Discovery of derivatives of 6(7)-amino-3-phenylquinoxaline-2-carbonitrile 1,4-dioxides: novel, hypoxia-selective HIF-1α inhibitors with strong antiestrogenic potency.

In this article, we describe the synthesis of 3-phenylquinoxaline-2-carbonitrile 1,4-dioxides bearing cyclic diamine residues at positions 6 or 7; the synthesis is based on the nucleophilic substitution of halogens. All synthesized 6(7)-aminoquinoxaline-2-carbonitrile 1,4-dioxides 3-6 demonstrated higher cytotoxicity and hypoxia selectivity compared to the reference agent tirapazamine against breast adenocarcinoma cell lines (MCF7, MDA-MB-231). The structure and position of the diamine residue considerably affects the antiproliferative properties of the quinoxaline-2-carbonitrile 1,4-dioxides. The introduction of a halogen atom at position 7 in the quinoxaline ring of 4a considerably increases the cytotoxicity of compounds 5a and 6a under both normoxic and hypoxic conditions. However, the most hypoxia-selective derivatives were non-halogenated 7-aminosubstituted 3-phenylquinoxaline-2-carbonitrile 1,4-dioxides 3a-j. Of the 32 novel synthesized derivatives, approximately 20 of the 6(7)-amino-3-phenylquinoxaline-2-carbonitrile 1,4-dioxides demonstrated high antiproliferative potency against wild type leukemia cells K562 and drug-resistant subline K562/4 with the expression of p-glycoprotein (p-gp) compared to the reference agent doxorubicin, which exhibited one order of magnitude lower activity towards K562/4 cells than towards K562 cells. Lead compounds 5a and 3f inhibited HIF-1α expression and activity and induced apoptosis in hypoxic tumor cells, which was confirmed by poly(ADP-ribose)polymerase (PARP) cleavage. Moreover, 5a and 3f showed strong antiestrogenic potencies in MCF7 breast cancer cells. Thus, the described series of quinoxaline 1,4-dioxides has high anticancer potential and good aqueous solubility. Therefore, these compounds are promising for further drug development of hypoxia-targeted anticancer agents.

Piper Species: A Comprehensive Review on Their Phytochemistry, Biological Activities and Applications.

Piper species are aromatic plants used as spices in the kitchen, but their secondary metabolites have also shown biological effects on human health. These plants are rich in essential oils, which can be found in their fruits, seeds, leaves, branches, roots and stems. Some Piper species have simple chemical profiles, while others, such as Piper nigrum, Piper betle, and Piper auritum, contain very diverse suites of secondary metabolites. In traditional medicine, Piper species have been used worldwide to treat several diseases such as urological problems, skin, liver and stomach ailments, for wound healing, and as antipyretic and anti-inflammatory agents. In addition, Piper species could be used as natural antioxidants and antimicrobial agents in food preservation. The phytochemicals and essential oils of Piper species have shown strong antioxidant activity, in comparison with synthetic antioxidants, and demonstrated antibacterial and antifungal activities against human pathogens. Moreover, Piper species possess therapeutic and preventive potential against several chronic disorders. Among the functional properties of Piper plants/extracts/active components the antiproliferative, anti-inflammatory, and neuropharmacological activities of the extracts and extract-derived bioactive constituents are thought to be key effects for the protection against chronic conditions, based on preclinical in vitro and in vivo studies, besides clinical studies. Habitats and cultivation of Piper species are also covered in this review. In this current work, available literature of chemical constituents of the essential oils Piper plants, their use in traditional medicine, their applications as a food preservative, their antiparasitic activities and other important biological activities are reviewed.

In Vitro Antileishmanial Activity of Sterols from Trametes versicolor (Bres. Rivarden).

Two ergostanes, 5α,8α-epidioxy-22E-ergosta-6,22-dien-3ß-ol (1) and 5α-ergost-7,22-dien-3ß-ol (2), and a lanostane, 3ß-hydroxylanostan-8,24-diene-21-oic acid (trametenolic acid) (3), were isolated from an n-hexane extract prepared from the fruiting body of Trametes versicolor (Bres. Rivarden). The activity of the isolated sterols was evaluated against promastigotes and amastigotes of Leishmania amazonensis Lainson and Shaw, 1972. The lanostane, compound (3), showed the best inhibitory response (IC50 promastigotes 2.9 ± 0.1 µM and IC50 amastigotes 1.6 ± 0.1 µM). This effect was 25-fold higher compared with its cytotoxic effect on peritoneal macrophages from BALB/c mice. Therefore, trametenolic acid could be regarded as a promising lead for the synthesis of compounds with antileishmanial activity.

