Essential oil from Myrica rubra leaves inhibits cancer cell proliferation and induces apoptosis in several human intestinal lines

The leaves of Myrica rubra (Sieb. et Zucc), a subtropical Asian fruit tree with traditional use in folk medicines, were extracted by hydrodistillation. The antiproliferative effect of obtained M. rubra essential oil (MEO) was tested in human colon and ileocecal adenocarcinoma cell lines HCT8, SW620, SW480, HT29 and Caco2. Cytostatic drug paclitaxel was used as a positive control. MEO significantly inhibited cell proliferation in concentration-dependant manner in all cell lines. The efficacy of ME differed in individual cell lines, with Caco2 being the most sensitive. In these cells, MEO, IC50 value of 1.5 mu g/mL was obtained using xCelligence system for real-time cell monitoring. In cancer cells, MEC) induces apoptosis and caused significant increase of activities of initiator as well as effector caspases. Contrary to cancer cells, MEC) did not affect viability of isolated hepatocytes (as a model of normal non-cancerous cells). GC x GC-TOFMS analysis of MEC, chemical composition revealed beta-caryophyllene, alpha-humulene, humulene epoxide I, valencene, epi-alpha-selinene, gamma-muurolene, beta-caryphyllene-oxide, and trans-nerolidol as dominant compounds. (C) 2014 Elsevier B.V. All rights reserved.