Eliades Ledezma

Ajoene, el principal compuesto activo derivado del ajo (Allium sativum), un nuevo agente antifúngico

Resumen Desde tiempos inmemoriales el ajo ha transitado junto al hombre por los caminos de la tierra, multiples son los beneficios que la humanidad ha obtenido de sus propiedades medicinales y magico-religiosas, pero fue en las ultimas tres decadas cuando el estudio de sus propiedades permitio establecer una base racional para sus potencialidades clinicas. Se conocio la existencia de la alicina, el ajoene, los tiosulfinatos y una gama de compuestos organosulfurados como componentes esenciales de este bulbo y se comprobo, para muchos de ellos, una diversidad de efectos que abarcan desde propiedades antitromboticas, antitumorales, antiparasitarias y antifungicas. Sin embargo, el ajoene, un producto de gran estabilidad, que se origina de la ruptura y la reparacion no enzimatica de la alicina, y que puede tambien ser obtenido sinteticamente, demostro poseer la mayor actividad biologica en todos los sistemas estudiados. En este articulo nos referiremos a las propiedades antifungicas del ajoene y a las potencialidades que posee esta novel molecula para ser utilizada en la terapeutica de las infecciones micoticas.

Efficacy of ajoene, an organosulphur derived from garlic, in the short‐term therapy of tinea pedis

Summary. The present report shows the efficacy of ajoene, a garlic‐derived organic trisulphur, for short‐term therapy of tinea pedis. The use of ajoene as a 0.4% (w/w) cream resulted in complete clinical and mycological cure in 27 of 34 patients (79%) after 7 days of treatment. The remaining seven patients (21%) achieved complete cure after seven additional days of treatment. All patients were evaluated for recurrence of mycotic infections 90 days after the end of treatment, yielding negative cultures for fungus. These results show that ajoene is an alternative, efficient and low‐cost antimycotic drug for short‐term therapy of tinea pedis. The fact that ajoene can be easily prepared from an alcoholic extract of garlic may make it suitable for Third World public health care.

Seasonal and nocturnal domiciliary human landing/biting behaviour of Lutzomyia (Lutzomyia) evansi and Lutzomyia (Psychodopygus) panamensis (Diptera; Psychodidae) in a periurban area of a city on the Caribbean coast of eastern Venezuela (Barcelona; Anzoátegui State).

In recent years, in addition to American cutaneous leishmaniasis (ACL), a significant number of cases of American visceral leishmaniasis (AVL) have been reported in periurban areas of Barcelona city (Anzoátegui State, Venezuela). We studied the bionomics of Lutzomyia (Lutzomyia) evansi and Lutzomyia (Psychodopygus) panamensis, possible vectors of AVL and ACL, respectively, in El Rincón, a periurban village of that city. To evaluate the seasonal domiciliary landing/biting activity of sandflies on human bait, a house was chosen in El Rincón. Landing catches were carried out between 18:00 and 06:00, once a month for a year. The results show the presence of 2 species, Lu. (Lu.) evansi (89.9%) and Lu. (Psy.) panamensis (10.1%). Lu. evansi was most abundant in the months of October and July, associated with the bimodal cycle of annual rainfall in the area. Maximum landing/biting activity of Lu. evansi was observed at 24:00 and 03:00. These findings suggest that at this time of the year and at these hours there is heightened risk of the transmission of AVL. Lu. panamensis monthly abundance also shows a direct association with rainfall and maximum landing/biting activity was observed between 02:00 and 03:00. The lower domiciliary abundance of Lu. panamensis suggests its greater importance in the extradomiciliary transmission of ACL.

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

Scorpion poisoning was surveyed in Acosta and Caripe counties, located in the Turimiquire subregion of Monagas State, Venezuela, aiming to expand information on stings by characterizing some epidemiological aspects. From 1987 to 1993, 298 cases of scorpion stings were recorded in Acosta and Caripe counties. Acosta had 212 cases, with an annual incidence rate of 18.3 (cases per 10,000 inhabitants) and a period median incidence rate of 128 . The scorpion poisoning index is 4.18 times greater in Acosta than in Caripe, confirming the former as a hyperendemic zone for this type of injury, with a phenomenon of cyclical temporal fluctuations and an upward trend. This area is infested with scorpions of the genus Tityus. Our results show that the region surveyed in Monagas State is endemic for scorpion stings, posing a major public health problem.

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.

Sandfly fauna of endemic leishmaniasis foci in Anzoátegui State, Venezuela

A census of the sandfly fauna was undertaken in 1993-98 in 5 endemic leishmaniasis foci situated at different altitudes in Anzoátegui State, Venezuela. From the 17 species of Lutzomyia identified, we believe that Lu. ovallesi, Lu. panamensis and Lu. gomezi are the probable vectors of cutaneous leishmaniasis, while Lu. evansi might transmit visceral leishmaniasis.

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.