Search Results (159)

Leishmaniasis, a vector-borne neglected tropical disease, affects over 6.2 million people globally. Case acquisition is increasingly recognized in the United States, and in Texas, most reported cases are locally acquired and speciated to Leishmania mexicana. We conducted a scoping literature review to systematically assess contemporary research on Leishmania in humans, animals, reservoir hosts, or vectors in Texas after 2000. Out of 22 eligible studies, the most prevalent themes were case reports, followed by studies on domestic animals, reservoirs, and vectors, with several studies bridging multiple disciplines. Climate change, urbanization, and habitat encroachment appear to be driving the northward expansion of L. mexicana, which is primarily attributed to shifts in the habitats of key vectors (Lutzomyia anthophora) and reservoirs (Neotoma spp.). Leishmania appears to be expanding into new areas, with potential for further spread. As ecological conditions evolve, strengthening surveillance and clinician awareness is crucial to understanding disease risk and improving early detection and treatment in affected communities. Full article

Masting, or the synchronous and intermittent production of seeds, can have profound consequences for Tropical Montane Cloud Forest (TMCF) tree populations and the trophic webs that depend on their mass flowering and seeds. Over the past 80 years, the importance of Fagus mexicana Martínez (Mexican beech) masting has become apparent in terms of conservation and management, promoting regeneration, and conserving endangered tree species, as well as the conscientious development of edible beechnuts as a non-timber forest product. The establishment of the relict-endemic Mexican beech is unknown, and several microenvironmental factors could influence natural regeneration. Thus, this study was conducted in two well-preserved Mexican beech forests to assess the influence of light incidence and soil moisture on the natural germination and seedling establishment of beeches. During two masting years (2017 and 2024), we assessed in situ beechnut germination and establishment. We tested the effect of the microenvironment of the oldest beeches on beechnut germination and seedling establishment. Our study highlights the complexity of the microenvironment of old beeches influencing the early stages of establishment and provides insights into possible conservation actions aimed at mitigating the impact of environmental change and humans. Full article

Water availability is a major constraint on socioeconomic development in northeastern Mexico, highlighting the need for effective water resource planning that accounts for the variability and extremes of precipitation. In this study, seasonal precipitation reconstructions were developed using tree-ring chronologies from spruce species (Picea spp.). A representative chronology for Picea mexicana Martínez was developed from two populations and spans the period 1786–2020, while a chronology for Picea martinezii T.F. Patterson was established from three populations covering 1746–2020. Both species exhibited significant positive correlations with January–May precipitation (r = 0.65 and 0.71, respectively; p < 0.01) and negative correlations with maximum temperature over the same period (r = −0.52 and −0.59, respectively). Two January–May precipitation reconstructions were produced for periods with adequate sample depth (EPS > 0.85): 1851–2020 for P. mexicana and 1821–2020 for P. martinezii. Both reconstructions revealed pronounced interannual variability, with recurrent droughts and persistently dry conditions, particularly evident in the P. mexicana series. Spatial correlation analyses indicated a historical link between reconstructed precipitation and the El Niño–Southern Oscillation (ENSO). These results highlight the value of spruce species for dendroclimatic reconstruction and their sensitivity to precipitation variability, especially as rising maximum temperatures may compromise their persistence in the Sierra Madre Oriental. Full article

This study offers a detailed assessment of the polyphenolic composition and antioxidant, anti-inflammatory, and cardioprotective properties of lyophilized extracts derived from the aerial parts of Agastache mexicana and Agastache scrophulariifolia. The polyphenolic content was determined through the quantification of total polyphenols, flavonoids, and caffeic acid derivatives, complemented by LC-MS profiling. The antioxidant activity was evaluated in vitro using DPPH and FRAP assays, while the in vivo antioxidant and anti-inflammatory effects were investigated in a rat model of turpentine-oil-induced acute inflammation. Cardioprotective potential was assessed in a separate rat model of isoprenaline-induced myocardial infarction. Phytochemical analysis revealed a complex polyphenolic profile for both species, with tilianin and rosmarinic acid identified as predominant compounds. In the DPPH assay, both extracts exhibited marked radical scavenging activity (IC₅₀: 65.91 ± 1.21 μg/mL for A. mexicana; 68.64 ± 2.48 μg/mL for A. scrophulariifolia). In the in vivo assays, the administration of the extracts significantly decreased pro-oxidant biomarkers (TOS, OSI, MDA, NO) and enhanced antioxidant markers (TAC, SH groups). Furthermore, the extracts led to a significant reduction in serum levels of GOT, GPT, and CK-MB in rats subjected to myocardial injury, supporting their cardioprotective efficacy. Overall, the results suggest that A. mexicana and A. scrophulariifolia represent promising natural sources of polyphenolic compounds with potential therapeutic value in oxidative-stress-related inflammatory and cardiovascular disorders. Full article

