Scorpion venom and the inflammatory response

Antivenom Potential of the Latex of Jatropha mutabilis Baill. (Euphorbiaceae) against Tityus stigmurus Venom: Evaluating its Ability to Neutralize Toxins and Local Effects in Mice

ETHNOPHARMACOLOGICAL RELEVANCE

Species of the Jatropha genus (Euphorbiaceae) are used indiscriminately in traditional medicine to treat accidents involving venomous animals. Jatropha mutabilis Baill., popularly known as "pinhão-de-seda," is found in the semi-arid region of Northeastern Brazil. It is widely used as a vermifuge, depurative, laxative, and antivenom.

AIM OF THE STUDY

Obtaining the phytochemical profile of the latex of Jatropha mutabilis (JmLa) and evaluate its acute oral toxicity and inhibitory effects against the venom of the scorpion Tityus stigmurus (TstiV).

MATERIALS AND METHODS

The latex of J. mutabilis (JmLa) was obtained through in situ incisions in the stem and characterized using HPLC-ESI-QToF-MS. Acute oral toxicity was investigated in mice. The protein profile of T. stigmurus venom was obtained by electrophoresis. The ability of latex to interact with venom components (TstiV) was assessed using SDS-PAGE, UV-VIS scanning spectrum, and the neutralization of fibrinogenolytic and hyaluronidase activities. Additionally, the latex was evaluated in vivo for its ability to inhibit local edematogenic and nociceptive effects induced by the venom.

RESULTS

The phytochemical profile of the latex revealed the presence of 75 compounds, including cyclic peptides, glycosides, phenolic compounds, alkaloids, coumarins, and terpenoids, among others. No signs of acute toxicity were observed at a dose of 2000 mg/kg (p.o.). The latex interacted with the protein profile of TstiV, inhibiting the venom's fibrinogenolytic and hyaluronidase activities by 100%. Additionally, the latex was able to mitigate local envenomation effects, reducing nociception by up to 56.5% and edema by up to 50% compared to the negative control group.

CONCLUSIONS

The latex of Jatropha mutabilis exhibits a diverse phytochemical composition, containing numerous classes of metabolites. It does not present acute toxic effects in mice and has the ability to inhibit the enzymatic effects of Tityus stigmurus venom in vitro. Additionally, it reduces nociception and edema in vivo. These findings corroborate popular reports regarding the antivenom activity of this plant and indicate that the latex has potential for treating scorpionism.

The geographical distribution of scorpions, implication of venom toxins, envenomation, and potential therapeutics in Southern and Northern Africa

Scorpions are predatory arachnids whose venomous sting primarily affects people in tropical and subtropical regions. Most scorpion stings can only cause localized pain without severe envenomation. Less than one-third of the stings cause systemic envenoming and possibly lead to death. About 350,000 scorpion stings in Northern Africa are recorded yearly, resulting in about 810 deaths. In Eastern/Southern Africa, there are about 79,000 stings recorded yearly, resulting in 245 deaths. Farmers and those living in poverty-stricken areas are among the most vulnerable to getting stung by scorpions. However, compared to adults, children are at greater risk of severe envenomation. Scorpion venom is made up of complex mixtures dominated by peptides and proteins that confer its potency and toxicity. These venom toxins have intra- and interspecies variations associated with the scorpion's habitat, sex, diet, and age. These variations alter the activity of antivenoms used to treat scorpion sting envenomation. Thus, the study of the proteome composition of medically important scorpion venoms needs to be scaled up along their geographical distribution and contributions to envenomation in Southern and Northern Africa. This will help the production of safer, more effective, and broad-spectrum antivenoms within these regions. Here, we review the clinical implications of scorpion sting envenomation in Southern and Northern Africa. We further highlight the compositions of scorpion venoms and tools used in scorpion venomics. We discuss current antivenoms used against scorpion sting envenomation and suggestions for future production of better antivenoms or alternatives. Finally, we discuss the therapeutic properties of scorpion venom.

Cytokines and their regulators in rat lung following scorpion envenomation

Nowadays, more than two billion inhabitants of underdeveloped tropical and subtropical countries are at risk of being stung by scorpions. Scorpion stings annually cause 2000-3000 deaths as they can lead to the respiratory and/or cardiovascular complications. Pathogenesis of lung damage under scorpion envenomation is often comprehensive. Respiratory failure can have a cardiogenic origin, associated with venom neurotoxin action. However, some venom components can stimulate pro-inflammatory signaling cascades followed by cytokines synthesis, recruit and activate immune cells, participating in the inflammatory response in lung injury. Scorpions of the Leiurus genus ("deathstalker") are one of the most dangerous Arthropoda. To date, 22 species of this genus have been described, but the venom composition and the mechanisms of tissues damage under envenomation have been studied to some extent only for L. quinquestriatus, L. hebraeus, and L. abdullahbayrami. Scorpions of L. macroctenus species are expected to be very hazardous, but the possibility of their venom cause inflammation in the lung tissue has not been investigated to date. Therefore, in this study, we focused on evaluating the levels of cytokines and their regulators - transcription factors (HIF-1α and NF-κB) and growth factors (FGF-2, VEGF, and EGF) - in rat lung homogenates after L. macroctenus envenomation. The results revealed a decrease in the levels of most pro-inflammatory cytokines (IL-6, IL-8, IL-1β and TNF-α) with simultaneous rise in the content of both anti-inflammatory cytokines (IL-4 and IL-10) and interferon-γ. Furthermore, the levels of all researched transcription factors and growth factors were shown to be increased too. The detected changes peak occurred at 24 h, whereas a tendency towards all indicators values normalization was observed in 72 h after venom injection. Thus, our results did not reveal signs of a classic inflammatory process in the lungs of rats injected with L. macroctenus venom. However, the obtained data indicate venom influence both on cytokine profile and on their regulators content in the rat lungs, which is a feature of certain alterations in the innate immune response, caused by studied venom components. But, the mechanisms of the changes we found require additional researches.

VISH-Pred: an ensemble of fine-tuned ESM models for protein toxicity prediction

Peptide- and protein-based therapeutics are becoming a promising treatment regimen for myriad diseases. Toxicity of proteins is the primary hurdle for protein-based therapies. Thus, there is an urgent need for accurate in silico methods for determining toxic proteins to filter the pool of potential candidates. At the same time, it is imperative to precisely identify non-toxic proteins to expand the possibilities for protein-based biologics. To address this challenge, we proposed an ensemble framework, called VISH-Pred, comprising models built by fine-tuning ESM2 transformer models on a large, experimentally validated, curated dataset of protein and peptide toxicities. The primary steps in the VISH-Pred framework are to efficiently estimate protein toxicities taking just the protein sequence as input, employing an under sampling technique to handle the humongous class-imbalance in the data and learning representations from fine-tuned ESM2 protein language models which are then fed to machine learning techniques such as Lightgbm and XGBoost. The VISH-Pred framework is able to correctly identify both peptides/proteins with potential toxicity and non-toxic proteins, achieving a Matthews correlation coefficient of 0.737, 0.716 and 0.322 and F1-score of 0.759, 0.696 and 0.713 on three non-redundant blind tests, respectively, outperforming other methods by over $10\%$ on these quality metrics. Moreover, VISH-Pred achieved the best accuracy and area under receiver operating curve scores on these independent test sets, highlighting the robustness and generalization capability of the framework. By making VISH-Pred available as an easy-to-use web server, we expect it to serve as a valuable asset for future endeavors aimed at discerning the toxicity of peptides and enabling efficient protein-based therapeutics.

