Terpenes from essential oils and hydrolate of Teucrium alopecurus triggered apoptotic events dependent on caspases activation and PARP cleavage in human colon cancer cells through decreased protein expressions

Abstract

This study focused on characterizing the Hydrophobic and Hydrophilic fractions of Teucrium alopecurus in the context of cancer prevention and therapy. The goal was also to elucidate the molecular mechanisms involved and to determine its efficacy against cancer by triggering apoptosis and suppressing tumorigenesis in human colon cancer. The data here clearly demonstrated that oily fractions of Teucrium alopecurus act as free radical scavengers, antibacterial agent and inhibited the proliferation of HCT-116, U266, SCC4, Panc28, KBM5, and MCF-7 cells in a time- and concentration-dependent manner. The results of live/dead and colony formation assays further revealed that Teucrium essential oil has the efficacy to suppress the growth of colon carcinoma cells. In addition, essential oil of Teucrium alopecurus induced apoptosis, as indicated by cleavage of caspases-3, -8, and -9 and poly-adenosine diphosphate ribose polymerase. Moreover, Teucrium alopecurus essential oil suppressed gene expression involved in survival, proliferation, invasion, angiogenesis, and metastasis in human colon cancer cells. No sign of toxicity was detected in vivo after treatment with increasing concentrations of essential oil. Oral administration of T.alopecurus inhibited LPS-induced colon inflammation. This anticancer property of this specie Teucrium alopecurus fractions could be due to their phenolic and/or sesquiterpene content (d-limonene, α-Bisabolol, Humulene, Thymol, and (+)-epi-Bicyclosesquiphellandrene). Hence our study reveals the anticancer activity of Teucrium alopecurus oil mediated through the suppression of cell growth, cell proliferation, and the induction of apoptosis of cancer cells. Thus, it has potential to be developed as an anticancer agent; however more in vitro and in vivo studies are warranted.