Potent Anti-amoebic Effects of Ibogaine, Voacangine and the Root Bark Alkaloid Fraction of Tabernaemontana arborea.

Plants of Tabernaemontana species have several pharmacological activities including antimicrobial effects. Amoebiasis continues to be a public health problem, with increasing evidence of resistance to metronidazole. In this study, we assessed the effect of the alkaloid fraction of T. arborea root bark and the alkaloids ibogaine and voacangine on the viability and infectivity of Entamoeba histolytica trophozoites. Cultures were exposed to 0.1 - 10 µg/mL for 24, 48 and 72 h, and viability was then determined using a tetrazolium dye reduction assay and type of cellular death analyzed by flow cytometry. Results showed that the alkaloid fraction, but mainly ibogaine and voacangine alkaloids, exhibited potent dose-dependent anti-amoebic activity at 24 h post-exposure (IC50 4.5 and 8.1 µM, respectively), comparable to metronidazole (IC50 6.8 µM). However, the effect decreased after 48 and 72 h of exposure to concentrations below 10 µg/mL, suggesting that the alkaloids probably were catabolized to less active derivatives by the trophozoites. The treatment of trophozoites with the IC50 s for 24 h induced significant morphological changes in the trophozoites, slight increase in granularity, and death by apoptonecrosis. The capacity of T. arborea alkaloids to inhibit the development of amoebic liver abscesses in hamsters was evaluated. Results showed that even when the treatments reduced the number of amoebic trophozoites in tissue sections of livers, they were unable to limit the formation of abscesses, suggesting their rapid processing to inactive metabolites. This work leaves open the possibility of using Tabernaemontana alkaloids as a new alternative for amoebiasis control.

Field study of parasitic contamination of fruits, vegetables and leafy greens in the Ecuadorian Andes.

Background: Raw vegetables have been considered vehicles of enteroparasites. South American countries are among the most important exporters of fresh vegetables, including Ecuador, which has a tropical climate and soils rich in organic matter that allow it to harvest throughout the year for sale to different countries. The aim of the study was to assess the occurrence of the parasitic contamination of fruits, vegetables and leafy greens grown in an agricultural area of the Ecuadorian Andes. Methods: A cross-sectional field study was conducted with snowball sampling on 1,416 samples (516 fruits, 488 vegetables, and 412 leafy greens). Each sample were washed with water, and the resulting solution after removing the vegetables, was subjected to 24-hour sedimentation. The concentrated sediment underwent microscopic analysis. Results: The overall positivity for parasitic contamination was 63.4%, with leafy greens having the highest contamination rate (76.9%) (P<0.0001), surpassing vegetables (67.8%) and fruits (48.4%). Cabbage (100%), onions (84%), and strawberries (60.2%) emerged as the most contaminated within their respective groups. Protozoa were more prevalent (49.6%) than helminths (15.5%) (P<0.0001). Blastocystis sp. (33.5%) ranked highest, followed by Eimeria spp. (26.3%), Entamoeba spp. (10.3%), Giardia spp. (8.3%), Balantidium spp. (6.9%), Cryptosporidium spp. (6.6%), Cyclospora spp. (4.4%), Cystoisospora spp. (0.5%), Strongylida (15.5%), and Ascaris spp. (0.4%). Conclusions: The study reveals that vegetables and fruits for human consumption from this area of the Ecuadorian Andes are highly contaminated with various parasites, constituting a possible source of infection for humans and animals in this area, or in non-endemic areas where these products are marketed. The finding emphasizes the need for strict hygienic measures in agricultural crops, which will be properly achieved through the treatment of soil, manure and water used for cultivation.

Influence of Environmental Pollution and Living Conditions on Parasite Transmission among Indigenous Ecuadorians.

The purpose of this study was to evaluate the influence of environmental pollution and the living conditions of indigenous Ecuadorians on the transmission of enteroparasites in an Andean agricultural area located at high altitude. Environmental pollution was recorded after observation in each community. The parasites were identified by microscopic sediment analysis using physiological saline solution from macerated arthropods, washed vegetables, and human stools, utilizing four coproparasitological techniques (direct examination, Kato-Katz, ether concentration, and Ziehl-Neelsen). The results show that the inadequate disposal of human and animal excreta that contaminate soil and water, incorrect food hygiene, inadequate sanitary infrastructure in houses, a lack of animal veterinary care, and rodent proliferation are important reservoirs of zoonotic parasites. The use of excrement as fertilizer increases the number of flies, which act as mechanical vectors, and vegetables grown in areas with disperse infective parasitic forms act as vehicles that are marketed at the local, regional, and international levels. These analyses verify contamination levels of 52.7% in mechanical vectors, 70.6% in vegetables, and 98.2% in human stools. The agricultural communities analyzed maintained poor hygienic-sanitary and environmental conditions, which had a significant influence on the transmission of enteroparasites that affect human health.

Ocurrence of enteroparasites with zoonotic potential in animals of the rural area of San Andres, Chimborazo, Ecuador.