Novel Scorpion Toxin ω-Buthitoxin-Hf1a Selectively Inhibits Calcium Influx via CaV3.3 and CaV3.2 and Alleviates Allodynia in a Mouse Model of Acute Postsurgical Pain

Venom peptides have evolved to target a wide range of membrane proteins through diverse mechanisms of action and structures, providing promising therapeutic leads for diseases, including pain, epilepsy, and cancer, as well as unique probes of ion channel structure-function. In this work, a high-throughput FLIPR window current screening assay on T-type CaV3.2 guided the isolation of a novel peptide named ω-Buthitoxin-Hf1a from scorpion Hottentotta franzwerneri crude venom. At only 10 amino acid residues with one disulfide bond, it is not only the smallest venom peptide known to target T-type CaVs but also the smallest structured scorpion venom peptide yet discovered. Synthetic Hf1a peptides were prepared with C-terminal amidation (Hf1a-NH2) or a free C-terminus (Hf1a-OH). Electrophysiological characterization revealed Hf1a-NH2 to be a concentration-dependent partial inhibitor of CaV3.2 (IC50 = 1.18 μM) and CaV3.3 (IC50 = 0.49 μM) depolarized currents but was ineffective at CaV3.1. Hf1a-OH did not show activity against any of the three T-type subtypes. Additionally, neither form showed activity against N-type CaV2.2 or L-type calcium channels. The three-dimensional structure of Hf1a-NH2 was determined using NMR spectroscopy and used in docking studies to predict its binding site at CaV3.2 and CaV3.3. As both CaV3.2 and CaV3.3 have been implicated in peripheral pain signaling, the analgesic potential of Hf1a-NH2 was explored in vivo in a mouse model of incision-induced acute post-surgical pain. Consistent with this role, Hf1a-NH2 produced antiallodynia in both mechanical and thermal pain.

Snake and arthropod venoms: Search for inflammatory activity in human cells involved in joint diseases

Most anti-inflammatory drugs currently adopted to treat chronic inflammatory joint diseases can alleviate symptoms but they do not lead to remission. Therefore, new and more efficient drugs are needed to block the course of joint inflammatory diseases. Animal venoms, rich in bioactive compounds, can contribute as valuable tools in this field of research. In this study, we first demonstrate the direct action of venoms on cells that constitute the articular joints. We established a platform consisting of cell-based assays to evaluate the release of cytokines (IL-6, IL-8, TNFα, IL-1β, and IL-10) by human chondrocytes, synoviocytes and THP1 macrophages, as well as the release of neuropeptides (substance-P and β-endorphin) by differentiated sensory neuron-like cells, 24 h after stimulation of cells with 21 animal venoms from snake and arthropod species, sourced from different taxonomic families and geographic origins. Results demonstrated that at non-cytotoxic concentrations, the venoms activate at varying degrees the secretion of inflammatory mediators involved in the pathology of articular diseases, such as IL-6, IL-8, and TNF-α by chondrocytes, synoviocytes, and macrophages and of substance P by neuron-like cells. Venoms of the Viperidae snake family were more inflammatory than those of the Elapidae family, while venoms of Arthropods were less inflammatory than snake venoms. Notably, some venoms also induced the release of the anti-inflammatory IL-10 by macrophages. However, the scorpion Buthus occitanus venom induced the release of IL-10 without increasing the release of inflammatory cytokines by macrophages. Since the cell types used in the experiments are crucial elements in joint inflammatory processes, the results of this work may guide future research on the activation of receptors and inflammatory signaling pathways by selected venoms in these particular cells, aiming at discovering new targets for therapeutic intervention.

Takotsubo cardiomyopathy following scorpion envenomation: a literature review

BACKGROUND

Takotsubo syndrome is comparable to microvascular acute coronary syndrome. It may partly share the same pathophysiology debated during scorpion envenomation (SE), with an adrenergic storm, without myocardial infarction due to the absence of coronary artery stenosis. Takotsubo cardiomyopathy can help to better understand the pathophysiology of cardiac involvement during scorpion envenomation. However, Takotsubo syndrome seems to be underestimated in the literature in patients suffering from cardiac failure following SE.

METHODS

In this review, we aimed to detail all described cases, the mechanism, and outcomes of scorpion envenomation complicated by Takotsubo cardiomyopathy. We used the PubMed database by using the following keywords in MeSH research: scorpion envenomation, Takotsubo cardiomyopathy, and Takotsubo syndrome.

RESULTS

The literature analysis showed the existence of only four cases of confirmed Takotsubo cardiomyopathy following severe SE. All four patients developed a transient reversible left ventricular systolic dysfunction in the absence of coronary artery disease, following a positive history of scorpion envenomation. A cardiac MRI was performed in all cases, showing a ballooning in the left ventricle associated with a left ventricular ejection fraction in all cases. All patients were improved under symptomatic treatment, and complete recovery of the wall motion was observed.

CONCLUSION

Takotsubo syndrome, although not often reported in the literature in severe SE, can represent an effective hypothesis explaining the pathophysiology of cardiac involvement during SE. In severe scorpion envenomation, multiple mechanisms exist and can explain the development of Takotsubo syndrome. Its management is based on oxygen, with invasive or non-invasive ventilator support in patients with respiratory failure and/or cardiogenic shock. Beta-blockers, mineralocorticoid receptor antagonists, and diuretics are usually used in Takotsubo syndrome. However, in severe scorpion envenomation, all reported cases of Takotsubo cardiomyopathy are associated with cardiogenic shock and acute pulmonary edema. As a consequence, we advise the use of Dobutamine since it has already been confirmed that cardiac dysfunction following scorpion envenomation improves well and safely under Dobutamine infusion.

Scorpion venom peptides: Molecular diversity, structural characteristics, and therapeutic use from channelopathies to viral infections and cancers

Animal venom is an important evolutionary innovation in nature. As one of the most representative animal venoms, scorpion venom contains an extremely diverse set of bioactive peptides. Scorpion venom peptides not only are 'poisons' that immobilize, paralyze, kill, or dissolve preys but also become important candidates for drug development and design. Here, the review focuses on the molecular diversity of scorpion venom peptides, their typical structural characteristics, and their multiple therapeutic or pharmaceutical applications in channelopathies, viral infections and cancers. Especially, the group of scorpion toxin TRPTx targeting transient receptor potential (TRP) channels is systematically summarized and worthy of attention because TRP channels play a crucial role in the regulation of homeostasis and the occurrence of diseases in human. We also further establish the potential relationship between the molecular characteristics and functional applications of scorpion venom peptides to provide a research basis for modern drug development and clinical utilization of scorpion venom resources.

