title: Induction of apoptosis by ethanol extracts of Ganoderma lucidum in human gastric carcinoma cells.
abstract: Ganoderma lucidum, a well-known medicinal mushroom, is highly valued and commonly used in Oriental medicine. Although recent experimental data has revealed the proapoptotic potency of G. lucidum extracts, the underlying mechanisms of this apoptotic activity have not yet been studied in detail. In the present study, the effects of ethanol extracts of G. lucidum (EGL) on the growth of an AGS human gastric carcinoma cell line were investigated. We found that EGL treatment resulted in a dose and time-dependent significant decrease in the viability of AGS cells. This decreased viability was caused by apoptotic cell death, with observed chromatin condensation and an accumulation of apoptotic fraction. EGL treatment induced the expression of death receptor-related proteins such as death receptor 5 and tumor necrosis factor-related apoptosis-inducing ligand, which further triggered the activation of caspase-8 and the cleavage of Bid. In addition, the increase in apoptosis that was induced by EGL was correlated with activation of caspase-9 and -3, downregulation of IAP family proteins such as XIAP and survivin, and concomitant degradation of poly (ADP-ribose) polymerase. Moreover the activity of Akt was downregulated in EGL-treated cells, and the phosphatidylinositol-3 kinase/ Akt inhibitor LY294002 sensitized the cells to EGL-induced apoptosis. The results indicated that EGL induces the apoptosis of AGS cells through a signaling cascade of death receptor-mediated extrinsic, as well as mitochondria-mediated intrinsic, caspase pathways which are associated with inactivation of the Akt signal pathway.
authors.affiliation: Department of Acupuncture and Moxibustion, College of Oriental Medicine, Dongeui University, Busan, Korea.
authors.forename: Kyung-Jun
authors.initials: KJ
authors.lastname: Jang
authors.forename: Min-Ho
authors.initials: MH
authors.lastname: Han
authors.forename: Byung-Hoon
authors.initials: BH
authors.lastname: Lee
authors.forename: Byung-Woo
authors.initials: BW
authors.lastname: Kim
authors.forename: Cheol-Hong
authors.initials: CH
authors.lastname: Kim
authors.forename: Hyun-Min
authors.initials: HM
authors.lastname: Yoon
authors.forename: Yung-Hyun
authors.initials: YH
authors.lastname: Choi
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002277:Carcinoma / Q000188:drug therapy / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology*; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D010936:Plant Extracts / Q000494:pharmacology*; D020940:Reishi / Q000737:chemistry*; D015398:Signal Transduction / Q000187:drug effects; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000201:enzymology / Q000235:genetics / Q000503:physiopathology*
chemical_list: D010936:Plant Extracts; D020169:Caspases