Histopathological changes induced by Hemiscorpius lepturus scorpion venom in mice

The Enzymatic Core of Scorpion Venoms

Enzymes are an integral part of animal venoms. Unlike snakes, in which enzymes play a primary role in envenomation, in scorpions, their function appears to be ancillary in most species. Due to this, studies on the diversity of scorpion venom components have focused primarily on the peptides responsible for envenomation (toxins) and a few others (e.g., antimicrobials), while enzymes have been overlooked. In this work, a comprehensive study on enzyme diversity in scorpion venoms was performed by transcriptomic and proteomic techniques. Enzymes of 63 different EC types were found, belonging to 330 orthogroups. Of them, 24 ECs conform the scorpion venom enzymatic core, since they were determined to be present in all the studied scorpion species. Transferases and lyases are reported for the first time. Novel enzymes, which can play different roles in the venom, including direct toxicity, as venom spreading factors, activators of venom components, venom preservatives, or in prey pre-digestion, were described and annotated. The expression profile for transcripts coding for venom enzymes was analyzed, and shown to be similar among the studied species, while being significantly different from their expression pattern outside the telson.

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.

Mast Cells Modulate the Immune Response and Redox Status of the Gastrointestinal Tract in Induced Venom Pathogenesis

The pathogenesis of Androctonus autralis hector (Aah) scorpion venom involved cellular and molecular mechanisms resulting in multi-organ dysfunction. However, little is reported about the effects of venom on the gastrointestinal axis. Mast cells (MCs) are known to play a crucial role in modulating immune response of the gut. This study aims to investigate the involvement of this cell type in venom-induced gastric and intestinal disorders in a time course (3 and 24h). The obtained results revealed that Aah scorpion venom induced inflammatory cell infiltration as shown by the increase of the myeloperoxidase and eosinophil peroxidase activities. Overexpression of the c-kit receptor (CD117) severely imbalanced the redox status with depletion of antioxidant systemic accompanied by gastrointestinal tissue damage. Moreover, an increased level of lactate dehydrogenase in the serum was correlated with tissue injuries. Pharmacological inhibition of MCs targeting tyrosine kinase (TK) reduces the generation of reactive oxygen species and normalizes catalase, and gluthation S-transferase activities to their physiological levels. In addition, histopathological alterations were restored after pretreatment with c-kit receptor inhibitor associated with a considerable reduction of MC density. Interestingly, obtained results indicate that MCs might be involved in gastric modulation and intestinal inflammation through c-kit signaling following sub-cutaneous Aah venom injection.

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.

Sajedi R, Pooshang Bagheri K, Sabatier JM, Shahbazzadeh D. Novel Mutant Phospholipase D from Hemiscorpius lepturus Acts as A Highly Immunogen in BALB/c Mice Against the Lethality of Scorpion Venom

Hemiscorpius lepturus (H. lepturus) which belongs to the Scorpionidae family, is the deadliest scorpion in Iran. It causes pathological manifestations like dermonecrosis, hemolysis, renal failure, necrotic ulcers, and in some cases, even death. The venom of this scorpion is well-known for its cytotoxic effects in comparison with the other venomous scorpions which show significant neurotoxic effects. Due to the painless nature of the sting of this scorpion, the clinical symptoms occur in victims 24 to 72 h post-sting. In our previous studies during the last decade, we demonstrated that the medical complications are attributable to the presence of phospholipase D (PLD) as a major toxin in the venom. With the purpose of designing and constructing a vaccine against H. lepturus for humans, animal model experiments were performed. To achieve this goal, non-toxic PLD was developed by mutation of two critical catalytic residues-His12 and His48-into alanines and the product was then denominated mut-rPLD1. The in-vivo tests showed that the mice immunized with interval doses of 10 µg of mut-rPLD1, were completely protected against 10× the LD100 of the venom. In conclusion, this mutant may be an effective vaccine candidate against scorpion envenomation by H. lepturus in future clinical studies.

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.

In vitro therapeutic effect of Hemiscorpius lepturus venom on tachyzoites of Toxoplasma gondii

Pyrimethamine which is a main anti-Toxoplasma gondii drug has a serious side and toxic effects on the host. Accordingly, the development of new treatment options for toxoplasmosis with less toxic effects, low teratogenicity and parasiticidal effect against the various stage of T. gondii are dramatically crucial. Currently, natural molecules from scorpion and snake venoms are widely used as an alternative treatment against human disease, these compounds considered to be safe and to have low toxicity in comparison with synthetic drugs. Therefore, the goal of our study was to investigate the anti-Toxoplasma gondii activities of Hemiscorpius lepturus venom. We measured cytotoxicity of H. lepturus whole venom on Vero cells as well as effectiveness of this compound on viability of T. gondii applying colorimetric assay, according to mitochondrial oxidation of the MTT reagent (Methylthiazol tetrazolium 98%). The results of this study indicated that the H. lepturus whole venom has an anti-Toxoplasma effects with less toxic effect on Vero cells. Also, the T. gondii tachyzoites were treated with H. lepturus venom reached better results in comparison with Pyrimethamine-treated group. This research will serve as a base for future studies on toxoplasmosis and suggest a role for scorpion venom in promoting natural drugs.