Scorpion envenomation in the neotropical savannah: Environmental predictors and years of lost life

Scorpion stings envenomation (SSE) is a growing medical concern in Brazil, particularly in the state of Minas Gerais, which has recorded a significant number of incidents. This study aimed to investigate the potential predictors of scorpion sting incidence and evaluate the cost-effectiveness of interventions in Minas Gerais. Generalized Estimating Equations (GEE) models were constructed using socioeconomic and environmental variables as predictors and scorpion sting incidence as the response variable. The analysis revealed that mean annual temperature and major land use type were significant predictors of scorpion sting incidence, while precipitation and socioeconomic variables showed no relationship with incidence. The total number of cases and annual incidence of scorpion stings overlapped with regions experiencing higher forest conversion and agricultural land use, as well as higher temperatures. The estimated Disability-Adjusted Life Years (DALY) for scorpion sting incidents in Minas Gerais was substantial, indicating the need for effective prevention and treatment measures. The cost per DALY averted varied among municipalities, with some requiring minimal investment while others needing significant funding to address the scorpion risk. Mean annual temperature emerged as the main risk factor for scorpion stings, contributing to increased costs associated with antivenom treatment. These findings highlight the importance of considering environmental factors and implementing targeted interventions to mitigate scorpion sting incidents and reduce associated morbidity and mortality.

Pulmonary involvement from animal toxins: the cellular mechanisms

Venomous animals and their venom have always been of human interest because, despite species differences, coevolution has made them capable of targeting key physiological components of our bodies. Respiratory failure from lung injury is one of the serious consequences of envenomation, and the underlying mechanisms are rarely discussed. This review aims to demonstrate how toxins affect the pulmonary system through various biological pathways. Herein, we propose the common underlying cellular mechanisms of toxin-induced lung injury: interference with normal cell function and integrity, disruption of normal vascular function, and provocation of excessive inflammation. Viperid snakebites are the leading cause of envenomation-induced lung injury, followed by other terrestrial venomous animals such as scorpions, spiders, and centipedes. Marine species, particularly jellyfish, can also inflict such injury. Common pulmonary manifestations include pulmonary edema, pulmonary hemorrhage, and exudative infiltration. Severe envenomation can result in acute respiratory distress syndrome. Pulmonary involvement suggests severe envenomation, thus recognizing these mechanisms and manifestations can aid physicians in providing appropriate treatment.

When Venom Meets the Heart: A Rare Case of Scorpion Sting-Induced Acute Myocardial Infarction

Scorpion sting cases are everyday encounters in the Emergency Department (ED). However, scorpion sting-induced systemic manifestations are rarely seen. Signs and symptoms of envenomation involve the central nervous system, stimulation of the autonomic nervous system and rarely respiratory and heart failure leading to death. Cardiovascular manifestations are particularly prominent following stings by the Indian red scorpion. This case report is of an 18-year-old male patient who presented to ED with complaints of scorpion sting. Twelve lead electrocardiography (ECG) done was suggestive of acute inferior wall myocardial infarction with raised cardiac markers. He also had autonomic dysfunction in the form of hypertension, hypothermia and priapism. He was treated with an alpha-blocker, dual antiplatelets and analgesics. ECG changes reverted to normal the next day, and he was discharged. So, the anticipation of life-threatening complications of scorpion stings plays a vital role in the treatment and prognosis of patients presenting to ED.

Toxicity Mechanism of Dangerous Scorpion Stings in Iran

Background

Considering the importance of scorpions and recognizing the mechanisms of toxicity caused by their medically important species in Iran and adopting the best therapeutic approach based on these mechanisms, this study was performed by reviewing the clinical manifestations of scorpion stings.

Methods

The research was conducted by searching for articles and researches in related websites (PubMed, EMBASE, Scopus, Web of Science and CINAHL) and using domestic and international authoritative journals using the keywords of scorpion, clinical manifestations, in a review method. Finally, 104 qualified sources were selected and after reviewing and criticizing these studies, the author's point of view was presented.

Results

Clinical manifestations of Scorpion sting toxicity vary due to the existence of two toxic classes of neurotoxins and cytotoxins or hemotoxins in these arthropods in Iran. The number and distribution of species with neurotoxic venom are higher than the scorpions with cytotoxic venom and are reported throughout Iran. Scorpions with cytotoxic venom are mostly widespread in south and southwest of Iran.

Conclusion

Treatment and prevention of scorpion stings in Iran and neighboring countries in the Middle East should be planned based on the mechanism of toxicity and the presence of toxic classes with neurotoxic or cytotoxic venoms.

Protein and peptide profiles of rats' organs in scorpion envenomation

Problem of scorpion envenomation becomes more alarming each year. Main effects of scorpion venom are commonly believed to be related to its neurotoxic properties, yet severe symptoms may also be developed due to the uncontrolled enzymatic activity and formation of various bioactive molecules, including middle-mass molecules (MMMs). MMMs are considered as endogenous intoxication markers, their presence may indicate multiple organ failure. Scorpions, belong to the Leiurus macroctenus species, are very dangerous, nevertheless, effects of their venom on protein and peptide composition within the tissues remains unclear. In this work we have focused the attention on changes in protein and MMM levels and peptide composition in various organs during Leiurus macroctenus envenomation. The results revealed a decrease in protein level during envenomation as well as a significant increment of MMM₂₁₀ and MMM₂₅₄ levels in all assessed organs. Quantitative and qualitative compositions of various protein and peptide factions were continually changing. All of this may suggest that Leiurus macroctenus sting causes considerable destruction of cell microenvironment across all essential organs, providing systemic envenomation. In addition, MMM level increment may indicate endogenous intoxication development. Peptides, formed during envenomation, may possess various bioactive properties, analysis of which constitutes an area of further studies.

Investigating the inhibitory and penetrating properties of three novel anticancer and antimicrobial scorpion peptides via molecular docking and molecular dynamic simulation

The two types of bladder cancer, muscle invasive and non-muscle invasive (NMIBC), are among the most prevalent cancers worldwide. Despite this, even though muscle-invasive bladder cancer is more deadly, NMIBC requires more therapy due to a greater recurrence rate and more extended and expensive care. Immunotherapy, intravesical chemotherapy, cystoscopy, and transurethral resection (TUR) are among the treatments available. Crude scorpion venomand purified proteins and peptides, can suppress cancer metastasis in an in vitro or in vivo context, suppress cancer growth, halt the cell cycle, and cause cell apoptosis, according to an increasing number of experimental and preclinical studies. In this research, three novels discovered peptides (P2, P3 and P4. ProteomeXchange: PXD036231) from Buthotus saulcyi and, Odontobuthus doriae scorpions were used along with a peptide called pantinin (as a control). The phylogenetic tree showed that the peptides belong to Chaperonin HSP60, Chrysophsin2 and Pheromone-binding protein2, respectively. These peptides were docked with four known antigens, BAGE, BLCAP, PRAME and ROR1 related to bladder cancer and three bacterial antigens FliC, FliD and FimH to investigate their antimicrobial and anticancer properties. The results showed that peptides 2 and 3 have the best binding rate. The MD simulation results also confirmed the binding of peptides 2 and 3 to antigens. The penetration power of peptides 2 and 3 in the membrane of cancer cells and bacterial cells was also simulated, and the results of RMSD and PD confirmed it. QSAR suggests that peptides 2 and 3 can act as anti-cancer and anti-microbial peptides.Communicated by Ramaswamy H. Sarma.

