Distribution mapping of deadly scorpions in Iran.

Scorpion sting is a problem all over the world and becomes an acute problem when it is associated with death. Iran is known as a region with a large number of scorpions and, of course, with many cases of scorpion stings per year. So far, 11 scorpion species in Iran have been identified as dangerous, of which there are only three species for which deaths have been reported. Due to the importance of these three species, we prepared a distribution map of these three types of scorpions and discuss the implications of these findings in the larger context of dangerous scorpion stings in Iran.

Dataset of PLA2 family identified from transcriptomic high-throughput sequencing of Androctonus crassicauda (Scorpionida: Buthidae) venom gland.

Recently, RNA sequencing has been widely applied to deeply understand the molecular diversity of the venom compounds of various venomous animal species, including scorpions. Among the venomous scorpion species of the Buthidae family, there are many documents of stinging and severe envenoming of victims by the scorpion of Androctonus crassicauda. We present here a high-throughput RNA sequencing dataset of the venom glands from five A. crassicauda individuals, including male and female scorpions. Furthermore, the assembled data corresponding to annotated PLA2 transcripts are also presented. The dataset in this report is related to our research article entitled: "Whole transcriptome sequencing reveals the activity of the PLA2 family members in Androctonus crassicauda (Scorpionida: Buthidae) venom gland" [1]. Here, the venom gland transcriptome analysis of the A. crassicauda was performed. The analysis of concatenated clustered transcriptome assembly using TrinityStats.pl showed that de novo assembly of 517,799,704 clean read pairs generated 744,804 trinity transcripts representing 563,526 trinity genes. BUSCO score for the concatenated clustered transcriptome assembly against orthologs from Arachnida showed 96.7 % complete, 1.6 % fragmented, 1.7 % missing genes, and 2934 genes. Subsequently, the sequences represented PLA2 annotation were extracted from the transcriptome dataset using BLAST searches against the local PLA2 database. We found several cDNA sequences representing PLA2 annotations, which based on sequence similarity to previously found PLA2s, we named platelet-activating factor acetylhydrolases, calcium-dependent PLA2s, calcium-independent PLA2s, and secreted PLA2s. The PLA2 data significantly enrich KEGG pathways related to lipid metabolism. This manuscript complements the primary research article by providing additional data on the abundant estimation of PLA2s.

Evaluation of the immunoprotective power of a multiple antigenic peptide against Aah II toxin of Androctonus australis hector scorpion.

Scorpion envenoming (SE) is a public health problem in developing countries. In Algeria, the population exposed to the risk of SE was estimated at 86.45% in 2019. Thus, the development of a vaccine to protect the exposed population against scorpion toxins would be a major advance in the fight against this disease. This work aimed to evaluate the immunoprotective effect of a Multiple Antigenic Peptide against the Aah II toxin of Androctonus australis hector scorpion, the most dangerous scorpion species in Algeria. The immunogen MAP1Aah2 was designed and tested accordingly. This molecule contains a B epitope, derived from Aah II toxin, linked by a spacer to a universal T epitope, derived from the tetanus toxin. The results showed that MAP1Aah2 was non-toxic despite the fact that its sequence was derived from Aah II toxin. The immunoenzymatic assay revealed that the 3 immunization regimens tested generated specific anti-MAP1Aah2 antibodies and cross-reacted with the toxin. Mice immunized with this immunogen were partially protected against mortality caused by challenge doses of 2 and 3 LD50 of the toxin. The survival rate and developed symptoms varied depending on the adjuvant and the challenge dose used. In the in vitro neutralization test, the immune sera of mice having received the immunogen with incomplete Freund's adjuvant neutralized a challenge dose of 2 LD50. Hence, the concept of using peptide dendrimers, based on linear epitopes of scorpion toxins, as immunogens against the parent toxin was established. However, the protective properties of the tested immunogen require further optimizations.

Beyond the venom: Exploring the antimicrobial peptides from Androctonus species of scorpion.

