Bidens pilosa L. (Asteraceae) cultivated in Brazil on acute liver disease in dogs / [Bidens pilosa L. (Asteraceae) cultivada no Brasil na doença hepática aguda em cães]

Bidens pilosa L. is a medicinal plant popularly used for treatment of liver diseases. In this study, the dry extract of aerial parts of Bidens pilosa and Silymarin, a phytocomplex obtained from the Silybum marianum fruits and marketed as hepatoprotective, were tested in dogs experimentally acutely intoxicated with carbon tetrachloride. The liver activity was evaluated by hematological and biochemical profiles, and histological and ultrasound analyzes. It was observed that the lowest serum activities of ALT and serum concentrations of total bilirubin occurred in the groups treated with the dry extract of Bidens pilosa, while only decreased serum concentrations of total bilirubin occurred in the group treated with Silymarin. Best liver recovery was also observed for the dry extract of B. pilosa at a 400mg/Kg dose by ultrasonography. This study showed that the dry extract of Bidens pilosa acted more efficiently in the treatment of acute toxic hepatitis induced in dogs than Silymarin.(AU)

Bidens pilosa L. é uma planta medicinal utilizada popularmente para tratamento de doenças hepáticas. Neste trabalho, o extrato seco das partes aéreas da Bidens pilosa e a silimarina, um fitocomplexo obtido dos frutos da Silybum marianum e comercializado como hepatoprotetor, foram testados em cães intoxicados experimentalmente de forma aguda com tetracloreto de carbono. A atividade hepática foi avaliada por meio dos perfis hematológico e bioquímico, análises histológica e ultrassonográfica. Observou-se que, nos grupos tratados com o extrato seco da Bidens pilosa, ocorreram as menores atividades séricas da ALT e de concentrações séricas de bilirrubina total, enquanto no grupo tratado com silimarina, ocorreu apenas diminuição de concentrações séricas de bilirrubina total. Melhor recuperação hepática também foi verificada para o extrato seco de B. pilosa na dose de 400mg/kg por ultrassonografia. Este estudo evidenciou que o extrato seco da Bidens pilosa atuou de forma mais eficiente no tratamento da hepatite aguda tóxica induzida em cães do que a silimarina.(AU)

Avaliação da toxicidade aguda e da atividade cicatrizante dos extratos etanólicos das folhas e raízes da Memora nodosa (Silva Manso) Miers (Bignoniaceae) / Evaluation of acute and healing activity of ethanol extracts of Memora nodosa (Silva Manso) Miers (Bignoniaceae) leaves and roots

Memora nodosa (Silva Manso) Miers é uma espécie da flora do Cerrado cujas folhas e caules são utilizados popularmente no tratamento de feridas e úlceras externas, enquanto as raízes são empregadas para dores abdominais e no tratamento da sarna. O objetivo desse trabalho foi avaliar a toxicidade aguda dos extratos etanólicos das folhas e raízes nas doses de 2000 e 5000 mg kg-1 em ratos e camundongos e a atividade cicatrizante das soluções aquosas contendo 2% desses extratos em feridas cutâneas em ratos. A contração das bordas das feridas foi avaliada por análises histológicas e morfométricas após 4, 7 e 14 dias de tratamento e por reação imunohistoquímica após 7 dias de tratamento. Os extratos etanólicos das folhas e raízes não apresentaram toxicidade na dose de 2000 mg kg-1 para ratos e camundongos e na dose de 5000 mg kg-1 para ratos. Nos camundongos, a dose de 5000 mg kg-1 dos extratos das folhas e raízes provocou alterações histológicas no fígado. Não foram observadas diferenças significativas na contração das feridas entre os grupos tratados com os extratos das folhas e das raízes e o controle após 4 e 7 dias de tratamento. Após 14 dias de tratamento, 50% dos animais tratados com o extrato das raízes apresentaram reepitelização total das feridas e reconstrução parcial dos anexos. A alantoína, isolada do extrato etanólico da raiz, pode ser considerada como um dos metabólitos secundários responsáveis pela aceleração da reepitelização.

