Efficacy of Ropivacaine for Sub-Arachnoid Block in Patients with Recent History of Scorpion Sting: A case series.

Failure of sub-arachnoid block (SAB), due to resistance to bupivacaine after a recent scorpion sting can lead to multiple block attempts and subsequent conversion to general anaesthesia. We report this case series of 10 patients with successful SAB with newly launched 0.75% hyperbaric ropivacaine, in patients with recent scorpion sting. Thus, intrathecal hyperbaric ropivacaine may be considered as the local anaesthetic agent of choice in patients with scorpion sting to prevent failure of SAB.

Clinical outcomes in a murine model after envenoming by the Amazonian scorpions Tityus strandi and Tityus dinizi.

The Brazilian Amazon is home to a rich fauna of scorpion species of medical importance, some of them still poorly characterized regarding their biological actions and range of clinical symptoms after envenoming. The Amazonian scorpion species Tityus strandi and Tityus dinizi constitute some of the scorpions in this group, with few studies in the literature regarding their systemic repercussions. In the present study, we characterized the clinical, inflammatory, and histopathological manifestations of T. strandi and T. dinizi envenoming in a murine model using Balb/c mice. The results show a robust clinical response based on clinical score, hyperglycemia, leukocytosis, increased cytokines, and histopathological changes in the kidneys and lungs. Tityus strandi envenomed mice presented more prominent clinical manifestations when compared to Tityus dinizi, pointing to the relevance of this species in the medical scenario, with both species inducing hyperglycemia, leukocytosis, increased cytokine production in the peritoneal lavage, increased inflammatory infiltrate in the lungs, and acute tubular necrosis after T. strandi envenoming. The results presented in this research can help to understand the systemic manifestations of scorpion accidents in humans caused by the target species of the study and point out therapeutic strategies in cases of scorpionism in remote regions of the Amazon.

Scorpion-Induced Acute Coronary Syndrome: A Stinging Complication.

The Tityus trinitatis, a black scorpion species endemic to the fauna of Trinidad, has been implicated in envenomation with devastating clinical sequelae such as acute pancreatitis and major adverse cardiovascular events. We present the first in-Caribbean case of a 59-year-old Caribbean South Asian male with human immunodeficiency virus who presented with a non-ST-segment-elevation acute coronary syndrome after being stung, which was managed with comprehensive, guideline-directed medical therapy. The clinician should be cognizant of scorpion-induced acute coronary syndrome (ACS) as a potential sequela of envenomation and its clinical management.

Unveiling Tst3, a Multi-Target Gating Modifier Scorpion α Toxin from Tityus stigmurus Venom of Northeast Brazil: Evaluation and Comparison with Well-Studied Ts3 Toxin of Tityus serrulatus.

Studies on the interaction sites of peptide toxins and ion channels typically involve site-directed mutations in toxins. However, natural mutant toxins exist among them, offering insights into how the evolutionary process has conserved crucial sequences for activities and molecular target selection. In this study, we present a comparative investigation using electrophysiological approaches and computational analysis between two alpha toxins from evolutionarily close scorpion species of the genus Tityus, namely, Tst3 and Ts3 from T. stigmurus and T. serrulatus, respectively. These toxins exhibit three natural substitutions near the C-terminal region, which is directly involved in the interaction between alpha toxins and Nav channels. Additionally, we characterized the activity of the Tst3 toxin on Nav1.1-Nav1.7 channels. The three natural changes between the toxins did not alter sensitivity to Nav1.4, maintaining similar intensities regarding their ability to alter opening probabilities, delay fast inactivation, and induce persistent currents. Computational analysis demonstrated a preference for the down conformation of VSD4 and a shift in the conformational equilibrium towards this state. This illustrates that the sequence of these toxins retained the necessary information, even with alterations in the interaction site region. Through electrophysiological and computational analyses, screening of the Tst3 toxin on sodium isoform revealed its classification as a classic α-NaTx with a broad spectrum of activity. It effectively delays fast inactivation across all tested isoforms. Structural analysis of molecular energetics at the interface of the VSD4-Tst3 complex further confirmed this effect.

Mass spectrometric analysis of Odonthobuthus Doriae scorpion venom and its non-neutralized fractions after interaction with commercial antivenom.

