Sinergismo in vitro entre hidrazonas, ajoeno y posaconazol sobre aislados de Cryptococcus spp / In vitro synergisms among hydrazones, ajoeno and posaconazole against Cryptococcus spp

El objetivo de este trabajo fue estudiar la susceptibilidad in vitro de aislados de Cryptocococus spp con una nueva clase de antifúngicos, hidrazonas esteroidales y comparar su actividad antifúngica en combinación con ajoeno y posaconazol contra aislados de Cryptococcus spp. Se utilizaron tres aislados del género Cryptococcus 42794, 4050 y 44192 y se evaluaron su sensibilidad y efectos sinérgicos con las hidrazonas esteroidales, ajoeno y posaconazol, según el documento M27-A2 del CLSI. Se incluyeron las cepas Candida albicans (ATCC 90028) y Candida parapsilosis (ATCC 22019) como controles. Se observó con las hidrazonas (H1, H2, H3, H4) un efecto plateau a partir de 10 µM (CMI). Sin embargo, con la H4 se obtuvo bajo porcentaje de inhibición del crecimiento. Con el ajoeno, se obtuvieron valores de CMI de 25 y 50 µM. El posaconazol mostró altos valores de inhibición y un valor de CMI de 6 µM para 42794 y 44192 y un CMI de 20 µM para el aislado 4050. Se obtuvieron efectos sinérgicos al combinar posaconazol con ajoeno, ajoeno con hidrazona 3 y posaconazol con hidrazona 3. Los valores de concentración inhibitoria fraccional fueron de 0,24; 0,16 y 0,09 respectivamente, indicando un marcado efecto sinérgico. Se obtuvieron efectos sinérgicos importantes entre el posaconazol con ajoeno, ajoeno con hidrazona 3 y posaconazol con hidrazona 3, lo cual sería muy útil para futuros estudios clínicos.

The aim of this study was to assess the in vitro susceptibility to novel antifungal compounds, the steroidal hydrazones, and to compare their antifungal activity and synergistic effects with other compounds, such as ajoeno and posaconazole on Cryptocococus spp isolates. Three Cryptococcus strains were used for this study (42794, 4050 and 44192) and their antifungal sensitivity and synergistic effects with ajoeno and posaconazole were evaluated according to the CLSI protocol number M27-A2. Candida albicans (ATCC 90028) and Candida parapsilosis (ATCC 22019) were used as controls. A plateau effect with hydrazones (H1, H2, H3, H4) was observed after 10 µM (CMI). However, with H4 only a mild inhibition on the growth was obtained. Combining hydrazone and ajoeno, CMI values between 25 and 50 µM were obtained. The highest inhibitions values were obtained with posaconazole and a CMI value of 6 µM for the strains 42794 and 44192, and a CMI value of 20 µM for the strain 4050. Synergy was observed combining posaconazole with ajoeno, ajoeno with hydrazone 3 and posaconazole with hydrazone 3. Fractional inhibitory concentrations were 0.24, 0.16 and 0.09 respectively, which might indicate a synergistic effect. Important synergistic effects were obtained with posaconazole and ajoeno, ajoeno and hydrazone 3 and posaconazole with hydrazone 3, which would be very useful for clinical trials in the future.

[In vitro synergisms among hydrazones, ajoeno and posaconazole against Cryptococcus spp]. / Sinergismo in vitro entre hidrazonas, ajoeno y posaconazol sobre aislados de Cryptococcus spp.

The aim of this study was to assess the in vitro susceptibility to novel antifungal compounds, the steroidal hydrazones, and to compare their antifungal activity and synergistic effects with other compounds, such as ajoeno and posaconazole on Cryptocococus spp isolates. Three Cryptococcus strains were used for this study (42794, 4050 and 44192) and their antifungal sensitivity and synergistic effects with ajoeno and posaconazole were evaluated according to the CLSI protocol number M27-A2. Candida albicans (ATCC 90028) and Candida parapsilosis (ATCC 22019) were used as controls. A plateau effect with hydrazones (H1, H2, H3, H4) was observed after 10 microM (CMI). However, with H4 only a mild inhibition on the growth was obtained. Combining hydrazone and ajoeno, CMI values between 25 and 50 microM were obtained. The highest inhibitions values were obtained with posaconazole and a CMI value of 6 microM for the strains 42794 and 44192, and a CMI value of 20 microM for the strain 4050. Synergy was observed combining posaconazole with ajoeno, ajoeno with hydrazone 3 and posaconazole with hydrazone 3. Fractional inhibitory concentrations were 0.24, 0.16 and 0.09 respectively, which might indicate a synergistic effect. Important synergistic effects were obtained with posaconazole and ajoeno, ajoeno and hydrazone 3 and posaconazole with hydrazone 3, which would be very useful for clinical trials in the future.

Potentiated cytotoxic effects of statins and ajoene in murine melanoma cells.

