Role of the inflammatory response in the hemorrhagic syndrome induced by the hemolymph of the caterpillar Lonomia achelous.

INTRODUCTION: Contact with the caterpillar of Lonomia achelous causes a hemorrhagic syndrome in humans prompted by two processes, an initial mild DIC that is later masked by overwhelming fibrinolytic activity. Although the venom affects both the hemostatic and inflammatory systems separately, it is not clear whether the hematological and hemostatic disturbances may in part be due to an indirect effect via inflammatory mediators. Here we report results on the crosstalk between these systems, particularly the effect of the pro-inflammatory cytokine TNF-α on hemostatic parameters. MATERIALS AND METHODS: the nitric oxide and TNF-α responses, as well as activation of the coagulation and fibrinolytic systems, were measured in macrophages and endothelial cells treated with Lonomia achelous hemolymph (LAH). The same responses were then determined, in a mouse model of LAH envenomation, after treatment with an anti-TNF-α antibody. RESULTS: Both macrophages and endothelial cells responded strongly to LAH in terms of pro-inflammatory mediator release and fibrinolytic activities as well as pro-coagulant activity (TF activity) in endothelial cells. Treatment with antibody against TNF-α decreased both TNF-α and NO3-/NO2- serum levels in the mice, after LAH injection. Blocking TNF-α also modified significantly the serum levels of plasminogen, fibrinogen and FXIII in mice, as well as decreased TF activity in endothelial cells. CONCLUSIONS: LAH may induce a hemostatic effect through endothelial and macrophage activation. These activated cell release hemostatic enzymes as well as pro-inflammatory mediators, principally TNF-α, that potentiate this release in an autocrine fashion, amplifying the fibrinolytic effect, which may in turn exacerbate the hemorrhagic manifestations. As far as we are aware, this is the first report of the relationship between the hemostatic system and the inflammatory responses in a hemorrhagic syndrome induce by animal secretions.

Efecto in vitro de los terpenos lupeol y casearina G sobre células sanguíneas y tumorales / In vitro effect of lupeol and casearin G on peripheral blood mononuclear and tumor cells

Background: The rainforest is an important source of natural compounds with therapeutic properties. Although there are many anti-inflammatory and antineoplastic drugs available to the clinician, there is an ongoing need for new therapeutic drugs with fewer serious adverse effects. Aim: To evaluate the in vitro cytotoxic effects of lupeol and casearin G on tumor cells, on phagocytic activity and nitric oxide (NO) production by blood mononuclear cells. Material and Methods: The cytotoxic effect of these compounds on cell lines MCF-7 (human breast adenocarcinoma) and PC-3 (human prostate cancer) was measured by a colorimetric assay (MTS/PMS) and the sulphorhodamine B assay. Peripheral blood mononuclear cells were obtained from eight healthy volunteers. The effect of these compounds on nitric oxide (NO) production was measured using the Griess reaction. Their effect on phagocytic activity of PBMC was also evaluated. Results: Lupeol (≥ 2 mM) resulted in a reduction of both the phagocytic index and the percentage of phagocytic monocytes and macrophages. Treatment of monocytes/macrophages with lupeol (72 µM) and casearin G (4 µM) reduced the production of NO. Neither lupeol (< 969 µM) nor casearin G (< 55 µM) had cytotoxic effects on PBMC. Casearin G showed both cytotoxic (IC50, LC50) and cytostatic (GI50) effects against tumor cells, PC-3 (IC50 = 12.5 µM; GI50 = 13.3 µM; LC50 = 51.9 µM) and MCF-7 (IC50 = 112.8 µM; GI50 = 11.8 µM; LC50 = 49.4 µM), as well as a hemolytic effect (≥ 182 µM). Conclusions: These observations indicate that lupeol and casearin G might be useful compounds in the preparation of anti-inflammatory drugs, whereas casearin G might be useful in the elaboration of antitumor drugs.

[In vitro effect of lupeol and casearin G on peripheral blood mononuclear and tumor cells]. / Efecto in vitro de los terpenos lupeol y casearina G sobre células sanguíneas y tumorales.