It is believed that antivenoms play a crucial role in neutralizing venoms. However, uncontrolled clinical effects appear in patients stung by scorpions after the injection of antivenom. In this research, non-neutralized components of the venom of the Iranian scorpion Odonthobuthus doriae were analyzed after interacting with the commercial antivenom available in the market. The venom and antivenom interaction was performed, then centrifuged, and the supernatant was analyzed by high-performance liquid chromatography (HPLC). Two peaks of Odonthobuthus doriae venom were observed in the chromatogram of the supernatant. Two components were isolated by HPLC and analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) instruments. Peptide sequencing was done by Liquid Chromatography Quadrupole Time-of-Flight Tandem Mass Spectrometry (LC-Q-TOF MS/MS). Results indicate that the components of scorpion venom mainly have a molecular weight below 10 kDa, consisting of toxic peptides that disrupt the function of sodium and potassium channels. The MALDI-TOF MS results show that two toxic peptides with molecular masses of 6941 Da and 6396 Da were not neutralized by the antivenom. According to the MS/MS sequencing data, the components have been related to peptides A0A5P8U2Q6_MESEU and A0A0U4FP89_ODODO, which belong to the sodium and potassium channels toxins family, respectively.

Unveiling the Genetic Blueprint of a Desert Scorpion: A Chromosome-level Genome of Hadrurus arizonensis Provides the First Reference for Parvorder Iurida.

Over 400 million years old, scorpions represent an ancient group of arachnids and one of the first animals to adapt to life on land. Presently, the lack of available genomes within scorpions hinders research on their evolution. This study leverages ultralong nanopore sequencing and Pore-C to generate the first chromosome-level assembly and annotation for the desert hairy scorpion, Hadrurus arizonensis. The assembled genome is 2.23 Gb in size with an N50 of 280 Mb. Pore-C scaffolding reoriented 99.6% of bases into nine chromosomes and BUSCO identified 998 (98.6%) complete arthropod single copy orthologs. Repetitive elements represent 54.69% of the assembled bases, including 872,874 (29.39%) LINE elements. A total of 18,996 protein-coding genes and 75,256 transcripts were predicted, and extracted protein sequences yielded a BUSCO score of 97.2%. This is the first genome assembled and annotated within the family Hadruridae, representing a crucial resource for closing gaps in genomic knowledge of scorpions, resolving arachnid phylogeny, and advancing studies in comparative and functional genomics.

Proteomic analysis and lethality of the venom of Aegaeobuthus nigrocinctus, a scorpion of medical significance in the Middle East.

The scorpion Aegaeobuthus nigrocinctus inhabits areas in Turkey and the Levant region of the Middle East where severe/lethal envenomings have been reported. Previous research indicated its extreme venom lethality to vertebrates and distinct envenomation syndrome. We report on the composition of A. nigrocinctus venom from Lebanese specimens using nESI-MS/MS, MALDI-TOF MS, SDS-PAGE and RP-HPLC. Venom lethality in mice was also assessed (LD50 = 1.05 (0.19-1.91) mg/kg, i.p), confirming A. nigrocinctus venom toxicity from Levantine populations. Forty-seven peaks were resolved using RP-HPLC, 25 of which eluted between 20 and 40 % acetonitrile. In reducing SDS-PAGE, most predominant components were <10 kDa, with minor components at higher molecular masses of 19.6, 26.1, 46.3 and 57.7 kDa. MALDI-TOF venom fingerprinting detected 20 components within the 1,000-12,000 m/z range. Whole venom 'shotgun' bottom-up nLC-MS/MS approach, combined with in-gel tryptic digestion of SDS-PAGE bands, identified at least 67 different components belonging to 15 venom families, with ion channel-active components (K+ toxins (23); Na+ toxins (20); Cl- toxins (2)) being predominant. The sequence of a peptide (named α-KTx9.13) ortholog to Leiurus hebraeus putative α-KTx9.3 toxin was fully determined, which exhibited 81-96 % identity to other members of the α-KTx9 subfamily targeting Kv1.x and Ca2+-activated K+ channels. Chlorotoxin-like peptides were also identified. Our study underscores the medical significance of A. nigrocinctus in the region and reveals the potential value of its venom components as lead templates for biomedical applications. Future work should address whether available antivenoms in the Middle East are effective against A. nigrocinctus envenoming in the Levant area.

