As a noted medicinal mushroom, Ganoderma lucidum (G. lucidum) has been reported to have a number of pharmacological effects such as anti-tumor and liver protection. Compared with the common ethanol reflux method, supercritical CO₂ extraction has obvious advantages in obtaining antitumor extracts from G. lucidum fruiting body such as short extraction time, low temperature and no solvent residue. However, Using high-pressure supercritical CO₂ without entrainer to obtain the antitumor extracts from G. lucidum and studying their anti-hepatoma effect have not been reported. In this study, high-pressure supercritical CO₂ extracts obtained under 65, 85, and 105 MPa pressure named as G65, G85, G105 respectively and ethanol reflux extract (GLE) were used to investigate their anti-hepatoma activity and the underlying molecular mechanism. The total triterpenoid content of G85 was significantly higher than that of G65 and GLE, but did not differ significantly from that of G105 by UV and high-performance liquid chromatography. GLE, G65, and G85 could inhibit cell proliferation, arrest cell cycle in G2/M phase, and induce apoptosis in two liver cancer cell lines (QGY7703 and SK-Hep1), of which G85 had the strongest effect. The results showed that the potency of their cytotoxicity of the high-pressure supercritical CO₂ extracts on human hepatoma carcinoma cells in vitro was consistent with their total triterpenoid content. G85 exhibited significant anti-hepatoma effect with low toxicity In vivo. Further mechanistic investigation revealed that the anti-tumor effect of these extracts was associated with their inhibition of Ras/Raf/MEK/ERK signaling pathway. Our findings suggest that the high-pressure supercritical CO₂ extraction of G. lucidum fruiting body can be used to obtain a triterpenoid-rich anti-tumor agent, which may have potential clinical significance for the treatment of human hepatoma.

Ovarian cancer is a deadly disease. Inhibitors of apoptosis proteins (IAPs) are key regulators of apoptosis and are frequently dysregulated in ovarian cancer. Overexpression of IAPs proteins has been correlated with tumorigenesis, treatment resistance and poor prognosis. Reinstalling functional cell death machinery by pharmacological inhibition of IAPs proteins may represent an attractive therapeutic strategy for treatment of ovarian cancer. CCK-8 and colony formation assay was performed to examine cytotoxic activity. Apoptosis was analyzed by fluorescence microscopy, flow cytometry and TUNEL assay. Elisa assay was used to determine TNFα protein. Caspase activity assay was used for caspase activation evaluation. Immunoprecipitation and siRNA interference were carried out for functional analysis. Western blotting analysis were carried out to test protein expression. Ovarian cancer cell xenograft nude mice model was used for in vivo efficacy evaluation. APG-1387 demonstrated potent inhibitory effect on ovarian cancer cell growth and clonogenic cell survival. APG-1387 induced RIP1- and TNFα-dependent apoptotic cell death in ovarian cancer through downregulation of IAPs proteins and induction of caspase-8/FADD/RIP1 complex, which drives caspase-8 activation. NF-κB signaling pathway was activated upon APG-1387 treatment and RIP1 contributed to NF-κB activation. APG-1387 induced cytoprotective autophagy while triggering apoptosis in ovarian cancer cells and inhibition of autophagy enhanced APG-1387-induced apoptotic cell death. APG-1387 exhibited potent antitumor activity against established human ovarian cancer xenografts. Our results demonstrate that APG-1387 targets IAPs proteins to potently elicit apoptotic cell death in vitro and in vivo, and provide mechanistic and applicable rationale for future clinical evaluation of APG-1387 in ovarian cancer.

Elimination of quiescent slow-cycling cells via reducing quiescence depth by natural compounds purified from Ganoderma lucidum Elimination of quiescent slow-cycling cells via reducing quiescence depth by natural compounds purified from Ganoderma lucidum