Prevalent worldwide, the Androctonus scorpion genus contributes a vital role in scorpion envenoming. While diverse scorpionisms are observed because of several different species, their secretions to protect themselves have been identified as a potent source of antimicrobial peptide (AMP)-like compounds. Distinctly, the venom of these species contains around 24 different AMPs, with definite molecules studied for their therapeutic potential as antimicrobial, antifungal, antiproliferative and antiangiogenic agents. Our review focuses on the therapeutic potential of native and synthetic AMPs identified so far in the Androctonus scorpion genus, identifying research gaps in peptide therapeutics and guiding further investigations. Certain AMPs have demonstrated remarkable compatibility to be prescribed as anticancer drug to reduce cancer cell proliferation and serve as a potent antibiotic alternative. Besides, analyses were performed to explore the characteristics and affinities of peptides for membranes. Overall, the study of AMPs derived from the Androctonus scorpion genus provides valuable insights into their potential applications in medicine and drug development.

Molecular diversity assessed by MALDI mass spectrometry of two scorpion species venom from two different locations in Morocco.

Scorpion venom is a cocktail of molecules whose composition is remarkably plastic, controlled by several factors. The Moroccan scorpion fauna is characterized by its richness and high rate of endemism and the venom molecular variability of many species is not yet well characterized. The aim of the present study was to highlight the molecular variability of the venom composition of Androctonus amoreuxi and Buthacus stockmanni (endemic species), both belonging to the Buthidae family, collected from two Moroccan regions, Zagora and Tan-tan. Characterization of the molecular mass fingerprints (MFPs) of each specimen was performed by Matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) using a sandwich (Sand) and a dried-droplet (DD) sample preparation and dilutions. Considering these two methods, a total of 828 ion signals were detected, and Sand method produced more adducts (56%) than DD (44%). We observed interspecific variations in the venom composition between these two species showing they share 235 ion signals, while 226 and 367 are specific for these two species, respectively. Moreover, B. stockmanni specimens showed a clear difference in their MFPs between the two geographical areas studied, suggesting intraspecific variations. Moreover, specimens from each population also show an intraspecific variability. In addition, for the same individual, a variation in the venom composition was also recorded depending on the milking frequency. Our results confirmed the presence of characteristic components in each extracted venom sample. In conclusion, MFPs assessed by MALDI-MS represent a fast, non-supervised, sensitive, reliable and cost-efficient approach for taxonomic identification and molecular variability characterization. This study undoubtedly represents a step forward for understanding the scorpion venom plasticity, intra/inter variations, and their temporal and geographical variability.

Venomous gland transcriptome and venom proteomic analysis of the scorpion Androctonus amoreuxi reveal new peptides with anti-SARS-CoV-2 activity.

The recent COVID-19 pandemic shows the critical need for novel broad spectrum antiviral agents. Scorpion venoms are known to contain highly bioactive peptides, several of which have demonstrated strong antiviral activity against a range of viruses. We have generated the first annotated reference transcriptome for the Androctonus amoreuxi venom gland and used high performance liquid chromatography, transcriptome mining, circular dichroism and mass spectrometric analysis to purify and characterize twelve previously undescribed venom peptides. Selected peptides were tested for binding to the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein and inhibition of the spike RBD - human angiotensin-converting enzyme 2 (hACE2) interaction using surface plasmon resonance-based assays. Seven peptides showed dose-dependent inhibitory effects, albeit with IC50 in the high micromolar range (117-1202 µM). The most active peptide was synthesized using solid phase peptide synthesis and tested for its antiviral activity against SARS-CoV-2 (Lineage B.1.1.7). On exposure to the synthetic peptide of a human lung cell line infected with replication-competent SARS-CoV-2, we observed an IC50 of 200 nM, which was nearly 600-fold lower than that observed in the RBD - hACE2 binding inhibition assay. Our results show that scorpion venom peptides can inhibit the SARS-CoV-2 replication although unlikely through inhibition of spike RBD - hACE2 interaction as the primary mode of action. Scorpion venom peptides represent excellent scaffolds for design of novel anti-SARS-CoV-2 constrained peptides. Future studies should fully explore their antiviral mode of action as well as the structural dynamics of inhibition of target virus-host interactions.

A Fast Method for Detection of Fake Venoms and Investigation of Interspecies Variation Using Venoms of Androctonus, Buthus, and Leiurus (Scorpiones: Buthidae) Species.

