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We evaluated the efficacy of freeze-dried Bothrops-Lachesis-Crotalus antivenom and liquid Crotalus antivenoms to neutralize Crotalus durissus ruruima (Cdr) venom (Roraima, Brazil) comparing with C. d. terrificus (Cdt) venom. Lethal and phospholipase A₂ activities were similar between both spp. Crotamine was negative and individual Cdr venoms induced hemorrhage in mice. It was lower coagulant than Cdt venom. Only Bothrops-Lachesis-Crotalus antivenom neutralized all biological activities evaluated, suggesting that it could be used in snakebites in this region.

The structural similarity between aristolactams (ALs) and aristolochic acids (AAs) raises constant concerns about the safety of ALs-containing plants. Natural ALs are distributed more extensively than AAs, leading to a higher risk of ALs exposure in daily consumption. This study aimed to evaluate and compare the in vitro nephrotoxicity on human renal tubular epithelial cells (HK-2 cells) of eight natural ALs with different substituents on the phenanthrene ring and amide ring, including aristolactam Ⅰ (AL Ⅰ), AL BⅡ, velutinam, AL AⅡ, sauristolactam, AL AⅠa, AL FⅠ and N-methyl piperolactam A. Their IC₅₀ values of cell viability were tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of kidney injury molecule-1 (KIM-1), transforming growth factor-β1 (TGF-β1) and fibronectin (FN). The reactive oxygen species (ROS) assay was used to detect the intracellular oxidative stress level. The results showed that the eight ALs all had specific nephrotoxicity on HK-2 cells. Particularly, AL Ⅰ, AL BⅡ and velutinam exhibited more potent cytotoxicity on HK-2 cells (IC₅₀ = 2.49-2.78 μM) than the other five ALs (IC₅₀ = 12.33-43.84 μM). The structure-toxicity relationships indicated that both methylenedioxy (-OCH₂O-) and methoxy (-OCH₃) were positively contributing functional groups of ALs on nephrotoxicity, while the hydroxy group (-OH) and methyl substitution on nitrogen (N-CH₃) accounted for a detrimental effect conversely. Consistent with this structure-toxicity relationship, the eight ALs increased KIM-1 levels in the same trend as their cytotoxicity at the same concentration of 2.5 μg/mL, associating with different levels of ROS generation. And the four most toxic ALs, AL Ⅰ, AL BⅡ, velutinam and AL AⅡ, could also induce fibrosis by increasing TGF-β1 and FN levels.

The venom of Colombian specimens of the rear-fanged snake Pseudoboa neuwiedii contains proteolytic and phospholipase A₂ (PLA₂) activities, but is devoid of esterases. Mass spectrometric analysis of electrophoretic bands indicated that this venom contains C-type lectins (CTL), cysteine-rich secretory proteins (CRiSP), PLA₂, snake venom metalloproteinases (SVMP), and snake venom matrix metalloproteinases (svMMP). In this investigation, we extended our characterization of P. neuwiedii by undertaking a shotgun proteomic analysis of the venom and comparing the results with a transcriptomic database for Brazilian P. neuwiedii; proteomic data previously obtained by in-gel digestion of electrophoretic bands coupled with mass spectrometry were also reanalyzed by comparing them with the transcriptomic results. The histology of the Duvernoy's venom gland was also examined. Histological analysis revealed a structural organization similar to that of other colubrids that consisted of a serous venom gland and a mucous supralabial gland. When the shotgun proteomic data were run against a general UniProt database for serpents, only metalloproteinases were identified (99% SVMPs, 1% snake endogenous matrix metalloproteinases-9 or seMMP-9). In contrast, when run against a transcriptomic database derived from the venom gland of Brazilian P. neuwiedii that contains predominantly SVMP, CRiSP, type IIE PLA₂ (PLA₂-IIE), CTL and seMMP-9, the main components identified were seMMP-9 (49%), SVMP (47%), CRiSP (3%) and minor components that included CTL and PLA₂-IIE. These findings confirmed the previously reported general composition of P. neuwiedii venom, with metalloproteinases (SVMP and seMMP-9) being the major components, and refined the identification of certain components, e.g., type IIA PLA₂ now identified as PLA₂-IIE and the detection of seMMP-9 rather than svMMP. The data also indicate compositional similarity between Brazilian and Colombian P. neuwiedii venoms, and stress the need for specific databases for non-front-fanged colubroid snakes to allow accurate and more comprehensive identification of the venom components of these snakes.

