L’envenimation scorpionique au Maroc : scorpions du genre Androctonus, Buthus et Hottentota

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

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

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.

Clinical features and prognosis of severe scorpion envenomation in children

BACKGROUND

Scorpionism is endemic and represents a real public health problem in Morocco. The most dangerous arthropod in the central area is Androctonus mauretanicus (Am) scorpion. Its venom can be lethal, especially for children. This study aimed to determine a clinico-epidemiological profile of severe scorpion envenomation among children and identify risk factors for mortality.

METHODS

This retrospective cohort study included 606 children admitted for severe scorpion envenomation (SSE) from January 2010 to July 2015 in the Pediatric Intensive Care Unit (PICU) of Mohammed VI Teaching Hospital.

RESULTS

The mean age of envenomed children was 6.3 ± 4.2 years. Seventy-four percent of them came from rural settings. Envenomation occurred mostly during the summer months and 78.4% of stings were nocturnal. The time between the sting and evaluation was greater than 2 h in 83% of cases. Bivariate analysis indicated that from 1 to 24 months of age (P = 0.001), hyperthermia (P = 0.022), episodes of diarrhea (P < 0.001), tachycardia (P < 0.001), abdominal distention (P < 0.001), skin marbling (P < 0.001), signs of respiratory distress (P < 0.001), irritability (P < 0.001), generalized seizures (P = 0.053), and Glasgow Coma Score (GCS) of 3 to 9 (P < 0.001) were significantly correlated with mortality. On multivariate analysis, diarrhea (P = 0.007), skin marbling (P = 0.006), and respiratory distress (P = 0.002), and GCS 3-9 (P = 0.007) were found to be independent risk factors for mortality in our patient population.

CONCLUSIONS

Children are at high risk of developing serious complications, even death, from severe scorpion envenomation. Here we identified multiple factors that appear to increase the mortality risk in children after scorpion envenomation, including previously described central nervous system alterations.

Tb II-I, a Fraction Isolated from Tityus bahiensis Scorpion Venom, Alters Cytokines': Level and Induces Seizures When Intrahippocampally Injected in Rats

Scorpion venoms are composed of several substances with different pharmacological activities. Neurotoxins exert their effects by targeting ion channels resulting in toxic effects to mammals, insects and crustaceans. Tb II-I, a fraction isolated from Tityus bahiensis scorpion venom, was investigated for its ability to induce neurological and immune-inflammatory effects. Two putative &beta;-sodium channel toxins were identified in this fraction, Tb2 II and Tb 4, the latter having been completely sequenced by mass spectrometry. Male Wistar rats, stereotaxically implanted with intrahippocampal cannulas and electrodes, were injected with Tb II-I (2 &micro;g/2 &micro;L) via the intrahippocampal route. The behavior, electrographic activity and cellular integrity of the animals were analyzed and the intracerebral level of cytokines determined. Tb II-I injection induced seizures and damage in the hippocampus. These alterations were correlated with the changes in the level of the cytokines tumoral necrosis factor-&alpha; (TNF-&alpha;) and interleukin-6 (IL-6). Therefore, the binding of Tb II-I to its target in the central nervous system may induce inflammation resulting in neuropathological and behavioral alterations.

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.

Updated catalogue and taxonomic notes on the Old-World scorpion genus Buthus Leach, 1815 (Scorpiones, Buthidae)

Since the publication of the ground-breaking "Catalogue of the scorpions of the world (1758-1998)" (Fet et al. 2000) the number of species in the scorpion genus Buthus Leach, 1815 has increased 10-fold, and this genus is now the fourth largest within the Buthidae, with 52 valid named species. Here we revise and update the available information regarding Buthus. A new combination is proposed: Buthus halius (C. L. Koch, 1839), comb. n. from Portugal and Spain. B. halius is removed from junior synonymy with Buthus occitanus (Amoreux, 1789), and proposed as a senior synonym of B. ibericus Lourenço & Vachon, 2004, syn. n. Moreover, following I.C.Z.N. article 23.9.2 we propose to maintain as valid B. ibericus(nomen protectum) and to consider the disued B. halius as a nomen oblitum . Buthus europaeus tridentatus Franganillo, 1918 is proposed as a junior synonym of B. occitanus (Amoreux, 1789), syn. n.Buthus sabulicola Touloun, 2012 is proposed as a junior synonym of Buthus bonito Lourenço & Geniez, 2005, syn. n.Buthus occitanus tunetanus neeli Gysin, 1969 is proposed as an informal senior synonym of Buthus tassili Lourenço, 2002, informal syn. n. Two taxa are rised to species rank, Buthus nigrovesiculosus Hirst, 1925, stat. n. and Buthus parroti Vachon, 1949, stat. n.. We further confirm the restricted distribution of B. occitanus that is confined to southeastern France and northwestern Iberian Peninsula and does not occur in North Africa. Additionally, Androctonus barbouri (Werner, 1932), comb. n. from the Agadir region of Morocco, is hereby transferred to the genus Androctonus. We summarize and provide a critical appraisal of the diagnostic characters currently in use for the genus. The catalogue section considers the names for species, subspecies and varieties that have been used for Buthus scorpions. Information about types, including collection numbers and localities are included when available. Finally, an annotated listing of synonymies and an updated bibliography are given.

Posterior Reversible Encephalopathy Syndrome in a Child Stung by Androctonus mauretanicus Scorpion

Posterior reversible encephalopathy syndrome (PRES) after scorpion sting was very rarely reported in literature. This is an authenticated report of PRES occurring, in a 3-year-old previously healthy girl, as a complication of the Moroccan Androctonus mauretanicus sting. According to the available and recent data, we attempt to discuss the potential mechanisms leading to this neurologic disorder and to determine the possible cause-effect relationship between scorpion venom and its development.

Clinical comparison of scorpion envenomation by Androctonus mauritanicus and Buthus occitanus in children

The clinical results of scorpion stings by Androctonus mauritanicus (Am) and Buthus occitanus (Bo) (main sources of scorpionism in Morocco) were evaluated in this work. The objective was to compare the clinical manifestations of envenoming from these species by investigating possible correlations among symptoms/signs and laboratory abnormalities of envenomed patients. 41 children (25 males, 18 months - 11 years) were admitted at the Provincial Hospital of El Jadida-Morocco. Their minor (18 children) or severe (23 children) systemic signs such as pallor (48.8%), pulmonary edema (APE) (36.6%), convulsion (26.8%), coma (7.3%) were more frequent in children envenomed by Am than Bo, but angioedema (Quincke's edema) (4.9%) was particularly developed in the latter group. The laboratory blood abnormalities (hyperglycemia, high levels of aspartate aminotransferase (AST), lactate dehydrogenase (LDH), creatinine, bilirubin, leukocytes, neutrophils, monocytes, platelets and low levels of lymphocytes and hemoglobin) were significantly higher (p < 0.05) in patients envenomed by Am than Bo, and in all population in comparison to control group. The correlation among these biological analyzes and clinical status showed that higher levels of LDH and value of leukocytes ≥19 × 10(3)/mm(3) were indices of cardiac dysfunction with APE. Pallor sign was correlated with a state of shock and/or low level of hemoglobin, associated or not to bilirubin increase. Fatalities (7.3%), presenting toxic myocarditis, had lowest count of lymphocytes (≤4.2%) in comparison to survivors. This is the first report on lymphopenia which may be useful for forecast the fatal outcome in scorpion envenomation.