Ethanol extract of Antrodia camphorata inhibits proliferation of HCT-8 human colorectal cancer cells by arresting cell cycle progression and inducing apoptosis

Antrodia camphorata (AC) is well known in Taiwan as a traditional Chinese medicine, with a long history of use in treating cancer and inflammation. Previous studies have revealed that AC exhibits anticancer effects in various cancer cell lines. However, the inhibitory influence of AC on colorectal cancer (CRC) cell growth and survival remains unknown. The present study investigated the effects of AC on the proliferation, survival, and cell cycle‑ and apoptosis‑associated gene and protein expression in the HCT‑8 human CRC cell line in vitro. The antitumor activity of AC against HCT‑8 cells was assessed using cell viability and colony formation assays. Cell cycle distribution was analyzed by flow cytometry. Cell apoptosis and morphological alterations were assessed by Hoechst 33258 staining and microscopy. The mRNA expression of cell cycle‑ and apoptosis‑associated genes was determined by reverse transcription‑quantitative polymerase chain reaction, and protein expression levels of B‑cell lymphoma 2 (Bcl‑2), Bcl‑2 X associated protein (Bax) cyclin D1, cyclin dependent kinase 4 (CDK4) and MYC proto‑oncogene bHLH transcription factor (c‑Myc) were determined by western blotting. Treatment of HCT‑8 cells with various concentrations of AC (0.4‑1.2 mg/ml) resulted in dose‑ and time‑dependent reductions in cell viability. HCT‑8 cell cycle was arrested in the G0/G1 phase or G0/G1 and G2/M phases following AC treatment, compared with untreated cells. Furthermore, AC markedly inhibited HCT‑8 cell growth with induction of apoptotic alterations and inhibition of proliferation. AC treatment induced HCT‑8 cell apoptosis, upregulated expression of the apoptosis gene Bax, and downregulated Bcl‑2, cMyc, cyclin D1 and CDK4 protein expression levels. The present data demonstrated that AC exhibited antiproliferative and growth inhibition effects on HCT‑8 cells via induction of apoptosis and blocking of cell cycle progression, thus suggesting that it may have anticancer properties valuable for potential future therapeutic application for the treatment of CRC.