Exploring the potential of eco-friendly silver nanoparticles to inhibit azole-resistant clinical isolates of Candida spp.

The antimicrobial activity and biological efficiency of silver nanoparticles (AgNps) have been widely described and can be modeled through stabilizing and reducing agents, especially if they exhibit biocidal properties, which can enhance bioactivity against pathogens. The selective action of AgNps remains a major concern. In this regard, the use of plant extracts for the green synthesis of nanoparticles offers advantages because it improves the toxicity of Nps for microorganisms and is harmless to normal cells. However, biological evaluations of the activity of AgNps synthesized using different reducing agents are determined independently, and comparisons are frequently overlooked. Thus, we investigated and compared the antifungal and cytotoxic effects of two ecological AgNps synthesized from Moringa oleifera aqueous leaf extract (AgNp-M) and glucose (AgNp-G) against azole-resistant clinical isolates of Candida spp. and nontumor mammalian cells. Synthesized AgNps exhibited an antifungal effect on planktonic cells of drug-resistant C. albicans and C. tropicalis (MIC 0.21-52.6 µg/mL). The toxicity was influenced by size. However, the use of M. oleifera extracts allows us to obtain AgNps that are highly selective and nongenotoxic to Vero cells due to modifications of the shape and surface. Therefore, these results suggest that AgNp-M has antimicrobial potential and deserves further investigation for biomedical applications.

Nanoemulsions with Chloroaluminium Phthalocyanine and Paromomycin for Combined Photodynamic and Antibiotic Therapy for Cutaneous Leishmaniasis.

BACKGROUND: Photodynamic therapy (PDT) using chloroaluminium phthalocyanine (ClAlPc) and paromomycin sulfate (PM) can be effective against New World Leishmania species involved in cutaneous leishmaniasis (CL). The aim of this study is to assay the skin permeation and the antileishmanial effects of a nanoemulsion (NE) containing both ClAlPc and PM in experimental CL by Leishmania (Viannia) braziliensis. MATERIAL AND METHODS: Cremophor ELP/castor oil-based NEs were prepared by a low-energy method and characterized for their physicochemical parameters. The NEs were used to deliver both ClAlPc and PM to leishmania cells. The in vitro toxicity of NEs were tested in vitro against L. (V.) braziliensis and THP-1 cells. The in vivo toxicity was assessed in non-infected BALB/c mice. Ex-vivo permeation and retention studies using healthy mice skin were also conducted. Finally, the in vivo activity of NE-PM+ClAlPc after PDT was tested in BALB/c mice infected with parasites. RESULTS: NEs are colloidally stable with average droplet diameter of 30 nm, polydispersity index (PDI) below 0.2, and zeta potential near zero. Both promastigotes and intracellular amastigotes treated with NE-PM, NE-ClAlPc and NE-PM+ClAlPc were inhibited at >50%, >95%, >88%, respectively, after PDT with a phototoxic index (PI) >1.2. No skin ClAlPc permeation was observed. In contrast, PM skin permeation was 80-fold higher using PM-loaded NE formulation in comparison to aqueous PM solution. Topical treatment with NE formulations showed no signs of local toxicity or genotoxicity. In addition, concentrations of PM between 27.3 - 292.5 µM/25 mg of tissue were detected in different organs. In vivo, the NE-PM+ClAlPc treatment did not reduce skin lesions. CONCLUSION: The Cremophor ELP/castor oil NE formulation increases the permeation of PM through the skin and can be used to co-deliver PM plus ClAlPc for combined PDT protocols. However, the lack of efficacy in the in vivo model evidences that the therapeutical scheme has to be improved.

In vitro susceptibility of Microsporum spp. and mammalian cells to Eugenia caryophyllus essential oil, eugenol and semisynthetic derivatives.