The phytochemical screening of extracts of Tacca leontopetaloides tubers has afforded the isolation of two novel chalcones, tarkalynins A and B, along with taccalonolide A and its 12-propanoate. The screening of Zanthoxylum zanthoxyloides stem bark yielded taraxerol acetate, dihydrochelerythrin and fagaramide. These compounds were obtained through column and thin-layer chromatography and identified using NMR and LC-HRMS. The compounds were tested against Trypanosoma brucei brucei s427 and its multi-drug-resistant clone B48, against Trypanosoma evansi, Trypanosoma equiperdum and Trypanosoma congolense, and against Leishmania mexicana. Cytotoxicity was tested against the human HEK293 cell line. The highest activities were observed with dihydrochelerythrin and fagaramide against T. b. brucei s427 and B48, T. evansi, and L. mexicana, with EC₅₀ values of 1.37, 2.559, 1.09, and 5.44 µM and 17.8, 10.9, 10.9, and 13.3 µM, respectively. In addition, tarkalynin A and taraxerol acetate displayed promising activity against T. equiperdum (EC₅₀ = 21.4 and 21.3 µM, respectively). None of these compounds showed significant cross-resistance with existing trypanocides (RF ≈ 1; p > 0.05). The compounds displayed low toxicity to human cells, with most exhibiting no growth inhibition at concentrations of 100, or even 300 µM. This report provides further evidence of the potential use of natural products for combating parasitic diseases. Full article

Forage scarcity, intensified by climate variability and edaphoclimatic limitations in the Brazilian semiarid region, challenges regional livestock production. In this context, forage palm is a strategic alternative due to its drought resistance and environmental adaptability. However, little is known about the spatial and temporal dynamics of its cultivation. This study aimed to characterize the spatio-temporal dynamics of forage palm cultivation in Capoeiras-PE between 2019 and 2022 using remote sensing data and multitemporal analysis of the Normalized Difference Vegetation Index (NDVI), processed via Google Earth Engine. Experimental areas with Opuntia stricta (“Mexican Elephant Ear”) and Nopalea cochenillifera (“Miúda”) were monitored, with field validation and descriptive statistical analysis. NDVI values ranged from −0.27 to 0.93, influenced by rainfall, cultivar morphology, and seasonal conditions. The “Miúda” cultivar showed a lower coefficient of variation (CV%), indicating greater spectral stability, while “Orelha de Elefante Mexicana” was more sensitive to climate and management, showing a higher CV%. Land use and land cover (LULC) analysis indicated increased sparse vegetation and exposed soil, suggesting intensified anthropogenic activity in the Caatinga biome. Reclassified NDVI enabled spatial estimation of forage palm, despite sensor resolution and spectral similarity with other vegetation. The integrated use of satellite data, field validation, and geoprocessing tools proved effective for agricultural monitoring and territorial planning. Full article