The Activity of Metalloproteases and Serine Proteases in Various Organs after Leiurus macroctenus Envenomation

Background

Scorpion stings may be life-threatening since their venoms are comprised of a wide range of toxins and other bioactive molecules, such as enzymes. At the same time, scorpion envenomation may increase matrix metalloproteases (MMPs) levels, which enhance proteolytic tissue destruction by venom. However, investigations on the impact of many scorpions' venoms, such as those of Leiurus macroctenus, on tissue proteolytic activity and MMP levels have not yet been conducted.

Methods and Results

The present study aimed to examine the total proteolysis levels in various organs after Leiurus macroctenus envenomation and evaluate the metalloproteases and serine proteases' contributions to the total proteolytic activity. Changes in MMPs and TIMP-1 levels were tested as well. Envenomation led to a significant increase in proteolytic activity levels in all assessed organs, mostly in the heart (by 3.34 times) and lungs (by 2.25 times).

Conclusions

Since EDTA presence showed a noticeable decrease in total proteolytic activity level, metalloproteases appeared to play a prominent role in total proteolytic activity. At the same time, MMPs and TIMP-1 levels were increased in all assessed organs, suggesting that Leiurus macroctenus envenomation causes systemic envenomation, which may induce multiple organ abnormalities, mostly because of the uncontrolled metalloprotease activity.

Bioactive peptides from scorpion venoms: therapeutic scaffolds and pharmacological tools

Evolution and natural selection have endowed animal venoms, including scorpion venoms, with a wide range of pharmacological properties. Consequently, scorpions, their venoms, and/or their body parts have been used since time immemorial in traditional medicines, especially in Africa and Asia. With respect to their pharmacological potential, bioactive peptides from scorpion venoms have become an important source of scientific research. With the rapid increase in the characterization of various components from scorpion venoms, a large number of peptides are identified with an aim of combating a myriad of emerging global health problems. Moreover, some scorpion venom-derived peptides have been established as potential scaffolds helpful for drug development. In this review, we summarize the promising scorpion venoms-derived peptides as drug candidates. Accordingly, we highlight the data and knowledge needed for continuous characterization and development of additional natural peptides from scorpion venoms, as potential drugs that can treat related diseases.

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.

Intraspecific differences in Androctunus crassicauda venom and envenomation symptoms

Envenomation by Androctunus crassicauda is very frequent in Iran, especially in the south-west. This scorpion is one of the six scorpions whose venom is used to prepare anti-venom. Using HPLC, we discovered venom components of A. crassicauda varies from one specimen to another depending on geographical location, and this result is confirmed by those first found in various symptoms of A. crassicauda sting in envenomed persons from two separate geographical places (north and south of Khuzestan province). There was a significant relationship between symptoms and location of envenomation by A. crassicauda. Muscle spasm was more dominant in envenomed people from Northern cities, and venom chromatogram analysis showed the presence of at least six main sharp peaks in Northern A. crassicauda rather than Southern A. crassicauda. It shows intraspecific differences in venom of A. crassicauda that must be considered in treatment of stung people from different geographical locations as well as in the preparation of anti-venom. See also Figure 1(Fig. 1).

Investigation of Peptide Toxin Diversity in Ribbon Worms (Nemertea) Using a Transcriptomic Approach

Nemertea is a phylum of nonsegmented worms (supraphylum: Spiralia), also known as ribbon worms. The members of this phylum contain various toxins, including peptide toxins. Here, we provide a transcriptomic analysis of peptide toxins in 14 nemertean species, including Cephalothrix cf. simula, which was sequenced in the current study. The summarized data show that the number of toxin transcripts in the studied nemerteans varied from 12 to 82. The most represented groups of toxins were enzymes and ion channel inhibitors, which, in total, reached a proportion of 72% in some species, and the least represented were pore-forming toxins and neurotoxins, the total proportion of which did not exceed 18%. The study revealed that nemerteans possess a much greater variety of toxins than previously thought and showed that these animals are a promising object for the investigation of venom diversity and evolution, and in the search for new peptide toxins.

ToxinPred2: an improved method for predicting toxicity of proteins

Proteins/peptides have shown to be promising therapeutic agents for a variety of diseases. However, toxicity is one of the obstacles in protein/peptide-based therapy. The current study describes a web-based tool, ToxinPred2, developed for predicting the toxicity of proteins. This is an update of ToxinPred developed mainly for predicting toxicity of peptides and small proteins. The method has been trained, tested and evaluated on three datasets curated from the recent release of the SwissProt. To provide unbiased evaluation, we performed internal validation on 80% of the data and external validation on the remaining 20% of data. We have implemented the following techniques for predicting protein toxicity; (i) Basic Local Alignment Search Tool-based similarity, (ii) Motif-EmeRging and with Classes-Identification-based motif search and (iii) Prediction models. Similarity and motif-based techniques achieved a high probability of correct prediction with poor sensitivity/coverage, whereas models based on machine-learning techniques achieved balance sensitivity and specificity with reasonably high accuracy. Finally, we developed a hybrid method that combined all three approaches and achieved a maximum area under receiver operating characteristic curve around 0.99 with Matthews correlation coefficient 0.91 on the validation dataset. In addition, we developed models on alternate and realistic datasets. The best machine learning models have been implemented in the web server named 'ToxinPred2', which is available at https://webs.iiitd.edu.in/raghava/toxinpred2/ and a standalone version at https://github.com/raghavagps/toxinpred2. This is a general method developed for predicting the toxicity of proteins regardless of their source of origin.

Predictive Value of Glycemia and Free Fatty Acid Levels upon Admission of Children with Scorpionism in Egypt

Scorpion envenomation is a life-threatening emergency and causes serious health problems in tropical and subtropical regions. The aim of this study was to correlate the serum levels of biochemical parameters at admission in children with scorpion envenomation with subsequent morbidity and mortality. It was a prospective, observational, and descriptive study conducted for scorpion-envenomed children who presented to emergency and intensive care units between April 2019 and September 2019. Demographic, clinical, and laboratory findings of patients were recorded and tabulated. Routine investigations were done for all patients in addition to blood levels of lactate, free fatty acids (FFA), and insulin. All patients were compared according to outcome as survivors and nonsurvivors and according to glucose level as normoglycemic and hyperglycemic groups. There were 62 scorpion sting cases; their mean age was 8.6 ± 3.2 years. Patients aged more than 6 years (74.2%), and males (66.1%) were more affected than others. As regards severity, 25.8% were suffering organ dysfunction, 40.3% suffered systemic manifestations without organ dysfunction, and (33.9%) with only local manifestations. Serum glucose and FFA were significantly higher in nonsurvivors compared with survivors. Shock, convulsion, coma, heart failure, and pulmonary edema were significantly more common in hyperglycemic than normoglycemic group. Hyperglycemia, and raised FFA were associated with severe scorpion envenomation. Raised FFA was well correlated with presence of heart failure, leucocytosis, and hyperglycemia. Adding serum glucose and FFA to monitoring parameters of scorpionism severity can help the prediction of high-risk patients.

