Terpenes and Biological Activities of Euphorbia tortilis

Background: Euphorbia species are known for the diversity of terpenes, and the presence of toxic diterpenoids in Euphorbia species have raised occupational and eco-toxicological concerns. The present study reports the terpene profile of Euphorbia tortilis Rottler ex Ainslie, along with cytotoxicity assay. Method: Triterpenes were isolated from the hexane extract of E. tortilis through column chromatography and were characterized by various spectroscopic techniques. Phorbol esters were detected from the methanol extract of the latex through high performance liquid chromatography-electrospray ionizationquadrupole time of flight tandem mass spectrometry (HPLC-QTOF- MS/MS). Cytotoxicity of the extract was tested against human cervical cancer cell line HeLa and normal cardiac myoblasts cell line H9C2 using MTT assay. Results: The pentacyclic triterpenoids 3β-friedelinol, 3α-friedelinol, friedelin, epi-friedelinyl acetate and taraxerol were isolated and characterized from E. tortilis. Ten phorbol esters belonging to the tigliane family of diterpenoids were detected through HPLC-ESI-QTOF-MS/MS method. The major tumor promoting phorbol ester TPA (phorbol-12-myristate-13-acetate) reported from Euphorbiaceae family could not be detected in E. tortilis, whereas the potential anti HIV and cytotoxic phorbol ester prostratin has been detected. Latex extract was inactive on the normal cell line H9C2 within the concentration range of 10-100μg/ml, while the cell growth inhibition of the extract at 100μg/ml on Hela cell line was negligible (3.06%). Conclusion: Pentacyclic triterpenes were the major compounds isolated and characterized from E. tortilis. HPLC-ESI-QTOF-MS/MS method has been found as an ideal tool for the detection of minor phorbol esters. The terpenoid profile revealed the absence of toxic TPA. Furthermore, the latex extract was non toxic towards normal cell line H9C2. The findings are relevant in the context of toxicological concerns related to Euphorbia members.