The effect of culture liquid ethyl acetate mycelium extracts of medicinal mushrooms on the viability of human pancreatic cancer cells

Pancreatic cancer, one of the deadliest of all solid malignancies, is one of the leading causes of cancer death worldwide, with 232,000 new cases and 213,000 deaths reported each year. These unfortunate statistics reflect the advanced stage at which most patients with pancreatic cancer are diagnosed and the paucity of effective chemotherapeutic regimens. Fungal metabolites have been gaining scientific interest because of their medicinal properties. In the present study, 31 different mushroom extracts of 12 medicinal mushroom species were screened for their effect on the viability of human pancreatic adenocarcinoma cells. Extraction procedures were executed with organic solvents-ethanol (EAL), ethyl acetate (EAC), and chloroform (CHL). In some cases, culture liquid (CL) extraction was also performed. All extracts were diluted to a concentration of 50 mg/mL dimethyl sulfoxide. Extract effects on cell viability were examined in human pancreatic adenocarcinoma cells HPAF-II (well differentiated) and PL5 (porrly differentiated), using XTT assay and crystal violet assay (CV). Furthermore, extract effects on LDH leakage were also studied in order to exclude necrotic damage of the extract. The screening phase revealed that among the total 31 extracts examined with various treatment doses (50-500 μg/mL) administered for 72 h, the CL extract of the mushroom Cyathus striatus exhibited the most prominent decrease in cell viability. Moreover, exposure of cells to lower concentrations then the above (1, 2.5, 5, 7.5, 10, 15, 20, and 50 μg/mL) for 24, 48, and 72 h showed a significant decrease in cell viability. Crystal violet results support these findings, and LDH levels measured suggest the lack of a necrotic effect of the extract. Our results indicate that C. striatus CL extract inhibits the viability of human pancreatic adenocarcinoma cells; HPAF-II and PL45. Growth inhibition can be achieved in low concentrations of the extract and a short exposure period. This effect can be mediated through apoptosis induction and/or cell cycle arrest; therefore, additional experiments are needed in order to elucidate the extract mechanism of action. These findings may lead to the development of new therapeutic strategies for the treatment of pancreatic cancer.