The effect of Myrica rubra essential oil and its components α-humulene and trans-nerolidol on adhesion and apoptosis of colorectal cancer cells

Essential oil from leaves of Myrica rubra (MEO), a subtropical Asian fruit tree with traditional use in folk medicines, had significant antiproliferative effect in several intestinal cancer cell lines. In present study, we tested the influence of MEO and its most effective compounds α-humulene and trans-nerolidol on the cell adhesion, expression of adhesion molecules (ICAM-1; E-cadherin; β-catenin) and apoptotic molecules (NF-κB, caspases) in colorectal cancer cell line HT29. All parameters were followed up and compared in presence or absence of pro-inflammatory agent TNFα. The results showed that MEO was able to decrease adhesion of colon cancer HT29 cells to collagen. Furthermore MEO, α-humulene and trans -nerolidol significantly suppressed adhesion of TNFα-induced cells probably due to down-regulation of ICAM-1. Moreover, MEO and α-humulene could diminish tumor invasion and metastasis via up-regulation of E-cadherin. In presence of TNFα, MEO and trans- nerolidol decreased activation (phosphorylation) of NF-κB, increased activity of caspases and by this way induced apoptosis of cancer cells. More pronounced effects of MEO than those of α-humulene and trans -nerolidol indicate synergism and/or contribution of other components.