Background: Within the scorpion family Buthidae, some of the most dangerous venomous genera are Androctonus (A), Buthus (B), and Leiurus (L). This venom is valuable raw material for numerous therapeutic formulations because of its pharmacological potential; however, because of its high prices in the global market, fake "venom mixes" are being made to market illegally, and it is important that these unknown mixes be evaluated. A fast and accurate response to the request for this identification is necessary. Method: This study was conducted in Turkey in 2022. Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) is a linear positive-ionization mode was used for identification of scorpion species. The mass spectra of the three scorpion venoms were examined in detail. The peptide and protein profiles in the venoms of congenerous three scorpion venoms and the proportional differences in these venoms were investigated. For interspecific variation, a principal component analysis of all venoms was conducted, and variance values and distance-proximity indices were determined. Results: The top three peptide masses in the highest relative abundance for A. australis, B. mardochei, and L. quinquestriatus quinquestriatus, respectively, were 6901, 7431, and 7447; 4238, 5283, and 4055; and 3828, 7868, and 6799 Da. While the variance rate between A. australis and the other two venoms was 40%, this rate was 38% between B. mordochei and L. quinquestriatus quinquestriatus venoms. Conclusion: A very simple protocol of species identification using scorpion venom samples was created using recent advances in MALDI-TOF MS.

Antihelimentic effect of Androctonus crassicauda scorpion venom against Trichuris arvicolae isolated from Psammomys obesus in Egypt.

Trichuridae family has a genetic and morphological variability between species affecting rodents, but it is considerably hard to morphologically diagnose species within the genus of Trichuris and the individuals of these species are identified according to their host, as it is known that Trichuris spp. is strictly host-specific. However, some species lack host specificity. So, it is necessary to use molecular data in order to well identify the Trichuris spp. in Egyptian rodents. The host examined in the current research is Psammomys obesus and the molecularly identified species from its cecum is Trichuris arvicolae. In addition, Trichuris arvicolae was subjected to in vitro treatment with Androctonus crassicauda Crude Venom as a model of natural alternative treatment for gastrointestinal nematodes that increasingly develop anthelmintic drug resistance. The changes in Trichuris arvicolae were monitored using scanning electron microscopy, Androctonus crassicauda Crude Venom made a significant ultrastructural surface changes in Trichuris arvicolae, including marked cuticular sloughing, disintegrated bacillary glands, bursting of vulva and edema of anal region. This study was done for closer identification of Trichuris spp. infecting rodents in Egypt and evaluating the efficacy of Androctonus crassicauda Crude Venom in vitro.

Insights into the mechanisms governing P01 scorpion toxin effect against U87 glioblastoma cells oncogenesis.

The emerging concept of small conductance Ca2+-activated potassium channels (SKCa) as pharmacological target for cancer treatment has significantly increased in recent years. In this study, we isolated the P01 toxin from Androctonus australis (Aa) scorpion venom and investigated its effect on biological properties of glioblastoma U87, breast MDA-MB231 and colon adenocarcinoma LS174 cancer cell lines. Our results showed that P01 was active only on U87 glioblastoma cells. It inhibited their proliferation, adhesion and migration with IC50 values in the micromolar range. We have also shown that P01 reduced the amplitude of the currents recorded in HEK293 cells expressing SK2 channels with an IC50 value of 3 pM, while it had no effect on those expressing SK3 channels. The investigation of the SKCa channels expression pattern showed that SK2 transcripts were expressed differently in the three cancer cell lines. Particularly, we highlighted the presence of SK2 isoforms in U87 cells, which could explain and rely on the specific activity of P01 on this cell line. These experimental data highlighted the usefulness of scorpion peptides to decipher the role of SKCa channels in the tumorigenesis process, and develop potential therapeutic molecules targeting glioblastoma with high selectivity.

Comparative Proteomic Analysis of the Venoms from the Most Dangerous Scorpions in Morocco: Androctonus mauritanicus and Buthus occitanus.

