ABSTRACT
The hymenolepiosis by Hymenolepis nana is a major public health problem in developing countries, and the commercial drugs against this parasitosis are not enough effective. The combination of antiparasitic and antioxidant agents has improved the treatment of some parasitoses. Thus, the development of new cestocidal and antioxidant agents to treat the hymenolepiosis cases is important. In the present study, four hydroxy- and four dihydroxy-chalcones were synthesized using the catalyst boron trifluoride diethyl etherate (BF3â¢OEt2). The antioxidant activity and antiparasitic against H. nana of chalcones were tested, as well as the toxicity by the brine shrimp lethality bioassay and the method of Lorke. The antioxidant activity was measured by three radical scavenging assays: 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP). The hydroxyl substitution pattern (number and position), mainly in ring B, was responsible for the chalcone antiparasitic activity. At least one meta or para hydroxyl group in ring B was essential for activity of the synthetic chalcones against H. nana; The time taken for the parasite to die by the 3b and 3e chalcones (20 mg/mL) treatment was up to six times lower than the control drug Praziquantel. On the other hand, chalcones with catechol structure in ring B (3g and 3h) showed the highest antioxidant values. The toxicity evaluations suggests that synthetic hydroxychalcones with cestocidal (3b and 3e) and antioxidant (3g and 3h) activities are safe compounds and potential in vivo agents to treat this parasitosis
Subject(s)
Parasitic Diseases/drug therapy , Hymenolepis nana/immunology , Chalcones/administration & dosage , Antioxidants/adverse effects , Antiparasitic Agents/adverse effectsABSTRACT
Background Isothiocyanates (ITCs) are natural products obtained from plants of the Brassicas family. They represent an environmentally friendly alternative for the control of phytopathogenic fungi. However, as it has been observed with synthetic fungicides, the possibility of inducing ITC-resistant strains is a major concern. It is, therefore, essential to understanding the molecular mechanisms of fungal resistance to ITCs. We analyzed a subtractive library containing 180 clones of an Alternaria alternata strain resistant to 2-propenyl ITC (2-pITC). After their sequencing, 141 expressed sequence tags (ESTs) were identified using the BlastX algorithm. The sequence assembly was carried out using CAP3 software; the functional annotation and metabolic pathways identification were performed using the Blast2GO program. Results The bioinformatics analysis revealed 124 reads with similarities to proteins involved in transcriptional control, defense and stress pathways, cell wall integrity maintenance, detoxification, organization and cytoskeleton destabilization; exocytosis, transport, DNA damage control, ribosome maintenance, and RNA processing. In addition, transcripts corresponding to enzymes as oxidoreductases, transferases, hydrolases, lyases, and ligases, were detected. Degradation pathways for styrene, aminobenzoate, and toluene were induced, as well as the biosynthesis of phenylpropanoid and several types of N-glycan. Conclusions The fungal response showed that natural compounds could induce tolerance/resistance mechanisms in organisms in the same manner as synthetic chemical products. The response of A. alternata to the toxicity of 2-pITC is a sophisticated phenomenon including the induction of signaling cascades targeting a broad set of cellular processes. Whole-transcriptome approaches are needed to elucidate completely the fungal response to 2-pITC.
Subject(s)
Isothiocyanates , Drug Resistance, Fungal , Alternaria/genetics , Alternaria/metabolism , Fungicides, Industrial , Computational Biology , Subtractive Hybridization Techniques , Hybridization, GeneticABSTRACT
Nanchi (Byrsonima crassifolia), arrayan (Psidium sartorianum) and ayale (Crescentia alata) are wild and under-utilized plants from Mexico; their fruits have been used as food and as Mexican traditional remedies against human bacterial infections (e.g. bacillary dysentery). However, scientific reports which support such uses or promote their consumption are scarce. In this work, the antibacterial activities of fruit extracts (i.e. hexanic, HE; chloroformic, CE; and methanolic, ME) were determined by the micro-dilution assay, establishing the Minimum Inhibitory Concentration (MIC) and Minimum Bactericide Concentration (MBC) against 21 human pathogenic bacteria. The HE of arrayan and ayale showed the highest activity against enterobacteria (E. coli, Salmonella spp. and Shigella spp.) (MIC 0.25-2 mg/mL; MBC 0.5-16 mg/mL). The arrayan ME was the most active against the Gram-positive bacteria, showing Staphylococcus aureus the highest sensitivity (MIC 2 mg/mL; MBC 2-4 mg/mL). The presented results support the traditional uses of these plant materials for treating bacterial infectious diseases.
Nanchi (Byrsonima crassifolia), arrayán (Psidium sartorianum) y ayale (Crescentia alata) son plantas silvestres subutilizadas de México; sus frutos son comestibles y usados como medicamentos tradicionales contra infecciones bacterianas humanas (e.g. disentería bacilar). Sin embargo, los reportes científicos que avalen los usos y promuevan su consumo son escasos. En este trabajo se determinó, ensayo de micro-dilución en caldo, la Concentración Mínima Inhibitoria (CMI) y Concentración Mínima Bactericida (CMB), de los extractos de frutos (hexánico, EH; clorofórmico, EC; y metanólico, EM) contra 21 bacterias patógenas humanas. Los EH de arrayán y ayale mostraron la mayor actividad (CMI 0.25-2 mg/mL; CMB 0.5-16 mg/mL) contra enterobacterias (Escherichia coli, Salmonella spp. y Shigella spp.). El EM de arrayán fue el más activo contra bacterias Gram positivas, presentando Staphylococcus aureus la mayor sensibilidad (CMI 2 mg/mL; CMB 2-4 mg/mL). Estos resultados apoyan el uso tradicional de estos materiales en padecimientos asociados al tratamiento de infecciones bacterianas.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bignoniaceae/chemistry , Plant Extracts/pharmacology , Malpighiaceae/chemistry , Psidium/chemistry , Gram-Negative Bacteria , Gram-Positive Bacteria , Dietary Supplements , Phenols/analysis , Fruit/chemistry , Microbial Sensitivity TestsABSTRACT
El propósito del presente estudio fue determinar las especies de aves, principalmente ictiófagas, que fungen como dispersoras de Gnathostoma sp y describir las lesiones causadas por larvas de nemátodos pertenecientes a este género en los paquetes musculares donde son albergadas. Veinticinco aves pertenecientes a cuatro familias en seis localidades fueron estudiadas, de ellas se recolectaron 15 larvas del tercer estadio avanzado (L3A) de seis aves ictiófagas por medio de digestión artificial de tejido muscular; secciones de músculo esquelético infectados con larvas se fijaron en formalina al 10 por ciento para estudios histológicos. Las evidencias señalan que las larvas contenidas en los músculos de las aves causan una reacción inflamatoria de tipo granulomatosa.