Background/Objectives: Nifuroxazide (Nfz) is a drug that has been used as a scaffold for designing antimicrobial and antiparasitic agents. This study aimed to synthesize and evaluate in vitro of Nfz and twenty-five 4-hydroxybenzhydrazone derivatives as potential anti-Trypanosoma cruzi, anti-Leishmania mexicana, and anti-Mycobacterium tuberculosis agents. Methods: The compounds were synthesized by condensing 4-hydroxybenzhydrazide with appropriate aldehydes in acidic conditions and structurally confirmed by spectroscopic techniques. All compounds were evaluated in vitro against T. cruzi strains (NINOA and A1), L. mexicana (M379 and FCQEPS strains), and M. tuberculosis (H37Rv strain), followed by enzymatic assays against T. cruzi cysteine proteases. Results: Compound Nfz-24 (IC₅₀ = 6.8 μM) had better trypanocidal activity than the reference drugs benznidazole (IC₅₀ > 30 μM) and nifurtimox (IC₅₀ > 7 μM) against the NINOA strain, and Nfz-8 (IC₅₀ = 7.2 μM) was the compound most active against the A1 strain with a high inhibition of T. cruzi cysteine proteases (IC₅₀ = 4.6 μM) and low cytotoxic effects (CC₅₀ >100 μM). On the other hand, compound Nfz-5 (IC₅₀ = 5.2 μM) had a 25-fold better leishmanicidal effect than glucantime (IC₅₀ > 125 μM) against the L. mexicana M379 strain, and compound Nfz-13 had the best leishmanicidal effects (IC₅₀ = 10.2 μM) against the FCQEPS strain. Finally, Nfz, Nfz-1, and Nfz-2 had minimum inhibitory concentration (MIC) values of 12.3, 5.1, and 18.8 μg/mL against M. tuberculosis, respectively. Conclusions: In summary, these results suggest that the compounds Nfz-1, Nfz-2, Nfz-5, Nfz-8, Nfz-10, Nfz-15, Nfz-24, and Nfz-25 are candidates for further studies to develop new and more potent anti-T. cruzi, anti-leishmaniasis, and anti-M. tuberculosis agents. Full article

Strongyloidiasis represents a public health problem in tropical and subtropical regions. The medicinal plants demonstrate the potential of plants as a source of molecules with helminthic activity. In this research, we assessed the potential of five extracts medicinally used in Mexico against Strongyloides venezuelensis third-stage infective larvae (L3). Plant methanol (MeOH) extracts of Argemone mexicana (chicalote), Jatropha dioica (Sangre de Drago), Lippia graveolens (oregano), Thymus vulgaris (tomillo), and Kalanchoe daigremontiana (aranto) were prepared by the maceration technique. The toxicity of the extracts was evaluated in human red blood cells by the hemolysis test and in monkey kidney epithelial cells (Vero cells) using the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In addition, we showed their antioxidant potential by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The methanolic extracts of A. mexicana, J. dioica, L. graveolens, and T. vulgaris exhibited significant activity against L3 cultures at 72 and 96 h post-incubation. None of the extracts showed hemolytic effects on red cells or Vero cells. L. graveolens demonstrated the strongest antioxidant activity, with an EC₅₀ of 19.80 µg/mL. Plant MeOH extracts used in this study showed a promising anthelmintic effect in vitro, making it a suitable candidate for future research in nematocidal therapies. Full article

The Neotropical genus Nudopeza (Micropezidae, Taeniapterinae) is described for a group of 41 species, including Nudopeza tapanti sp. nov. (type species) and Nudopeza pronigra (Hennig) n. comb. for Grallipeza pronigra Hennig 1934, Nudopeza arcuata (Hennig) n. comb. for Grallipeza arcuata Hennig 1934, and the following 38 additional new species: N. cegex sp. nov, N. cura sp. nov, N. duplitheca sp. nov, N. gilli sp. nov., N. glypha sp. nov., N. gracei sp. nov., N. hansoni sp. nov., N. horologia sp. nov., N. laselva sp. nov., N. mephitis sp. nov., N. mexicana sp. nov., N. micromephitis sp. nov., N. nigrivertex sp. nov., N. nigriscutellum sp. nov., N. nudarcuata sp. nov., N. penai sp. nov., N. palenque sp. nov., N. paramephitis sp. nov., N. peruviensis sp. nov., N. quadrivitta sp. nov., N. ruficincta sp. nov., N. rutilans sp. nov, N. sirena sp. nov., N. sumaco sp. nov., N. trinidadensis sp. nov., N. uniseta sp. nov., N. variterga sp. nov., N. venezuelensis sp. nov., N. verpa sp. nov., N. versivitta sp. nov., N. viriola sp. nov., N. viva sp. nov., N. yungasensis sp. nov., N. zarza sp. nov., N. zostera sp. nov., N. zumera sp. nov., N. zygoma sp. nov., and N. zytha sp. nov. Full article

