Browsing by Autor "Juan C. Ticona"

Now showing 1 - 13 of 13

An unprecedented chlorine-containing piperamide from Piper pseudoarboreum as potential leishmanicidal agent
(Elsevier BV, 2019) Ninoska Flores; Juan C. Ticona; Pablo Bilbao-Ramos; María Auxiliadora Dea‐Ayuela; Juan Celidonio Ruiz Macedo; Isabel L. Bazzocchi; F. Bolás‐Fernández; Ignacio A. Jiménez
Antiparasitic activity of flavonoids from Piper species
(Thieme Medical Publishers (Germany), 2010) Juan C. Ticona; N Flores; David Gutiérrez; A. Giménez; Ignacio A. Jiménez; Isabel L. Bazzocchi
Parasitic diseases, including leishmaniasis, chagas and malaria, are serious problems for public health throughout the world, especially in tropical and subtropical regions [1]. Due to the absence of effective vaccines, inadequate chemotherapy and the emergence of drug resistance, currently, there is an urgent need to search for novel, effective and safe drugs for the treatment of these diseases [2]. Several Piper species have been used in the traditional medicine in Latin America, including for the treatment of parasitic diseases [3]. As part of our research aiming to uncover antiparasitic compounds from Bolivian Piper species, we studied the dichloromethane extract from the leaves of Piper aduncum, P. acutifolium, P. glabratum, P. heterophyllum, P. pilliraneum and P. rusbyi. This study has led to the isolation of eight known flavonoids and a new compound, 5,5′-dihydroxy-7,3′-dimethoxy-flavanone. Their structures were elucidated on the basis of spectroscopic data, including homo- and heteronuclear correlation NMR experiments (COSY, ROESY, HSQC and HMBC). In the search for new antiparasitic agents, these compounds were evaluated in vitro against three strains of Leishmania (L. amazonensis, L. braziliensis and L. donovani), Trypanosoma cruzi and Plasmodium falciparum. 4′,7-Dimethoxy-5-hydroxy-flavanone (IC50 4.0µg/mL) showed a moderate activity against P. falciparum. The most active compound against promastigote forms of the three Leishmania strains was flavokavain B (IC50 5.4µg/mL), with twice the activity of the control pentamidine (IC50 10.0µg/mL). These results support the use of Piper species as a traditional remedy in the treatment of parasitic diseases.
Antiparasitic Metabolites from Hyptis brevipes, a Tacana Medicinal Plant
(SAGE Publishing, 2019) Ivan Limachi; Claudia Condo; Camila Palma; Nélida Nina; Efraín Salamanca; Juan C. Ticona; Enrique Udaeta; Ninoska Flores; Alcides Serato; Natalio Marupa
A bioassay screening against protozoa parasites of several Tacana medicinal plants gave Hyptis brevipes (Id'ene eidhue), traditionally used as decoction for intestinal parasites, as the most active extract. In this work we did a bioguided isolation of active constituents found in leaves. Structure elucidation was carried out by NMR spectroscopy and MS spectrometry analyses. Active constituents showed differentiated activity towards Giardia lamblia, Trypanosoma cruzi, several Leishmania strains, Plasmodium falciparum and cytotoxicity against HeLa cells. Brevipolide H (1) was the less cytotoxic and best antiparasitic, while the catechol derivative (2) the most active and cytotoxic.
(E)-Piplartine Isolated from Piper pseudoarboreum, a Lead Compound against Leishmaniasis
(Multidisciplinary Digital Publishing Institute, 2020) Juan C. Ticona; Pablo Bilbao-Ramos; Ninoska Flores; María Auxiliadora Dea‐Ayuela; F. Bolás‐Fernández; Ignacio A. Jiménez; Isabel L. Bazzocchi
The current therapies of leishmaniasis, the second most widespread neglected tropical disease, have limited effectiveness and toxic side effects. In this regard, natural products play an important role in overcoming the current need for new leishmanicidal agents. The present study reports a bioassay-guided fractionation of the ethanolic extract of leaves of Piper pseudoarboreum against four species of Leishmania spp. promastigote forms, which afforded six known alkamides (1-6). Their structures were established on the basis of spectroscopic and spectrometric analysis. Compounds 2 and 3 were identified as the most promising ones, displaying higher potency against Leishmania spp. promastigotes (IC50 values ranging from 1.6 to 3.8 µM) and amastigotes of L. amazonensis (IC50 values ranging from 8.2 to 9.1 µM) than the reference drug, miltefosine. The efficacy of (E)-piplartine (3) against L. amazonensis infection in an in vivo model for cutaneous leishmaniasis was evidenced by a significant reduction of the lesion size footpad and spleen parasite burden, similar to those of glucantime used as the reference drug. This study reinforces the therapeutic potential of (E)-piplartine as a promising lead compound against neglected infectious diseases caused by Leishmania parasites.
