Effect of the vinegar-process on chemical compositions and biological activities of Euphorbia kansui: A review

In traditional Chinese medicine (TCM) the root of Euphorbia kansui S.L.Liou ex S.B.Ho (EK), is used for treating edema and ascites but is also of toxicological concerns. And the clinical applications of EK have been seriously restricted for its severe toxicity. To reduce its toxicity, a commonly used clinical practice is processing it with vinegar.This review aimed to summarize and discuss updated information on biological activities and phytochemistry of EK before and after vinegar-processing, and provide feasible insights for further research on the chemical composition, toxicity and pharmacological effects of EK before and after vinegar-processing.The relevant information on chemical compositions and biological activities of EK before and after vinegar-processing was collected from scientific databases (Google Scholar, PubMed, CNKI, SpringerLink, Web of Science, Wiley Online Library and SciFinder). Additionally, published and unpublished Ph.D. and MSc. dissertations were also obtained from online databases.Diuretic and purgative effect of EK are well documented pharmacologically as are acute, irritant and organic toxic effects. Some of about terpenoids reported have antiproliferative effects on cancer cells and potential antiviral effect. After processing with vinegar, the contents of terpenoids mostly were reduced (ingenane and jatrophane type) with some new compounds being generated (unclear). Also, the toxicity of EK was decreased (using mice, rats and zebrafish embryos model), while the diuretic and purgative effects were retained (using cancerous ascites model rats and mice).While some evidence exists for the reduction of toxicity without compromising the pharmacological effects of EK after vinegar processing, the specific mechanism of action remains unknown. Consequently, further research is necessary to investigate the mechanisms and the relationship between vinegar processing and changes in the chemical composition as well as pharmacological effects/toxicity. This is essential before a safe clinical use can be endorsed.