Because statins and ajoene inhibit the 3-hydroxy-3-methyl-glutaryl coenzyme A reductase, we evaluated the hypothesis that the cytotoxic effect of these compounds may be potentiated when both are used in combination on tumor cells. We showed that cotreatment of the murine melanoma B16F10 cell with statins (atorvastatin and pravastatin) and ajoene, all at nontoxic doses, dramatically increased their cytotoxicity. B16F10 cell death induced by statins, but not by ajoene, was prevented by mevalonate and geranylgeranylpyrophosphate. To our knowledge, this is the first report that the combination of statins and ajoene, which alters the mevalonate pathway, might potentiate their cytotoxic effects on tumor cells.

[Synergy between ajoene and ketoconazole in isolates of Microsporum canis. A preliminary study using fractional inhibitory concentration technique (FIC)]. / Sinergismo entre ajoeno y ketoconazol en aislamientos de Microsporum canis. Un estudio preliminar mediante la determinación de la concentración inhibitoria fraccional (CIF).

Fungal infections are probably the most frequent infectious diseases affecting human being. Resistance to different anti-fungal drugs, and their bioavailability in the infection site, represent a problem for treatment. Looking for effective solutions, combination of two or more antifungal drugs to obtain an additive effect or synergic effect that potent antifungal activity has been investigated. In this study, the effect (additive, antagonist or synergistic) of ajoene and ketoconazole combination was evaluated in the growth and proliferation of filamentous fungi. Interactions in vitro were investigated in three isolates of Microsporum canis through a preliminary study using micro dilution, according to recommendations of NCCLS M-38A, with several modifications. Results obtained for CIF of each isolates studied (CIF = 0.18 0.36 microM), demonstrate that exists a very potent synergistic effect, when they are combined, and it represents a hope for future clinic trials to treat resilient fungal infections caused by M. canis.

Sinergismo entre ajoeno y ketoconazol en aislamientos de Microsporum canis. Un estudio preliminar mediante la determinaci¨®n de la concentraci¨®n inhibitoria fraccional (CIF) / Synergy between ajoene and ketoconazole in isolates of Microsporum canis. A preliminary study using fractional inhibitory concentration technique (FIC)

Las enfermedades infecciosas originadas por hongos son, probablemente, lasque m¨¢s frecuentemente afectan al ser humano. Aunque una variedad deagentes antif¨²ngicos est¨¢n disponibles para su control, la existencia deresistencia a diversas clases de antif¨²ngicos, as¨ª como tambi¨¦n labiodisponibilidad de la droga en el sitio de la infecci¨®n, representan unproblema serio durante su tratamiento. Una aproximaci¨®n en la b¨²squeda desoluciones efectivas ha sido la combinaci¨®n de dos o m¨¢s agentes antif¨²ngicoscon la finalidad de obtener alg¨²n efecto aditivo o sin¨¦rgico que potenciesustancialmente la actividad antif¨²ngica de las drogas. En este estudioevaluamos si el efecto producido por la combinaci¨®n de ajoeno y ketoconazolsobre el crecimiento y la proliferaci¨®n de hongos filamentosos es de naturalezaaditiva, antag¨®nica o sin¨¦rgica. Para ello, se investigaron sus interacciones invitro en tres aislamientos de Microsporum canis mediante un estudio preliminar,utilizando la t¨¦cnica de microdiluci¨®n, siguiendo las recomendacionesdescritas en el documento NCCLS M-38A con algunas modificaciones.Los resultados de concentraci¨®n inhibitoria fraccional obtenidos para cadauna de las tres cepas estudiadas (valores de 0,18 - 0,36 ¦ÌM) demuestran laexistencia de un efecto sin¨¦rgico muy potente cuando se combinan estasdrogas, y configura un panorama muy prometedor para la realizaci¨®n defuturos estudios cl¨ªnicos, donde se utilicen para el tratamiento de infeccionescausadas por M. canis, tradicionalmente de dif¨ªcil tratamiento(AU)

Fungal infections are probably the most frequent infectious diseases affectinghuman being. Resistance to different anti-fungal drugs, and their bioavailabilityin the infection site, represent a problem for treatment. Looking for effectivesolutions, combination of two or more antifungal drugs to obtain an additiveeffect or synergic effect that potent antifungal activity has been investigated.In this study, the effect (additive, antagonist or synergistic) of ajoene andketoconazole combination was evaluated in the growth and proliferation offilamentous fungi. Interactions in vitro were investigated in three isolates ofMicrosporum canis through a preliminary study using micro dilution, accordingto recommendations of NCCLS M-38A, with several modifications. Resultsobtained for CIF of each isolates studied (CIF = 0,18 - 0,36 ¦ÌM), demonstratethat exists a very potent synergistic effect, when they are combined, and itrepresents a hope for future clinic trials to treat resilient fungal infectionscaused by M. canis(AU)

[Ajoene the main active compound of garlic (Allium sativum): a new antifungal agent]. / Ajoene, el principal compuesto activo derivado del ajo (Allium sativum), un nuevo agente antifúngico.

