Inhibitory mechanisms of the ethanolic extract of mycelia of Antrodia cinnamomea on the growth of human lung cancer and hepatoma cells

Antrodia cinnamomea is well-known as a traditional Chinese medicine in Taiwan. Because the growth rate of the natural A. cinnamomea in the wild is very slow, it is difficult to be cultured in green house. It is very expensive to obtain its fruiting bodies. Additionally, it might be a possible and economical way to utilize the submerged fermentation to produce the product of A. cinnamomea with stronger bioactivity. Previous researches have shown A. cinnamomea has many biological activities, such as anti-cancer activity, hepatoprotection, anti-oxidation, anti-inflammation, neuroprotection, and so on. In addition, lung and liver cancer are very common malignant tumors in Taiwan. This study was to investigate the effect of ethanolic extract of mycelia of A. cinnamomea (EMA) in submerged fermentation on the human lung (A549) and liver (SK Hep-1 and HA 22T/VGH) cancer cell lines and their possible mechanisms. The results showed that EMA inhibit the cell viability of A549, SK Hep-1 (p53-positive) and HA 22T/VGH (p53-deletion, HBsAg [+]) for 48hr, and their IC50 value were 30.9、48.2 and 117.1 μg/ml, respectively. The results of cell cycle analysis showed that EMA induced cell cycle arrest in S (A549, 40 μg/ml), G0/G1 (SK Hep-1, 20 μg/ml) and S (HA 22T/VGH, 160 μg/ml) phase. Furthermore, EMA induced apoptosis (accumulation of sub G1 phase) in A549 (80 μg/ml), SK Hep-1 (80 μg/ml) and HA 22T/VGH (160 μg/ml), and the DNA ladder were presented in these three cell lines by DNA electrophoresis. According to the results of fluorescence microscope, it indicated that EMA induced A549, SK Hep-1 and HA 22T/VGH apoptosis through induction of caspase-3 activity. It also indicated that EMA increased caspase-3 and -9 and PARP proteins expression, and decreased the Bcl-2 protein expression and the ratio of Bcl-2/Bax of A549, SK Hep-1 and HA 22T/VGH. In conclusion, EMA could induce these three cell lines apoptosis through mitochondrial pathway by regulating the expression of apoptosis-related proteins.