Here we describe a new cosmocercid nematode, Aplectana nebulosa sp. nov., from the small and large intestines of Pleurodema nebulosum (Anura: Leptodactylidae), from the Monte desert of San Juan, Argentina. The new species belongs to the Aplectana group that possesses a gubernaculum and unpaired adcloacal papilla anteriorly to cloaca. It resembles A. membranosa, A. paraelenae and A. travassosi by the presence of four adcloacal papillae, but differs from those species by the following characters: number and arrangement of precloacal papillae; number and arrangement of postcloacal papillae; shape and size of spicules and gubernaculum, and by the presence of lateral alae in caudal region of males. The description of the new species is based on light microscopy and scanning electron microscopy (SEM) and we also provide a key to Neotropical species of Aplectana.

This research was designed to investigate the metabolite profiling, phenolics and flavonoids content and the potential antioxidant, antibacterial and nematicidal activities of “yellow-brown resins” from Larrea divaricata Cav (LdRe) and L. nitida Cav (LnRe). Metabolite profiling was obtained using an ultrahigh resolution liquid chromatography orbitrap MS analysis (UHPLC-ESI-OT-MS). The antioxidant properties were screened by four methods: 2,2-diphenyl-1-picrylhydrazyl assay (DPPH), trolox equivalent antioxidant activity assay (TEAC), ferric-reducing antioxidant power assay (FRAP) and lipid peroxidation in erythrocytes (LP). The antibacterial activity was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. In addition, the potential combinatory effect was analyzed with the fractional inhibitory concentration index (FICI) values using the checkerboard design. The nematicidal activity was carried out according to a standardized protocol. LdRe and LnRe showed a strong capture of the DPPH radical withvalues around 8.4 µg resin/mL; FRAP (1.69–1.94 mgTE/ g resin), TEAC (1.08–1.09 mgTE/g resin) and LP (81–82% at 100 µg of resin/mL) assays. A strong antimicrobial activity was displayed by both resins against methicillin-sensitive Staphylococcus aureus ATCC 25923(MSSA) and methicillin-resistant S. aureus ATCC 43300(MRSA) (MICs = 16–32 µg resin/mL). Additionally, the combination of LdRe or LnRe with the antibiotic cefotaxime showed an indifferent effect (FICI values = 1–1.25), however, this combinationcould be a potential strategy to reduce the drug doses, and in this way can be a potential alternative to reduce bacterial resistance. On the other hand, the resins showed a scarce nematicidal potential toward J2 Meloidogyne incognita; an important nematode infecting horticultural crops. Phenolics compounds were identified by UHPLC-PDA-OT-MS analysis, updating the knowledge on the chemical profile of these species. These results, together with the high content of quantified phenolics and flavonoids, allow the phenolics-enriched resins of these two Larrea species to be considered as a promising sustainable source of compounds of pharmacological interest.

Background: Hippeastrum species have a wide range of biological properties. In Argentina, this genus comprises ten widely distributed species. Purpose: To evaluate the antiparasitic and anticholinesterase activities and chemical profiles of seven Argentinean Hippeastrum species and determine the synergism between the major isolated alkaloid—montanine—and benznidazole in anti-Trypanosoma cruzi activity. Methods: The antiparasitic activity was evaluated through antiproliferative and viability assays against T. cruzi epimastigotes. Synergism assays were performed using the Chou–Talalay method. AChE and BuChE inhibitory activities were also assessed. The alkaloid composition was obtained using GC-MS analysis. Results: All extracts showed strong growth inhibition of T. cruzi epimastigote proliferation. The extracts from H. aglaiae, H. aulicum, and H. hybrid stand out for their potent and total growth inhibition, which was comparable to benznidazole. The H. reticulatum extract showed strong Acetylcholinesterase (AChE) inhibitory activities, while five species showed moderate Butyrylcholinesterase (BuChE) inhibition. Fifteen alkaloids were identified by means of GC-MS. Regarding the synergism assessment, the highest synergistic effect was obtained from the combination of montanine and benznidazole. Conclusion: Hippeastrum species bulb extracts from Argentina were shown to be a good source of antiparasitic alkaloids and cholinesterase inhibitors. The synergism between montanine and benznidazole emerges as a potential combination for future studies to treat Chagas disease.

This research was designed to investigate the metabolite profiling, phenolics content, and the trypanocidal, nematicidal, antibacterial, antifungal, and free radical scavenging properties of Usnea lethariiformis Motyka. The air-dried U. lethariiformis material was extracted successively with dichloromethane and methanol (UlMeOH). Two phases were obtained from the extract with dichloromethane, one soluble in methanol (UlDCM-s) and the other insoluble (UlDCM-i). The metabolite profiling was obtained using ultra-high-resolution liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS) system. The trypanocidal and nematicidal activities were determined according to standardized protocols. The antimicrobial activity was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) rules. The total phenolic content of lichen extracts was determined by the Folin–Ciocalteu method. Antioxidant properties were assessed through 2,2-diphenyl-1-picrylhydrazyl (DPPH), Trolox equivalent antioxidant activity (TEAC), ferric-reducing antioxidant power (FRAP), and inhibition of lipid peroxidation in erythrocytes (ILP) assays, and the extracts exhibited robust antioxidant activity. Seventeen compounds were detected, of which thirteen were identified by UHPLC-ESI-QTOF-MS analysis, including depsides, depsidones, fatty acids, dibenzofurans, benzoic acids, and triterpenes. The UlDCM-s and UlMeOH extracts displayed strong trypanocidal activity against Trypanosoma cruzi epimastigotes at 50 μg/mL and 100 μg/mL and a nematicidal activity toward J2 Meloidogyne incognita, an important nematode infecting horticultural crops. Regarding the antimicrobial activity, the results showed that all bacteria and yeasts tested were inhibited by the different extracts with minimum inhibitory concentration (MIC) values between 25 μg/mL and 500 μg/mL. The UlDCM-s and UlMeOH extracts showed phenolic content of 107 mg and 48 mg gallic acid equivalents (GAE)/g dried extract, respectively. The UlDCM-s, UIDCM-i, and UlMeOH extracts showed moderate free radical scavenging activity in the DPPH, FRAP, and TEAC assays until 1 mg/mL and ILP tests at 250 μg/mL. The results indicated that U. lethariiformis may constitute a potential source of diverse bioactivities with application in the food, pharmaceutical, and agronomic industries.