Diethyl Azelate for the Treatment of Brown Recluse Spider Bite, a Neglected Orphan Indication

BACKGROUND/AIM

Brown recluse spider bite releases hemolytic and cytotoxic phospholipase D to the wound that may cause necrosis or even death. We examined diethyl azelate (DEA), a plasma membrane fluidizer with a broad range of immunomodulatory activities, as a potential treatment for the brown recluse spider bite.

MATERIALS AND METHODS

Topical DEA was used in emergency to treat brown recluse spider bites in a human subject. We subsequently evaluated the effects of DEA on hemolysis induced by the brown recluse spider venom, recluse recombinant phospholipase D (rPLD), and venoms from honey bee and moccasin snake, and on phospholipase A2 activity in the bee and snake venoms and in human urine.

RESULTS

Topical DEA resolved the consequences of human brown recluse spider envenomation in two weeks. In vitro, DEA inhibited hemolysis caused by the brown recluse spider venom and rPLD and suppressed phospholipase A2 activity in a dose-dependent manner.

CONCLUSION

DEA is a promising novel therapy for the brown recluse spider bite and perhaps even unrelated envenomations involving PLDs.

Relationships between constituents of energy drinks and beating parameters in human induced pluripotent stem cell (iPSC)-Derived cardiomyocytes

Consumption of energy drinks has been associated with adverse cardiovascular effects; however, little is known about the ingredients that may contribute to these effects. We therefore characterized the chemical profiles and in vitro effects of energy drinks and their ingredients on human induced pluripotent stem cell (iPSC)-derived cardiomyocytes, and identified the putative active ingredients using a multivariate prediction model. Energy drinks from 17 widely-available over-the-counter brands were evaluated in this study. The concentrations of six common ingredients (caffeine, taurine, riboflavin, pantothenic acid, adenine, and L-methionine) were quantified by coupling liquid chromatography with a triple quadrupole mass spectrometer for the acquisition of LC-MS/MS spectra. In addition, untargeted analyses for each beverage were performed with a platform combining LC, ion mobility spectrometry and mass spectrometry (LC-IMS-MS) measurements. Approximately 300 features were observed across samples in the untargeted studies, and of these ~100 were identified. In vitro effects of energy drinks and some of their ingredients were then tested in iPSC-derived cardiomyocytes. Data on the beat rate (positive and negative chronotropy), ion channel function (QT prolongation), and cytotoxicity were collected in a dilution series. We found that some of the energy drinks elicited adverse effects on the cardiomyocytes with the most common being an increase in the beat rate, while QT prolongation was also observed at the lowest concentrations. Finally, concentration addition modeling using quantitative data from the 6 common ingredients and multivariate prediction modeling was used to determine potential ingredients responsible for the adverse effects on the cardiomyocytes. These analyses suggested theophylline, adenine, and azelate as possibly contributing to the in vitro effects of energy drinks on QT prolongation in cardiomyocytes.