title: Apoptosis induction by 13-acetoxyrolandrolide through the mitochondrial intrinsic pathway.
abstract: The aim of this study was to evaluate the mechanisms of cytotoxicity of the sesquiterpene lactone 13-acetoxyrolandrolide, a nuclear factor kappa B (NF-κB) inhibitor that was previously isolated from Rolandra fruticosa. The effects associated with the inhibition of the NF-κB pathway included dose-dependent inhibition of the NF-κB subunit p65 (RelA) and inhibition of upstream mediators IKKβ and oncogenic Kirsten rat sarcoma (K-Ras). The inhibitory concentration of 13-acetoxyrolandrolide on K-Ras was 7.7 µM. The downstream effects of the inhibition of NF-κB activation were also investigated in vitro. After 24 h of treatment with 13-acetoxyrolandrolide, the mitochondrial transmembrane potential was depolarized in human colon cancer (HT-29) cells. The mitochondrial oxidative phosphorylation was also negatively affected, and reduced levels of nicotinamine adenine dinucleotide phosphate (NAD(P)H) were detected after 2 h of 13-acetoxyrolandrolide exposure. Furthermore, the expression of the pro-apoptotic protein caspase-3 increased in a concentration-dependent manner. Cell flow cytometry showed that 13-acetoxyrolandrolide induced cell cycle arrest at G1 , indicating that the treated cells had undergone caspase-3-mediated apoptosis, indicating negative effects on cancer cell proliferation. These results suggest that 13-acetoxyrolandrolide inhibits NF-κB and K-Ras and promotes cell death mediated through the mitochondrial apoptotic pathway.
authors: Division of Pharmacy Practice and Administration, College of Pharmacy, The Ohio State University, Parks Hall 500  W 12th Avenue, Columbus, OH, 43210, USA; Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Parks Hall 500 W 12th Avenue, Columbus, OH, 43210, USA.
authors: Ulyana Muñoz
authors: UM
authors: Acuña
authors: Susan
authors: S
authors: Matthew
authors: Li
authors: L
authors: Pan
authors: A Douglas
authors: AD
authors: Kinghorn
authors: Steven M
authors: SM
authors: Swanson
authors: Esperanza J Carcache
authors: EJ
authors: de Blanco
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D059447:Cell Cycle Checkpoints; D019073:HT29 Cells; D006801:Humans; D051550:I-kappa B Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000378:metabolism*; D009249:NADP / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras); D012717:Sesquiterpenes / Q000494:pharmacology*; D051996:Transcription Factor RelA / Q000037:antagonists & inhibitors* / Q000378:metabolism; D018631:ras Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: C552274:13-acetoxyrolandrolide; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; C498143:RELA protein, human; D012717:Sesquiterpenes; D051996:Transcription Factor RelA; D009249:NADP; D051550:I-kappa B Kinase; C505407:CASP3 protein, human; D053148:Caspase 3; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins
keywords: HT-29; K-Ras; NF-κB; apoptosis; colon cancer; mitochondria; reactive oxygen species; sesquiterpene