The toxinology of stingrays

Background: Stingrays belong to Chondrichthyes class.They live in freshwaters and oceans all over the world. They have venomous spines next to the root of the tail. Their barbed stingers covered with secretory cells that cause a large number of serious human injuries. In this review, we evaluate the toxinology of these venomous animals. Results: Some of inoculated venom symptoms included the immediate and intense pain, inflammation and skin necrosis, bleeding wounds, acute edema, salivation, nausea, vomiting, diarrhea, fever, headaches, muscle cramps, tremors, paralysis, dyspnea, cardiovascular collapse, local vasoconstriction, seizures, coma, and rarely death. The venom contains 5-HT, 5-nucleotidase, acetylcholine , phosphodiesterase, proteolytic enzymes against casein, gelatin, and fibrinogen, and several toxins such as cystatins, galectin, peroxiredoxin 6, orpotrin and porflan, and other peptids and proteins including alpha subunit haemoglobin, ganglioside GM2 activator, glutathione s-transferase µ, leukocyte elastase inhibitor, transaldolase, ATP synthase, nucleoside diphosphate kinase and type III intermediate filament. Galectin has a diverse functions including anticoagulant, procoagulant, platelet-modulating, myotoxic and haemagglutination activities. Cystatins are potent inhibitors of cysteine proteinases, including papain and the cathepsins. Hydrolysis of lipids through PLA2 activity is one of the most important functions of peroxiredoxin-6. Orpotrin and porflan have vasoconstrictive and inflammatory effects, respectively. Conclusion: Stingray venoms have different toxins and bioactive molecules with diverse mechanisms of toxicities. A thorough understanding of the toxicities mechanisms and clinical manifestations of stingrays’ venoms will provide the ability to treat effectively and manage injuries with this animals by clinicians and toxinologists