BACKGROUND: The rainforest is an important source of natural compounds with therapeutic properties. Although there are many anti-inflammatory and antineoplastic drugs available to the clinician, there is an ongoing need for new therapeutic drugs with fewer serious adverse effects. AIM: To evaluate the in vitro cytotoxic effects of lupeol and casearin G on tumor cells, on phagocytic activity and nitric oxide (NO) production by blood mononuclear cells. MATERIAL AND METHODS: The cytotoxic effect of these compounds on cell lines MCF-7 (human breast adenocarcinoma) and PC-3 (human prostate cancer) was measured by a colorimetric assay (MTS/PMS) and the sulphorhodamine B assay. Peripheral blood mononuclear cells were obtained from eight healthy volunteers. The effect of these compounds on nitric oxide (NO) production was measured using the Griess reaction. Their effect on phagocytic activity of PBMC was also evaluated. RESULTS: Lupeol (≥ 2 mM) resulted in a reduction of both the phagocytic index and the percentage of phagocytic monocytes and macrophages. Treatment of monocytes/macrophages with lupeol (72 µM) and casearin G (4 µM) reduced the production of NO. Neither lupeol (< 969 µM) nor casearin G (< 55 µM) had cytotoxic effects on PBMC. Casearin G showed both cytotoxic (IC50, LC50) and cytostatic (GI50) effects against tumor cells, PC-3 (IC50 = 12.5 µM; GI50 = 13.3 µM; LC50 = 51.9 µM) and MCF-7 (IC50 = 112.8 µM; GI50 = 11.8 µM; LC50 = 49.4 µM), as well as a hemolytic effect (≥ 182 µM). CONCLUSIONS: These observations indicate that lupeol and casearin G might be useful compounds in the preparation of anti-inflammatory drugs, whereas casearin G might be useful in the elaboration of antitumor drugs.

Screening of Venezuelan medicinal plant extracts for cytostatic and cytotoxic activity against tumor cell lines.

There are estimated to be more than 20,000 species of plants in Venezuela, of which more than 1500 are used for medicinal purposes by indigenous and local communities. Only a relatively small proportion of these have been evaluated in terms of their potential as antitumor agents. In this study, we screened 308 extracts from 102 species for cytostatic and cytotoxic activity against a panel of six tumor cell lines using a 24-h sulphorhodamine B assay. Extracts from Clavija lancifolia, Hamelia patens, Piper san-vicentense, Physalis cordata, Jacaranda copaia, Heliotropium indicum, and Annona squamosa were the most cytotoxic, whereas other extracts from Calotropis gigantea, Hyptis dilatata, Chromolaena odorata, Siparuna guianensis, Jacaranda obtusifolia, Tapirira guianensis, Xylopia aromatica, Protium heptaphyllum, and Piper arboreum showed the greatest cytostatic activity. These results confirm previous reports on the cytotoxic activities of the above-mentioned plants as well as prompting further studies on others such as C. lancifolia and H. dilatata that have not been so extensively studied.

Synthesis, characterization and biological activity of trans-platinum(II) complexes with chloroquine.

Three platinum-chloroquine complexes, trans-Pt(CQDP)(2)(I)(2) [1], trans-Pt(CQDP)(2)(Cl)(2) [2] and trans-Pt(CQ)(2)(Cl)(2) [3], were prepared and their most probable structure was established through a combination of spectroscopic analysis and density functional theory (DFT) calculations. Their interaction with DNA was studied and their activity against 6 tumor cell lines was evaluated. Compounds 1 and 2 interact with DNA primarily through electrostatic contacts and hydrogen bonding, with a minor contribution of a covalent interaction, while compound 3 binds to DNA predominantly in a covalent fashion, with weaker secondary electrostatic interactions and possibly hydrogen bonding, this complex also exerted greater cytotoxic activity against the tumor cell lines.

Effective radiotherapy of primary tumors and metastasis with 18F-2-deoxy-2-fluoro-D-glucose in C57BL/6 mice.

INTRODUCTION: The radiochemical 18F-2-deoxy-2-fluoro-D-glucose (18F-FDG), a positron emitter, is taken up preferentially by malignant tumors with high metabolic rates. This concentration of 18F-FDG in the tumor permits diagnosis and staging by positron emission tomography but also may represent a means of targeting radiotherapy. In this study, we determined the effect of a higher dose of 18F-FDG on tumor growth in a mouse model. MATERIALS AND METHODS: The effect of 18F-FDG on the growth and viability of 3 tumor cell lines was determined in vitro. Primary tumor growth and metastasis of B16/BL6 melanoma cells were determined in C57BL/6 mice injected with 5 mCi doses of 18F-FDG (2/3 doses). RESULTS: 18F-FDG was cytostatic for all 3 cell lines at the lowest dose tested. It significantly reduced the growth of primary tumors, by 89% at day 19 postinoculation, and also almost totally inhibited the appearance of lung metastases after intravenous inoculation of the same cells. CONCLUSIONS: 18F-FDG proved to be an effective radiotherapeutic agent in this model. The possible problems associated with the accumulation of this radiochemical at other sites besides the tumor must be addressed.

Expression of human soluble complement receptor 1 by a pig endothelial cell line inhibits lysis by human serum.