Whole transcriptome sequencing reveals the activity of the PLA2 family members in Androctonus crassicauda (Scorpionida: Buthidae) venom gland.

Phospholipase A2 is the most abundant venom gland enzyme, whose activity leads to the activation of the inflammatory response by accumulating lipid mediators. This study aimed to identify, classify, and investigate the properties of venom PLA2 isoforms. Then, the present findings were confirmed by chemically measuring the activity of PLA2. The sequences representing PLA2 annotation were extracted from the Androctonus crassicauda transcriptome dataset using BLAS searches against the local PLA2 database. We found several cDNA sequences of PLA2 classified and named by conducting multiple searches as platelet-activating factor acetylhydrolases, calcium-dependent PLA2s, calcium-independent PLA2s, and secreted PLA2s. The largest and smallest isoforms of these proteins range between approximately 70.34 kDa (iPLA2) and 17.75 kDa (cPLA2). Among sPLA2 isoforms, sPLA2GXIIA and sPLA2G3 with ORF encoding 169 and 299 amino acids are the smallest and largest secreted PLA2, respectively. These results collectively suggested that A. crassicauda venom has PLA2 activity, and the members of this protein family may have important biological roles in lipid metabolism. This study also revealed the interaction between members of PLA2s in the PPI network. The results of this study would greatly help with the classification, evolutionary relationships, and interactions between PLA2 family proteins in the gene network.

Does Covid-19 influence the dynamics of envenomation by animals in a country strongly affected by both conditions? Epidemiological data from Brazil.

The impact of Covid-19 on envenomations by venomous animals in countries heavily affected by both conditions has not been quantified yet. Brazil shows high incidence of envenomations by scorpions, spiders and snakes and was heavily affected by waves of Covid-19. To determine how the pandemic impacted the epidemiology of envenomations by those three groups of venomous animals, we used online databases from two surveillance sources on number of cases and mortality. During the years before and during the pandemic, scorpion stings typically occurred in adults of both sexes in urban zones in the Southeast and Northeast regions. Spider bites occurred mainly in the South region, in adults of both sexes in urban zone. Snakebites affected mainly rural adult men in the Amazon. Between 2007 and 2021, overall incidence of cases by scorpions, spiders and snakes decreased after the beginning of the pandemic, snakebites did not show changes after the pandemic started in Brazil, but cases by scorpions and spiders decreased. No changes in the incidence of deaths were observed. On national level, Covid-19 affected some demographic, clinical and epidemiological aspects in cases by scorpions, spiders and snakes.

Similar neurotoxin expression profiles of traditional Chinese scorpion medicine material between juvenile and adult Mesobuthus martensii scorpions revealed by multiple strategic proteomics.

ETHNOPHARMACOLOGICAL RELEVANCE: The Mesobuthus martensii scorpions, called as "Quanxie", are known Chinese medicinal material base on the "Combat poison with poison" strategy for more than one thousand years, and still widely used to treat various diseases according to the Pharmacopoeia of the People's Republic of China nowadays. AIM OF STUDY: The study aims to investigate the similarity of scorpion neurotoxins at the protein level between the juvenile and adult Mesobuthus martensii scorpions as Chinese medicine materials. MATERIALS AND METHODS: The second-, third- and fourth-instar, and adult Mesobuthus martensii scorpions were collected for the characterization of neurotoxin expression through multiple strategic proteomics, including undigested scorpion venom, endopeptidase-digested, and undigested scorpion telson extract for the sample analysis. RESULTS: Based on the known 107 scorpion neurotoxins from the genomic and transcriptomic analysis of adult Mesobuthus martensii scorpions, the multiple strategic proteomics first revealed that neurotoxins exhibited more stability in telson extract than secreted venom. In the reported transcripts of scorpion neurotoxins, approximately 53%, 56%, 66% and 78% of neurotoxins were detected through undigested scorpion venom, the endopeptidase Arg-C-, Lys-C-digested telson extract, and undigested telson extract strategies, respectively. Nearly 79% of scorpion neurotoxins detected in third-instar Mesobuthus martensii scorpions represent the largest number of scorpion neurotoxins from proteomic analysis to date. Moreover, a total of 84% of scorpion neurotoxins were successfully identified at the protein level, and similar neurotoxin expression profiles in second-, third- and fourth-instar, and adult Mesobuthus martensii scorpions were first revealed by the multiple strategic proteomics. CONCLUSION: These findings for the first time demonstrate the similar neurotoxin expression profiles between the juvenile and adult Mesobuthus martensii scorpions as Chinese medicinal material, which would serve as a paradigm for further toxin analysis from different venomous animals.

