Pro-apoptotic effects of Paecilomyces hepiali, a Cordyceps sinensis extract on human lung adenocarcinoma A549 cells in vitro.

BACKGROUND

Paecilomyces hepiali (PH) is a derivative of Cordyceps sinensis (CS), a fungus that has been shown to have anti-cancer and pro-apoptotic effects. Here, we aimed to investigate the effect of in vitro PH treatment on cell proliferation, cell cycling, apoptosis, and tumor necrosis factor-alfa (TNF-α) mRNA expression in human lung adenocarcinoma A549 cells (A549).

MATERIALS AND METHODS

A549 cells were treated with an aqueous extract of PH at concentrations of 0.25, 0.5, 1, 2, and 4 mg/ml. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to evaluate cellular viability and proliferation, while flow cytometry (FCM) was used to examine cell cycling. Apoptosis was assayed using Annexin V Fluorescein Isothiocyanate / Propidium Iodide (V-FITC/PI) and FCM. TNF-α mRNA expression was measured with reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

Cell proliferation was significantly suppressed by treatment with 1, 2, and 4 mg/ml of PH extract. Furthermore, the MTT assay showed that cell proliferation was inhibited in a concentration-time-dependent manner. As the concentration of the PH treatment increased, there were fewer cells in the S phase, and more cells in the G0/G1 and G2 phases. After 24 h of treatment, apoptosis was induced by a dose of 2 mg/ml of PH. TNF-α mRNA expression was significantly higher in the intervention groups and was positively associated with treatment concentration.

CONCLUSIONS

These results indicate that in vitro treatment with an aqueous extract from PH limits cell proliferation, induces apoptosis, and causes cell cycle arrest of A549 cells; this suggests that it may have potential as a therapy for lung adenocarcinoma.