Antiprotozoal screening of the Cuban native plant Scutellaria havanensis.

CONTEXT: Scutellaria havanensis Jacq. (Lamiaceae) is a native medicinal herb with a history of use in Cuba. OBJECTIVE: This study screens the antiprotozoal activity of S. havanensis. MATERIALS AND METHODS: Chloroform and methanol extracts from leaves and stems were evaluated in vitro at doses between 0.015 and 200 µg/mL against protozoan parasites: Plasmodium berghei, Trichomonas vaginalis and Leishmania amazonensis. Chloroform and methanol extracts were characterized by GC/MS. Cytotoxicity against mouse peritoneal macrophages was tested in parallel. RESULTS: Scutellaria havanensis extracts exhibited IC50 values between 7.7 and 32.2 µg/mL against trophozoites of P. berghei and T. vaginalis; while the extracts were inactive against L. amazonensis promastigotes. Trichomonicidal activity of methanol extract exhibited the best selectivity but chloroform extract showed the highest antiplasmodial, trichomonicidal and cytotoxic activity. The majority of compounds in the chloroform extract were hydroxy and/or methoxyflavones (77.96%), in particular, wogonin (48.27%). In methanol extract, wogonin (5.89%) was detected. Trichomonicidal effect of wogonin was moderate (IC50 = 56 µM) and unspecific with respect to macrophages (SI = 2). On the contrary, antiplasmodial activity of wogonin were particularly active (IC50 = 15 µM) demonstrating a higher selectivity index (SI = 7.4). CONCLUSIONS: Wogonin is an active principle compound of the chloroform extract of S. havanensis against P. berghei and T. vaginalis trophozoites, whereas the methanol extract of S. havanensis should be investigated more deeply as a trichomonicide. Our findings suggest that wogonin is potentially useful for the development of antimalarial alternative treatments.

The efficacy of 2-nitrovinylfuran derivatives against Leishmania in vitro and in vivo.

Despite recent advances in the treatment of some forms of leishmaniasis, the available drugs are still far from ideal due to inefficacy, parasite resistance, toxicity and cost. The wide-spectrum antimicrobial activity of 2-nitrovinylfuran compounds has been described, as has their activity against Trichomonas vaginalis and other protozoa. Thus, the aim of this study was to test the antileishmanial activities of six 2-nitrovinylfurans in vitro and in a murine model of leishmaniasis. Minimum parasiticide concentration (MPC) and 50% inhibitory concentration (IC50) values for these compounds against the promastigotes of Leishmania amazonensis, Leishmania infantum and Leishmania braziliensis were determined, as were the efficacies of two selected compounds in an experimental model of cutaneous leishmaniasis (CL) caused by L. amazonensis in BALB/c mice. All of the compounds were active against the promastigotes of the three Leishmania species tested. IC50 and MPC values were in the ranges of 0.8-4.7 µM and 1.7-32 µM, respectively. The compounds 2-bromo-5-(2-bromo-2-nitrovinyl)-furan (furvina) and 2-bromo-5-(2-methyl-2-nitrovinyl)-furan (UC245) also reduced lesion growth in vivo at a magnitude comparable to or higher than that achieved by amphotericin B treatment. The results demonstrate the potential of this class of compounds as antileishmanial agents and support the clinical testing of Dermofural(r) (a furvina-containing antifungal ointment) for the treatment of CL.

In Vitro and In Vivo Antileishmanial Activity of Thioridazine.

INTRODUCTION: Leishmaniasis is a neglected disease with high prevalence and incidence in tropical and subtropical areas. Existing drugs are limited due to cost, toxicity, declining efficacy and unavailability in endemic places. Drug repurposing has established as an efficient way for the discovery of drugs for a variety of diseases. PURPOSE: The objective of the present work was testing the antileishmanial activity of thioridazine, an antipsychotic agent with demonstrated effect against other intracellular pathogens. METHODS: The cytotoxicity for mouse peritoneal macrophages as well as the activity against Leishmania amazonensis, Leishmania mexicana and Leishmania major promastigotes and intracellular amastigotes, as well as in a mouse model of cutaneous leishmaniasis, were assessed. RESULTS: Thioridazine inhibited the in vitro proliferation of promastigotes (50% inhibitory concentration-IC50-values in the range of 0.73 µM to 3.8 µM against L. amazonensis, L. mexicana and L. major) and intracellular amastigotes (IC50 values of 1.27 µM to 4.4 µM for the same species). In contrast, in mouse peritoneal macrophages, the 50% cytotoxic concentration was 24.0 ± 1.89 µM. Thioridazine inhibited the growth of cutaneous lesions and reduced the number of parasites in the infected tissue of mice. The dose of thioridazine that inhibited lesion development by 50% compared to controls was 23.3 ± 3.1 mg/kg and in terms of parasite load, it was 11.1 ± 0.97 mg/kg. CONCLUSIONS: Thioridazine was effective against the promastigote and intracellular amastigote stages of three Leishmania species and in a mouse model of cutaneous leishmaniasis, supporting the potential repurposing of this drug as an antileishmanial agent.