ESTUDIO FITOQUÍMICO DE LAS HOJAS DE BOWDICHIA VIRGILIOIDES
(Universidad Autónoma del Estado de México, 2006) Juan C. Ticona; David Gutiérrez; Efraín Salamanca; Grace Ruiz; Crispín Paredes; Enrique Udaeta; Nayra Rodríguez; Gabriel García; Isabel López; A. Jiménez
"Bowdichia virgilioides, es una planta medicinal utilizada por la etnia Tacana, las hojas de este árbol fueron colectadas, en época seca, en la Prov. Abel Iturralde, Bolivia. Las hojas secas y pulverizadas fueron sometidas a maceración con diclorometano y el extracto crudo no presento actividad antipalúdica a dosis de 10μg/mL, frente a Plasmodium falciparum (cepa F32, sensible a la cloroquina). Estudios cromatográficos del extracto crudo y análisis espectroscópicos de las sustancias aisladas nos han permitido identificar: Lupeol (1), Lupenona (2), β-sitosterol (3), estigmasterol (4) y β-amirina (5), como los principales componentes triterpénicos acompañados de ácidos grasos no identificados."
ESTUDIOS QUÍMICOS, BIOLÓGICOS Y FARMACOLÓGICOS DE Galipea longiflora, KRAUSE
(Universidad Autónoma del Estado de México, 2005) Alberto Giménez; J. Antonio Avila; Grace Ruiz; Magali Paz; Enrique Udaeta; Juan C. Ticona; Efraín Salamanca; Crispín Paredes; Norka Rodríguez; Katia Quints
"La especie medicinal Galipea longiflora (Evanta) es utilizada por las etnias amazónicas: Tacana, Mosetene y Tsimane, como antiparasitario. Los alcaloides totales de esta especie vegetal serán centro de estudios clínicos como tratamiento alternativo para la leishmaniasis cutánea. Nuestros estudios detallan el aislamiento y caracterización de alcaloides quinolínicos, de la corteza y hojas, todos con actividad leishmanicida evaluada sobre promastigotes de: L. amazonensis, L. braziliensis, L. donovani y L. chagasi. Mediante modelos toxico cinéticos, se ha determinado la toxicidad aguda, subcrónica y parámetros fármaco-cinéticos, para el extracto crudo, en modelo murino. Se establecen las condiciones para el cultivo semi-continuo, in vitro, de células de Evanta."
Flavonoids from Piper delineatum modulate quorum-sensing-regulated phenotypes in Vibrio harveyi
(Elsevier BV, 2015) Alberto J. Martín‐Rodríguez; Juan C. Ticona; Ignacio A. Jiménez; Ninoska Flores; José J. Fernández; Isabel L. Bazzocchi
Flavonoids from Piper Species as Promising Antiprotozoal Agents against Giardia intestinalis: Structure-Activity Relationship and Drug-Likeness Studies
(Multidisciplinary Digital Publishing Institute, 2022) Juan C. Ticona; Pablo Bilbao-Ramos; Ángel Amesty; Ninoska Flores; María Auxiliadora Dea‐Ayuela; Isabel L. Bazzocchi; Ignacio A. Jiménez
Diarrhea diseases caused by the intestinal protozoan parasite Giardia intestinalis are a major global health burden. Moreover, there is an ongoing need for novel anti-Giardia drugs due to drawbacks with currently available treatments. This paper reports on the isolation and structural elucidation of six new flavonoids (1-6), along with twenty-three known ones (7-29) from the Piper species. Their structures were established by spectroscopic and spectrometric techniques. Flavonoids were tested for in vitro antiprotozoal activity against Giardia intestinalis trophozoites. In addition, structure-activity relationship (SAR) and in silico ADME studies were performed to understand the pharmacophore and pharmacokinetic properties of these natural compounds. Eight flavonoids from this series exhibited remarkable activity in the micromolar range. Moreover, compound 4 was identified as having a 40-fold greater antiparasitic effect (IC50 61.0 nM) than the clinical reference drug, metronidazole (IC50 2.5 µM). This antiprotozoal potency was coupled with an excellent selectivity index (SI 233) on murine macrophages and in silico drug-likeness. SAR studies revealed that the substitution patterns, type of functional group, and flavonoid skeleton played an essential role in the activity. These findings highlight flavonoid 4 as a promising candidate to develop new drugs for the treatment of Giardia infections.
