Inhibition of Proliferation and Induction of Apoptosis in Triple-Negative Breast Cancer HCC1937 Cells by Carvacrol

Breast cancer is the most commonly diagnosed cancer in women worldwide. Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer with a poor prognosis. Studies have shown the benefits of natural alternatives as an adjuvant breast cancer therapy, including the phenolic monoterpene, carvacrol. However, reports on the antitumor activity of carvacrol against basal-like subtypes of TNBC are scarce. Therefore, the present study investigated the antiproliferative effect of carvacrol on HCC1973 cells and explored the underlying mechanisms. Carvacrol inhibited the proliferation of HCC1973 cells with an IC50 of 223.5 μM and induced cell cycle arrest at G0/G1 phase in the treated cells. Furthermore, carvacrol also induced apoptotic cell death in HCC1973 cells as determined by flow cytometry and transmission electron microscopy techniques. Induction of apoptosis was further confirmed at the molecular level using Western blot, where it was shown that carvacrol altered the expression of antiapoptotic and proapoptotic proteins in treated HCC1973 cells. These results suggest that carvacrol could be a potential candidate for basal-like TNBC drug development.