Different Cytotoxic Effects of Vetiver Oil on Three Types of Cancer Cells, Mainly Targeting CNR2 on TNBC

OBJECTIVE: To investigate vetiver oil (VO) selectivity effects on several cancer cell types and identify the β-caryophyllene role and mechanisms to prevent cancer development. METHODS: Cytotoxic effects of VO on three types of cancer cells (WiDr, 4T1, T47D) were determined using MTT assay. VO’s effects on the cell cycle and apoptosis were analyzed using flow cytometry. Intracellular Reactive Oxygen Species (ROS) of cells after treatment with VO was observed with DCFDA staining. Bioinformatics study and molecular docking were used to determine the molecular targets of VO. RESULTS: VO contained various essential oils in which β-caryophyllene was the most abundant. 4T1 cells performed the lowest IC(50) value. WiDr and 4T1 cells showed an arrest in the G2/M phase, while T47D showed an increase of sub G1 population after VO treatment. On the other hand, apoptosis was only observed in WiDr and T47D cells. ROS levels were increased significantly in WiDr and T47D cells but not in 4T1 cells. Cannabinoids CB2 receptor (CNR2) was highly expressed in 4T1 cells and commonly exhibited a low survival rate on Triple Negative Breast Cancer (TNBC) patients. CNR2 was the notable target of β-caryophyllene and performed agonistic interaction, which might have contributed to its cytotoxic activity against 4T1 cells. CONCLUSION: The molecular interaction of VO cannabinoid agonists and the CNR2 receptor was the underlying cause of VO cytotoxicity, which is a VO distinction on TNBC. Therefore, VO is better suited for use as an anti-cancer agent in TNBC cells.