Antileishmanial activity of 5-nitroindazole derivatives.

Background: Currently, there is no safe and effective vaccine against leishmaniasis and existing therapies are inadequate due to high toxicity, cost and decreased efficacy caused by the emergence of resistant parasite strains. Some indazole derivatives have shown in vitro and in vivo activity against Trichomonas vaginalis and Trypanosoma cruzi. On that basis, 20 indazole derivatives were tested in vitro against Leishmania amazonensis. Objective: To evaluate the in vitro activity of twenty 2-benzyl-5-nitroindazolin-3-one derivatives against L. amazonensis. Design: For the selection of promising compounds, it is necessary to evaluate the indicators for in vitro activity. For this aim, a battery of studies for antileishmanial activity and cytotoxicity were implemented. These results enabled the determination of the substituents in the indazole derivatives responsible for activity and selectivity, through the analysis of the structure-activity relationship (SAR). Methods: In vitro cytotoxicity against mouse peritoneal macrophages and growth inhibitory activity in promastigotes were evaluated for 20 compounds. Compounds that showed adequate selectivity were tested against intracellular amastigotes. The SAR from the results in promastigotes was represented using the SARANEA software. Results: Eight compounds showed selectivity index >10% and 50% inhibitory concentration <1 µM against the promastigote stage. Against intracellular amastigotes, four were as active as Amphotericin B. The best results were obtained for 2-(benzyl-2,3-dihydro-5-nitro-3-oxoindazol-1-yl) ethyl acetate, with 50% inhibitory concentration of 0.46 ± 0.01 µM against amastigotes and a selectivity index of 875. The SAR study showed the positive effect on the selectivity of the hydrophilic fragments substituted in position 1 of 2-benzyl-5- nitroindazolin-3-one, which played a key role in improving the selectivity profile of this series of compounds. Conclusion: 2-bencyl-5-nitroindazolin-3-one derivatives showed selective and potent in vitro activity, supporting further investigations on this family of compounds as potential antileishmanial hits.

Efficacy and Safety of Zataria multiflora Boiss Essential Oil against Acute Toxoplasmosis in Mice.

BACKGROUND: Broad spectrums of pharmacological properties, including antimicrobial activity have been attributed to Zataria multiflora Boiss (Laminaceae). The in vivo efficacy and safety of Z. multiflora essential oil (ZM-EO) were evaluated against acute toxoplasmosis caused by Toxoplasma gondii (Sarcocystidae) in mice. METHODS: Z. multiflora (aerial parts) was obtained from the rural districts of Kerman city (Kerman Province) Southwestern Iran, in May of 2016. Male NMRI mice were orally treated with normal saline (control group) and ZM-EO at the doses of 0.2 and 0.4 mL/kg once a day for 14 d (8 mice in each group). On the 15th day, the mice were infected with 104 tachyzoites of T. gondii RH strain by intraperitoneal route. The mortality rate and parasite load were determined in the infected mice. Additionally, 24 mice were applied to examine the sub-acute toxicity of ZM-EO at the above doses after treatment during 14 d. RESULTS: GC/MS analysis displayed that the key constituents were thymol (45.4%), carvacrol (23%) and p-cymene (10.6%), respectively. Overall, 100% mortality was observed on the 8th and 9th days in treated mice with the concentrations of 0.2 and 0.4 mL/kg, respectively. The mean number of tachyzoites in the mice treated with 0.2 and 0.4 mL/kg of ZM-EO were 189×104 and 76×104 cell/mL, respectively, meaningfully (P<0.05) reduced compared with the control mice. Results also demonstrated that ZM-EO had no important toxicity on mice. CONCLUSION: The results demonstrated the efficacy of ZM-EO against acute toxoplasmosis. Nevertheless, supplementary surveys are mandatory to examine its precise effects, mainly immunomodulatory effect on toxoplasmosis.