Stonefish (Synanceia spp.) possess a medically significant venom and are widely distributed throughout the Indo-Pacific. Yet, little is known about how the ecology of these animals may influence their venom. The aim of this study was to explore the effect of species and geographic location on stonefish venom composition. We collected the venom of Synanceia horrida (Estuarine Stonefish) and Synanceia verrucosa (Reef Stonefish) from various locations across Australia (Cairns, Brisbane, Caloundra, and Onslow), and Southeast Asia (Kota Kinabalu, and Cebu) and analysed these samples using SDS-PAGE, FPLC, and HPLC. Stonefish have a complex venom comprised of numerous components. Stonefish venom exhibited both similarities and variations in composition within species between geographically isolated populations, as well as between species in a single location. We speculate that the observed geographic and interspecific trends may be driven by similarities and differences in the selective pressures faced by these animals, particularly those associated with predator dynamics. The findings of this study have furthered our understanding of the ecology of stonefish and their toxins.

L-Mimosine is the main active component of the plant Leucaena leucocephala. Due to its metal-chelating mechanism, it interacts with various metabolic pathways in living organisms, making it a potential pharmacological target, although it also leads to toxicity. The present study aimed to investigate the transplacental passage of L-mimosine and its effects on embryofetal development. Pregnant Wistar rats were divided into control groups (CO2; n = 8 or CO3; n = 6, according to experimental design 2 or 3) that received only the vehicle, and groups that received doses of 60 (n = 9), 100 (n = 8), 140 (n = 9), and 240 (n = 7) mg/kg of L-mimosine from gestational day (GD) 6-19. For the transplacental analysis, five rats were used: two as controls and three treated with a dose of 140 mg/kg L-mimosine from GD12 to 14. All the animals received food and water ad libitum. The parameters analyzed were body weight gain; water and food consumption; serum biochemistry; blood cell counts; reproductive indices; and histopathological, visceral and skeletal analyses of the fetuses. In the groups that received doses of 60, 100, and 140 mg/kg, alterations (P < 0.05) in the skeletal development of the fetuses were observed. In the 240 mg/kg group, a decrease (P < 0.05) in total food consumption; a decrease (P < 0.05) in absolute leukocyte and neutrophil counts; alterations (P < 0.05) in the levels of ALT, GGT, and creatinine enzymes; a decrease (P < 0.05) in the relative weight of the thymus along with a loss of the corticomedullary distinction; coalescence of lymphoid follicles in the spleen; and skeletal and visceral alterations and alopecia were observed. L-Mimosine was detected in the amniotic fluid of the rats. These results demonstrate the complex action of L-mimosine, leading to toxic effects on both dams and fetuses, highlighting the risk of exposure to this substance during the perinatal period, which negatively impacts embryo/fetal and neonatal growth and development.

Detailed cases of envenoming by a non-front-fanged snake (NFFS) from North, Central, and South America have had limited representation in the toxicology and toxinology literature. The NFFS, Conophis lineatus, has been reported to deliver bites that resulted in moderately severe envenoming. However, most of these reported cases have been via personal communication, or self-reported and lacking in detailed medical evaluations. Reported here is a case of an amateur naturalist who was traveling in Mexico and was envenomed following extensive protracted bites to both hands from a wild Conophis lineatus concolor. There was rapid development of extensive localized edema, intense pain, and ecchymoses. The patient was transported to a hospital and after arrival the administration of antivenom was considered due to the severe appearance of local symptoms. The patient requested the medical team contact a consultant toxinologist who advised against the administration of antivenom because of the absence of any supporting evidence demonstrating therapeutic benefit in treating envenoming by C. l. concolor. Consequently, all treatments were limited to supportive symptomatic care. Despite the development of prominent localized symptoms, all laboratory evaluations, including coagulopathy assessment values, revealed no remarkable abnormal alterations. The patient was discharged after two days and symptoms gradually resolved with two months of supportive care.