title: The selective target of capsaicin on FASN expression and de novo fatty acid synthesis mediated through ROS generation triggers apoptosis in HepG2 cells.
abstract: The inhibition of the mammalian de novo synthesis of long-chain saturated fatty acids (LCFAs) by blocking the fatty acid synthase (FASN) enzyme activity in tumor cells that overexpress FASN can promote apoptosis, without apparent cytotoxic to non-tumor cells. The present study aimed to focus on the potent inhibitory effect of capsaicin on the fatty acid synthesis pathway inducing apoptosis of capsaicin in HepG2 cells. The use of capsaicin as a source for a new FASN inhibitor will provide new insight into its possible application as a selective anti-cancer therapy. The present findings showed that capsaicin promoted apoptosis as well as cell cycle arrest in the G0/G1 phase. The onset of apoptosis was correlated with a dissipation of mitochondrial membrane potential (ΔΨm). Apoptotic induction by capsaicin was mediated by inhibition of FASN protein expression which was accompanied by decreasing its activity on the de novo fatty acid synthesis. The expression of FASN was higher in HepG2 cells than in normal hepatocytes that were resistant to undergoing apoptosis following capsaicin administration. Moreover, the inhibitory effect of capsaicin on FASN expression and activity was found to be mediated by an increase of intracellular reactive oxygen species (ROS) generation. Treatment of HepG2 cells with capsaicin failed to alter ACC and ACLY protein expression, suggesting ACC and ACLY might not be the specific targets of capsaicin to induce apoptosis. An accumulation of malonyl-CoA level following FASN inhibition represented a major cause of mitochondrial-dependent apoptotic induction instead of deprivation of fatty acid per se. Here, we also obtained similar results with C75 that exhibited apoptosis induction by reducing the levels of fatty acid without any change in the abundance of FASN expression along with increasing ROS production. Collectively, our results provide novel evidence that capsaicin exhibits a potent anti-cancer property by targeting FASN protein in HepG2 cells.
authors.affiliation: Department of Physiology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand.
authors.forename: Hathaichanok
authors.initials: H
authors.lastname: Impheng
authors.affiliation: Department of Medicine, Faculty of Medicine, Naresuan University, Phitsanulok, Thailand.
authors.forename: Sutatip
authors.initials: S
authors.lastname: Pongcharoen
authors.affiliation: Laboratoire de Toxicologie Cellulaire, Faculté de Médecine et de Pharmacie, Université de Franche-Comté, Besançon, France.
authors.forename: Lysiane
authors.initials: L
authors.lastname: Richert
authors.affiliation: Department of Pharmacy Practice, Faculty of Pharmaceutical Sciences, Naresuan University, Phitsanulok, Thailand.
authors.forename: Dumrongsak
authors.initials: D
authors.lastname: Pekthong
authors.affiliation: Department of Physiology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand.
authors.forename: Piyarat
authors.initials: P
authors.lastname: Srisawang
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002211:Capsaicin / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002951:Citrates / Q000378:metabolism; D064429:Fatty Acid Synthases / Q000378:metabolism*; D005227:Fatty Acids / Q000096:biosynthesis*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D056945:Hep G2 Cells; D006801:Humans; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D002951:Citrates; D005227:Fatty Acids; D017382:Reactive Oxygen Species; D014280:Triglycerides; D064429:Fatty Acid Synthases; D002211:Capsaicin