The apoptotic mechanism of Taiwanofungus camphoratus fruiting bodies’ extracts on human liver cancer HepG2 cell line

• Main Authors: I-Kai Kao, 高翊愷
• Other Authors: Tzong-Zeng Wu
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/19692805233198524249

碩士 === 國立東華大學 === 生命科學系 === 100 === Taiwanofungus is a kind of unique fungi species which only grow in the inner cavity of the endemic species Cinnamomum kanehirae . The fruiting body of Taiwanofungus had been identified that contained several different physiological active compounds, especially the triterpenoids, which were found having anticarcinoma and antiangiogenesis abilities. Recently, more and more studies focused on the functions of using Taiwanofungus mycelium, fermented broth, or fruiting body’s extracts as experimental reagents in cancer cell lines study. Few of them focused on the fractionated extracts or purified components to elucidate the effectiveness on cancer cell lines . This study focused on the various partilly purified fractions, FK1~FK6, prepared from series extraction and purification steps by using Soxlet, column chromatography and Semi-preparative HPLC method. The primary results showed FK6 fraction was the most effective one on hepatic cancer cell line, HepG2. Subsequenly, FK6 was further separated into two single peaks with purity more then 95% subfractions samples, FK6-1 and FK6-2, by using Semi-preparative HPLC. The viabilites of HepG2 cancer cell line was inhibited by FK6-1 with IC50 values about 26 μg/ml. Then apoptosis induced by FK6-1 in HepG2 cells was characterized by flow cytometry cell cycle analysis and Annexin V/PI double staining in HepG2 cells. The result of western blot showed that FK6-1 activated the Fas/FasL apoptosis pathway in HepG2 cell line. The activation of Fas/FasL by FK6-1 induced caspase-8 activation. Caspase-8 activated tBid, and then tBid further stimulated with the increase of Bax and decrease of Bcl-2. As Bcl-2 family inactivated, cytochrome c released from mitochondria to cytoplasm and activated caspase-9. Finally, caspase-9 activated caspase-3 and inhibited the function of ICAD, breaking DNA into pieces. According to the results of this study, FK6-1 should have a great potential to develop into a new anticancer drug.