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

Abstract

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.