Morocco is known to harbor two of the world's most dangerous scorpion species: the black Androctonus mauritanicus (Am) and the yellow Buthus occitanus (Bo), responsible for 83% and 14% of severe envenomation cases, respectively. Scorpion venom is a mixture of biological molecules of variable structures and activities, most of which are proteins of low molecular weights referred to as toxins. In addition to toxins, scorpion venoms also contain biogenic amines, polyamines, and enzymes. With the aim of investigating the composition of the Am and Bo venoms, we conducted an analysis of the venoms by mass spectrometry (ESI-MS) after separation by reversed-phase HPLC chromatography. Results from a total of 19 fractions obtained for the Am venom versus 22 fractions for the Bo venom allowed the identification of approximately 410 and 252 molecular masses, respectively. In both venoms, the most abundant toxins were found to range between 2-5 kDa and 6-8 kDa. This proteomic analysis not only allowed the drawing of an extensive mass fingerprint of the Androctonus mauritanicus and Buthus occitanus venoms but also provided a better insight into the nature of their toxins.

Recombinant expression and antigenicity of two peptide families of neurotoxins from Androctonus sp.

Background: Scorpion neurotoxins such as those that modify the mammalian voltage-gated sodium ion channels (Nav) are the main responsible for scorpion envenomation. Their neutralization is crucial in the production of antivenoms against scorpion stings. Methods: In the present study, two in silico designed genes - one that codes for a native neurotoxin from the venom of the Anatolian scorpion Androctonus crassicauda, named Acra 4 - and another non-native toxin - named consensus scorpion toxin (SccTx) obtained from the alignment of the primary structures of the most toxic neurotoxins from the Middle Eastern and North African scorpions - were recombinantly expressed in E. coli Origami. Results: Following bacterial expression, the two expressed neurotoxins, hereafter named HisrAcra4 and HisrSccTx, were obtained from inclusion bodies. Both recombinant neurotoxins were obtained in multiple Cys-Cys isoforms. After refolding, the active protein fractions were identified with molecular masses of 8,947.6 and 9,989.1 Da for HisrAcra4 and HisrSccTx, respectively, which agreed with their expected theoretical masses. HisrAcra4 and HisrSccTx were used as antigens to immunize two groups of rabbits, to produce either anti-HisrAcra4 or anti-HisrSccTx serum antibodies, which in turn could recognize and neutralize neurotoxins from venoms of scorpion species from the Middle East and North Africa. The antibodies obtained from rabbits neutralized the 3LD50 of Androctonus australis, Leiurus quinquestriatus hebraeus and Buthus occitanus venoms, but they did not neutralize A. crassicauda and A. mauritanicus venoms. In addition, the anti-HisrAcra4 antibodies did not neutralize any of the five scorpion venoms tested. However, an antibody blend of anti-HisrAcra4 and anti-HisrSccTx was able to neutralize A. crassicauda and A. mauritanicus venoms. Conclusions: Two recombinant Nav neurotoxins, from different peptide families, were used as antigens to generate IgGs for neutralizing scorpion venoms of species from the Middle East and North Africa.

Differential venom gland gene expression analysis of juvenile and adult scorpions Androctonus crassicauda.

BACKGROUND: The Androctonus crassicauda, belonging to the genus Androctonus of the family Buthidae, is the most venomous scorpion in Middle East countries. However, the venom gland transcriptome profile of A. crassicauda scorpion has not yet been studied. In this study, we elucidated and compared the venom gland gene expression profiles of adult and juvenile male scorpion A. crassicauda using high-throughput transcriptome sequencing. This is the first report of transcriptional analysis of the venom glands of scorpions in different growth stages, with insights into the identification of the key genes during venom gland development. RESULTS: A total of 209,951 mRNA transcripts were identified from total RNA-seq data, of which 963 transcripts were differentially expressed (DE) in adult and juvenile scorpions (p < 0.01). Overall, we identified 558 up-regulated and 405 down-regulated transcripts in the adult compared to the juvenile scorpions, of which 397 and 269 unique unigenes were annotated, respectively. GO and KEGG enrichment analyses indicated that the metabolic, thermogenesis, cytoskeleton, estrogen signaling, GnRH signaling, growth hormone signaling, and melanogenesis pathways were affected by two different growth conditions and the results suggested that the DE genes related to those pathways are important genes associated with scorpion venom gland development, in which they may be important in future studies, including Chs, Elovl, MYH, RDX, ACTN, VCL, PIP5K, PP1C, FGFR, GNAS, EGFR, CREB, CoA, PLCB, CALM, CACNA, PKA and CAMK genes. CONCLUSIONS: These findings broadened our knowledge of the differences between adult and juvenile scorpion venom and opened new perspectives on the application of comparative transcriptome analysis to identify the special key genes.