OBJECTIVE: The aim of this research was the identification of the enteroparasites harbored by the animals of the San Andrés community, to evaluate their role as susceptible hosts and sources of infection for other animals, humans (zoonoses), as well as parasite forms spreaders to the environment in this rural area, located in the province of Chimborazo, Ecuadorian Andean region. MATERIAL AND METHODS: The study was carried out combining 3 coproparasitological techniques: direct examination, Ritchie and Ziehl-Neelsen in 300 animal stool samples RESULTS: Blastocystis sp., Entamoeba spp., Giardia spp., Balantidium spp., Cryptosporidium spp., Ascaris spp., Toxocara spp., Ancylostoma spp., Strongylida, Hymenolepis nana and Echinococcus spp., were detected. Infection by protozoa (87.3%) was higher than helminths (31.0%). All cattle, sheep and guinea pigs were found parasitized, and the presence of Blastocystis sp., Entamoeba spp. and Cryptosporidium spp. by all groups of animals stands out. It is also remarkable the presence of Giardia spp. in swine (19.2%), big herbivores-livestock (11.5%), leporids (8.3%) and carnivores (5.9%); Balantidium spp. in swine (19.2%), big herbivores-livestock (5.8%) and carnivores (1.2%); Hymenolepis nana in guinea pigs (2.1%); and Toxocara spp. (15.7%), Echinococcus spp. (9.6%) and Ancylostoma spp. (6.0%) in dogs. CONCLUSION: Animals from San Andrés have a wide spectrum of intestinal parasitic forms in their feces, being a source of infection to other animals and humans, and a source of contamination of the environment, posing a risk factor and reinforcing the idea of the need for more effective treatments and hygienic measures to improve livestock production and cutting its transmission.

Toxicological Evaluations in Macrophages and Mice Acutely and Chronically Exposed to Halloysite Clay Nanotubes Functionalized with Polystyrene.

Halloysite clay nanotubes (HNTs) have been proposed as highly biocompatible for several biomedical applications. Various polymers have been used to functionalize HNTs, but scarce information exists about polystyrene for this purpose. This work evaluated polystyrene-functionalized HNTs (FHNTs) by comparing its effects with non-FHNTs and innocuous talc powder on in vitro and in vivo models. Monocyte-derived human or murine macrophages and the RAW 264.7 cell line were treated with 0.01, 0.1, 1, and 100 µg mL-1 FHNTs, HNTs, or talc to evaluate the cytotoxic and cytokine response. Our results show that nanoclays did not cause cytotoxic damage to macrophages. Only the 100 µg mL-1 concentration induced slight proinflammatory cytokine production at short exposure, followed by an anti-inflammatory response that increases over time. CD1 mice treated with a single dose of 1, 2.5, or 5 mg Kg-1 of FHNTs or HNTs by oral and inhalation routes caused aluminum accumulation in the kidneys and lungs, without bodily signs of distress or histopathological changes in any treated mice, evaluated at 48 h and 30 days post-treatment. Nanoclay administration simultaneously by four different parenteral routes (20 mg Kg-1) or the combination of administration routes (parenteral + oral or parenteral + inhalation; 25 mg Kg-1) showed accumulation on the injection site and slight surrounding inflammation 30 days post-treatment. CD1 mice chronically exposed to HNTs or FHNTs in the bedding material (ca 1 mg) throughout the parental generation and two successive inbred generations for 8 months did not cause any inflammatory process or damage to the abdominal organs and the reproductive system of the mice of any of the generations, did not affect the number of newborn mice and their survival, and did not induce congenital malformations in the offspring. FHNTs showed a slightly less effect than HNTs in all experiments, suggesting that functionalization makes them less cytotoxic. Doses of up to 25 mg Kg-1 by different administration routes and permanent exposure to 1 mg of HNTs or FHNTs for 8 months seem safe for CD1 mice. Our in vivo and in vitro results indicate that nanoclays are highly biocompatible, supporting their possible safe use for future biomedical and general-purpose applications.

Systematics and geographical distribution of Galba species, a group of cryptic and worldwide freshwater snails.

Cryptic species can present a significant challenge to the application of systematic and biogeographic principles, especially if they are invasive or transmit parasites or pathogens. Detecting cryptic species requires a pluralistic approach in which molecular markers facilitate the detection of coherent taxonomic units that can then be analyzed using various traits (e.g., internal morphology) and crosses. In asexual or self-fertilizing species, the latter criteria are of limited use. We studied a group of cryptic freshwater snails (genus Galba) from the family Lymnaeidae that have invaded almost all continents, reproducing mainly by self-fertilization and transmitting liver flukes to humans and livestock. We aim to clarify the systematics, distribution, and phylogeny of these species with an integrative approach that includes morphology, molecular markers, wide-scale sampling across America, and data retrieved from GenBank (to include Old World samples). Our phylogenetic analysis suggests that the genus Galba originated ca. 22 Myr ago and today comprises six species or species complexes. Four of them show an elongated-shell cryptic phenotype and exhibit wide variation in their genetic diversity, geographic distribution, and invasiveness. The remaining two species have more geographically restricted distributions and exhibit a globose-shell cryptic phenotype, most likely phylogenetically derived from the elongated one. We emphasize that no Galba species should be identified without molecular markers. We also discuss several hypotheses that can explain the origin of cryptic species in Galba, such as convergence and morphological stasis.

Dipylidiasis in children, a generally misdiagnosed cestodiasis. First case reported in Venezuela / Dipylidiasis en niños, una cestodiasis generalmente mal diagnosticada. Primer caso reportado en Venezuela

The first case report of human dipylidiasis in Venezuela is presented, including the diagnosis and treatment of a two-year-old child's infection. The diagnosis was parasitologically confirmed, the child was treated with praziquantel and the animal reservoir and its fleas were identified

Se presenta el primer caso de dipylidiasis humana en Venezuela, incluyendo el diagnóstico y el tratamiento de la infección de un niño de dos años. El diagnóstico fue confirmado parasitológicamente, se trató al niño con praziquantel y fueron identificados el reservorio animal y sus pulgas