The Leishmania HSP20 is antigenic during natural infections, but, as DNA vaccine, it does not protect BALB/c mice against experimental L. amazonensis infection.

Protozoa of the genus Leishmania are causative agents of leishmaniasis, an important health problem in both human and veterinary medicine. Here, we describe a new heat shock protein (HSP) in Leishmania, belonging to the small HSP (sHSP) family in kinetoplastids. The protein is highly conserved in different Leishmania species, showing instead significant divergence with sHSP's from other organisms. The humoral response elicited against this protein during Leishmania infection has been investigated in natural infected humans and dogs, and in experimentally infected hamsters. Leishmania HSP20 is a prominent antigen for canine hosts; on the contrary, the protein seems to be a poor antigen for human immune system. Time-course analysis of appearance of anti-HSP20 antibodies in golden hamsters indicated that these antibodies are produced at late stages of the infection, when clinical symptoms of disease are patent. Finally, the protective efficacy of HSP20 was assessed in mice using a DNA vaccine approach prior to challenge with Leishmania amazonensis.

Morphometric changes of Triatoma flavida Neiva, 1911 (Hemiptera:Triatominae) in the transition from sylvatic to laboratory conditions.

The one-generational metric changes occurring in Triatoma flavida (Hemiptera: Triatominae) when carried from its wild habitat (caves) to laboratory, were examined using traditional morphometric techniques. As for other species of Triatoma, Rhodnius or Panstrongylus studied in similar conditions, a significant reduction of head, thorax and wing size was observed. Sexual dimorphism of the wings, while present in the wild sample, was not detected anymore in the laboratory individuals. Biological significance and epidemiological importance are discussed.

Eficacia de la artemisina en modelos murinos de leishmaniasis cutánea experimental causada por Leishmania amazonensis / Artemisine efficacy in murine models of experimental cutaneous leishmaniasis caused by Leishmania amazonensis

Los limitados tratamientos disponibles para enfrentar la leishmaniasis requieren el desarrollo de investigaciones para buscar nuevos agentes terapéuticos. Una estrategia recomendada es el reposicionamiento farmacológico, en el que la artemisina figura como un posible candidato. El objetivo de este estudio es evaluar las potencialidades de la artemisina en dos modelos murinos de leishmaniasis cutánea experimental. Para ello, se emplearon ratones BALB/c (susceptibles) y C57BL/6 (resistentes) infectados con Leishmania amazonensis. El tratamiento se realizó por vía oral o intralesional con cinco dosis de artemisina a 30 mg/kg cada 4 días. Se determinó el comportamiento del peso, la evolución del tamaño de la lesión y la carga parasitaria. En ambos modelos animales se observó que el tratamiento con artemisina (oral e intralesional) disminuyó el tamaño de la lesión y la carga parasitaria con respecto a los grupos infectados sin tratamiento (p 0,05). Los ratones C57BL/6 tratados por vía oral fueron los únicos capaces de controlar las lesiones hasta el final del experimento. Se demuestra la eficacia in vivo de la artemisina en dos modelos de leishmaniasis cutánea inducida por L. amazonensis y se destaca la administración por vía oral en el control de la enfermedad. Se sugiere el futuro desarrollo de este fármaco para el tratamiento de la leishmaniasis cutánea.

The limited treatments available for leishmaniasis require the development of research for new therapeutic agents. One recommended strategy is the pharmacological repositioning, where artemisinin stands out as a possible candidate. The aim of this study is to evaluate the potential of artemisinin in two murine models of experimental cutaneous leishmaniasis. For this purpose, BALB/c (susceptible) and C57BL/6 (resistant) mice infected with Leishmania amazonensis were used. Oral or intralesional treatment was performed with five doses of artemisinin at 30 mg/kg every four days. Weight behavior, evolution of lesion size, and parasitic load were determined. In both animal models it was observed that treatment with artemisinin (oral and intralesional) decreased lesion size and parasitic load with respect to the untreated infected groups (p 0.05). Orally treated C57BL/6 mice were the only ones able to control lesions until the end of the experiment. The in vivo efficacy of artemisinin in two models of cutaneous leishmaniasis induced by L. amazonensis is demonstrated and oral administration is highlighted in the control of the disease. Further development of this drug for the treatment of cutaneous leishmaniasis is suggested.

Chemical profile and anti-leishmanial activity of three Ecuadorian propolis samples from Quito, Guayaquil and Cotacachi regions.

