Behavioral, histopathological and biochemical impairments observed in mice envenomed by the scorpion: Hottentota gentili (Pallary, 1924)

Epidemiological, toxicological and physiopathological characteristics of scorpion stings and their management in Morocco: A literature review

All around the world, scorpion envenomation represents a public health issue. In Morocco, it represents the first cause of poisoning. The aim of this review is to highlight the epidemiological, toxicological and physiopathological characteristics of scorpion stings and envenomation in Morocco as well as their management. According to the bibliography, the most areas affected by scorpion stings and envenomation are those in the center and south of Morocco. Lethality rate is more important in children than adult. Age, admission class, season, serum venom concentration, and the time elapsed between the scorpion sting and medical intervention are risk factors for a poor prognosis. Until now, we have only known the LD50 of 14 scorpion species from three genera: Androctonus, Buthus and Hottentota, and only 6 species, out of 61 moroccan scorpions, have been assessed for their venom toxicity on mice organs. The venom of harmful moroccan scorpions induces several histopathological changes in the myocardium, brain, liver, pulmonary alveoli, and kidneys in rats, as well as severe consequences in the lungs with intra-alveolar hemorrhage. There was also a significant increase in serum enzyme levels of aspartate transaminase (AST), alanine transaminase (ALT), creatine phosphokinase (CPK), and lactate dehydrogenase (LDH), as well as high levels of plasma albumin, creatine and glucose. In the absence of a specific treatment, the management of scorpion envenomation is based only on symptomatic therapy. We noted a widely use of traditional remedies. Despite the magnitude of the scorpion problem in Morocco, it remains understudied and continues to claim lives, particularly given the lack of an efficient etiological cure.

Comparison of the Scorpionism Caused by Centruroidesmargaritatus, Tityuspachyurus and Tityus n. sp. aff. metuendus Scorpion Venoms in Colombia

Among other scorpion species, Colombia has two genera of the Buthidae family Centruroides and Tityus, considered to be dangerous to humans. This research shares scientific knowledge aiming to a better understanding about the pathophysiological effects of such venoms. The venom of the three species: Centruroides margaritarus, Tityus pachyurus, and T. n. sp. aff. metuendus with biomedical interest were studied. An initial pre-glycemic sample was taken from ICR mice. They were later intraperitoneally inoculated with doses of 35% and 70% of LD₅₀ of total venom. Poisoning signs were observed during a 6-h period to determine the level of scorpionism. After observation, a second glycemic sample was taken, and a histopathological evaluation of different organs was performed. This work revealed that all three venoms showed considerably notorious histopathological alterations in main organs such as heart and lungs; and inducing multiple organ failure, in relation to the glycemia values, only C. margaritatus and T. n. sp. aff. metuendus showed significant changes through manifestation of hyperglycemia. According to the Colombian scorpionism level; signs were mild to severe affecting the autonomous nervous system.

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.

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.

Androctonus genus species in arid regions: Ecological niche models, geographical distributions, and envenomation risk

Aim

The objective of this study was to establish environmental factors related to scorpion species occurrence and their current potential geographic distributions in Morocco, to produce a current envenomation risk map and also to assess the human population at risk of envenomation.

Materials and Methods

In this study, 71 georeferenced points for all scorpion species and nine environmental indicators were used to generate species distribution models in Maxent (maximum entropy modeling of species geographic distributions) version 3.3.3k. The models were evaluated by the area under the curve (AUC), using the omission error and the binomial probability. With the data generated by Maxent, distribution and envenomation risk maps were produced using the "ESRI^® ArcGIS 10.2.2 for Desktop" software.

Results

The models had high predictive success (AUC >0.95±0.025). Altitude, slope and five bioclimatic attributes were found to play a significant role in determining Androctonus scorpion species distribution. Ecological niche models (ENMs) showed high concordance with the known distribution of the species. Produced risk map identified broad risk areas for Androctonus scorpion envenomation, extending along Marrakech-Tensift-Al Haouz, Souss-Massa-Draa, and some areas of Doukkala-Abda and Oriental regions.

Conclusion

Considering these findings ENMs could be useful to afford important information on distributions of medically important scorpion species as well as producing scorpion envenomation risk maps.

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.

Peripheral and central effects of intracerebroventricular microinjection of Hottentotta gentili (Pallary, 1924) (Scorpiones, Buthidae) venom

Central effects of scorpion venom toxins have been neglected, due both to the common belief that scorpion venoms act by targeting peripheral organs and also to the misunderstanding that these peptides do not cross the brain-blood barrier (BBB). Determining whether scorpion neurotoxicity is restricted to peripheral actions or whether a central mechanism may be partly responsible for systemic manifestations could be crucial in clinical therapy trends. The present study therefore aims to assess histopathological damages in some organs (heart, kidney, liver, and lungs) and the related biochemical impairments, together with a neurobehavioral investigation following an intracerebroventricular (i.c.v) micro-injection of Hottentotta gentili (Scorpiones, Buthidae) venom (0.47 μg/kg). I.c.v. injection of venom produced focal fragmentation of myocardial fibers, while lungs showed rupture of the alveolar structure. Concurrently, there was a significant rise in the serum enzymes levels of ASAT, ALAT, CPK and LDH. Meanwhile, we observed behavioral alterations such as a hypoactivity, and in addition the venom seems to have a marked anxiogenic-like effect. The present investigation has brought new experimental evidence of a peripheral impact of central administration of H. gentili venom, such impact was manifested by physiological and behavioral disturbances, the last of these appearing to reflect profound neuro-modulatory action of H. gentili venom.