Memora nodosa (Silva Manso) Miers is a Brazilian Cerrado species whose leaves and stems are commonly used to treat external wounds and ulcers and the roots are used for abdominal pain and to treat scabies. The purpose of this study was to evaluate the acute toxicity of ethanol extracts from the leaves and roots of M. nodosa at 2000 and 5000 mg kg-1 doses in rats and mice and to evaluate the healing activity of aqueous solutions containing 2% of these extracts on skin wounds in rats. The contraction of the wounds was evaluated by histological and morphometric analysis after 4, 7 and 14 days of treatment and by immunohistochemistry analysis after 7 days of treatment. The ethanol extracts of leaves and roots presented no toxicity at a 2000 mg kg-1 dose for rats and mice, and at a 5000 mg kg-1 dose for rats. Histological changes in the liver of mice were verified with a 5000 mg kg-1 dose of the leaf and root extracts. Macroscopic and histological differences were not observed in the contraction of wounds between the groups treated with leaf and root extracts and the control group after 4 and 7 days of treatment. After 14 days of treatment, 50% of the animals treated with the root extract presented total re-epithelialization of wounds and partial reconstruction of the annexes. Allantoin, isolated from the root ethanol extract, can be considered one of the secondary metabolites responsible for accelerating re-epithelialization.

Evidence for the neuronal origin of immunoreactive interleukin-1 beta released by rat hypothalamic explants.

In this study, we have investigated the release of immunoreactive interleukin-1 beta (irIL-1 beta) from the rat hypothalamus in vitro. It was found that (1) tissue explants release sizable amounts of irIL-1 beta (ranging from 0.43 to 0.52 pg/mg of wet tissue) in 20 min incubations; (2) basal release in significantly increased by depolarization induced with 56 mM KCl; (3) K(+)-induced irIL-1 beta release is inhibited by the specific blocker of N-type calcium channels, omega-conotoxin, and by verapamil, but not by nifedipine; (4) K(+)-induced release is also inhibited by the Na+ channel blockers tetrodotoxin and lidocaine; (5) irIL-1 beta release is significantly increased by noradrenalin; such increase is antagonized by verapamil and the beta-blocker propranolol, but not by the alpha-blocker phentolamine. The present evidence suggests that irIL-1 beta released by rat hypothalamic explants following KCl depolarization is neuronal in origin.

Synthetic alleles at position 121 define a functional domain of human interleukin-1 beta.

The non-conservative substitution of the tyrosine residue at position 121 of human interleukin-1 beta (IL-1 beta) generates protein mutants showing strong reduction of the capacity to induce (a) prostaglandin E2 (PGE2) release from fibroblasts and smooth muscle cells, (b) murine T-cells proliferation and (c) activation of interleukin-6 (IL-6) gene expression. It is generally accepted that these functions are mediated by the type-I interleukin-1 receptor (IL-1RI). However, the mutant proteins maintain the binding affinity to the types-I and II IL-1 receptors, which is the same as the control IL-1 beta, suggesting that this amino acid substitution does not alter the structure of the molecule, except locally. Thus we have identified a new functional site of IL-1 beta different from the known receptor binding region, responsible for fundamental IL-1 beta functions. Moreover, we show that the same mutants maintain at least two hypothalamic functions, that is, the in vitro short-term PGE2 release from rat hypothalamus and the induction of fever in rabbits. This result suggests that there is yet another site of the molecule responsible for the hypothalamic functions, implying that multiple active sites on the IL-1 beta molecule, possibly binding to more than one receptor chain, trigger different signals.

Evidence that the interleukin-1 beta-induced prostaglandin E2 release from rat hypothalamus is mediated by type I and type II interleukin-1 receptors.

Interleukin-1 beta (IL-1 beta) has been shown to specifically increase the release of prostaglandin (PG) E2 from rat hypothalamic explants in short-term experiments. In this study we attempted to characterize the receptor subtype(s) involved in this response. Rat hypothalamic explants were incubated with mouse monoclonal antibodies (mAbs) raised against human IL-1 type I or type II receptors, IL-1 receptor antagonist (IL-1ra) and alpha-melanocyte-stimulating hormone (alpha-MSH) (which appears to antagonize certain IL-1 induced inflammatory effects in vivo), alone and in the presence of IL-1 beta. PGE2 released into the incubation medium was measured by radioimmunoassay. The anti-type I mAb reduced both basal and IL-1 beta-stimulated PGE2 release at 10 micrograms/ml, but not at lower concentrations. The anti-type II mAb also produced a significant decrease in stimulated release but had no effect on basal release. IL-1ra mimicked the effects of the anti-type I mAb, while alpha-MSH failed to alter either basal or stimulated PGE2 release. These findings suggest that IL-1 beta controls production and release of PGE2 by the rat hypothalamus via both type I and type II receptors, although the latter appear to be involved only in the response to high levels of IL-1.