Scorpion Sting Management at Tertiary and Secondary Care Emergency Departments

Objectives

We sought to review the management of scorpion stings in tertiary and secondary care emergency departments in Oman and determine physician’s knowledge of management protocols.

Methods

We conducted a retrospective study of all scorpion stings cases seen in Sultan Qaboos University Hospital (SQUH) emergency department (ED) from March 2016 to July 2017. Additionally, we conducted a survey of ED physicians regarding their management of scorpion stings in three different EDs including SQUH.

Results

The total number of scorpion stings seen at SQUH during the study period was 128. Localized pain was seen in 97.7% (n = 125), swelling in 14.8% (n = 19), and local redness in 7.0% (n = 9) of patients. Around 13.0% (n = 17) of patients were found to have systemic symptoms with tachycardia being the most common. Bedside clotting test was done for 11.7% (n = 15) of patients. The most commonly used treatment was local anesthesia (54.7%, n = 70). No patient received scorpion antivenom. In the 89 surveyed physicians the main management method used was analgesia (88.8%, n = 71) followed by local anesthesia (81.1%, n = 65). Most physicians (80.0%, n = 64) believed that local anesthesia was the most effective management. However, 32.5% (n = 26) ordered a whole blood bedside clotting test, 69.2% (n = 18) of which were junior doctors.

Conclusions

Most scorpion sting cases managed in SQUH had local symptoms. Tachycardia was the most common systemic manifestation. Bedside clotting test was not commonly ordered and mainly requested by junior doctors. Local anesthesia infiltration is the recommended management for scorpion sting. Analgesia was the main management followed by local anesthesia.

Serological, pathological, and scintigraphic assessment of Hemiscorpius lepturus effects on renal dysfunction in rats

Objective(s):

Hemiscorpius lepturus is one of the dangerous scorpions of Iran leading to acute kidney injury (AKI) especially in infants. The purpose of this animal study was to compare the serological, pathological and scintigraphic data to quickly predict the occurrence of this disorder.

Materials and Methods:

In two groups of animals, each contained five rats, H. lepturus venom (1200 µg/Kg) were injected intravenously via the tail vein. At three hours and one week later, ^99m Tc-DMSA (3 mCi) was intravenously injected and renal scintigraphy was performed after an hour. Moreover, plasma levels of creatinine, sodium, potassium, and blood urea nitrogen (BUN) were measured. At the end of the study, renal tissues were excised and prepared to perform pathological evaluation after Hematoxylin and Eosin staining.

Results:

All serological indices were remained unchanged compared to control. A large number of glomerular fibrin thrombi with entrapped red blood cells and simplified tubular epithelium in dilated and ectatic tubules were observed in high power field (×100) four hours after envenomation, which reduced significantly one week later. In our scintigraphic study, there was a statistically significant difference (P<0.05) in kidney count rate per pixels (CRPP) in both acute and chronic phases compared to the sham group that received normal saline (0.84±0.05 and 1.36±0.07 versus 1.7±0.05).

Conclusion:

The results of this preliminary animal study suggest renal scintigraphy is a non-invasive method to predict the occurrence of the AKI in H. lepturus envenomation. It leads the way for more investigation to counteract the renal failure induced by this venom.

Remarkable apoptotic pathway of Hemiscorpius lepturus scorpion venom on CT26 cell line

OBJECTIVE

Scorpion venom, considered as a treasure trove of various bioactive molecules, is a new approach to induce cancer cell death via apoptosis pathways. In the present study, we evaluated for first time the anti-proliferative efficacy of Hemiscorpius lepturus scorpion venom and its pathway on a colon carcinoma cell.

MATERIALS AND METHODS

The CT26 and VERO cell lines were treated with various concentrations of the venom. The IC50 values were estimated by MTT assay test, and the apoptosis was evaluated by flow cytometry. Moreover, RT-PCR analysis was used to investigate the levels of Bax, Bcl2, Trp53, and Casp3 mRNA expression. The mice xenograft model was established to evaluate the therapy efficiency of venom. Some valuable exponential growth parameters were evaluated in treated mice.