TanP: A Multifunctional Anionic Peptide From Tityus stigmurus Scorpion Venom

Anionic peptides of scorpions are molecules rich in aspartic and/or glutamic acid residues and correspond to a class of peptides without disulfide bonds that are still little explored. TanP is a linear anionic peptide (50 amino acid residues and net charge -20) present in the venom gland of the scorpion, Tityus stigmurus, with chelating properties for Cu2+ ion and immunomodulatory properties. The therapeutic application of chelating molecules is related to cases of acute or chronic intoxication by metals, neurodegenerative diseases, hematological diseases, healing of skin wounds, cardiovascular diseases, and cancer. In this approach, the chelating activity of TanP was evaluated in relation to new metal ions (Fe2+ and Zn2+) of biological importance, as well as its antioxidant, hemostatic, immunomodulatory, and healing potential, aiming to expand the biological and biotechnological potential of this peptide. TanP (25 µM) was able to form stable complexes with Fe2+ in a ratio of 1:5 (TanP: Fe2+). Theoretical results suggest that TanP can work as a sensor to identify and quantify Fe2+ ions. The fluorescence intensity of TanP (1.12 µM) decreased significantly after the addition of Fe2+, obtaining the highest ratio 1: 7.4 (TanP: Fe2+) that led to the lowest fluorescence intensity. For Zn2+, no relevant spectral change was noted. TanP (50 µM) showed a maximum of 3% of hemolytic activity, demonstrating biocompatibility, as well as exhibiting a 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity of above 70% at all the concentrations tested (1-25 μM), and 89.7% iron-chelating activity at 25 μM and 96% hydroxyl radical-scavenging activity at 73.6 μM. In addition, TanP (12.5 and 25 µM) revealed an anticoagulant effect, prolonging the clotting time in prothrombin time and activated partial thromboplastin time assays, with no fibrinogenolytic activity. TanP (12.5 and 25 µM) induced the release of TNF-α by murine macrophages, in the absence of lipopolysaccharides, with a concentration-dependent increase and also stimulated the migration of 3T3 cells in the in vitro healing assay. Thus, TanP revealed a multifunctional potential, being useful as a prototype for the development of new therapeutic and biotechnological agents.

Phyto-Phospholipid Conjugated Scorpion Venom Nanovesicles as Promising Carrier That Improves Efficacy of Thymoquinone against Adenocarcinoma Human Alveolar Basal Epithelial Cells

Lung cancer is a dangerous type of cancer in men and the third leading cause of cancer-related death in women, behind breast and colorectal cancers. Thymoquinone (THQ), a main compound in black seed essential oils, has a variety of beneficial effects, including antiproliferative, anti-inflammatory, and antioxidant properties. On the other hand, scorpion venom peptides (SV) induce apoptosis in the cancer cells, making it a promising anticancer agent. THQ, SV, and Phospholipon^® 90H (PL) were incorporated in a nano-based delivery platform to assess THQ’s cellular uptake and antiproliferative efficacy against a lung cancer cell line derived from human alveolar epithelial cells (A549). Several nanovesicles were prepared and optimized using factorial experimental design. The optimized phytosome formulation contained 79.0 mg of PL and 170.0 mg of SV, with vesicle size and zeta potential of 209.9 nm and 21.1 mV, respectively. The IC50 values revealed that A549 cells were significantly more sensitive to the THQ formula than the plain formula and THQ. Cell cycle analysis revealed that THQ formula treatment resulted in significant cell cycle arrest at the S phase, increasing cell population in this phase by 22.1%. Furthermore, the THQ formula greatly increased cell apoptosis (25.17%) when compared to the untreated control (1.76%), plain formula (11.96%), or THQ alone (13.18%). The results also indicated that treatment with THQ formula significantly increased caspase-3, Bax, Bcl-2, and p53 mRNA expression compared to plain formula and THQ. In terms of the inflammatory markers, THQ formula significantly reduced the activity of TNF-α and NF-κB in comparison with the plain formula and THQ only. Overall, the findings from the study proved that a phytosome formulation of THQ could be a promising therapeutic approach for the treatment of lung adenocarcinoma.

Neglected Venomous Animals and Toxins: Underrated Biotechnological Tools in Drug Development

Among the vast repertoire of animal toxins and venoms selected by nature and evolution, mankind opted to devote its scientific attention—during the last century—to a restricted group of animals, leaving a myriad of toxic creatures aside. There are several underlying and justifiable reasons for this, which include dealing with the public health problems caused by envenoming by such animals. However, these studies became saturated and gave rise to a whole group of animals that become neglected regarding their venoms and secretions. This repertoire of unexplored toxins and venoms bears biotechnological potential, including the development of new technologies, therapeutic agents and diagnostic tools and must, therefore, be assessed. In this review, we will approach such topics through an interconnected historical and scientific perspective that will bring up the major discoveries and innovations in toxinology, achieved by researchers from the Butantan Institute and others, and describe some of the major research outcomes from the study of these neglected animals.

Amazonian scorpions and scorpionism: integrating toxinological, clinical, and phylogenetic data to combat a human health crisis in the world's most diverse rainfores

Venom from Amazonian scorpions of the genus Tityus contains components capable of eliciting a distinct clinical, mostly neurological, syndrome. This contrasts with the mainly autonomic manifestations produced after envenomation by congeneric southern and northern South American species. Herein, we summarize Pan-Amazonian scorpionism by synthesizing available toxinological, clinical, and molecular data gathered from all affected areas in Amazonia, including Brazil, Ecuador, Colombia, Peru, Venezuela, and French Guiana. We searched multiple databases, as well as our own records, for reports of scorpion envenomations in Amazonia by confirmed Tityus spp., and compared the clinical manifestations. To help uncover clinical and venom relationships among problematic species, we explored phylogenetic relationships with a rate-calibrated analysis of mitochondrial COI data from available species. The possible existence of diversity gradients for venom toxic and immunogenic components despite the predicted strong phylogenetic association among species is underscored by discussed clinical and toxinological findings. A multicentric effort, involving all nations affected by this neglected disease, is urgently needed to offer alternatives for treating and understanding this pathology, including the preparation of neutralizing antibodies with a broad range of efficacy.

Expression and purification of recombinant alpha-toxin AnCra1 from the scorpion Androctonus crassicauda and its functional characterization on mammalian sodium channels

BACKGROUND

Alpha-scorpion toxins with long-chain peptide and four disulfide bonds represent diverse pharmacological profiles for various subtypes of voltage-gated sodium channels. Obtaining the natural toxins are difficult and time-consuming process, which represents the major difficulty to interpreting analysis of their structural and functional properties.

METHODS AND RESULTS

This study describes the toxin peptide and plasmid construct containing the gene coding for mammalian toxin AnCra1 from the scorpion Androctonus crassicauda venom. We have established genetic construction of fusion protein in pET32a + vector containing thioredoxin (Trx-tag), enterokinase cleavage site and 6xhistidine-tag for efficient expression in Escherichia coli strain RG2 (DE3). The soluble expressed peptide, then purified by Ni-NTA resin affinity chromatography and its purity was confirmed by reverse-phase HPLC and mass spectrometry (7433.54 Da.). The electrophysiological data showed that recombinant AnCra1 selectively inhibits the fast inactivation of hNav1.7 channel (EC₅₀ = 136.7 ± 6.6 nM).

CONCLUSIONS

Our findings demonstrate that the AnCra1 is structurally and functionally analogous to alpha excitatory toxins; furthermore, expression and purification of bioactive scorpion toxins in bacterial cells can be a practicable and efficient way to obtain a novel source of toxin peptides as tools to study the function and physiological responses of ion channels.