Inhibition of interleukin-1 beta-induced pyresis in the rabbit by peptide 204-212 of lipocortin 5.

The intracerebroventricular administration of interleukin-1 beta (12.5 ng/kg) in rabbits caused a prompt rise of prostaglandin E2 concentration (+ 632.6 +/- 243.9%) in the cerebrospinal fluid followed by hyperthermia (+ 1.61 +/- 0.14 delta degrees C). The intracerebroventricular administration of an anti-inflammatory nonapeptide (amino acids 204-212, SHLRKVFDK) derived from lipocortin 5, thereafter referred to as lipocortin 5-(204-212)-peptide, inhibited in a significant manner both the increase in cerebrospinal fluid [prostaglandin E2] and the febrile response induced by the cytokine. This inhibitory effect is probably due to interference by the peptide with phospholipase A2 activity. A control peptide (FKRVHDLKS) formed by the same amino acids in a randomly shuffled sequence had no effect. These results show that, in addition to the anti-inflammatory effect previously reported, the peptide 204-212 of lipocortin 5 possesses, like glucocorticoids, anti-pyretic activity. The research on lipocortin-derived peptides may lead to the development of novel anti-inflammatory and anti-pyretic compounds.

Prostaglandin E2 and bacterial lipopolysaccharide stimulate bioactive interleukin-1 release from rat hypothalamic explants.

While interleukin-1 (IL-1) is intimately involved in locally modulating the acute inflammatory response, it is also able to influence processes at remote sites, i.e., in an endocrine manner. While there is as yet little evidence that IL-1 can cross the blood-brain barrier, many effects such as fever, increased slow-wave sleep, anorexia and the modulation of neuroendocrine function suggest an action of circulating IL-1 at regulatory sites within the hypothalamus. However, there is accumulating evidence for IL-1 originating within the central nervous system (CNS), and it is currently unclear as to whether the neurally mediated manifestations of the acute inflammatory response are due to activation of central or peripheral (circulating) IL-1. In this study we have characterized the release of IL-1 from rat hypothalamic explants, and we have investigated the effects of putative modulators of IL-1 release, lipopolysaccharide (LPS) and the prostaglandins E2 (PGE2) and F2 alpha (PGF2 alpha). After 1 h of incubation, IL-1-like activity in hypothalamic supernatants ranged between 175 and 2,304 munits/mg of protein; this was substantially inhibited by the addition to the bioassay system of antibodies (1:200) against IL-1 alpha, but not against IL-1 beta. LPS and PGE2 significantly stimulated IL-1 release at 100 and 1 ng/ml respectively, whereas PGF2 alpha had no effect in the range of doses tested. It is therefore concluded that the control of hypothalamic IL-1 release may be investigated by means of acute rat hypothalamic explants.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-inflammatory effect of tuftsin and its retro-inverso analogue in rat adjuvant arthritis.

Tuftsin, an immunostimulating tetrapeptide derived from immunoglobulin heavy chain, and its retro-inverso analogue have been tested in rat adjuvant arthritis. The secondary lesion of rats injected with Freund's adjuvant was significantly inhibited by both the natural and retro-inverso tuftsin administered orally. The retro-inverso analogue was at least tenfold more potent than the parent molecule, suggesting an increased stability to degradation, because of its molecular modification. The anti-inflammatory effect of tuftsin may be due to its ability to modulate macrophage function.

Immunostimulation by a partially modified retro-inverso-tuftsin analogue containing Thr1 psi[NHCO](R,S)Lys2 modification.

The tuftsin retro-inverso analogue H-Thr psi[NHCO](R,S)Lys-Pro-Arg-OH was synthesized through a novel procedure for the high-yield incorporation of isolated retro-inverso bonds into peptide chains and the use of the new Meldrum's acid derivative (CH3)2C(OCO)2CH(CH2)4NHCOCF3 followed by its efficient coupling in solution to trimethylsilylated H-D-Thr(t-Bu)NH2. Closely related peptide impurities were eliminated both from the crude final peptide and the fully protected tetrapeptide amide precursor via ion-exchange and reversed-phase displacement chromatography, respectively. The tuftsin retro-inverso analogue proved to be completely resistant to enzymatic degradation in vitro, either against isolated aminopeptidases or human plasma proteolytic enzymes. When administered either orally or intravenously, it was significantly more active than normal tuftsin in increasing the number of specific antibody secreting cells in spleen of mice immunized with sheep erythrocytes. Furthermore, the analogue exerted an enhanced stimulatory effect on the cytotoxic activity of splenocytes against YAC-1 tumor cells. Finally, retro-inverso-tuftsin was about 10-fold more potent than the native peptide in reducing rat adjuvant arthritis. The resistance of the retro-inverso analogue to peptidases might explain the increased in vivo activities and allows its further immunopharmacological characterization.

