Cordyceps pruinosa extracts induce apoptosis of HeLa cells by a caspase dependent pathway

Aim of the studyCordyceps is a parasitic fungus and has long been used as a traditional Chinese medicine to treat illnesses, promote longevity, increase athletic power, and relieve exhaustion and cancer. In this study, we reveal the mechanisms underlying apoptosis induced by Cordyceps pruinosa butanol fraction (CPBF) in the human cervical adenocarcinoma cell line, HeLa.Materials and methodsProliferation and apoptosis of cells were examined by MTT assay, DNA fragmentation, phosphatidyl serine distribution assay, Western blot analysis, and immunocytochemistry. To determine the association between CPBF related apoptosis and ROS, electron spin resonance (ESR) trapping experiments were used.ResultsCPBF inhibited proliferation and induced apoptosis in HeLa cells in a dose-dependent manner using a MTT assay, DNA fragmentation, and a phosphatidyl serine distribution assay. Western blot analysis showed that apoptosis in HeLa cells was caspase-3- and -9-dependent. Proteolytic cleavage of PARP and the release of cytochrome c from the mitochondria into the cytosol were significantly increased and the Bcl-2/Bax protein ratio was decreased. Apoptosis induced by CPBF was not prevented by various antioxidants.ConclusionsThese results indicate that apoptotic effects of CPBF on HeLa cells are mediated by mitochondria-dependent death-signaling pathway independent of reactive oxygen species, suggesting that CPBF might be effective as an anti-proliferative agent for cancer.

Graphical abstractCordyceps pruinosa is a fungal parasite on larvae of Lepidoptera. In Asian countries, the fungus, which is used as a traditional folk medicine for the treatment of circulatory, immune, respiratory, stomach disorders and inflammatory diseases, has been widely investigated for its medicinal effects.Figure optionsDownload full-size imageDownload as PowerPoint slide