Scorpion Stings and Antivenom Use in Arizona

BACKGROUND

Arizona's rugged desert landscape harbors many venomous animals, including a small nocturnal scorpion, Centruroides sculpturatus, whose venom can cause severe neuromotor disturbance. An effective antivenom is available at selected health care facilities in the state.

METHODS

We analyzed 4398 calls of scorpion stings to the Arizona Poison and Drug Information Center (APDIC) in Tucson over a period of 3 years, from January 2017 to December 2019.

RESULTS

We followed 1952 (44.4%) of the victims to resolution. We excluded 2253 callers with minimal effects of the sting and 193 victims with possible toxic effects who were lost to follow-up. The most common complaints among callers were pain at the sting site in 88.9% and local numbness in 62.2%. Detailed clinical information was obtained from 593 calls from a health care facility. Neuromotor signs consistent with C. sculpuratus envenomation included nystagmus in 163 (27.5%), hypersalivation in 91 (15.3%), and fasciculations in 88 (14.8%). Antivenom (Anascorp; Rare Disease Therapeutics, Inc., Franklin, Tenn) was administered to 145 patients. Most were children <5 years old (n = 76, or 54.4%); 27 (18.6%) were 5-9 years old and 42 (30.0%) were ≥10 years of age. About half, 79 of 145 (54.5%) victims who received antivenom, met the APDIC recommended use criteria.

CONCLUSIONS

Patients treated with antivenom exhibited a rapid resolution of symptoms without immediate or delayed hypersensitivity reactions. We recommend broadened availability of antivenom at sites where it is most needed.

The lethality, histological, haematological and biochemical alterations in mice envenomated with Aegaeobuthus nigrocinctus venom

There is currently no data regarding the toxicity or the in vivo effects of the venom the Aegaeobuthus nigrocinctus species, since it has not been studied thus far according to the best of our knowledge. In the present study, and for the first time, the median lethal dose, the in vivo toxic effects, the histological changes in some of the vital organs were all determined as well as an assessment was made of the histological, biochemical and haematological changes which were caused by the venom injected in mice. The median lethal dose (LD₅₀) of the scorpion venom for mice was found to be 0.38 mg/kg in terms of body weight. The results of the study show that the A. nigrocintus is a potentially lethal scorpion. The evidence related to the venom indicated that it could cause tissue injury in some vital organs. In conclusion, this scorpion venom could cause significant medical complications, and may lead to death, regarding at-risk patients. Therefore, health professionals should be aware of the various scorpion species in their regions and should follow current medical approaches concerning scorpion envenomation.

Clinical Effects and Predictive Factors Affecting the Clinical Severity of Scorpion Envenomations in Western Turkey

BACKGROUND

Scorpion envenomation is a common medical emergency in many countries, including Turkey. Severe systemic symptoms occur more easily in children and mortality rates are higher. The aim of this study is to describe the clinical effects and predictive factors affecting the clinical severity of scorpion envenomations in Western Turkey.

METHODS

Two hundred one children (138 mild cases, 34 moderate, and 29 severe) with scorpion envenomation aged between 1 month and -17 years were included in the study. The patients' demographic and laboratory characteristics were compared among clinical severity subgroups.

RESULTS

The patients' median age was 7 (4-11) years. The median age of the severe group was significantly lower than that of the mild and moderate groups (p < 0.001). Seventeen patients (8.5%) developed myocarditis, while no pulmonary edema was observed in any case. Leukocyte, neutrophil and platelet (PLT) counts, and plateletcrit (PCT) and glucose levels increased significantly with the severity of envenomation (p < 0.001). PLT counts and PCT levels exhibited positive correlation with leukocyte and neutrophil counts (p < 0.001, r = 0.781, r = 0.638, r = 0.772, and r = 0.629, respectively). Supraventricular tachycardia developed in 1 (5.9%) patient, and dilated cardiomyopathy in another (5.9%). No mortality occurred in any case.

CONCLUSION

Increased PLT counts and PCT levels may be helpful in evaluating clinical severity in patients with scorpion sting envenomation. The possibility of myocarditis development in children should be remembered and cardiac enzymes should be checked, even if patients are asymptomatic and cardiac enzymes are normal on admission.

Utilisation of compounds from venoms in drug discovery

Difficult drug targets are becoming the normal course of business in drug discovery, sometimes due to large interacting surfaces or only small differences in selectivity regions. For these, a different approach is merited: compounds lying somewhere between the small molecule and the large antibody in terms of many properties including stability, biodistribution and pharmacokinetics. Venoms have evolved over millions of years to be complex mixtures of stable molecules derived from other somatic molecules, the stability comes from the pressure to be ready for delivery at a moment's notice. Snakes, spiders, scorpions, jellyfish, wasps, fish and even mammals have evolved independent venom systems with complex mixtures in their chemical arsenal. These venom-derived molecules have been proven to be useful tools, such as for the development of antihypotensive angiotensin converting enzyme (ACE) inhibitors and have also made successful drugs such as Byetta® (Exenatide), Integrilin® (Eptifibatide) and Echistatin. Only a small percentage of the available chemical space from venoms has been investigated so far and this is growing. In a new era of biological therapeutics, venom peptides present opportunities for larger target engagement surface with greater stability than antibodies or human peptides. There are challenges for oral absorption and target engagement, but there are venom structures that overcome these and thus provide substrate for engineering novel molecules that combine all desired properties. Venom researchers are characterising new venoms, species, and functions all the time, these provide great substrate for solving the challenges presented by today's difficult targets.

Cytotoxic Effects of Blue Scorpion Venom (Rhopalurus junceus) in a Glioblastoma Cell Line Model

BACKGROUND

Cancer is one of the leading cause of death worldwide. Besides current therapies and treatments to counter cancer, new alternatives are required to diminish the cell proliferation of oncogenic processes.

METHODS

One of the most promissory therapy includes the use of blue scorpion venom as a specific cytotoxic agent to kill tumoral cells, including Glioblastoma multiforme.

OBJECTIVES

We show evidence of the cytotoxic effect of blue scorpion venom in a cellular model of Glioblastoma multiforme.

RESULTS

Our results demonstrate that 50 μg/ml of scorpion venom is capable to diminish the viability of Glioblastoma populations.

CONCLUSION

It is possible that the action mechanism could be associated with a loss of membrane integrity. Additionally, some metalloproteinases as MMP2 and MMP9 may also participate in the potential action mechanism.

Immunological Responses to Envenomation

Venoms are complex mixtures of toxic compounds delivered by bite or sting. In humans, the consequences of envenomation range from self-limiting to lethal. Critical host defence against envenomation comprises innate and adaptive immune strategies targeted towards venom detection, neutralisation, detoxification, and symptom resolution. In some instances, venoms mediate immune dysregulation that contributes to symptom severity. This review details the involvement of immune cell subtypes and mediators, particularly of the dermis, in host resistance and venom-induced immunopathology. We further discuss established venom-associated immunopathology, including allergy and systemic inflammation, and investigate Irukandji syndrome as a potential systemic inflammatory response. Finally, this review characterises venom-derived compounds as a source of immune modulating drugs for treatment of disease.