Evidence that interleukin-1 and lipoxygenase metabolites mediate the lethal effect of complete Freund's adjuvant in adrenalectomized rats.

Injection of complete Freund's adjuvant (CFA) into the right hind paw of adrenalectomized (ADX) rats caused a lethal effect, maximal after 3 days. Treatment of animals with polyclonal sera raised against either murine recombinant (mr) IL-1 alpha or mrIL-1 beta gave significant protection, suggesting the involvement of this cytokine in the observed lethality. Death was also caused by the intravenous injection of human recombinant (hr) IL-1 beta in ADX rats. No lethality was induced by either CFA or hrIL-1 beta in sham-operated (SHO) rats. The administration of dexamethasone or the dural cyclooxygenase/lipoxygenase inhibitor BW 755c significantly protected against the lethality induced by both CFA and hrIL-1 beta. The cyclooxygenase inhibitors, indomethacin and acetylsalicyclic acid, were ineffective. WEB 2086, a PAF-acether receptor antagonist, gave partial but not significant protection. These results suggest that activation of arachidonic acid metabolism is involved in the observed lethality, with lipoxygenase metabolites as possible final effectors. These experimental models of lethalities may be useful for the in vivo evaluation of drugs interfering with the synthesis and/or biological effects of IL-1.

Mechanism of acute toxicity of IL-1 beta in mice.

Human recombinant IL-1 beta was able to kill C3H/HeJ mice only when inoculated intravenously at very high doses. IL-1 beta, inoculated at 100 mg/kg i.v. as a bolus, induced a shock-like state characterized by anorexia, severe hypothermia and hypoglycemia and persistent neutrophilia, leading to death in 55% of animals generally between 24 and 48 h. In contrast, the noninflammatory adjuvant IL-1 beta peptide VQGEESNDK (position 163-171) did not induce any toxic effect in vivo, when administered following the same schedule. At variance with what was previously observed in endotoxin induced shock, IL-1 beta induced death was not preceded by appearance of circulating TNF. On the other hand, very high and persistent levels of circulating IL-6 could be detected after lethal IL-1 beta administration. Treatment of mice with ibuprofen or with chlorpromazine, both known to counteract some of the toxic effects of IL-1 in vivo, could protect from IL-1 beta induced mortality. Both drugs, at doses protecting from IL-1 beta induced death, were able to abolish IL-1 beta-induced rise of circulating phospholipase A2 (PLA2) activity, and the subsequent generation of toxic PLA2-derived metabolites.

[Research on heterocyclic compounds. II.- Imidazo ( 1,2-a) pyridin-2-acetic acids]. / Ricerche su composti eterociclici II - Acidi imidazo [1,2-a] piridin-2-acetici

A series of ethyl imidazo [1,2-a]pyridin-2-acetates was prepared by reaction between several substituted 2-aminopyridines and ethyl-4-bromoacetate. From these esters the corresponding acids were prepared and their anti-inflammatory activity was tested.

[Isoxazoles substituted with 4-pyridyl and o-chlorophenyl radicals]. / Isossazoli sostituiti con i radicali 4-piridilico ed o-clorofenilico

By reaction of suitable hydroxamic acids chlorides with beta-ketoesters, we have prepared the ethyl esters of isoxazol-4-carboxylic acids, substituted in the 3- and 5-positions with 4-pyridyl and o-chlorophenyl groups, and some of their esters and amides of pharmaceutical interest. 3-(4-Pyridyl)-5-(o-chlorophenyl)isoxazole was obtained either by decarboxylation of the acid or by oxidation of the syn and anti oximes of 3-(o-chlorophenyl)-1-(4-pyridyl)-2-propen-1-one; from the syn oxime the corresponding isoxazoline was also obtained. Pharmacological screening shows that some of the new compounds have a myolytic activity.