Induced pathophysiological alterations by the venoms of the most dangerous Moroccan scorpions Androctonus mauretanicus and Buthus occitanus: A comparative pathophysiological and toxic-symptoms study.

Scorpion envenomation is a serious public health issue. Androctonus mauretanicus (Am) and Buthus occitanus (Bo) are the most dangerous scorpions in Morocco. Despite their medical relevance, no study has yet related their kinetics of symptom apparition and the consequent tissue disorders at the same interval post-injection. This work achieved the first comparative pathophysiological and toxic-symptoms study between the Am and Bo venoms from a biochemical, toxicological and physiopathological standpoint. The activity of venoms and their subletal dose were determined by administration of increasing concentrations of the venoms. 30, 60 and 120 min following the experimental envenomation in mice, the profile of clinical symptoms was underlined and the main organs: brain, heart, lungs, liver and kidneys were removed for histological examination. The Am venom is a rich source of proteins and three-times more toxic than the Bo. The most observed clinical symptoms are neurological and cardiopulmonary. The Am venom caused histopathological alterations at 30, 60, and 120 min which were more important than the Bo. This study highlighted that both venoms exhibited a strong toxicity with variable intensities. Moreover, we showed the presence of correlation between the level of histopathological disorders observed and the intensity of signs appeared at the same time following venom inoculation.

The Evaluation of Androctonus crassicauda Antivenom against the Effects of Aegaeobuthus nigrocinctus Scorpion Venom on Autophagy, Apoptosis and Necroptosis.

Background: In this study aimed to show the role of autophagy acting as a seesaw between apoptosis and necroptosis in certain vital organs under the effects of the Aegaeobuthus nigricinctus venom and different dosages of the Androctonus crassicauda antivenom administration in mice. Methods: In the venom group (VG), mice (n= 6) were inoculated with 2LD50 A. nigrocinctus venom. In the antivenom administered groups (AVG), the effects of the potency of the A. crassicauda antivenom were evaluated to have a neutralization effect against 20LD50 of the A. nigrocinctus venom. After histopathological examination, expressions of mammalian target of rapamycin (mTOR) as an autophagy activator, receptor-interacting serine/threonine-protein kinase 3 (RIPK3) as a necroptosis activator, and caspase-3, caspase-9 as the markers of apoptotic cell death signals were evaluated by the immunoperoxidase method in addition to DNA in-situ fragmentations by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method. Results: Only in VG, caspases and TUNEL expressions were found to be higher after the envenomation process in contrast to the elevated RIPK3 expressions. mTOR expressions remained almost stable in the organs. In AG, mTOR expressions were further increased in the 30LD50 and 40LD50 groups. Conclusion: There were an increased mTOR expression and stabilized caspases and TUNEL expression in these subgroups, the RIPK3 expressions were found to be low when compared with all of the antivenom administration groups. Increasing doses of the antivenom drifts more the cells to autophagy while cell fate in organs under envenomation getting rid of apoptosis and necroptosis pathways.

Molecular Survey of Mitochondrial Genes in Different Populations of the Black Fat-Tailed Scorpion, Androctonus crassicauda.