The importance of complement activation and naturally occurring anti-pig antibodies in the hyperacute rejection (HAR) observed in models of pig-to-human xenotransplantation is well established. To overcome this, much effort has been dedicated to preparing transgenic pigs by knocking out Galalpha(1-3)Gal expression in these animals, or knocking in the expression of human complement regulatory proteins (CRPs), such as CD59 or decay accelerating factor. A soluble form of another membrane CRP, complement receptor type 1 (CR1), has also been shown to inhibit complement activation. Here, we show that transfection of a pig endothelial cell line with a truncated form of human soluble complement receptor 1 (sCR1) almost completely protected these cells from complement-mediated lysis by human AB serum. Pigs genetically manipulated to express human sCR1 may represent an additional strategy to inhibit HAR of pig-to-human transplanted organs.

Ajoene inhibits both primary tumor growth and metastasis of B16/BL6 melanoma cells in C57BL/6 mice.

Ajoene is an organosulphur compound derived from garlic with important effects on several membrane-associated processes such as platelet aggregation, as well as being cytotoxic for tumor cell lines in vitro. In the present study, we investigated the effect of ajoene on different cell types in vitro, as well as its inhibitory effects on both primary tumors and metastasis in a mouse model. We found ajoene to inhibit tumor cell growth in vitro, but also to inhibit strongly metastasis to lung in the B16/BL6 melanoma tumor model in C57BL/6 mice. As far as we are aware, this is the first report of the anti-metastatic effect of ajoene. Ajoene also inhibited tumor-endothelial cell adhesion, as well as the in vivo TNF-alpha response to lipopolysaccharide. Possible mechanisms of its antitumoral activity are discussed in the light of these results.

Effect of a gold-chloroquine complex on inflammation-related leukocyte functions and cell viability. Comparison with auranofin.

This study evaluates a new gold-chloroquine complex [hexafluorophosphate triphenylphosphine chloroquine gold (I), Au(CQ)(PPh3)PF6, referred to hereinafter as CQAu] in terms of its anti-inflammatory and toxic effects on immune cells compared to auranofin (AF). CQAu and AF were compared for their effects on a) tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) release by human lymphocytes and murine macrophages, b) functionality and survival of polymorphonuclear leukocytes (PMN), c) PMN function in the presence of human serum albumin as a competitive inhibitor, d) mitogen-induced proliferation of human lymphocytes and e) TNF-alpha and IL-6 response of mice to lipopolysaccharide (LPS). CQAu was found to be generally similar to AF, or somewhat less effective, in terms of its activity in different assays of human immune cell function. For several of the assays, this was related to the greater cytotoxicity of AF. However, the two drugs did show comparable inhibitory effects on TNF-alpha and IL-6 production in a mouse model in vitro and in vivo, which were independent of a cytotoxic effect. CQAu merits further investigation as a gold drug with potential applications in treating inflammatory disease.

Effect of 3 plant extracts on b16-bl6 melanoma cell growth and metastasis in C57bl/6 mice

En el presente estudio, se investigaron los posibles efectos de extractos acuosos de tres plantas amazónicas, Uncaria tomentosa (UT), Petiveria alliacea (PA) y Phyllantus niruri (PN), sobre el crecimiento y la metástasis de células de melanoma B16/BL6 en ratones C57BL/6, y sobre los niveles séricos del factor de necrosis tumoral alfa (TNF-iÀ), la interleucina-6 (IL-6) y el componente amiloide P (SAP). Ninguno de los tres extractos inhibió el crecimiento de las células B16/BL6, ni de las líneas celulares tumorales humanas, HT 29 y Caco-2, in vitro. Los niveles séricos de IL-6 y SAP, y la respuesta de TNF-¡À sérico a LPS resultaron elevados en los animales inoculados i.v. con las células de melanoma. Sólo el UT, inyectado i.p., redujo significativamente la metástasis a pulmón de un inóculo i.v. de células B16/BL6, y produjo un retardo en el crecimiento de un tumor primario. Además, sólo el extracto de UT produjo disminución de la respuesta sérica de las dos citocinas proinflamatorias, TNF-¡À e IL-6. UT amerita futuros estudios como potencial agente anticáncer.

Several useful anticancer drugs have been derived from plants. The growth and metastasis of tumours in the mousemay be used to study plant extracts with therapeutic potential. In the present study we investigated the possible effects of aqueous extracts of three Amazonian plants (Uncaria tomentosa [UT], Petiveria alliacea [PA] and Phyllantus niruri [PN]) on the growth and metastasis of B16/BL6 melanoma cells in the C57BL/6 mouse, and on the serum levels of tumor necrosis factor alpha (TNF-a), interleukin-6 (IL-6) and serum amyloid P component (SAP). None of the three extracts inhibited the growth of the B16/BL6 cells in vitro, or of two other tumor cell lines, HT-29 and Caco-2. Serum levels of IL-6 and SAP, and the TNF-¦Á serum response to LPS rose in the animals inoculated i.v. with melanoma cells. Only UT, when injected i.p. every other day for 14 days, was able to significantly reduce lung metastases after an i.v. inoculation of melanoma cells or to delay the appearance and growth of solid tumors after s.c. inoculation. In addition, only UT was able to reduce the serum response of the two proinflammatory cytokines, TNF-a and IL-6. No effect on SAP levels was observed. UT merits further study as an anticancer agent.

