Pathological features of cantharidin-induced toxic cardiomyopathy: lack of correlation between electron-microscopic and histopathologic myocardial damage

RNA-sequencing-based transcriptome analysis of cantharidin-induced myocardial injury

The cardiotoxicity of cantharidin has been well characterized, but the understanding of the underlying mechanism(s) is incomplete. To more fully understand the differentially expressed genes (DEGs) in cantharidin-induced myocardial injury, Sprague-Dawley rats were exposed to cantharidin (1.34 mg/kg or 2.67 mg/kg) for 24 h and then the heart was sampled for pathologic changes analysis and RNA-sequencing-based transcriptomic profiling. In addition, serum troponin T (TN-T) levels were also tested using the enzyme-linked immunosorbent assay method. The results showed that cantharidin could cause myocardial damage and elevated serum TN-T levels. The genes with a fold change ≥2 were considered as DEGs and we found 38 DEGs that were mainly enriched in eight pathways revealed by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The cellular component of gene ontology analysis showed that the DEGs were mostly enriched in the extracellular matrix. In conclusion, our present study demonstrated that cantharidin induces myocardial injury by multiple modulatory mechanisms, which provide new insights for further study of the pathophysiologic mechanism of cantharidin-induced myocardial injury.

Poisoning from "Spanish fly" (cantharidin)

Cantharidin, known popularly as Spanish fly, has been used for millennia as a sexual stimulant. The chemical is derived from blister beetles and is notable for its vesicant properties. While most commonly available preparations of Spanish fly contain cantharidin in negligible amounts, if at all, the chemical is available illicitly in concentrations capable of causing severe toxicity. Symptoms of cantharidin poisoning include burning of the mouth, dysphagia, nausea, hematemesis, gross hematuria, and dysuria. Mucosal erosion and hemorrhage is seen in the upper gastrointestinal (GI) tract. Renal dysfunction is common and related to acute tubular necrosis and glomerular destruction. Priapism, seizures, and cardiac abnormalities are less commonly seen. We report four cases of cantharidin poisoning presenting to our emergency department with complaints of dysuria and dark urine. Three patients had abdominal pain, one had flank pain, and the one woman had vaginal bleeding. Three had hematuria and two had occult rectal bleeding. Low-grade disseminated intravascular coagulation, not previously associated with cantharidin poisoning, was noted in two patients. Management of cantharidin poisoning is supportive. Given the widespread availability of Spanish fly, its reputation as an aphrodisiac, and the fact that ingestion is frequently unwitting, cantharidin poisoning may be a more common cause of morbidity than is generally recognized. Cantharidin poisoning should be suspected in any patient presenting with unexplained hematuria or with GI hemorrhage associated with diffuse injury of the upper GI tract.

Cantharidin toxicosis in horses

Cantharidin toxicosis in horses has become an increasing problem in certain regions of the United States. Toxicosis occurs when horses ingest alfalfa hay or products that are contaminated with "blister" beetles. Clinical signs may vary from depression to severe shock and death, depending upon the amount of toxin ingested. The most frequently observed signs include varying degrees of abdominal pain, anorexia, depression, and signs suggestive of oral irritation. Many horses make frequent attempts to void urine. Less commonly observed signs include synchronous diaphragmatic flutter and erosions of the oral mucosal surfaces. Clinical laboratory abnormalities suggestive of cantharidin toxicosis include persistent hypocalcemia and hypomagnesemia, development of hypoproteinemia, microscopic hematuria, and mild azotemia with inappropriate urine specific gravity. Chemical analysis for cantharidin is accomplished by evaluation of urine or stomach contents. Treatment of cantharidin toxicosis is symptomatic, but must include removal of toxin source. Gastrointestinal protectants, laxative, intravenous fluids, analgesics, diuretics, calcium gluconate, and magnesium are all included in the treatment regimen. Early and vigorous therapy is imperative if it is to be successful. In horses that remain alive for several days, persistence of elevated heart and respiratory rates and increasing serum creatine kinase concentration are associated with a deteriorating condition. Prevention is aimed at timely harvesting of alfalfa hay. Hay fields should be inspected for the presence of beetle clusters before harvesting. Involved areas of the field should not be harvested.