Gastroprotective activity of alkaloid extract and 2-phenylquinoline obtained from the bark of Galipea longiflora Krause (Rutaceae)
(Elsevier BV, 2009) Francielle Zanatta; Renan Becker Gandolfi; Marivane Lemos; Juan C. Ticona; Alberto Giménez; Bruna Kurz Clasen; Valdir Cechinel Filho; Sérgio Faloni de Andrade
Leishmanicidal and cytotoxic activity from plants used in Tacana traditional medicine (Bolivia)
(Elsevier BV, 2018) Diandra Arévalo-Lopéz; Nélida Nina; Juan C. Ticona; Ivan Limachi; Efraín Salamanca; Enrique Udaeta; Crispín Paredes; Boris Espinoza; Alcides Serato; David Garnica
Registro de insuficiencia cardíaca en Santa Cruz de la Sierra, Bolivia. Registro SEPE-HF
(Sociedad Argentina de Cardiología, 2025) Roberto Cristodulo; Juan C. Ticona; Ligia Isabel Arguello Flores; Juan Manuel Vaca Villarroel; Nathalie Rojas; Johann S. Serrate; José Antonio Candelas Villagómez; E. Hornez; Luis Lijeron Alba; Jorge Montero
Introducción: La insuficiencia cardíaca es una verdadera pandemia, con más de 64 millones de personas con este síndrome en todo el mundo. Realizamos un registro de insuficiencia cardíaca en Santa Cruz de la Sierra – Bolivia, el REGISTRO SEPE-HF. Objetivos: determinar las características epidemiológicas, clínica, evaluación, tratamiento y pronóstico de la insuficiencia cardíaca en nuestra región. Material y métodos: Desde enero 2023 hasta abril 2024 fueron incluidos pacientes con historia de insuficiencia cardíaca internados por dicha causa en 7 centros participantes. Resultados: Se incluyeron 418 pacientes, el 49% hombres, con una media de edad de 67,4 ± 13,1 años. Tenía antecedentes de hipertensión arterial el 64%, de diabetes mellitus el 21%, de fibrilación auricular un 20%, de cardiopatía isquémica el 12%. La predominante fue la chagásica (37%). En el ecocardiograma transtorácico el 51% presentaba fracción de eyección ventricular izquierda menor de 40%. La incidencia de mortalidad cardiovascular fue del 5,5%. Se observaron similitudes en cuanto a nues-tra incidencia en muchos factores epidemiológicos, comorbilidades, perfil clínico y ecocardiograma con el Registro argentino de internación por insuficiencia cardíaca ARGEN-IC. Conclusión: El registro SEPE refleja las características y evolución de los pacientes internados por insuficiencia cardíaca en Santa Cruz de la Sierra, Bolivia. La etiología chagásica es responsable de más de un tercio de los casos, lo que hace imprescindible avanzar en el desarrollo de medidas que favorezcan el diagnóstico precoz de la afección y la erradicación de la endemia.
Trichilianones A-D, Novel Cyclopropane-Type Limonoids from Trichilia adolfi
(Multidisciplinary Digital Publishing Institute, 2021) Ivan Limachi; Mariela González-Ramírez; Sophie Manner; Juan C. Ticona; Efraín Salamanca; Alberto Giménez; Olov Sterner
The fractionation of an ethanol extract of the bark of Trichilia adolfi yielded four novel limonoids (trichilinones A-D, 1-4), with five fused rings and related to the hortiolide-type limonoids. Starting with an ε-lactone, which is α,β-unsaturated in trichilinones A and D (1 and 4), attached to a tetrahydrofuran ring that is connected to an unusual bicyclo [5.1.0] hexane system, joined with a cyclopentanone with a 3-furanyl substituent [(2-oxo)-furan-(5H)-3-yl in trichilinone D (4)], the four compounds isolated display a new 7/5/3/5/5 limonoid ring system. Their structures were established based on extensive analysis of NMR spectroscopic data. As the crude extract possessed anti-leishmanial properties, the compounds were assayed for cytotoxic and anti-parasitic activities in vitro in murine macrophages cells (Raw 264.7) and leishmania promastigotes (L. amazoniensis and L. braziliensis), respectively. The compounds showed moderate cytotoxicity (approximately 70 μg/mL), but are not responsible for the leishmanicidal effect of the extract.
Trichilones A–E: New Limonoids from Trichilia adolfi
(Multidisciplinary Digital Publishing Institute, 2021) Mariela González-Ramírez; Ivan Limachi; Sophie Manner; Juan C. Ticona; Efraín Salamanca; Alberto Giménez; Olov Sterner
In addition to the trichilianones A-D recently reported from Trichilia adolfi, a continuing investigation of the chemical constituents of the ethanol extract of the bark of this medicinal plant yielded the five new limonoids 1-5. They are characterized by having four fused rings and are new examples of prieurianin-type limonoids, having a ε-lactone which in 4 and 5 is α, β- unsaturated. The structures of the isolated metabolites were determined by high field NMR spectroscopy and HR mass spectrometry. The new metabolites were shown to have the ε-lactone fused with a tetrahydrofuran ring which is connected to an oxidized hexane ring joined with a cyclo-pentanone having a 3-furanyl substituent. As the crude extract possesses antileishmanial activity, the compounds were assayed for cytotoxic and antiparasitic activities in vitro in murine macrophage cells (raw 264.7 cells) and in Leishmania amazoniensis as well as L. braziliensis promastigotes. Metabolites 1-3 and 5 showed moderate cytotoxicity (between 30-94 µg/mL) but are not responsible for the antileishmanial effect of the extract.