Androcin 18-1, a novel scorpion-venom peptide, shows a potent antitumor activity against human U87 cells via inducing mitochondrial dysfunction.

Scorpion venom is a potent natural source for antitumor drug development due to the multiple action modes of anticancer components. Although the sequence of Androcin 18-1 has been identified from the transcriptome profile of the scorpion venom Androctonus bicolor, its bioactivity remains unclear. In this study, we described the antitumor mechanism whereby Androcin 18-1 inhibits the proliferation and induces apoptosis by inducing cell membrane disruption, ROS accumulation, and mitochondrial dysfunction in human U87 glioblastoma cells. Moreover, Androcin 18-1 could suppress cell migration via the mechanisms associated with cytoskeleton disorganization and MMPs/TIMPs expression regulation. The discovery of this work highlights the potential application of Androcin 18-1 in drug development for glioblastoma treatment.

Development and Efficacy of the Antivenom Specific to Severe Envenomations in Morocco and North Africa: Advancements in Scorpion Envenomation Management.

Scorpion envenomation poses a global public health issue, with an estimated 1,500,000 cases worldwide annually resulting in 2600 deaths. North Africa, particularly Morocco, experiences severe envenomations, mainly attributed to Androctonus mauretanicus and Buthus occitanus in Morocco, and Buthus occitanus and Androctonus australis hector in Algeria and Tunisia, with case numbers often underestimated. Current treatment relies mainly on symptomatic approaches, except in Morocco, where management is limited to symptomatic treatment due to controversies regarding specific treatment. In Morocco, between 30,000 and 50,000 scorpion envenomation cases are reported annually, leading to hundreds of deaths, mainly among children. Controversies among clinicians persist regarding the appropriate course of action, often limiting treatments to symptomatic measures. The absence of a specific antivenom for the venoms of the most lethal scorpions further exacerbates the situation. This study aims to address this gap by developing a monovalent antivenom against the endemic and most dangerous scorpion, Androctonus mauretanicus. The antivenom was produced by immunizing albino rabbits with a mixture of Androctonus mauretanicus venom collected from high-risk areas in Morocco. Immunizations were performed by subcutaneous injections at multiple sites near the lymphatic system, following an immunization schedule. Production control of neutralizing antibody titers was conducted through immunodiffusion. Once a sufficient antibody titer was achieved, blood collection was performed, and the recovered plasma underwent affinity chromatography. The efficacy of purified IgG was evaluated by determining the ED50 in mice, complemented by histological and immunohistochemical studies on its ability to neutralize venom-induced tissue alterations and the neutralization of toxins bound to receptors in the studied organs. The monovalent antivenom demonstrated specificity against Androctonus mauretanicus venom and effective cross-protection against the venom of the scorpions Buthus occitanus and Androctonus australis hector, highly implicated in lethal envenomations in the Maghreb. This study shows that the developed monovalent antivenom exhibits notable efficacy against local scorpions and a surprising ability to neutralize the most lethal envenomations in North Africa. These results pave the way for a new, more specific, and promising therapeutic approach to countering severe scorpion envenomations, especially in Morocco, where specific treatment is lacking.

[Site-specific PCR identification of animal species and formula particles of Scorpio].

