Hepatoma Cell Growth Inhibition by Inducing Apoptosis with Polysaccharide Isolated from Turkey Tail Medicinal Mushroom, Trametes versicolor (L.: Fr.) Lloyd (Aphyllophoromycetideae)

Abstract

The Trametes (=Coriolus) versicolor polysaccharide (CVP) is well known as an anti-tumor drug in clinical applications. Although recent studies have demonstrated that CVPs can inhibit the proliferation of cancer cells in vitro and in vivo, different purity levels of CVPs have a different affect on various cancer cells. In this study, crude CVPs were extracted and purified from T. versicolor dry fruit bodies by hot-water extraction, ethanol precipitation, and phenol-vitriolic colorimetry. The in vitro cytotoxic activities of CVPs were examined on the human hepatoma cancer (QGY) cell lines by using an MTT assay. The cell cycle and cell death (apoptosis) of QGY cells were investigated by flow cytometry. The expression of genes involved in the apoptosis process, such as p53, Bcl-2, and Fas, was also studied using reverse transcriptase-polymerase chain reaction (RT-PCR) techniques. These results showed that CVPs inhibited the proliferation of QGY in low concentrations (<20 mg/L) and the IC50 value was 4.25 mg/L. Changes that are characteristic of apoptosis, such as a found trapezoidal belt with DNA, were observed in the QGY cells treated with CVPs. There was a significant decrease in the expression of the cell cycle-related genes (p53, Bcl-2, and Fas,) in these cells following treatment with CVPs. These results thus indicate that CVPs can be a potential candidate to ameliorate toxic effects when used in cancer therapy.