The curative properties of garlic in medicine have been known for a long time. But, it was only in the last three decades when garlic properties were seriously investigated confirming its potential as therapeutic agent. Allicin, ajoene, thiosulfinates and a wide range of other organosulphurate compounds, are known to be the constituents linked to the garlic properties. Regarding the biochemical properties of these compounds, ajoene [(E,Z)-4,5,9 Trithiadodeca 1,6,11 Triene 9-oxide] is stable in water, and it can be obtained by chemical synthesis. There is evidence that some of the garlic constituents exert a wide variety of effects on different biological systems. However, ajoene is the garlic compound related to more biological activities, as showed in in vitro and in vivo systems. Those studies found that ajoene has antithrombotic, anti-tumoral,antifungal, and antiparasitic effects. This study deals with a recently described antifungal property of ajoene, and its potential use in clinical trails to treat several fungal infections.

Apoptotic and anti-adhesion effect of ajoene, a garlic derived compound, on the murine melanoma B16F10 cells: possible role of caspase-3 and the alpha(4)beta(1) integrin.

In this study we evaluated the hypothesis that the antitumor activity of ajoene could be associated with its apoptosis-inducing effect, and with its ability to block the expression of the alpha(4)beta(1) integrin, in the murine melanoma B16F10 cells. Ajoene induced a significant reduction in B16F10 viability (IC(50)=62 microM), in a dose-dependent manner. Flow cytometric analysis showed that the cytotoxic effect of this compound was associated with caspase-3 activation. Ajoene at 25 microM altered the alpha(4)beta(1) integrin expression on B16F10, and induced a significant reduction in the adhesion of these cells to an endothelial cell monolayer.

Antiproliferative and leishmanicidal effect of ajoene on various Leishmania species: ultrastructural study.

Ajoene [(E,Z)-4,5,9 trithiadodeca 1,6,11 triene 9-oxide], the major bioactive compound derived from garlic, shows a potent trypanolytic and antimicotic activity. In this paper we evaluate its effect on Leishmania mexicana(Lm:MHOM/VE/80/NR), L eishmania mexicana venezuelensis (Lmv: MHOM/VE/80/H16), L eishmania mexicana amazonensis (Lma: M112, IFLA/BR/67/PH8) and L eishmania donovani chagasi (Ldch: MHOM/BR/74/PP75). Ajoene showed a potent leishmanicidal activity in vitro against all species studied. Concentrations higher than 0.3 microM led to total inhibition of growth, and 10 microM induced 100% lysis of Leishmaniaafter 96 h of incubation in a chemically defined culture medium. The 50% inhibitory concentration (IC(50)) for lysis, for all species, was about to 2 microM. The effect was dose-dependent and a threefold increase in concentration (30 microM) produced 100% lysis of cultured forms after 72 h. Ultrastructural studies showed a time- and dose-dependent morphological alteration of the mitochondrial membrane and nuclear envelope, as well as the formation of large autophagic vacuoles.

Prevalencia de marcadores serológicos para hepatitis B y C en mujeres gestantes del estado Anzoategui / Serological markers in hepatitis B and C in pregnant women from the Anzoategui state

Los marcadores serológicos de los virus de hepatitis B y C (VHB y VHC) fueron evaluados en 500 mujeres gestantes del Estado Anzoátegui. El 0,4 por ciento (n=2) resultó positivo para AgSHB y ninguna de ellas presentó positividad para anticuerpos contra la cápside del VHC. De 90 muestras escogidas al azar ensayadas para la presencia de anti-HBc, un 8,8 por ciento (n=8) resultó positivo. Uno de los dos hijos de las madres portadoras de AgSHB presentó el antígeno en su sangre al ser evaluado al año de su nacimiento. A pesar de que estos resultados muestran una prevalencia de los marcadores serológicos en el estado Anzoátegui menor a la obtenida en otras ciudades Venezolanas, demuestran que está presente la enfermedad y que la transmisión vertical puede suceder en la población Venezolana, por lo que se resalta la utilidad de realizar estos marcadores vírales durante el embarazo

Scorpion poisoning in the Acosta and Caripe Counties of Monagas State, Venezuela. Part 1: Characterization of some epidemiological aspects

Apresenta o perfil epidemiológico do escorpiäo nos municípios Acosta e Caripe, localizados na subregiäo geográfica do maciço montanhoso do Turimiquire do Estado de Monagas, Venezuela. Durante o período de 1987 a 1993, registrou-se um total de 298 acidentes causados por escorpiöes, correspondendo 212 ao município de Acosta e 86 ao de Caripe. Acosta apresentou um índice de incidência anual de 18,3 casos por 10.000 habitantes e 128 por cento para o período meio de estudo; o índice de escorpionismo foi 4,18 vezes maior que o apresentado em Caripe. Os dados indicam que o município de Acosta é hiperendêmico para este acidente, com um comportamento variável e uma tendência ao incremento ao longo dos anos. Os resultados obtidos evidenciam que estas regiöes do Estado de Monagas säo endêmicas para o acidente peçonhento causado por escorpiöes que assumem importância com problema de saúde pública, mais ainda quando säo de áreas de dispersäo do gênero Tityus.