The inhibitory properties of ethanol extracts of white button mushrooms on interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF) secretion and PC3 cancer cell proliferation

IL-8, a cytokine produced by immune and non-immune cells induces VEGF secretion. Both cytokines induce angiogenesis and promote tumor growth. IL-8 and VEGF plasma levels correlate with cancer severity implying that their inhibition by bioactive compounds in food may delay tumor growth. Available data suggest that white button mushrooms (WBM) inhibit PC3 prostate cancer cell proliferation by blocking aromatase activity. However, their effect on IL-8 and VEGF secretion is unknown. In this study, we tested the hypothesis that WBM may also inhibit PC3 cell proliferation via IL-8 and VEGF axis. PC3 cells, 5×105 were incubated with 0–100 μg/ml of ethanol extracts of WBM for 3–48 h in medium containing 0–10% fetal calf serum (a source of growth factors). IL-8 and VGEF secreted into media were assayed by ELISA. Regardless of the culture conditions, WBM extracts decreased IL-8 secretion in a time and dose depended fashion, i.e. 42% after 24 h incubation period (p<0.05). WBM extracts also inhibited VEGF by 20% after 3 h and 6 h. The decrease was not due to cell death since trypan blue exclusion test did not indicate significant altered cell viability. WBM extracts decreased cell proliferation (tetrazolium bromide reduction) in a dose dependent fashion, varying from 20% to 40% (p<0.05). Our data suggest that WBM may modulate PC3 cell proliferation through inhibition of IL-8 and VEGF. The mechanisms involved are under investigation. Funded by OCAST & Oklahoma State University. Grant Funding Source: OCAST & Oklahoma State University