Anti-tumor Effect And Mechanisms Of Sterols From Amauroderma Rude And Ganoderma Lucidum Spore

The anti-tumor effect of ergosterol and ergosterol peroxide purified from both Amauroderma rude and Ganoderma lucidum spore were studied, respectively.It has been previously confirmed that the water extracts from either Amauroderma rude basidiocarp or Ganoderma lucidum spore possessed the remarkable anti-cancer activity in vivo and in vitro. In the following study, anti-cancer compounds were purified and identified from the two materials, and certain signaling mediating cancer cell apoptosis were also clarified.In A. rude ethanol extract, four compounds were obtained within it’s chloroform fraction by silica gel chromatography and HPLC, and identified as ergosta-5, 7, 22-trien-3β-ol(ergosterol), ergosta-7, 22-dien-3β-ol, palmic acid and arachidic acid by EI-MS/ESI-MS and NMR. In Ganoderma spore oil(extract of Ganoderma lucidum spore powder by Supercritical Fluid Extraction, SFE), five compounds were obtained and identified as ergosta-7, 22-dien-3β-ol, ergosta-4, 6, 8(14), 22-tetraen-3-one, 5, 8-epidioxiergosta-6, 22-dien-3β-ol(ergosterol peroxide), palmic acid and tetracosanoicacidglyceride.Ergosta-5, 7, 22-trien-3β-ol(ergosterol), a highly accumulated compound in A. rude, showed anti-tumor activity with a time and concentration dependent manner in vivo. In vitro, mice implanted a severe murine cancer cell B16 maintained their life span remarkably when administrated with ergosterol. Human breast cancer cell MDA-MB-231 proliferation was also suppressed by ergosterol in vitro through apoptosis induction. The expression of a tumor suppressor Foxo3, and it’s down-stream signaling proteins Fas, Fas L, Bim L and Bim S were up-regulated in the cells. All results suggest that the main anti-cancer ingredient in A. rude is ergosterol, which activated the apoptotic signal pathway. Ergosterol may serve as a potential lead for cancer therapy.Ergosterol peroxide, a natural oxidant compound of ergosterol, inhibited human cancer cell Hep G2 proliferation and colony formation. The transcripts and protein accumulation of Foxo3 a in Hep G2 cells were clearly increased in response to ergosterol peroxide treatment. Cell immuno-fluorescence assay further demonstrated that ergosterol peroxide increased Foxo3 a expression and nucleus localization in Hep G2 cells. However, p AKT and c-Myc, antagonists of Foxo3 a, were evidently decreased in Hep G2 cells after treated with ergosterol peroxide. In turn, Foxo3 a effectively enhanced proapoptotic proteins Puma and Bax, which were pivotal factors to induce cell apoptosis. These results suggest that ergosterol peroxide effectively induced Foxo3 a activity by inhibiting p AKT and c-Myc, in turn, which activated proapoptotic protein Puma and BAX to induce cells death.