[Molecular and serological diagnosis of a dengue outbreak in Coro, Falcón state, Venezuela]. / Diagnóstico molecular y serológico de un brote de dengue en Coro, estado Falcón, Venezuela.

Dengue virus (DV) is responsible for a spectrum of diseases, from a self-limited fever disease (DF, dengue fever) to the more severe forms of hemorrhagic fever/dengue shock syndrome (DHF/DSS). The aim of this study was the serological and molecular confirmation of an outbreak of dengue in Falcon state, Venezuela. A total of 54 sera from patients with clinical diagnosis of DV infection were analyzed by an enzyme immunoassays developed in Venezuela (ELISA -IgM e -IgG) and by PCR. From them, 78% exhibited DV infection (PCR+ y/o IgM+), 48% exhibited viremia by PCR and 57% were positive to IgM. An interesting observation was the high percent (76%) of patients with past or secondary infection (IgG positive), which included all the patients exhibiting clinical symptoms of DHF (n = 8). From the PCR positive sera, serotype 1 was found in 27%, serotype 2 in 54% and serotype 4 in 19%. No serotype 3 was found circulating in this population, although this serotype was already circulating in the nearby island of Aruba. The combination of serological and molecular methods allow us to obtain a fairly precise information of this outbreak.

Diagnóstico molecular y serológico de un brote de dengue en Coro, estado Falcón-Venezuela / Molecular and serological diagnóstic of an outbreak of dengue in Coro, state Falcon-Venezuela

El virus dengue (VD) es responsable de un espectro de enfermedades que van desde una enfermedad febril autolimitante (FD, fiebre por dengue) hasta las formas severas, fiebre hemorrágica/síndrome de shock por dengue (FHD/SSD). El propósito del presente estudio fue la confirmación serológica y molecular de un brote de dengue en el Estado Falcón, Venezuela con la finalidad de confirmar la etiolgía de la enfermedad, determinar los serotipos infectantes y la relación del diagnóstico clínico con las respuestas inmunitarias en los pacientes con infección activa. Se analizaron 54 sueros de pacientes con diagnóstico clínico de infección por VD, mediante inmunoensayos enzimaticos desarrollados en Venezuela (ELISA, IgM e IgG) y por PCR. El 78 por ciento de los pacientes mostró evidencia de infección por VD (PCR+ y/o IgM), 48 por ciento presentaron viremia demostrada por PCR+ y 57 resultaron positivos a IgM, lo que sugiere que un alto número de los casos reportados como dengue en el país se deben efectivamente a la infección por VD. Un hecho resaltante fue el alto porcentaje (76 por ciento) de pacietnes con infección pasada o secundaria al VD (IgG positivos), dentro de los cuales se encontraban la totalidad de los pacientes diagnósticados clínicamente con FHD (n=8). De los pacientes PCR positivos, el 27 por ciento correspondió al serotipo 1,54 por ciento al serotipo 2 y 19 al serotipo 4. Para el momento de esta evaluación no se determinó la presencia del serotipo 3, aunque se conocía de su presencia en la cercana Isla de Aruba, la combinación de métodos serológicos y moleculares nos permitió obtener una información bastante precisa de este brote.

Comparación del control de la secreción de ácido y de pepsinogeno por la célula oxintopéptica del anfibio / Compasison of the control of acid and pepsinogen secretion by oxyntopeptic all of amphibians

La secreción de pepsinógeno y de HCI en el estómago de anfibio tiene lugar en un solo tipo celular, la célula oxintopéptica. La distribución de pepsinógeno es heterógena en la mucosa gástrica de Bufo marinus y la mayor concentración se encuentra en el fundus. Las dos secreciones responden a los mismos secretagogos. La histamina produce la mayor respuesta en ambas secreciones, mientras que el carbacol, por sí solo, sin el componente de histamina endógena, tiene un efecto pequeño. La forskolina y el 8Br-cAMP tienen un efecto parecido al producido por la histamina. El ionóforo de Ca2+, A23187, y el análogo de diacilglicerol, el octanoilacilglicerol (OAG), tienen un efecto pequeño sobre ambas secreciones, como el carbacol. La adición conjunta de histamina y carbacol, o de forskolina y carbacol, o el OAG y 8Br-cAMP induce una respuesta potenciada en las dos secreciones. El análisis cuantitativo de las respuestas y el estudio de la relación entre ellas durante las estimulaciones con histamina y carbacol muestran un patrón de estimulación no paralela y desacoplada