Three propolis samples were collected from different regions of Ecuador (Quito, Guayaquil and Cotacachi) and their methanolic extracts were prepared. Preliminary information supplied by TLC and NMR data, allowed us to define two main types of propolis: Cotacachi propoli sample (CPS), rich in flavonoids and Quito and Guayaquil samples (QPS and GPS) containing triterpenic alcohols and acetyl triterpenes as the main constituents. Two different approaches based on RP-HPLC preparative procedure and NMR structural determination (CPS) and GC-MS analysis (QPS and GPS) were successfully used for the chemical characterization of their major compounds. All three propolis extracts were able to inhibit Leishmania amazonensis growth but propolis sample rich in flavonoids was the most active (IC50=17.1±1.7µg/mL). In the literature this is the first study on propolis from Ecuador.

Efecto in vitro del antirretroviral tipranavir sobre taquizoitos de Toxoplasma gondii

La introducción de la terapia antirretroviral de alta eficiencia ha conllevado a una disminución en la frecuencia de neurotoxoplasmosis en personas con VIH. Experimentalmente se demostró que los antirretrovirales inhibidores de proteasas pueden tener además una acción directa sobre el parásito, en este caso Toxoplasma gondii. El objetivo es evaluar la actividad antitoxoplasma in vitro del tipranavir, un antirretroviral inhibidor de proteasa de tercera generación. Para ello se determinó la inhibición del crecimiento causada por el tipranavir sobre taquizoitos intracelulares de Toxoplasma gondii, así como su citotoxicidad frente a macrófagos residentes en el peritoneo de ratones OF-1. En paralelo, se evaluaron el atazanavir, la sulfadiazina y pirimetamina como fármacos de referencia. El tipranavir mostró actividad inhibitoria frente a taquizoitos de T. gonddi, con una CI50 de 21,2 ± 3,0 µM, la cual fue similar (p> 0,05) a la obtenida con la sulfadiazina (CI50= 23,3 ± 3,6 µM) y mayor (p< 0,05) que el atazanavir (CI50= 2,8 ± 0,7 µM) y la pirimetamina (CI50= 1,2 ± 0,2 µM). Sin embargo, mostró un valor de CC50 (105,9 ± 10,0 µM) superior (p< 0,05) con respecto a los fármacos de referencia (atazanavir (CC50= 25,0 ± 0,5 µM), sulfadiazina (CC50= 25,2 ± 3,2 µM) y pirimetamina (CC50= 4,4 ± 1,2 µM). En conclusión, este trabajo describe por primera vez la actividad in vitro del tipranavir sobre taquizoitos de T. gondii.

The introduction of highly efficient antiretroviral therapy has brought about a decrease in the frequency of neurotoxoplasmosis among people with HIV. It was demonstrated experimentally that protease inhibitor antiretrovirals may also have a direct action against the parasite, in this case Toxoplasma gondii. The purpose of the study was to evaluate the antitoxoplasma activity in vitro of tipranavir, a third-generation protease inhibitor antiretroviral. To achieve this aim, determination was made of the growth inhibition caused by tipranavir in Toxoplasma gondii intracellular tachyzoites, as well as its cytotoxicity against macrophages living in the peritoneum of OF-1 mice. Additionally, evaluation was conducted of atazanavir, sulfadiazine and pyrimethamine as reference drugs. Tipranavir displayed inhibitory activity against T. gondii tachyzoites, with a IC50 of 21.2 ± 3,0 µM, similar (p> 0.05) to the one obtained with sulfadiazine (IC50= 23.3 ± 3.6 µM) and higher (p< 0.05) than atazanavir (IC50= 2.8 ± 0.7 µM) and pyrimethamine (IC50= 1.2 ± 0.2 µM). However, its CC50 value (105.9 ± 10.0 µM) was higher (p< 0.05) than that of the reference drugs atazanavir (CC50= 25.0 ± 0.5 µM), sulfadiazine (CC50= 25.2 ± 3.2 µM) and pyrimethamine (CC50= 4.4 ± 1.2 µM). This is the first time a description is provided of the in vitro activity of tipranavir against T. gondii tachyzoites.

