascular endothelium. Moreover, defibrotide preserved gastric lysosomal membranes in vitro. These results indicate that the protective effect of intravenous administration of defibrotide on SAO shock may be related to its endothelial preserving effect reducing PMN adherence and protection of endothelial and lysosomal membrane integrity.

Absorption through the peritoneum of the macromolecular profibrinolytic drug defibrotide in the rabbit

Defibrotide is the sodium salt of a polydeoxyribonucleotide extracted from mammalian lungs by controlled depolymerization. This macromolecular compound (mean molecular weight 20,000 d) has profibrinolytic activity. It also is antithrombotic after both intravenous and oral administration. The purpose of this study was to see whether defibrotide could activate the fibrinolytic system after intraperitoneal administration, because it has been observed that in ascitic patients treated intraperitoneally with defibrotide, no occlusion of the peritoneal-jugular catheter valve draining the ascitic fluid (according to LeVeen et al.) occurred. The profibrinolytic activity of defibrotide and its plasma levels were dose dependent, with a statistically significant correlation between the fibrinolytic activities and the AUC of the plasma levels of defibrotide. No rebound effect was observed during the duration of the experiments (24 hours). We hypothesize that the fibrinolytic activity elicited by defibrotide prevented the deposition of fibrin in the catheter valve, enabling normal drainage of the ascitic fluid. The lack of rebound makes defibrotide a safe drug. The mechanism by which this macromolecular compound is absorbed is still unknown.

7-Substituted theophyllines. Part VI--N-[2-(4-chlorophenoxy)-1-phenyl-alkyl]-alkylamido derivatives

The new amides are inhibitors of cholesterol biosynthesis in vitro as well as in vivo. These compounds are also inhibitors in vivo of triglyceride biosynthesis and of platelet aggregation. All tests showed activity (values expressed as percentage variation) much greater than clofibrate. Besides, all compounds have no effect on coagulation or diuresis and showed low acute toxicity.

Defibrotide affects the anticoagulant and lipase-releasing activities of heparin

Defibrotide (DEF), an antithrombotic drug with no anticoagulant activity, given concomitantly with heparin potentiates its effects on thrombin time and lipase-releasing activity. Unlike heparin, DEF has hardly any lipase-releasing activity of its own. Most likely DEF interferes with pharmacokinetics of heparin. It is clear from the data reported here that when used in combination with DEF heparin should be administered at low doses and the coagulation parameters carefully followed.

Thrombolytic activity of defibrotide against old venous thrombi

The age of the thrombus is probably a very important determinant of the outcome of thrombolysis. The clinical potential for rapidly dissolving thrombi by thrombolytic therapy is considerable because restoration of the blood flow can rescue the jeopardized district served by the occluded vessel such as for myocardial infarction, deep vein thrombosis, arterial thrombosis, pulmonary embolism, and occlusion of retinal vessels. Defibrotide was effective against 3-, 7-, or 10-day-old thrombi; its ED50s were 32, 65, or 118 mg/kg-1 hour-1, respectively, suggesting that the age of the thrombus could play a role in the outcome of thrombolysis. A similar pattern was also shown for urokinase.

Profibrinolytic activities of chemically modified heparins with very low anticoagulant activities

Many evidences indicate that heparin is an activator of fibrinolysis, but the most important side effect of heparin is bleeding which is a problem particularly in the high risk patient. Here we describe how chemical modifications, associated with separation techniques, can sharply reduce the anticoagulant activities of a heparin while its ability to stimulate fibrinolysis is retained.

Amides of beta-(4-chlorophenoxy)-alpha-phenyl-ethylamines are inhibitors of cholesterol biosynthesis in vitro

Amides of beta-(4-chlorophenoxy)-alpha-phenyl-ethylamines were prepared and tested for their inhibitory activity on cholesterol biosynthesis in vitro. Among the substances prepared, (II e), (II g), (II k) and (II m) had much greater inhibitory activity than clofibrate.

Defibrotide decreases cholesterol amount in hypercholesterolemic rabbit aorta, with no modification of plasma or lipoprotein cholesterol

Defibrotide, (D) an antithrombotic agent, when administered i.v. to cholesterol-fed rabbits decreased cholesterol in the aorta without changing total plasma cholesterol, triglyceride or phospholipid, nor the cholesterol, triglyceride, phospholipid and protein of plasma lipoproteins. Platelet aggregation was decreased in rabbits treated with D. There were fewer vascular lesions in the hearts and kidneys of animals treated with D than in animals fed cholesterol and treated with placebo. These data suggest that the antithrombotic activity of D and its ability to reduce platelet sensitivity could help to reduce the amount of cholesterol in the cardiovascular system in atherosclerosis-prone situations.

The anticoagulant, hepatic lipase-releasing and lipoprotein lipase-releasing activities of several natural and chemically modified heparins differ

Several 'natural' heparins have been found to have different potencies for releasing hepatic lipase and lipoprotein lipase. These differences can also be obtained by treating heparins with physical and chemical methods, which also affect the anticoagulant activity. These differences in potency in hepatic lipase-releasing activity are discussed in terms of the role of this lipase in lipoprotein and cholesterol metabolism.