Scorpio, a commonly used animal medicine in China, is derived from Buthus martensii as recorded in the Chinese Pharmacopoeia. China harbors rich species of Scorpionida and adulterants exist in the raw medicinal material and deep-processed products of Scorpio. The microscopic characteristics of the deep-processed products may be incomplete or lost during processing, which makes the identification difficult. In this study, the maximum likelihood(ML) tree was constructed based on the morphology and cytochrome C oxidase subunit I(COⅠ) to identify the species of Scorpio products. The results showed that the main adulterant of Scorpio was Lychas mucronatus. According to the specific SNP sites in the COⅠ sequence of B. martensii, the stable primers were designed for the identification of the medicinal material and formula granules of Scorpio. The polymerase chain reaction(PCR) at the annealing temperature of 61 ℃ and 30 cycles produced bright specific bands at about 150 bp for both B. martensii and its formula particles and no band for adulterants. The adaptability of the method was investigated, which showed that the bands at about 150 bp were produced for Scorpio medicinal material, lyophilized powder, and formula granules, and commercially available formula granules. The results showed that the established method could be used to identify the adulterants of Scorpio and its formula granules, which could help to improve the quality control system and ensure the safe clinical application of Scorpio formula granules.

Exploring the Therapeutic Potential of Scorpion-Derived Css54 Peptide Against Candida albicans.

Candida albicans (C. albicans) is one of the most common opportunistic fungi worldwide, which is associated with a high mortality rate. Despite treatment, C. albicans remains the leading cause of life-threatening invasive infections. Consequently, antimicrobial peptides (AMPs) are potential alternatives as antifungal agents with excellent antifungal activity. We previously reported that Css54, found in the venom of Centrurodies suffusus suffusus (C. s. suffusus) showed antibacterial activity against zoonotic bacteria. However, the antifungal activity of Css54 has not yet been elucidated. The objective of this study was to identify the antifungal activity of Css54 against C. albicans and analyze its mechanism. Css54 showed high antifungal activity against C. albicans. Css54 also inhibited biofilm formation in fluconazole-resistant fungi. The antifungal mechanism of action of Css54 was investigated using membrane-related assays, including the membrane depolarization assay and analysis of the membrane integrity of C. albicans after treatment with Css54. Css54 induced reactive oxygen species (ROS) production in C. albicans, which affected its antifungal activity. Our results indicate that Css54 causes membrane damage in C. albicans, highlighting its value as a potential therapeutic agent against C. albicans infection.

Use of point-of-care ultrasound to assess the severity of scorpion stings in hospitalized patients.

INTRODUCTION: Scorpionism is a public health problem, especially in tropical regions. In Brazil, the prevalence of envenomation by scorpions is high, and the average national lethality is around 0.16 percent. The Tityus serrulatus scorpion is the primary species of medical importance. However, objective tools to predict and define the severity of these envenomations are lacking. MATERIALS AND METHODS: This was an observational study conducted among patients aged 0-19 years with scorpionism. Patients were admitted to a reference hospital between December 2020 and May 2022. Point-of-care ultrasound was performed within 24 hours of the scorpion sting. RESULTS: Forty-nine patients were included, with a median age of 3.6 (interquartile range 2.3-5.3) years and a predominance of females (51 percent). Fifteen patients (30.6 percent) presented major life-threatening signs, 32 (65.3 percent) minor systemic manifestations, and two (4.1 percent) only local manifestations. Left ventricular dysfunction was identified in 13 patients (26.5 percent). Ten patients (20.4 percent) presented pattern B (visualization of three or more B lines in the evaluated quadrant) in at least one lung window. The sensitivity and specificity of cardiac and pulmonary ultrasound to identify the most severely ill patients were 86 percent and 94 percent, respectively. DISCUSSION: The changes found on point-of-care ultrasound were associated with life-threatening signs. All patients with class III envenomation were referred to the intensive care unit, showing the importance of early identification of this subgroup. The main limitations were the small sample size and the fact that admission to intensive care was not based on systematic criteria. CONCLUSIONS: Point-of-care ultrasound is able to identify early signs of pulmonary congestion and heart failure in scorpionism. It can be useful for the objective selection of patients who are at a higher risk of complications and death and who require intensive support; it may also be valuable for periodic reassessments. Point-of-care ultrasound is a valuable tool for identifying and monitoring severe cases of scorpionism.

Differential fluorescence features and recovery speeds of different scorpion exoskeleton parts during the molting process.

