Inhibition of breast cancer cell growth by the Pteris semipinnata extract ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid.

Previous studies have demonstrated strong anti-tumor effects of ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F), an extract from Pteris semipinnata, in liver, lung, stomach and anaplastic thyroid cancer cells. However, whether 5F inhibits the growth of breast cancer cells remains unclear. The present study assessed the effect of 5F on breast cancer cells. The breast cancer cell lines MCF-7, MDA-MB-231 and SK-BR-3 were each treated with 0, 5, 10, 20 and 40 µg/ml 5F. Morphological changes in the breast cancer cells were assessed using fluorescence microscopy. The proliferation and apoptosis of the breast cancer cells were also examined using Cell Counting Kit-8 and flow cytometry. The levels of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X apoptosis regulator (Bax), Bcl-2 antagonist/killer (Bak) 1 and caspase-3 in the breast cancer cells were assessed. The results of the present study demonstrated that 5F inhibited the proliferation of MCF-7, MDA-MB-231 and SK-BR-3 breast cancer cells in a concentration- and time-dependent manner. Treatment with 5F also induced the apoptosis of breast cancer cells. MDA-MB-231, MCF-7, and SK-BR-3 cells exhibited apoptotic rates of 40.13, 60.44, and 70.49%, respectively, following incubation with 5F for 24 h. Furthermore, 5F significantly decreased the expression of Bcl-2 and increased the expression of Bax, Bak, and caspase-3 in a concentration-dependent manner. The results of the present study revealed that the P. semipinnata extract 5F inhibited the growth of human breast cancer cells in a time- and concentration-dependent manner, and that 5F induced apoptosis of human breast cancer cells.