A novel sesquiterpene Hirsutanol A induces autophagical cell death in human hepatocellular carcinoma cells by increasing reactive oxygen species.
OBJECTIVE
Hirsutanol A is a novel sesquiterpene compound purified from fungus chondrostereum sp in Sarcophyton tortuosum. Its pharmacologic effect has not been reported yet. This study aimed to investigate cytotoxic effect of Hirsutanol A on hepatocellular carcinoma (HCC) cells and its mechanism.


METHODS
Hep3B cells were treated with different concentrations of Hirsutanol A. Cell proliferation was detected by MTT assay. The protein expression of LC3 was determined by Western blot. The generation of reactive oxygen species (ROS) was monitored by flow cytometry.


RESULTS
Hirsutanol A significantly inhibited proliferation of Hep3B cells with 50% inhibition concentrations (IC50) of 14.54, 6.71, and 3.59 micromol/L when exposed to Hirsutanol A for 24, 48, and 72 h, respectively. Incubation of Hep3B cells with Hirsutanol A markedly increased the level of ROS and the autophagy marker MAP-LC3 conversion from type I to type II. Pre-incubation with an antioxidant N-acetyl cystein (NAC) decreased the level of ROS, and reduced MAP-LC3 I-II conversion, and suppressed cell death. Blocking autophagy with a specific autophagy inhibitor 3-methyladenine (3-MA), the cytotoxic effect of this compound was attenuated.


CONCLUSIONS
Hirsutanol A has potent cytotoxic effect, and can induce autophagic cell death via increasing ROS production.
Yang
Fen
F
State Key Laboratory of Oncology in South China, Guangzhou, Guangdong 510060, PR China.
Gao
You-Heng
YH
Wu
Ke-Wei
KW
Deng
Rong
R
Li
Dan-Dan
DD
Wei
Zhi-Xiong
ZX
Jiang
Shan
S
Wu
Xiao-Qi
XQ
Feng
Gong-Kan
GK
Li
Hou-Jin
HJ
Zhu
Xiao-Feng
XF
D000111:Acetylcysteine / Q000494:pharmacology; D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000363:Agaricales / Q000737:chemistry; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology; D001343:Autophagy / Q000187:drug effects*; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology; D016923:Cell Death / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers / Q000494:pharmacology; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012717:Sesquiterpenes / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*
D000970:Antineoplastic Agents; D016166:Free Radical Scavengers; C477012:MAP1LC3A protein, human; D008869:Microtubule-Associated Proteins; D017382:Reactive Oxygen Species; D012717:Sesquiterpenes; C569055:hirsutanol A; C025946:3-methyladenine; D000225:Adenine; D000111:Acetylcysteine