Evaluation of the anti-carcinogenic effect of tea tree oil (Melaleuca alternifolia) on SK-BR-3 breast cancer cells

Abstract

Breast cancer cells that overexpress HER2 are related to poorer survival outcomes compared to HER2-negative tumors and are recognized for their higher aggressiveness. The study aimed to evaluate the possible effects of Melaleuca alternifolia (tea tree oil, TTO), a plant known for its broad antimicrobial and anticancer characteristics, on cell viability, cell migration, and oxidative stress in SK-BR-3 cells, which represent HER2+ breast cancer, for the first time. The efficacy of different concentrations of TTO on cell viability was measured via MTT. A scratch assay was conducted to evaluate the effects of TTO on cell migration, and reactive oxygen species (ROS) activity was examined with the DCF-DA assay. SK-BR-3 cells inhibited cell viability when exposed to TTO. Cell proliferation was decreased at 48 and 72 hours, especially at high doses. It was observed that cells reached the IC50 value at a lower concentration at 24 (66.76 µg/mL) and 48 (65.57 µg/mL) hours and at a higher concentration at 72 hours (88.24 µg/mL). TTO didn’t significantly inhibit wound healing and cell migration at the 67.5 µg/mL dose in SK-BR-3 cells. In the control group, the wound healed completely at 72 hours, while cell migration was repressed by the 112.5 µg/mL dose of TTO compared to untreated cells. Furthermore, TTO didn’t show a remarkable effect on ROS-dependent cell death in SK-BR-3 cells at the 24th hour; however, 48th hour exposure to both 67.5 µg/mL and 112.5 doses cause oxidative stress. Tea tree oil may suppress cell proliferation, inhibit cell migration, and increase reactive oxygen radicals in the SK-BR-3 cell line at higher doses.

Keywords

• Cytotoxicity
• Breast cancer
• HER2
• SK-BR-3
• Tea tree oil

Ethical Statement

Ethics Committee Approval is not needed due to the study is based on cell culture experiments.

Thanks

The design of this study is a key part of collaborative research funded and supported by Scientific and Technological Research Council of Turkey (TUBITAK) 2209-A Program and Istanbul Yeni Yüzyil University.

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