Background: Androctonus crassicauda is the most medically relevant scorpion and understanding its genetic forms is essential for improvement of anti-venom sera, and risk management of scorpionism. Present study was designed to identify the variations of mitochondrial genes in different populations of A. crassicauda. Methods: Adults of A. crassicauda were collected from Zanjan Province during 2016-2017. Genomic DNA of samples was extracted and fragments of mitochondrial 16S, COI and ND1 genes were amplified and some of the amplicons were sequenced. Haplotype of samples were identified by multiple alignment of sequences, then phylogenetic trees of haplotypes were constructed. Results: Fragments of 352bp, 618bp and 680bp were amplified from 16S, COI and ND1 genes respectively. Nucleotide sequence in COI fragments was conserved, however, five haplotypes with some specific polymorphic sites were detected in 16S and ND1 fragments. Haplotype I was dominant and found in all areas. Other haplotypes were rare and limited to specific regions. Analysis of the phylogenetic trees inferred from 16S and COI genes, confirmed a strong positive correlation between geographic and genetic distance. Conclusion: Mitochondrial COI, 16S and ND1 genes were detected suitable for identifying the population structure. Five genotypes were found using 16S and ND1 genes. To prepare and improve the anti-venoms quality, additional studies are necessary to identify the toxin electrophoretic profile and geographical/ecological niche models of these genotypes in future.

Morphometric Indices and Venom Protein Profile in Different Populations of Androctonus crassicauda.

Background: Androctonus crassicauda is the most medically relevant animal and understanding its morphological characteristics is essential in the production of antiscorpion sera. Methods: Adults of A. crassicauda were collected from different areas of Zanjan Province and the morphometric parameters and the cuticular fluorescence patterns of samples were studied. The crude venom of samples was extracted by electric stimulation, and their biochemical properties were analyzed by the SDS-PAGE method. Results: Values of the morphometric parameters depended on sex and altitude of the area. Except for values of the pectinal organ, these parameters in females were higher than in males. No significant difference was in the number, shape, and intensity of cuticular fluorescence patterns. The body length of males in high and lowlands was 72.53±1.53 and 77.33±2.70mm, respectively. Females' body lengths in that area were 81.66±2.19 and 86.55±2.33mm, respectively. Analysis of toxin proteins showed two isotypes that the 12, 13, 15, 16, 18, and 19kDa proteins were in all areas. However, the 41 and 74kDa proteins, and 46 and 63kDa proteins were detected in low and highlands, respectively. Conclusion: Black fat-tailed scorpion has a considerable dominancy and developing preventive programs and providing treatment facilities in studied areas are necessary. Values of the morphological parameters and venom electrophoresis patterns depended on the geographical location. Therefore, pool crude toxin is suggested for the production of effective antivenoms. Moreover, additional field complementary works in the geographic information system based niche modeling and mass fingerprinting of scorpion venoms are suggested for screening effective isotypes.

Clinical features and prognosis of severe scorpion envenomation in children.

BACKGROUND: Scorpionism is endemic and represents a real public health problem in Morocco. The most dangerous arthropod in the central area is Androctonus mauretanicus (Am) scorpion. Its venom can be lethal, especially for children. This study aimed to determine a clinico-epidemiological profile of severe scorpion envenomation among children and identify risk factors for mortality. METHODS: This retrospective cohort study included 606 children admitted for severe scorpion envenomation (SSE) from January 2010 to July 2015 in the Pediatric Intensive Care Unit (PICU) of Mohammed VI Teaching Hospital. RESULTS: The mean age of envenomed children was 6.3 ± 4.2 years. Seventy-four percent of them came from rural settings. Envenomation occurred mostly during the summer months and 78.4% of stings were nocturnal. The time between the sting and evaluation was greater than 2 h in 83% of cases. Bivariate analysis indicated that from 1 to 24 months of age (P = 0.001), hyperthermia (P = 0.022), episodes of diarrhea (P < 0.001), tachycardia (P < 0.001), abdominal distention (P < 0.001), skin marbling (P < 0.001), signs of respiratory distress (P < 0.001), irritability (P < 0.001), generalized seizures (P = 0.053), and Glasgow Coma Score (GCS) of 3 to 9 (P < 0.001) were significantly correlated with mortality. On multivariate analysis, diarrhea (P = 0.007), skin marbling (P = 0.006), and respiratory distress (P = 0.002), and GCS 3-9 (P = 0.007) were found to be independent risk factors for mortality in our patient population. CONCLUSIONS: Children are at high risk of developing serious complications, even death, from severe scorpion envenomation. Here we identified multiple factors that appear to increase the mortality risk in children after scorpion envenomation, including previously described central nervous system alterations.

Cross Pharmacological, Biochemical and Computational Studies of a Human Kv3.1b Inhibitor from Androctonus australis Venom.