Scorpion fluorescence under ultraviolet light is a well-known phenomenon, but its features under excitation in the UVA, UVB and UVC bands have not been characterized. Systematic fluorescence characterization revealed indistinguishable fluorescence spectra with a peak wavelength of 475 nm for whole exuviae from second-, third- and fifth-instar scorpions under different ultraviolet light ranges. In-depth investigations of the chelae, mesosoma, metasoma and telson of adult scorpions further indicated heterogeneity in the typical fluorescence spectrum within the visible light range and in the newly reported fluorescence spectrum with a peak wavelength of 320 nm within the ultraviolet light range, which both showed excitation wavelength-independent features. Dynamic fluorescence changes during the molting process of third-instar scorpions revealed the fluorescence heterogeneity-dependent recovery speed of scorpion exoskeletons. The typical fluorescence spectra of the molted chelae and telson rapidly recovered approximately 6 h after ecdysis under UVA light and approximately 36 h after ecdysis under UVB and UVC light. However, it took approximately 12 h and 24 h to obtain the typical fluorescence spectra of the molted metasoma and mesosoma, respectively, under UVA irradiation and 72 h to obtain the typical fluorescence spectra under UVB and UVC irradiation. The fluorescence heterogeneity-dependent fluorescence recovery of the scorpion exoskeleton was further confirmed by tissue section analysis of different segments from molting third-instar scorpions. These findings reveal novel scorpion fluorescence features and provide potential clues on the biological function of scorpion fluorescence.

[Research progress on chemical constituents and pharmacological activities of small molecule compounds in scorpions].

Scorpions, a group of oldest animals with wide distribution in the world, have a long history of medicinal use. Scorpio, the dried body of Buthus martensii, is a rare animal medicine mainly used for the treatment of liver diseases, spasm, and convulsions in children in China. The venom has been considered as the active substance of scorpions. However, little is known about the small molecules in the venom of scorpions. According to the articles published in recent years, scorpions contain amino acids, fatty acids, steroids, and alkaloids, which endow scorpions with antimicrobial, anticoagulant, metabolism-regulating, and antitumor activities. This paper summarizes the small molecule chemical components and pharmacological activities of scorpions, with a view to providing valuable information for the discovery of new active molecules and the clinical use of scorpions.

Characterization of Sodium Channel Peptides Obtained from the Venom of the Scorpion Centruroides bonito.

Five peptides were isolated from the venom of the Mexican scorpion Centruroides bonito by chromatographic procedures (molecular weight sieving, ion exchange columns, and HPLC) and were denoted Cbo1 to Cbo5. The first four peptides contain 66 amino acid residues and the last one contains 65 amino acids, stabilized by four disulfide bonds, with a molecular weight spanning from about 7.5 to 7.8 kDa. Four of them are toxic to mice, and their function on human Na+ channels expressed in HEK and CHO cells was verified. One of them (Cbo5) did not show any physiological effects. The ones toxic to mice showed that they are modifiers of the gating mechanism of the channels and belong to the beta type scorpion toxin (ß-ScTx), affecting mainly the Nav1.6 channels. A phylogenetic tree analysis of their sequences confirmed the high degree of amino acid similarities with other known bona fide ß-ScTx. The envenomation caused by this venom in mice is treated by using commercially horse antivenom available in Mexico. The potential neutralization of the toxic components was evaluated by means of surface plasmon resonance using four antibody fragments (10FG2, HV, LR, and 11F) which have been developed by our group. These antitoxins are antibody fragments of single-chain antibody type, expressed in E. coli and capable of recognizing Cbo1 to Cbo4 toxins to various degrees.

Unveiling the Diversity and Modifications of Short Peptides in Buthus martensii Scorpion Venom through Liquid Chromatography-High Resolution Mass Spectrometry.

More recently, short peptides in scorpion venom have received much attention because of their potential for drug discovery. Although various biological effects of these short peptides have been found, their studies have been hindered by the lack of structural information especially in modifications. In this study, small peptides from scorpion venom were investigated using high-performance liquid chromatography high-resolution mass spectrometry followed by de novo sequencing. A total of 156 sequences consisting of 2~12 amino acids were temporarily identified from Buthus martensii scorpion venom. The identified peptides exhibited various post-translational modifications including N-terminal and C-terminal modifications, in which the N-benzoyl modification was first found in scorpion venom. Moreover, a short peptide Bz-ARF-NH2 demonstrated both N-terminal and C-terminal modifications simultaneously, which is extremely rare in natural peptides. In conclusion, this study provides a comprehensive insight into the diversity, modifications, and potential bioactivities of short peptides in scorpion venom.