BACKGROUND: Microsporum spp. are keratinophilic dermatophytes that mainly invade the stratum corneum of the skin and hair causing clinical symptoms associated with tinea. Its treatment has several limitations, and the search for new active molecules is necessary. OBJECTIVE: To evaluate the antifungal and cytotoxic potential of Eugenia caryophyllus essential oil (EO), eugenol, isoeugenol and methylisoeugenol against Microsporum canis, M. gypseum and Vero cells. METHODS: The EO was extracted by conventional heating-assisted hydrodistillation, the eugenol obtained commercially and the derivatives through Williamson synthesis. Minimal inhibitory concentration (MICs), minimum fungicidal concentration, inhibition of radial mycelial growth and germination inhibition were used to evaluate the antifungal activity. In addition, a colorimetric test was conducted to evaluate cytotoxic activity. RESULTS: MIC and MFC values for all compounds were 62.5-500 µg/mL for both of the species of Microsporum evaluated. Also, concentrations of 300 µg/mL of the compounds inhibited 100% of M. canis mycelium. The inhibition of germination was observed after 6 hours of treatment (11.86 ± 3.46-85.31 ± 0%). No cytotoxicity was observed in Vero cells (CC50  > 105 µg/mL), whereas terbinafine showed CC50 31.00 ± 0.61 µg/mL. CONCLUSIONS: Our study indicates an interesting bioactivity of isoeugenol and methylisoeugenol against M. canis, M. gypseum and mammalian cells.

Nanostructured Systems for the Organelle-specific Delivery of Anticancer Drugs.

Nanotechnology has provided powerful tools to improve the chemotherapy of cancer. Different nanostructures have been developed which deliver the anticancer drugs more selectively to tumor than to healthy tissues. The result has generally been the increase in efficacy and safety of classical anticancer drugs. In recent years, several studies have focused not only on the delivery of anticancer drugs to tumors, but also on delivering the drugs to specific organelles of cancer cells. Endoplasmic reticulum, Golgi apparatus, lysosomes, mitochondria, and nucleus have been the targets of different nanostructured drug delivery systems developed with the goal of circumventing drugresistance, increasing drug efficacy, and so on. So far, the results described in the literature show that this strategy may be used to improve chemotherapy outcomes. In this review a discussion is presented on the strategies described in the literature to deliver anticancer drugs to specific organelles of cancer cells by using nanostructures.

Actividad antiparasitaria de nuevas dihidrodibenzo[c, f]tiazolo[3, 2-a]azepin-3(2H)-onas contra Leishmania chagasi y Trypanosoma cruzi / Antiparasitic activity of novel dihydrodibenzo[c, f]thiazolo[3, 2-a]azepin-3(2H)-ones agaisnt Leishmania chagasi and Trypanosoma cruzi

Introducción: La leishmaniasis y la enfermedad de Chagas son consideradas como problemas de salud pública en varios países, y nuevas estrategias quimioterapéuticas son necesarias para el control de estas enfermedades. Objetivo: El objetivo de este trabajo fue evaluar in vitro la actividad antiparasitaria de 7 nuevas dihidrodibenzo[c,f]tiazolo[3,2-a]azepin-3(2H)-onas contra Leishmania chagasi, Trypanosoma cruzi, y la citotoxicidad sobre células vero y THP-1. Materiales y métodos: La actividad antiparasitaria se determinó microscópicamente por conteo directo de parásitos vivos en comparación con el control no tratado, y la citotoxicidad en células de mamífero por el método de MTT. Las formas extracelulares e intracelulares de los parásitos utilizados así como las células de mamífero, fueron tratadas con diferentes concentraciones (0,3–600 µM) de los compuestos por 3-5 días. Los resultados de actividad de los compuestos fueron expresados en concentración inhibitoria (CI50) y concentración citotóxica (CC50). Resultados: En T. cruzi, 4 compuestos (4a, 4b, 4d, 4g) fueron activos contra epimastigotes con rangos de actividad de CI50 entre 11,28-32,66 µM, y tres (4a, 4c, 4g) contra la forma intracelular (CI50 = 18,42-23,62 µM), sin presentar toxicidad en células de mamífero. En L. chagasi, seis compuestos (4a-d, 4g) fueron activos contra promastigotes con CI50 entre 8,27-28,59 µM. El compuesto 4d fue parcialmente activo contra amastigotes intracelulares de L. chagasi (CI50 = 59,36 µM). Conclusiones: Los compuestos 4a y 4g presentaron actividad in vitro contra L. chagasi y T. cruzi y baja toxicidad en células de mamífero. Estudios posteriores con los compuestos activos encontrados, de genotoxicidad, mecanismos de acción y de evaluación de su actividad en modelos experimentales, son necesarios para establecer su posible uso como antiparasitarios.