Evaluación de la citotoxicidad de extractos marinos sobre un panel de líneas celulares / Evaluation of cytotoxicity of different marine extracts in a cell line panel

Introducción: los extractos naturales provenientes de fuentes marinas representan una importante fuente en el descubrimiento de nuevos compuestos con potencialidades como anticarcinogénicos. Objetivos: determinar el efecto de cinco extractos provenientes de diferentes organismos marinos sobre la viabilidad de un panel de cinco líneas celulares (A549, HEp-2, MDA-MB-231, SiHa y MRC-5). Metodos: el efecto de los extractos (Physalia physali, Cassiopea xamachana, Tripneustes ventricosus, Echinometra lucunter) se determinó mediante el ensayo colorimétrico con el empleo de bromuro de 3(4,5 dimetil-2-tiazoil)-2,5-difeniltetrazolio. Mediante de RT-PCR se determinó adicionalmente el efecto del extracto de Echinometra lucunter sobre la expresión de los genes apoptóticos p53, survivin, bcl-xL y noxa en SiHa. Resultados: todos los extractos afectaron la viabilidad celular de la línea normal MRC-5 de pulmón humano. Sin embargo, no disminuyeron la viabilidad de las líneas celulares de origen tumoral con excepción del extracto de Echinometra lucunter. Este extracto solo afectó la viabilidad de la línea celular tumoral SiHa. Los valores de las concentraciones inhibitorias medias (CI50) mostraron que solo para el extracto de Echinometra lucunter, la línea celular tumoral SiHa evidenció una CI50 de 52,07±11 µg/mL que es significativamente inferior a MRC-5 con una CI50 de 98,6±14 µg/mL, por lo que se muestra selectividad frente a las células tumorales. Adicionalmente, el extracto disminuyó significativamente la expresión de los genes proapoptóticos lo que sugiere la muerte celular por necrosis en las células SiHa. Conclusiones: el extracto proveniente de Echinometra lucunter resultó selectivo frente a las células tumorales SiHa. Experimentos que incluyan otras líneas celulares de cáncer cérvicouterino podrían confirmar el potencial de este extracto frente a esta variedad histológica de cáncer(AU)

Introduction: natural extracts from marine sources represent an important source for the discovery of new compounds with anti-carcinogenic potentialities. Objectives: to determine the effect of five extracts from several marine organisms pm the viability of a panel of five cell lines (A549, HEp-2, MDA-MB-231, SiHa y MRC-5). Methods: the effects of the extracts (Physalia physali, Cassiopea xamachana, Tripneustes ventricosus, Echinometra lucunter) were then determined by using the colorimetric assay with 3 (4,5 dimethyl-2-tiazoil)/2,5-difeniltetrazolium bromide. Additionally, the effect of extract of Echinometra lucunter was determined on the expression of apoptotic genes p53, survivin, bcl-xL and noxa in SiHa. Results: all the extracts affected the cell viability of the normal cell line MRC-5 of the human lung. However, viability of tumoral cell lines did not decrease except for the extract from Echinometra lucunter. This extract just affected the viability of tumor cell line SiHa. The mean inhibitory concentrations (IC50) showed that only for Echinometra lucunter extract, the tumor cell line SiHa revealed a IC50 of 52,07±11 µg/mL that is significantly lower than that of MRC-5 with IC50 of 98,6±14 µg/mL, therefore the selectivity against the tumor cells was shown. Moreover, the extract markedly decreased the expression of propapoptosis genes, thus indicating the cell death from necrosis in SIHa cells. Conclusions: extract from Echinometra lucunter was selective against tumor cells SiHa. Other experiments that will include other cervix uterine cancer cell lines can confirm the potential of this extract to have an effect on this histological cancer type(AU)

Activity of Cuban propolis extracts on Leishmania amazonensis and Trichomonas vaginalis.

In this paper we analyzed the antiprotozoal effects of eighteen Cuban propolis extracts (brown, red and yellow type) collected in different geographic areas, using Leishmania amazonensis (as a model of intracellular protozoa) and Trichomonas vaginalis (as a model of extracellular protozoa). All evaluated propolis extracts caused inhibitory effect on intracellular amastigotes of L. amazonensis. However, cytotoxicity on peritoneal macrophages from BALB/c mice was observed. Only five samples decreased the viability of T. vaginalis trophozoites at concentrations lower than 10 microg/mL. No correlation between the type of propolis and antiprotozoal activity was found. Cuban propolis extracts demonstrated activity against both intracellular and extracellular protozoa model, as well as the potentialities of propolis as a natural source to obtain new antiprotozoal agents.

