Detoxification mechanism of vinegar-processed Kansui revealed by systematic phytochemical analysis using ultrahigh-performance liquid chromatography diode array detection tandem mass spectrometry, ultrahigh-performance liquid chromatography high-resolution mass spectrometry and in silico drug target identification

Rationale The dried roots of Euphorbia kansui L., known as Kansui, are used to treat ascites and edema in traditional Chinese medicine. However, the toxicity of this herb has seriously restricted its clinical application. A unique vinegar-processing method has been used to reduce its toxicity since the time of ancient China. However, the detoxification mechanism underlying such vinegar processing has not been fully revealed. To find the answer, the process-induced changes in components should be carefully investigated. Methods We performed a systematic analysis of chemical components in raw and vinegar-processed Kansui using ultrahigh-performance liquid chromatography (UHPLC) diode array detection tandem mass spectrometry and UHPLC high-resolution mass spectrometry. Thirty-one chemical components in raw and vinegar-processed Kansui were found, the chemical structures of 28 components among them were proposed and the process-induced changes in components were then investigated. Results A comprehensive conclusion about the process-induced chemical change was drawn. It was found that jatrophane-type diterpenoids decreased markedly after vinegar processing, while ingenane-type diterpenoids were retained during vinegar processing. In silico drug target identification gave hints that jatrophane-type diterpenoids, which decreased markedly during vinegar processing, may have more intense toxicity involving cholinesterase and mitogen-activated protein kinases, while ingenane-type diterpenoids, which were retained during vinegar processing, may have a more intense therapeutic effect involving carbonic anhydrase. Conclusions The possible detoxification mechanism of vinegar-processed Kansui is presented. The research has significance for the therapeutic/toxic chemical basis of Kansui. Also, it has significance for drug discovery from terpenoids within the herb.