Introduction: Leishmaniasis and Chagas disease are considered public health problems in several countries and new chemotherapeutic approaches are needed to control these diseases. .Objetive: The aim of this study was to evaluate the antiparasitic activity of 7 new dihydrodibenzo[c,f]thiazolo[3.2-a]azepin-3(2H)-ones on Leishmania chagasi, Trypanosoma cruzi, and the cytotoxicity on Vero and THP-1 cells. Materials and methods: The antiparasitic activities were determined microscopically counting living parasites compared with untreated control, and the mammalian cell toxicities using the MTT colorimetric test. Extracellular and intracellular forms of the parasites used and mammalian cells were treated with different concentrations (0.3-600 µM) of compounds for 3-5 days. The activities of the compounds were expressed as the concentration to inhibit 50% percent of parasites (IC50) and the concentration to kill 50% of the mammalian cells (CC50). Results: 4 compounds (4a, 4b, 4d, 4g) were active against T. cruzi epimastigotes with ranges of IC50 from 11.28 to 32.66 ìM, and three (4a, 4c, 4g) inhibited the intracellular form (IC50 = 18.42-23.62 ìM), with low toxicity on mammalian cells. In L. chagasi, 6 compounds (4a-d, 4g) were active against promastigote forms (IC50 = 8.27-28.59 ìM). Compound 4d was partially active against intracellular amastigotes of L. chagasi (IC50 = 59.36 ìM). Conclusions: The compounds 4a and 4g were actives on both T. cruzi and L. chagasi parasites with low toxicity on mammalian cells. Further studies of genotoxicity, mechanisms of action and evaluation of its activity in experimental models are necessaries.

Actividad contra Trypanosoma cruzi, Leishmania chagasi y células de mamífero de nuevas N-bencil (2-furilmetil) cinamamidas / Activity against Trypanosoma cruzi, Leishmania chagasi and mammalian cells of new N-benzyl (2-furylmethyl) cinnamamides

Introducción: La quimioterapia contra la leishmaniasis y la enfermedad de Chagas es inefectiva, condición que agrava el problema de salud pública que estas enfermedades tropicales representan. Objetivo: Determinar la actividad de nuevas N-bencil (2-furilmetil) cinamamidas en las formas libres e intracelulares de Leismania chagasi y Trypanosoma cruzi y en células Vero y THP-1. Materiales y métodos: Los parásitos y las células fueron tratados con diferentes concentraciones de los compuestos y su actividad fue determinada microscópicamente y por ensayos de MTT en el caso de los parásitos y células de mamífero, respectivamente. Los resultados de actividad fueron expresados como la concentración que inhibe o destruye 50% o 90% de los parásitos o células. Resultados: Las N-arilalquilamidas 1, 2 y 5 fueron activos en epimastigotes de T. cruzi con actividades entre CI50 3,71-38,81 µM y CI90 entre 50,87-59,87 µM. El compuesto 2 presentó actividad en amastigotes intracelulares de L. chagasi con CI50 77,76 µM. Las amidas preparadas no presentaron toxicidad en células THP-1 y solo el compuesto 4 fue parcialmente tóxico en células Vero (CC50 65,9 ± 5,71 µM). Conclusiones: La baja toxicidad presentada por los compuestos 1, 2 y 5 y la actividad antiparasitaria mostrada soportan el diseño de nuevas moléculas relacionadas para ser evaluadas en sistemas in vitro e in vivo contra estas enfermedades parasitarias.

Introduction: The chemotherapy against leishmaniasis and Chagas disease is ineffective, a condition that is aggravating the public health problem caused by these tropical diseases. Objective: To determine the activity of new N-benzyl(2-furylmethyl) cinnamamides in the free and intracellular forms of Leishmania chagasi and Trypanosoma cruzi and Vero and THP-1 cells. Materials and Methods: The parasites and cells were treated with different concentrations of the compounds and the activity was determined microscopically and MTT assays in the case of parasites and mammalian cells. Antiparasitic activity of tested compounds was expressed as the concentration that inhibits or destroys 50% or 90% of parasites and cells. Results: The N-arylalkylamides 1, 2 and 5 were active against T. cruzi epimastigotes with a range of activities between IC50 3.71-38.81 ìM and IC90 between 50.87-59.87 ìM. The compound 2 was active on intracellular amastigotes of L. chagasi with IC50 77.76 ìM. The tested amides were not toxic to THP-1 cells; just only compound 4 resulted partially toxic on Vero cells (CC50 65.9 ± 5.71 ìM). Conclusions: The low toxicity and the antiparasitic activity showed by the cinnamanide compounds 1, 2 and 5 support the design of new related molecules in order to be evaluated on in vitro and in vivo systems for these parasitic diseases.