Neurological and Systemic Manifestations of Severe Scorpion Envenomation

Scorpion envenomation is a life-threatening toxicological emergency and considered as a major public health problem, especially in endemic regions (India, Africa, Latin America); it is generally characterized by low resources and tropical or subtropical weather. Scorpion envenomation is especially fatal in the first hours, usually due to respiratory and/or cardiovascular collapse. The neurologic manifestations, triggered by multiple neurotoxic mechanisms, are varied and complex and mostly reported in children. The aim of this review is to clarify the epidemiologic characteristics and clinical manifestations as well as diagnosis and management of neurologic complications following scorpion envenomation. The management of patients with severe clinical forms is based on early recognition of the sting, antivenom serum administration, and cardiorespiratory and systemic support.

Immunomodulatory properties of molecules from animal venoms

The immune system can amplify or decrease the strength of its response when it is stimulated by chemical or biological substances that act as immunostimulators, immunosuppressants, or immunoadjuvants. Immunomodulation is a progressive approach to treat a diversity of pathologies with promising results, including autoimmune disorders and cancer. Animal venoms are a mixture of chemical compounds that include proteins, peptides, amines, salts, polypeptides, enzymes, among others, which produce the toxic effect. Since the discovery of captopril in the early 1980s, other components from snakes, spiders, scorpions, and marine animal venoms have been demonstrated to be useful for treating several human diseases. The valuable progress in fields such as venomics, molecular biology, biotechnology, immunology, and others has been crucial to understanding the interaction of toxins with the immune system and its application on immune pathologies. More in-depth knowledge of venoms' components and multi-disciplinary studies could facilitate their transformation into effective novel immunotherapies. This review addresses advances and research of molecules from venoms that have immunomodulatory properties.

Involvement of the Endothelin Receptor Type A in the Cardiovascular Inflammatory Response Following Scorpion Envenomation

Elevated levels of endothelin-1 (ET-1) were recorded in sera of scorpion sting patients. However, no studies focused on the mechanism of ET-1 involvement in the pathogenesis of scorpion envenomation, particularly in the cardiovascular system which is seriously affected in severe cases of scorpion stings. Inflammation induced by Androctonus australis hector (Aah) scorpion venom in the heart together with the aorta was studied in mice pretreated with a specific endothelin A receptor (ETA-R) inhibitor. ETA-R inhibition resulted in the attenuation of the high amounts of cytokine (tumor necrosis factor alpha (TNF-α) and interleukin-17 (IL-17)) recorded in the sera of envenomed mice. The recovery of the oxidative stress marker balance and matrix metalloproteinase (MMP) expression were also observed, concomitantly with the reduction of tissular neutrophil infiltration. Additionally, the cardiac and the aortic tissue alterations, and the metabolic enzymes (creatine kinase (CK) and muscle–brain isoform creatine kinase (CK-MB)) overspread into sera were significantly attenuated. Obtained results suggest the implication of endothelin throughout its ETA receptors in the inflammatory response observed in the cardiovascular components during scorpion envenomation. Further knowledge is needed to better understand the implication of the endothelin axis and to improve the therapeutic management of severe scorpion sting cases.

Scorpion Venom: Detriments and Benefits

Scorpion venom may cause severe medical complications and untimely death if injected into the human body. Neurotoxins are the main components of scorpion venom that are known to be responsible for the pathological manifestations of envenoming. Besides neurotoxins, a wide range of other bioactive molecules can be found in scorpion venoms. Advances in separation, characterization, and biotechnological approaches have enabled not only the development of more effective treatments against scorpion envenomings, but have also led to the discovery of several scorpion venom peptides with interesting therapeutic properties. Thus, scorpion venom may not only be a medical threat to human health, but could prove to be a valuable source of bioactive molecules that may serve as leads for the development of new therapies against current and emerging diseases. This review presents both the detrimental and beneficial properties of scorpion venom toxins and discusses the newest advances within the development of novel therapies against scorpion envenoming and the therapeutic perspectives for scorpion toxins in drug discovery.

Chitosan nanoparticles as a delivery platform for neurotoxin II from Androctonus australis hector scorpion venom: Assessment of toxicity and immunogenicity

In recent years, biodegradable polymers based nanoparticles received high interest for the development of vaccine delivery vehicles. In this study, chitosan nanoparticles encapsulating Aah II toxin (AahII-CNPs) isolated from Androctonus australis hector venom, were investigated as vaccine delivery system. Particles obtained by ionotropic gelation were characterized for their size, surface charge, morphology and toxin release profile from Aah II-CNPs. Toxin-nanoparticles interactions were assessed by Fourier Transform Infrared Spectrometry and X-Ray Diffraction. An immunization protocol was designed in mice to investigate anti-toxin immunity and the protective status induced by different Aah II immune formulations. Unloaded chitosan nanoparticles presenting a spherical shape and smooth surface, were characterized by a size of 185 nm, a dispersion index (PDI) of 0.257 and a zeta potential of +34.6 mV. Aah II toxin was successfully entrapped into chitosan nanoparticles as revealed by FTIR and XRD data. Entrapment efficiency (EE) and Loading capacity (LC) were respectively of 96.66 and 33.5%. Aah II-CNPs had a diameter of 208 nm, a PDI of 0.23 and a zeta potential of +30 mV. Encapsulation of Aah II reduced its toxicity and protected mice until 10 LD₅₀. Mice were immunized via a dual prime-boost scheme. Nanoentrapped Aah II immunogen elicited systemic innate and humoral immune responses as well as local spleen parenchyma hyperplasic alterations. Aah II-CNPs immunized mice withstood high lethal doses of native Aah II, one-month post-boost inoculation. This study provided encouraging and promising results for the development of preventive therapies against scorpion envenoming mainly for the populations at-risk.

Scorpion stings in pregnancy: an analysis of outcomes in 66 envenomed pregnant patients in Iran

Background:

Scorpionism is one of the most important health problems in tropical regions, which unfortunately results in thousands of deaths annually. Pregnant women are potential victims in areas with high scorpion-sting prevalence. Limited medical data are available on the effects of scorpion envenomation in pregnant women. This study aimed to examine the effect of scorpion envenomation on pregnancy outcomes in 66 cases.

Methods:

The present descriptive/analytical cross-sectional study was performed on 66 scorpion-envenomed pregnant women referred to the clinical toxicology unit of Ahvaz Razi Hospital in Iran during 2015-2017. The variables assessed in all cases, via questionnaire and hospital medical records, were: age, patient residency, gestational week, status of the fetus, laboratory anomalies, clinical severity of envenomation, sting site and scorpion species. Pregnancy outcome (miscarriage, stillbirth, preterm birth, normal delivery) and status of the newborns were also evaluated. Data were analyzed using SPSS ^® software (version 24.0).

Results:

The following pregnancy outcomes were recorded from envenomed pregnant women: miscarriage = 1.5% (n = 1), stillbirth = 4.5% (n = 3), preterm birth = 10.6% (n = 7), normal birth = 83% (n = 55). Among participants whose pregnancy led to birth, 11(17.7%) cases had prenatal-neonatal complications. Neonatal complications, including Apgar score less than 8 points at 5 min, were found in 7 (11.3%) preterm birth cases and in 4 (6.4%) normal birth cases, along with birth weight below 2500 g in normal births. A significant relationship was found between adverse pregnancy outcomes and bite location, as well as scorpion species, but no relationship was found with other variables.

Conclusion:

Envenomation significantly contributes to preterm birth. Moreover, the location of bites and the type of scorpion species have a decisive role in the pregnancy outcome of scorpion-envenomed pregnant women.