Actividad anti-plasmodial de especies de Solanaceae presentes en Cuba / Antiplasmodial activity of Solanaceae species present in Cuba

Introducción: el control de la malaria depende en gran medida de una terapia efectiva. Muchos de los anti-maláricos actuales son de origen natural. Especies de la flora cubana contienen metabolitos anti-Plasmodium. En este estudio, se identifican extractos de Solanaceae con actividad antiplasmodial promisoria. Objetivo: evaluar la actividad esquizonticida frente a Plasmodium berghei de 31 extractos de 7 especies, correspondientes a 5 géneros de plantas de Solanaceae, colectadas en el occidente de nuestro país y sin antecedentes de un estudio similar. Métodos: se prepararon 31 extractos hidroalcohólicos (90 y 30 por ciento etanol) de diferentes órganos de: Brunfelsia undulata Sw., Datura stramonium L. var. tatula (L.) Torr., Physalis solanaceus (Schltdl.) Axelius, Solandra longiflora Tuss., Solanum myriacanthum Dunal, Solanum seaforthianum And. ySolanum umbellatum Mill.La actividad de los extractos se evaluó in vitro frente a P. berghei y se determinó su citotoxicidad frente a fibroblastos humanos MRC-5. Resultados: los extractos deB. undulata y S. umbellatumfueron inactivos.El extracto de tallos de S. seaforthianummostró la actividad antiplasmodial más potente (CI50 = 3,9µg/mL) con excelentes electividad (18,2). Conclusiones: se demostró la actividad anti-plasmodial in vitro de extractos de cinco especies de Solanaceae sin antecedentes de esta acción farmacológica. Se identificó un extracto con potente actividad esquizonticida frente a P. berghei y con excelente selectividad. Este resultado nos anima a continuar el estudio de la preparación vegetal de S. seaforthianum(AU)

The efficacy of 2-nitrovinylfuran derivatives against Leishmania in vitro and in vivo

Despite recent advances in the treatment of some forms of leishmaniasis, the available drugs are still far from ideal due to inefficacy, parasite resistance, toxicity and cost. The wide-spectrum antimicrobial activity of 2-nitrovinylfuran compounds has been described, as has their activity against Trichomonas vaginalis and other protozoa. Thus, the aim of this study was to test the antileishmanial activities of six 2-nitrovinylfurans in vitro and in a murine model of leishmaniasis. Minimum parasiticide concentration (MPC) and 50% inhibitory concentration (IC50) values for these compounds against the promastigotes of Leishmania amazonensis, Leishmania infantum and Leishmania braziliensis were determined, as were the efficacies of two selected compounds in an experimental model of cutaneous leishmaniasis (CL) caused by L. amazonensis in BALB/c mice. All of the compounds were active against the promastigotes of the three Leishmania species tested. IC50 and MPC values were in the ranges of 0.8-4.7 µM and 1.7-32 µM, respectively. The compounds 2-bromo-5-(2-bromo-2-nitrovinyl)-furan (furvina) and 2-bromo-5-(2-methyl-2-nitrovinyl)-furan (UC245) also reduced lesion growth in vivo at a magnitude comparable to or higher than that achieved by amphotericin B treatment. The results demonstrate the potential of this class of compounds as antileishmanial agents and support the clinical testing of Dermofural(r) (a furvina-containing antifungal ointment) for the treatment of CL.

Actividad antileishmanial de seis extractos de organismos marinos / Antileishmanial activity of six extracts from marine organisms

Introducción: las infecciones causadas por protozoos del género Leishmania constituyen un problema de salud mundial con una alta prevalencia en países subdesarrollados. En la actualidad no existe una vacuna contra esta enfermedad y el tratamiento utilizado es deficiente, por lo que la búsqueda de medicamentos más efectivos y seguros constituye una urgente necesidad. Objetivo: evaluar la actividad antileishmanial in vitro de 6 extractos acuosos e hidroalcohólicos de organismos marinos. Métodos: se determinó la actividad frente a promastigotes y amastigotes de Leishmania amazonensis, así como su toxicidad frente a macrófagos peritoneales de ratones BALB/c. Resultados: en el ensayo de promastigotes los extractos de Bryothamnion triquetrum, Bunodosoma granulifera, Halimeda opuntia, y Physalia physalis mostraron una inhibición del crecimiento a concentraciones menores de 100 µg/mL; mientras que frente a amastigotes, estos 2 últimos extractos fueron los más activos y menos tóxicos con un índice de selectividad de 6 y 8, respectivamente. Conclusiones: teniendo en cuenta estos resultados se consideró que los extractos de H. opuntia y P. physalis mostraron una promisoria actividad, por lo que se sugiere continuar los estudios de su actividad in vivo.