RESULT

The scorpion venom inhibited the growth of CT26 cells with an IC50 value about 120 μg/ml. However, VERO cells increased to 896 μg/ml under the same condition. A remarkable apoptotic cells in CT26 cells were revealed by flow cytometry assay. A significant over-expression was observed in Bax, Casp3, and Trp53 and downregulated in Bcl2 mRNA level in tumor tissue after treatment with scorpion venom (p < 0.05). All changes of valuable exponential growth parameters showed a shrinking tumor size.

CONCLUSION

Our findings indicated that Hemiscorpius lepturus venom has a special anti-proliferative effect on CT26 cells via Trp53/Bcl2/Casp3 pathway. Considering its powerful cytotoxic vigor against a colon cancer cell (CT26) and low toxicity to non-tumorigenic cell (VERO), we propose that this venom probably has a specific effect on other colon cancer cells and may turn out to be a novel therapeutic strategy in treating colon cancer.

TNF-α antagonist improves oxidative stress and lipid disorders induced by scorpion venom in the intestinal tissue

We previously reported that Androctonus australis hector (Aah) venom induces inflammation in several tissues, however limited information is available on its role in gastrointestinal tract. Here we evaluate the involvement of TNF-α in lipid metabolism in the small intestine after Aah envenomation. To address these issues, NMRI mice (3-month-old) were pre-treated with a TNF-α antagonist, 30 min prior to Aah venom injection. Redox status, cytotoxicity and histopathological changes were analyzed in small intestine 3 and 24 h after Aah injection. Lipid metabolism was evaluated through lipid tolerance test in sera. Lipid content in small intestine was also evaluated at different times after envenomation. Obtained results showed that Aah venom affects the intestinal integrity. This cytotoxicity could be associated with lipid peroxidation and altered or insufficient antioxidant system. These results also highlight the perturbation of lipid absorption in intestine tissue of envenomed mice. The use of TNF-α antagonist prior to Aah venom injection seems to be able to improve lipid profile, oxidative stress and antioxidant activity. These findings suggest that Aah venom induces lipid alterations in the intestinal tissue mechanisms involving of TNF- α.

Developing recombinant phospholipase D1 (rPLD1) toxoid from Iranian Hemiscorpius lepturus scorpion and its protective effects in BALB/c mice

Hemiscorpius lepturus (H. lepturus) is one of the most dangerous scorpions and the most medically important scorpion in Iran. The clinical signs of H. lepturus envenomation, including dermonecrosis, hematuria, renal failure and early death, are attributed to phospholipase D activity. This study was conducted to develop a novel recombinant phospholipase D1 (rPLD1) toxoid and investigate its immunogenicity and protective effects against the lethality of H. lepturus venom. The lethal protein recombinant phospholipase D1 was expressed from PLD H. lepturus venom gland. The rPLD1 toxin was converted into toxoid (the first toxoid of H. lepturus PLD) with a 0.25% concentration of formalin and stored for ten days at room temperature. In the toxicity test, the lethal activity of recombinant phospholipase D1 was fully inhibited. When it reached up to 3 times higher than the maximal effective concentration of the purified toxin (11.1 μg), rPLD1 toxoid was used. The sphingomyelinase activity was inhibited when up to 5.4 times of the LD100 of the purified toxin (20 μg), toxoid was used. It was then used to produce an antibody in BALB/c as an antigen and the mice were then challenged with rPLD1 toxin and the whole venom. The immunogenicity of rPLD1 toxoid was evaluated and the maximum titer of the raised antibodies was determined by ELISA assay. The optimum titer for anti-rPLD1 toxoid sera was obtained at the third intraperitoneal injection of rPLD1 toxoid, and a high titer was reached at the fourth injection in the mice. This toxoid increased the amount of antibodies and produced a protective antiserum against the whole venom of H. lepturus and rPLD1 toxin. The in-vivo test results showed that the mice were completely resistant against 200 times the LD100 of recombinant phospholipase D1 and the whole venom of H. lepturus. To conclude, rPLD1 can be used in toxoid form as an immunogen in the production of a new generation of neutralizing antibodies against the lethality and toxicity of H. lepturus whole venom.