Tricuspid Valve Endocarditis Following a Scorpion Sting: A Case Report

Scorpion sting envenoming is a common pediatric emergency in the Moroccan southern areas. Cardiomyopathy is the most common cardiovascular manifestation of envenoming, resulting from the stimulation of the sympathetic nervous system by the venom or from the direct effect of the venom toxins on the myocardium. Rare cases of infective endocarditis following a scorpion sting have been reported in the literature. We report a case of tricuspid valve infective endocarditis following a scorpion sting in a previously healthy eight-year-old child. The patient initially was managed medically before undergoing tricuspid valve replacement with a bioprosthesis. The postoperative course was uneventful with a full recovery.

Predictors for Mortality in Children with Scorpion Envenomation Admitted to Pediatric Intensive Care Unit, Qena Governorate, Egypt

This study aimed to identify the clinical and laboratory manifestations that affect outcome of scorpion envenomation in children. It included 154 children admitted with scorpion sting envenomation over a period of 2 years. The epidemiological, clinical, and laboratory findings of patients were recorded, and grading of severity was performed based on local and systemic involvement. Organ failure was determined according to diagnostic criterion of multiple organ dysfunction syndrome, and severity of illness was assessed by the Pediatric Risk of Mortality (PRISM III) score. Of studied children, 58.4% were males and 41.6% were females. Children aged > 5 years suffered more scorpion stings (79.9%) than others did. The place of residence was rural more than urban, outdoor stings more than indoors, nocturnal more than diurnal, and most stings were on the exposed areas of the limbs. Based on clinical evaluation, 37.7% of patients were classified as class I severity followed by class II (48.7%) and class III (13.6%). Among studied cases, 21 deaths (13.6%) were registered; all of them belonged to class III severity. Mortality was significantly higher in children with agitation, coma, convulsions, arrhythmia, heart failure, pulmonary edema, and priapism. There were significantly higher values of leukocytes, platelets, creatinine, liver enzymes, glucose, and creatine phosphokinase in non-survivors than in survivors. The presence of organ failure was associated with mortality. In addition, the need for mechanical ventilation and inotropic support were at increased risk of mortality. Moreover, a significant association was found between PRISM score and the number of failed organs with fatal outcome.

Renal Alterations Induced by the Venom of Colombian Scorpion Centruroides Margaritatus

BACKGROUND

Scorpion venom causes renal injury and affects vascular ion-channels function. Centruroides margaritatus scorpion is found in Colombia and is frequently the cause of envenomation accidents; however, its renal impact has never been investigated.

OBJECTIVE

To evaluate the effects of C. margaritatus venom (CmV) on renal parameters using isolated rat kidney and renal cell culture models.

METHODS

Wistar rats (n = 5, weighing 240-300 g) were first perfused with Krebs-Henseleit solution containing 6 g 100 mL-1 bovine serum albumin. After 30 minutes, the kidneys were perfused with CmV to a final concentration of 10 μgmL-1; evaluation was performed by measuring Perfusion Pressure (PP), Renal Vascular Resistance (RVR), Urinary Flow (UF), Glomerular Filtration Rate (GFR), and percentage of electrolyte tubular transport. Moreover, kidney histological analyses and cell cytotoxicity in renal tubule epithelial cells (MDCK) and proximal tubular cells (LLC-MK2) were assessed.

RESULTS

CmV increased PP and RVR 60 min after perfusion. On the other hand, UF, GFR, and the percentages of sodium, potassium and chloride tubular transport decreased after experimental envenomation. UF dropped after 120 min, while GFR and percentage of electrolyte tubular transport diminished after 60, 90 and 120 min. CmV was not toxic to MDCK cell line but reduced the viability of LLC-MK2 cells at concentrations ranging from 6.25 to 200 μgmL-1. Histological analyses disclosed hydropic degeneration, edema, and protein deposits. Flow cytometry disclosed that cell death occurred predominantly by necrosis.

CONCLUSION

Our results suggest that C. margaritatus venom can trigger renal impairment, mainly in the proximal kidney tubule.

Pharmacokinetics and Biodistribution of Rhopalurus junceus Scorpion Venom in Tumor-Bearing Mice after Intravenous and Oral Administration

Background

Rhopalurus junceus scorpion venom has shown potential for anticancer treatment. However, there are no scientific evidence about venom pharmacokinetic (PK) and biodistribution (BD) in tumor-bearing mice.

Methods

131I-labeled venom was administrated by intravenous (IV) and oral (PO) routes at the single dose of 12.5 mg/kg. Mice were sacrificed and blood samples, major organs, and tumor were taken at 10, 20, 40, 90, 180, 300, 480, and 1440 min.

Results

For IV route, maximum peak concentration (Cmax), elimination half-lives, total body clearance (CL), distribution volume (Vd), mean residence time (MRT), and area under curve (AUC) were 21.77 ± 2.45 %Dosis•h/mL, 12.65 ± 2.1 h, 4.59 ± 0.23 mL/h, 83.80 ± 12 mL, 12.49 ± 2.71 h, and 21.77 ± 2.45 %Dosis•h/mL, respectively. For PO route, they were 0.60 ± 0.07 %Dosis•h/mL, 9.33 ± 1.35 h, 36.94 ± 4.01 mL/h, 497.33 ± 30 mL, 12.40 ± 1.87 h, and 6.89 ± 1.18 %Dosis•h/mL, respectively. PK parameters (Cmax, CL, Vd, and AUC) showed significant differences between IV and PO routes. Bioavailability was 31.6 ± 4% for PO dose. Kidney, stomach, liver, and lung for IV and stomach, kidney, spleen, and lung for PO routes showed the major uptakes for 131I-labeled venom. In tumor tissue, after the maximum uptake for both routes, there was a consistent behavior of radioactivity respect to the major organs during the first 480 min.

Conclusion

The PK and BD of R. junceus venom in mice depend on the administration route. These data represent a starting point for future experiments with this scorpion venom in experimental models of cancer.

A Comparative Pathomorphological Findings Between Leiurus abdullahbayrami and Androctonus crassicauda (Scorpion: Buthidae) Envenomation in Rabbit Animal Model

BACKGROUND

The aim of study was to compare macroscopical and histopathological findings between venoms belonging to two scorpion species, Androdoctonus crassicauda, and the newly discovered Leirus abdullahbayrami.

METHODS

The animals used in this experimental study were fifteen New Zealand bred rabbits. Three groups were constituted as group I (L. abdullahbayrami group, n= 6), group II (A. crassicauda group, n= 6) and group III (control group, n= 3). The animals in the L. abdullahbayrami group and the A. crassicauda group were envenomed through an intravenous route. The rabbits were monitored for the first 24h following the envenomation. The animals dead within that time period were examined and all animals were sacrificed and standard necropsy process was performed at 24h.

RESULTS

The pathomorphological findings from group I were found to be more severe than those observed in group II. The venom from the newly identified L. abdullahbayrami has a greater effect than the venom from the A. crassicauda. Moreover, as this was a rabbit modeling study, the L. abdullahbayrami might pose the most serious health threat to infants in particular due to their smaller body weight.

CONCLUSION

These findings will provide a better understanding of envenomation of human beings in terms of the possible consequences of scorpion toxication on the organs.