Introduction: infections caused by protozoa of the genus Leishmania are a global health problem with a high prevalence in underdeveloped countries. There is no vaccine against this disease at present and the treatment used is poor, so the search for more effective and safe medicines is an urgent need. Objective: to assess the in vitro antileishmanial activity of six aqueous and hydroalcohol extracts from marine organisms. Methods: the activity of six extracts against Leishmania amazonensis promastigots and amastigots as well as their toxicity against peritoneal macrophages in BALB/c mice. Results: in the promastigot assay, the extracts from Bryothamnion triquetrum, Bunodosoma granulifera, Halimeda opuntia and Physalia physalis showed growth inhibition at concentrations lower than 100 µg/mL whereas in amastigots, these last two extracts were the most active and least toxic with a selectivity index of 6 and 8 respectively. Conclusions: taking these results into account, it was considered that the H. opuntia and P. physalis extracts showed a promising activity, so it is suggested that further studies on its in vivo activity be conducted.

Identificación de especies de Leishmania por la técnica de amplificación al azar del ADN polimórfico / Identification of Leishmania species by the random amplified polymorphic DNA technique

INTRODUCCIÓN: la leishmaniosis ha sido clasificada por la Organización Mundial de la Salud como una de las enfermedades tropicales más importantes. El control de esta parasitosis es muy difícil, porque no existen vacunas y el tratamiento es tóxico e insatisfactorio. Es de crucial importancia establecer un método de diagnóstico oportuno junto a la identificación del parásito, lo cual incide en la selección del tratamiento adecuado y en el diseño de las medidas de control apropiadas. Recientemente, los avances en biología molecular han permitido la caracterización de especies de Leishmania por diferentes métodos. La técnica de ADN polimórfico amplificado al azar es una técnica simple para detectar el polimorfismo genético del ADN. OBJETIVO: estandarizar la técnica de ADN polimórfico amplificado al azar para su utilización en la tipificación de especies de Leishmania del Nuevo Mundo. MÉTODOS: empleando una concentración de cebador de 5 pmol, 75 ng de ADN molde, 2 mM de cloruro de magnesio y 2 U de Taq ADN polimerasa en 25 mL de reacción, se obtuvieron patrones de amplificación reproducibles. La técnica optimizada de ADN polimórfico amplificado al azar se empleó para determinar las diferencias genéticas entre 10 cepas de referencia de Leishmania, con la utilización de 6 juegos de cebadores comerciales diseñados al azar. La relación filogenética entre las especies estudiadas se determinó utilizando la estrategia de agrupaciones mediante el método de UPGMA. RESULTADOS: los cebadores OPA 3, 4 y 8 permitieron diferenciar las 10 cepas de referencia de Leishmania estudiadas. Se obtuvieron 2 grupos genéticos bien definidos donde se agrupan las especies del subgénero Leishmania y Viannia, respectivamente; los 2 subgéneros mostraron diferencias genéticas. CONCLUSIONES: de esta forma se cuenta en el laboratorio con la técnica del ADN polimórfico amplificado al azar optimizada para la identificación de especies de Leishmania.

INTRODUCTION: leishmaniosis has been regarded by the World Health Organization as one of the most important tropical diseases. It is very difficult to control such parasitosis because there are not vaccines, and therapy is generally toxic and unsatisfactory. It is of vital importance to set prompt diagnostic method along with identification of the parasite in order to select the suitable treatment and to design the most convenient control measures. Recently, the advances in molecular biology have made it possible to characterize Leishmania species by different methods. The random amplified polymorphic DNA technique is a simple method to detect the genetic polymorphic DNA. OBJECTIVE: to standardize the random amplified polymorphic DNA technique for its use in New World Leishmania species typing. METHODS: by using 5 pmol primer concentration, 75 ng of template DNA, 2 mM of magnesium chloride and 2 U of polymerase DNA Taq in 25µL reaction, two reproducible amplification patters were obtained. The optimized random amplified polymorphic DNA technique served to determine the genetic differences among ten reference strains of Leishmania, with 6 sets of randomly designed conventional primers. The UP GMA method-based grouping strategy determined the phylogenetic relation among the studied species. RESULTS: OPA primers -3, 4 and 8 allowed distinguishing the ten reference strains of Leishmania under study. Two well defined genetic groups including species of Leishmania and Viannia subgenres were obtained; these 2 subgenres showed genetic differences. CONCLUSIONS: in this way, our laboratory has the optimized random amplified polymorphic DNA for the identification of Leishmania species.