The propolis produced by stingless bees is a complex mixture of natural sticky components mixed with soil or clay. Global research on propolis has focused on studying the biological and pharmacological properties and chemical composition of stingless bee propolis from Brazil, Indonesia, and other regions. However, studies of stingless bee propolis produced in Mexico are scarce. This study aimed to determine the chemical composition of the geopropolis of Scaptotrigona mexicana collected in the Totonacapan region and to evaluate its antioxidant and antibacterial activities. The phenolic contents of the ethanolic extract of the collected propolis ranged from 2.45 ± 0.03 mg GAE/g to 3.48 ± 0.56 mg GAE/g of dry extract. The total flavonoid content ranged from 0.69 ± 0.03 mg QE/g to 0.84 ± 0.009 mg QE/g of dry extract. The antioxidant activity of the ethanolic extracts was assessed via DPPH, ABTS, and FRAP assays. The minimum inhibitory concentration values exhibited by the ethanolic extract (>512 g/mL) for Gram-negative bacteria (Pseudomonas aerugunosa and Phorphyromonas gingivalis) were higher than those of Gram-positive bacteria. The stingless bee propolis extract showed the highest antibacterial activity against Streptococcus mutans (256 g/mL). Five known compounds, taraxeryl acetate (1), lupeol (3), cicloart-23-en-3β,25-diol (5), mangiferoic acid (6), and 5-(11’Z-heptadecenyl)-resorcinol (7), and two irresoluble mixtures of 3-O-acetyl-α-(2a) and 3-O-acetyl-β-amyrins (2b), and α- (4a) and -amyrins (4b), were identified by nuclear magnetic resonance spectroscopy and mass spectrometry. Additionally, 39 volatile compounds were identified via headspace-solid phase microextraction using the hyphenated gas chromatography coupled to mass spectrometry time-of-flight. The main volatile compounds detected include trans-α-bergamotene (8.15%), hexanal (7.17%), 2-heptanone (7.60%), and α-copaene (7.09%). Full article

Pentavalent antimonials are the first line for leishmaniasis treatment, although they induce many adverse side effects and treatment failure and parasite resistance have been detected. Cutaneous leishmaniasis is the main clinical manifestation of the disease in Oaxaca State, Mexico; however, its presence is under-registered, and information about the Leishmania species that circulate and cause the disease in the region is limited. In this study, the presence of Leishmania was analyzed in 24 skin smears and 2 biopsies from lesions suspicious for leishmaniasis in inhabitants of the Tehuantepec Isthmus and Papaloapan Basin regions, Oaxaca State. By ITS1-PCR, the species of clinical isolates were identified. Moreover, the susceptibility of clinical isolates to leishmanicidal drugs was assessed. Skin smears were negative for the presence of Leishmania spp.; meanwhile, parasite amastigotes were observed in tissue biopsies; however, by ITS1-PCR, 46% of the samples were determined to be positive for the parasite. Six clinical isolates were identified as L. mexicana and had lower susceptibility to Miltefosine and Amphotericin B than the L. mexicana reference strain. No leishmanicidal activity of Glucantime was detected. Further studies with increased patient sample sizes and genotypic studies will describe in detail parasite susceptibility to reference drugs in the region. Full article

This research investigated the inhibition of *Escherichia coli* ATCC 25922 (E. coli) bacterial growth in situ, specifically on the stems and aerial parts of *Agastache mexicana* subsp. mexicana (Amm) or “purple toronjil” and on food-grade paper, both contained within Kraft paper bags with a plastic window. The qualitative phytochemical profile of an aqueous extract of Amm revealed the presence of various compounds including alkaloids, coumarins, tannins, flavonoids, saponins, triterpenes, and sterols. The results indicate that these secondary metabolites exhibit a synergistic bactericidal effect, especially when combined with temperature and starvation stress. This was quantified using a decay equation referred to as the bacterial growth inhibition profile of E. coli (BGIPEc). Calculations, which included first derivatives, gradients based on substrate effects and temperature as well as the area under the curve of BGIPEc, demonstrated that higher temperatures led to the greater inhibition of colony forming units (CFUs), further enhanced by the presence of secondary metabolites. Additionally, a shorter half-life corresponded to a faster change rate and a lower area under the curve, indicating a reduced survival rate over time. At lower temperatures, E. coli exhibited a survival effect, which was corroborated by the preceding calculations. Full article

