Geographical distribution and new records of Ariamnes longissimus keyserling, 1891 (Araneae, Theridiidae) in South America

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  Geographical distribution and new records of Ariamnes longissimus keyserling, 1891 (Araneae, Theridiidae) in South America Abstract Ariamnes longissimus plays a relevant ecological role as a predator, yet its distribution remains underestimated, reflecting knowledge gaps. This study updates its distribution, reports new occurrences, and discusses biogeographic implications. Primary and secondary data (118 records) were compiled, georeferenced, and mapped according to biomes and political divisions. We report the first occurrence in Bahia (Northeast Brazil) and in the Cerrado. The species occurs in Argentina, Peru, and 10 Brazilian states, predominantly in the Atlantic Forest (78%) and Pampas (16%), with additional records in the Amazon and Cerrado. The concentration of records in southern and southeastern Brazil (94%) suggests either sampling bias or historical barriers, whereas its rarity in the Cerrado and absence in the Caatinga/Chaco indicate an association with humid enviro...

The recombinant protein of scorpion venom phospholipase A2 exhibits potential anti-leishmanial activity

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By Guy Haimovitch - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=630282

The recombinant protein of scorpion venom phospholipase A2 exhibits potential anti-leishmanial activity

Abstract

The venom of scorpions contains a diverse array of bioactive compounds, including mucoproteins, nucleotides, and enzymes. Among these, phospholipase A2 (PLA2) plays a critical role in hydrolyzing plasma membrane phospholipids, leading to the release of fatty acids and lysophospholipids. In this study, characterized Maurolipin was selected as a candidate for recombinant protein production and evaluation of its anti-leishmanial activity. The recombinant protein was expressed in Escherichia coli strain Origami (DE3) and purified using a Ni-NTA resin column. The anti-parasitic activity of Maurolipin was tested against Leishmania major promastigotes, the causative agent of zoonotic cutaneous leishmaniasis (ZCL). The growth inhibitory effect was assessed across a range of concentrations (40 to 0.07 μg/ml). Leishmanicidal activity was determined by propidium iodide (PI) staining and flow cytometry, while cytotoxicity to RAW 264.7 macrophages was evaluated using an MTT assay. Maurolipin exhibited potent anti-leishmanial effects, with a 24-hour growth inhibition IC50 of 6.5 μg/ml and a leishmanicidal LC50 of 9.06 μg/ml after 3 hours of exposure. Cytotoxic effects on macrophages were dose- and time-dependent. These findings suggest that recombinant Maurolipin possesses growth-inhibitory and apoptosis-inducing properties, highlighting its potential as a novel therapeutic agent for leishmaniasis.

Soltan-Alinejad, P., Ramezani, A., Asgari, Q. et al. The recombinant protein of scorpion venom phospholipase A2 exhibits potential anti-leishmanial activity. Sci Rep (2025). https://doi.org/10.1038/s41598-025-29796-4