Scorpionism by Hemiscorpius spp. in Iran: a review

Scorpions are distributed throughout Iran and the genus Hemiscorpius is particularly important in this region. Hemiscorpius lepturus is the most significant species within the genus in the country. Since scorpionism provoked by Hemiscorpius comprises a medical emergency, the present study is focused on this important issue. In order to perform the present work, a review of the medical and health-related literature was carried out in several databases. The current findings indicate that six species of Hemiscorpius are found in 15 states of Iran, mainly in the south and southwest. Deaths caused by stings were reported only for two species. The morphological characteristics and geographical distribution of H. lepturus in Iran, its venom and the toxic compounds, epidemiologic data and clinical manifestations of envenomation as well as treatment for affected people are herein reviewed and described. H. lepturus venom toxicity differs from other Iranian scorpions regarding duration and severity. Scorpionism is an important public health problem in Iran, especially in southwest and south regions and in urban areas. It is more prevalent in children and young people. H. lepturus venom is primarily a cytotoxic agent and has hemolytic, nephrotoxic and to some extent hepatotoxic activity. The use of polyvalent antivenom to prevent scorpion sting symptoms is recommended. A well-planned health education program might be useful in preventing scorpionism.

Anti-scorpion venom activity of Thapsia garganica methanolic extract: Histopathological and biochemical evidences

ETHNOPHARMACOLOGICAL RELEVANCE

Thapsia garganica, is a herbal medicine traditionally used as diuretic, emetic and purgative. It is also used as anti-scorpion venom in Morocco; however, its protective effects against scorpion venom remain elusive.

AIM OF THE STUDY

The present study was undertaken to evaluate anti-venom activity of T. garganica in vivo through histological and biochemical studies.

MATERIALS AND METHODS

Methanolic leaves extract of T. garganica was evaluated for anti-venom activity against buthus. occitanus under in vivo conditions. Histopathological and biochemical changes in envenomed and treated mice were also examined. Phytochemical screening was conducted to estimate the major constituents whereas DPPH, β -Carotene-linoleic acid and reducing power assays were performed to evaluate the anti-oxidant activity of T. garganica extract.

RESULTS

Methanolic leaves extract of T. garganica (2g/kg) increased the survival time (> 18h) of mice injected with lethal doses of B. occitanus venom, with remarkable recovery of histology damage. Furthermore T. garganica induced a significant decreased of biochemical markers of kidney, liver and heart function. Phytochemistry screening revealed the presence of phenolic compounds, flavonoids, tannins and steroids/terpenoids, which might explain the bioactivity of the extract. It was also shown that the extract has an exceptionally high antioxidant activity compared to well-known antioxidants used as standards.

CONCLUSION

The present study provides strong evidence that support the use of T. garganica as anti-scorpion venom in traditional medicine in Morocco. However, additional studies are required to isolate and identify the metabolites responsible for the activity.

Acute kidney injury due to tropical infectious diseases and animal venoms: a tale of 2 continents

South and Southeast Asia and Latin American together comprise 46 countries and are home to approximately 40% of the world population. The sociopolitical and economic heterogeneity, tropical climate, and malady transitions characteristic of the region strongly influence disease behavior and health care delivery. Acute kidney injury epidemiology mirrors these inequalities. In addition to hospital-acquired acute kidney injury in tertiary care centers, these countries face a large preventable burden of community-acquired acute kidney injury secondary to tropical infectious diseases or animal venoms, affecting previously healthy young individuals. This article reviews the epidemiology, clinical picture, prevention, risk factors, and pathophysiology of acute kidney injury associated with tropical diseases (malaria, dengue, leptospirosis, scrub typhus, and yellow fever) and animal venom (snakes, bees, caterpillars, spiders, and scorpions) in tropical regions of Asia and Latin America, and discusses the potential future challenges due to emerging issues.

In vitro studies with renal proximal tubule cells show direct cytotoxicity of Androctonus australis hector scorpion venom triggered by oxidative stress, caspase activation and apoptosis

Scorpion envenomation injures a number of organs, including the kidney. Mechanisms proposed to explain the renal tubule injury include direct effects of venom on tubule epithelial cells, as well as indirect effects of the autonomic nervous system, and inflammation. Here, we report direct effects of Androctonus australis hector (Aah) scorpion venom on the viability of Renal Proximal Tubule (RPT) cells in vitro, unlike distal tubule and collecting duct cells. Extensive NucGreen nuclear staining was observed in immortalized rabbit RPT cells following treatment with Aah venom, consistent with cytotoxicity. The involvement of oxidative stress is supported by the observations that 1) anti-oxidants mitigated the Aah venom-induced decrease in the number of viable RPT cells, and 2) Aah venom-treated RPT cells were intensively stained with the CellROX(®) Deep Red reagent, an indicator of Reactive Oxygen Species (ROS). Relevance to normal RPT cells is supported by the red fluorescence observed in Aah venom treated primary rabbit RPT cell cultures following their incubation with the Flica reagent (indicative of caspase activation and apoptosis), and the green fluorescence of Sytox Green (indicative of dead cells).