Wild edible trees (WETs) play an important role in the diet of many rural communities. Therefore, research on their use and management is important to support both food sovereignty and local conservation of biocultural resources. We evaluated the different uses of WETs by the community of Zacualpan, Colima, in western Mexico, through 32 semi-structured interviews registering the species richness, plant parts consumed, and non-food uses. Additional information was collected on their management, availability, and forms of preparation. We used a cultural salience index to determine the food importance of the WETs mentioned. We registered 33 edible tree species (26 wild, 3 native crops, and 4 exotic crops) that were most commonly consumed as fruits or seeds. WETs were also used for fuel, live fences, timber, handicrafts, medicine, shade, fodder, poles, utensils, construction, tanning, soap, and paper. Pithecellobium dulce had the highest food salience, followed by Spondias purpurea, Leucaena esculenta, Leucaena leucocephala, Enterolobium cyclocarpum, and Jacaratia mexicana. Salient wild trees were collected in the wild and promoted in agroforestry systems. These trees provided food during the dry season and also had the highest number of additional uses. Promoting the biocultural value of WETs and their sustainable use can favor ecosystem conservation and local food sovereignty. Full article

The objective of this study was to correlate the biophysical parameters of forage cactus with visible vegetation indices obtained by unmanned aerial vehicles (UAVs) and predict them with machine learning in different agricultural systems. Four experimental units were conducted. Units I and II had different plant spacings (0.10, 0.20, 0.30, 0.40, and 0.50 m) with East–West and North–South planting directions, respectively. Unit III had row spacings (1.00, 1.25, 1.50, and 1.75 m), and IV had cutting frequencies (6, 9, 12 + 6, and 18 months) with the clones “Orelha de Elefante Mexicana”, “Miúda”, and “IPA Sertânia”. Plant height and width, cladode area index, fresh and dry matter yield (FM and DM), dry matter content, and fifteen vegetation indices of the visible range were analyzed. The RGBVI and ExGR indices stood out for presenting greater correlations with FM and DM. The prediction analysis using the Random Forest algorithm, highlighting DM, which presented a mean absolute error of 1.39, 0.99, and 1.72 Mg ha⁻¹ in experimental units I and II, III, and IV, respectively. The results showed potential in the application of machine learning with RGB images for predictive analysis of the biophysical parameters of forage cactus. Full article

The objective of this study was to evaluate the structural characteristics, yield and water use efficiency of forage cactus under daytime and nighttime irrigation in a Brazilian semiarid region. The experiment followed a completely randomized design in a 3 × 2 factorial scheme, with ten replications: three clones of forage cactus (“IPA Sertânia”—IPA, “Miúda”—MIU, “Orelha de Elefante Mexicana”—OEM) and two irrigation schedules (daytime and nighttime). Irrigation was applied once a week using a graduated cylinder. The structural characteristics (i.e., plant height and width, total number of cladode—TNC; cladode number per emergence order—CN1, CN2 and CN3; cladode area—CA; cladode area index—CAI), productive characteristics (fresh mass production per plant—FM and dry mass—DM) and water use efficiency (WUE_FM and WUE_DM) were obtained from the plant harvests. Our results showed that the irrigation schedules did not lead to significant differences in most of the response variables (p > 0.05), except for the TNC (13.2 und), CN2 (7.4 und) and CAI (1.58 m² m⁻²) of MIU. It was observed that OEM presented the highest yield, WUE_FM and WUE_DM (p < 0.05). Adopting the OEM clone, regardless of the irrigation schedule, is the strategy that achieves the best production. Full article