Buthus occitanus (B.occitanus) is one of the most dangerous scorpions in the world. Despite the involvement of B.occitanus scorpion in severe cases of envenomation in Morocco, no study has focused yet on the proteomic composition of the Moroccan B.occitanus scorpion venom. Mass spectrometry-based proteomic techniques are commonly used in the study of scorpion venoms. The implementation of top-down and bottom-up approaches for proteomic analyses facilitates screening by allowing a global view of the structural aspects of such complex matrices. Here, we provide a partial overview of the venom of B.occitanus, in order to explore the diversity of its toxins and hereafter understand their effects. To this end, a combination of top-down and bottomup approaches was applied using nano-high liquid chromatography coupled to nano-electrospray tandem mass spectrometry (nano-LC-ESI-MS/MS). TheLC-MS results showed that B.occitanus venom contains around 200 molecular masses ranging from 1868 to 16,720 Da, the most representative of which are those between 5000 and 8000 Da. Interestingly, combined top-down and bottom-up LC-MS/MS results allowed the identification of several toxins, which were mainly those acting on ion channels, including those targeting sodium (NaScTxs), potassium (KScTxs), chloride (ClScTxs) and calcium channels (CaScTx), as well as antimicrobial peptides (AMPs), amphipathic peptides, myotropic neuropeptides and hypothetical secreted proteins. This study reveals the molecular diversity of B.occitanus scorpion venom and identifies components that may have useful pharmacological activities.

Hepatocellular carcinoma (HCC) is the most common primary liver cancer in adults, the fifth most common malignancy worldwide and the third leading cause of cancer related death. An alternative to the surgical treatments and drugs, such as sorafenib, commonly used in medicine is necessary to overcome this public health problem. In this study, we determine the anticancer effect on HCC of Moroccan cobra Naja haje venom and its fraction obtained by gel filtration chromatography against Huh7.5 cancer cell line. Cells were grown together with WI38 human fibroblast cells, LX2 human hepatic stellate cell line, and human endothelial cells (HUVEC) in MCTS (multi-cellular tumor spheroids) models. The hepatotoxicity of venom and its fractions were also evaluated using the normal hepatocytes cell line (Fa2N-4 cells). Our results showed that an anti HCC activity of Moroccan cobra Naja haje venom and, more specifically, the F7 fraction of gel filtration chromatography exhibited the greatest anti-hepatocellular carcinoma effect by decreasing the size of MCTS. This effect is associated with a low toxicity against normal hepatocytes. These results strongly suggest that the F7 fraction of Moroccan cobra Naja haje venom obtained by gel filtration chromatography possesses the ability to inhibit cancer cells proliferation. More research is needed to identify the specific molecule(s) responsible for the anticancer effect and investigate their mechanism of action.

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.