Effects of Tityus stigmurus (Thorell 1876) (Scorpiones: Buthidae) venom in isolated perfused rat kidneys

ABSTRACT Scorpions belonging to the Tityus genus are of medical interest in Brazil. Among them, Tityus stigmurus is the main scorpion responsible for stings in the Northeast region. After a sting, the scorpion venom distributes rapidly to the organs, reaching the kidneys quickly. However, there are few studies concerning the renal pathophysiology of scorpion poisoning. In this study, we evaluated the effects of T. stigmurus venom (TsV) on renal parameters in isolated rat kidneys. Wistar rats (n = 6), weighing 250-300 g, were perfused with Krebs-Henseleit solution containing 6 g/100 mL bovine serum albumin. TsV at 0.3 and 1.0 μg/mL was tested, and the effects on perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF), glomerular filtration rate (GFR), and electrolyte excretion were analyzed. Effects were observed only at TsV concentration of 1.0 μg/mL, which increased PP (controlPP40' = 92.7 ± 1.95; TsVPP40' = 182.0 ± 4.70* mmHg, *p < 0.05), RVR (controlRVR40' = 3.28 ± 0.23 mmHg; TstRVR40' = 6.76 ± 0.45* mmHg, *p < 0.05), UF (controlUF50' = 0.16 ± 0.04; TstUF50' = 0.60 ± 0.10* mL/g/min,*p < 0.05), GFR and electrolyte excretion, with histological changes that indicate renal tubular injury. In conclusion, T. stigmurus venom induces a transient increase in PP with tubular injury, both of which lead to an augmented electrolyte excretion.

Serological, biochemical and enzymatic alterations in rodents after experimental envenomation with Hadruroides lunatus scorpion venom

Toxic effects of Peruvian Hadruroides lunatus scorpion venom on different biochemical and enzymatic parameters in blood serum of Wistar rats and Swiss mice were determined after experimental envenomation. An increase in enzymatic activities of Aspartate Aminotransferase (AST), Lactate Dehydrogenase (LDH) and levels of serum protein and albumin were observed while a decrease in creatinine level in serum was perceived after 30 min of envenomation. No alterations in urea levels and in kidney histology were detected in the envenomed rats. The global leukocytes count was diminished, with decrease in lymphocytes, eosinophils and neutrophils levels in the bloodstream, while no alterations were found in hematological parameters of red series in rats injected with H. lunatus venom. IL-2, IL-4, IL-6, INF-γ, TNF, IL-17A and IL-10 levels were evaluated 0.5, 3 and 6 h after experimental envenomation of mice with H. lunatus venom. From all the analyzed cytokines, only IL-6 showed an increase in serum levels. Taken together, these results point out that envenomation by H. lunatus can impair hematological and immunological parameters and therefore might be monitored in accidents involving this species.

Assessment of immunogenic characteristics of Hemiscorpius lepturus venom and its cross-reactivity with venoms from Androctonus crassicauda and Mesobuthus eupeus

Hemiscorpius lepturus (H. lepturus), one of the most venomous scorpions in tropical and sub-tropical areas, belongs to the Hemiscorpiidae family. Studies of antibodies in sera against the protein component of the venom from this organism can be of great use for the development of engineered variants of proteins for eventual use in the diagnosis/treatment of, and prevention of reactions to, stings. In the present in vitro study, the proteins of H. lepturus venom, which could specifically activate the production of immunoglobulin G (IgG) in victims accidently exposed to the venom from this scorpion, were evaluated and their cross-reactivity with venoms from two other important scorpion species including Androctonus crassicauda and Mesobuthus eupeus assessed. H. lepturus venom was analyzed with respect to its protein composition and its antigenic properties against antibodies found in sera collected from victims exposed to the venom of this scorpion within a previous 2-month period. The cross-reactivity of the H. lepturus venom with those from A. crassicauda and M. eupeus was assessed using ELISA and immunoblotting. Electrophoretic analysis of the venom of H. lepturus revealed several protein bands with weights of 8-116 KDa. The most frequent IgG-reactive bands in the test sera had weights of 34, 50, and 116 kDa. A weak cross-reactivity H. lepturus of venom with venoms from A. crassicauda and M. eupeus was detected. The results of immunoblotting and ELISA experiments revealed that H. lepturus venom activated the host immune response, leading to the production of a high titer of antibodies. Clearly, a determination of the major immunogenic components of H. lepturus venom could be valuable for future studies and ultimately of great importance for the potential production of recombinant or hypo-venom variants of these proteins.