The voltage-gated K+ channels Kv3.1 display fast activation and deactivation kinetics and are known to have a crucial contribution to the fast-spiking phenotype of certain neurons. AahG50, as a natural product extracted from Androctonus australis hector venom, inhibits selectively Kv3.1 channels. In the present study, we focused on the biochemical and pharmacological characterization of the component in AahG50 scorpion venom that potently and selectively blocks the Kv3.1 channels. We used a combined optimization through advanced biochemical purification and patch-clamp screening steps to characterize the peptide in AahG50 active on Kv3.1 channels. We described the inhibitory effect of a toxin on Kv3.1 unitary current in black lipid bilayers. In silico, docking experiments are used to study the molecular details of the binding. We identified the first scorpion venom peptide inhibiting Kv3.1 current at 170 nM. This toxin is the alpha-KTx 15.1, which occludes the Kv3.1 channel pore by means of the lysine 27 lateral chain. This study highlights, for the first time, the modulation of the Kv3.1 by alpha-KTx 15.1, which could be an interesting starting compound for developing therapeutic biomolecules against Kv3.1-associated diseases.

The effects of antivenom administrations on the brain tissue of experimentally envenomed pregnant rats and their pups with Androctonus crassicauda scorpion venom during organogenesis period.

This study aims to show the changing effects of Androctonus crassicauda venom and A. crasicauda specific antivenom during pregnancy in brain tissue of dams and their pups. Totally, 12 pregnant-Wistar Albino rats were randomly divided into two groups as venom-antivenom administration (n = 6) and control groups (n = 6). In venom-antivenom administration group (VAV), the sublethal dose of A. crassicauda venom dissolved in 1 mL physiological saline solution was subcutaneously (s.c.) injected into pregnant rats during organogenesis period (between 7 and 13 days of pregnancy). Four hours after each venom injection, 1 mL/s.c. dose of the specific anti-venom was administered to rats of VAV group. The rats in control group were given sterile saline solution 1 mL/s.c. In both groups, the fetuses were surgically delivered on the 21st day of pregnancy; dams and pups were sacrificed on postnatal 21 days, and their brain tissues were removed. The brain tissue of dams and their pups were evaluated histopathologically and immunohistochemically. To show the neuronal damages, 8-hydroxy-2-deoxyguanosine (8-OHDG) and amyloid beta precursor protein (ABPP) immunoexpressions were scored in cerebrum, cerebellum, pons and medulla oblongata of brain. To show the neuroprotection, reelin and beta-arrestin immunoexpressions were scored again in the same way. In this context, 8-OHDG immunoexpressions were increased in neocortex, hippocampus and nucleus accumbens when compared with that of control group. Amyloid beta precursor protein was negative in both groups. Reelin and beta-arrestin partly increased in fore and mid brain of VAV group as a reaction against neuronal damages when compared with that of control pups. The authors believe that prompt intervention using anti-venom to scorpion envenomation can partly stop neuronal damages. This neuroprotection may be increased to high and serial doses of anti-venom to save neonatal lives.

The effect of change in mass distribution due to defensive posture on gait in fat-tailed scorpions.

In terrestrial legged locomotion, the distribution of mass can influence the gait characteristics. This can be due to a change in the magnitude or distribution of the load. The latter occurs in scorpions when they lift their large metasoma from a trailing position in ambulatory posture to the well-known arched forward position in the defensive posture. We measured how locomotion changes between these two postures by recording scorpions walking using high-speed video. We found that the metasoma in the fat-tailed scorpion (Androctonus australis) represents about a quarter of the total mass. Moving this mass anteriorly over the body changes the position of the center of mass forward 8.15 ± 1.86 mm. We found this increases the overall duty factor, and particularly that of the second leg pair, even when taking the reduced speed in defensive posture into account. In the five scorpions we recorded, also the ipsilateral phase of leg pairs 3 and 4 differed in defensive posture. We found that the trajectory the 4th foot describes during a single stride also differed significantly between postures, showing this to be a sensitive measure of changes in gait. The change from an ambulatory to a defensive posture places different demands on the gait of scorpions, possibly largely due to the forward displacement of the center of mass.