title: Enhancement of ajoene-induced apoptosis by conjugated linoleic acid in 3T3-L1 adipocytes.
abstract: Ajoene has been shown to induce apoptosis in 3T3-L1 adipocytes. In this report the effects on apoptosis of combinations of ajoene and trans-10, cis-12 conjugated linoleic acid (t10,c12CLA) in 3T3-L1 adipocytes were investigated. Although t10,c12CLA alone had no effect, ajoene plus t10,c12CLA reduced cell viability more than ajoene alone at 24 h (59.1 vs. 85.9% of control, respectively; p<0.05). Compared to treatment with t10,c12CLA, ajoene increased apoptosis 218% after 24 h (p<0.01), whereas ajoene plus t10,c12CLA increased apoptosis 122% over that caused by ajoene alone (p<0.01). Immunoblotting analysis also indicated that ajoene plus t10,c12CLA caused a greater increase in phosphorylation of c-Jun N-terminal kinase (JNK) and Bax expression and a greater release of mitochondrial proteins (cytochrome c, AIF) than additive responses to each compound alone. Ajoene plus t10,c12CLA also increased ROS production more than that resulting from ajoene treatment alone (264 vs 204% after 40 min, respectively; p<0.01). Furthermore, the antioxidant NAC prevented ROS generation and apoptosis by ajoene plus t10,c12CLA. Interestingly, the combination of ajoene and t10,c12CLA increased NF-kappaB activation and decreased the level of phosphorylated Akt more than each compound alone. Altogether, our observations indicate that t10,c12CLA potentiates the effect of ajoene on apoptosis in 3T3-L1 adipocytes.
authors.affiliation: Department of Animal & Dairy Science, 444 Edgar L. Rhodes Center for Animal and Dairy Science, University of Georgia, Athens, GA 30602-2771, USA.
authors.forename: Jeong-Yeh
authors.initials: JY
authors.lastname: Yang
authors.forename: Mary Anne
authors.initials: MA
authors.lastname: Della-Fera
authors.forename: Dorothy B
authors.initials: DB
authors.lastname: Hausman
authors.forename: Clifton A
authors.initials: CA
authors.lastname: Baile
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000166:cytology* / Q000187:drug effects*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D051033:Apoptosis Inducing Factor / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D053179:Caspase 7 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D045304:Cytochromes c / Q000378:metabolism; D004220:Disulfides / Q000494:pharmacology*; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D044243:Linoleic Acids, Conjugated / Q000494:pharmacology*; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013454:Sulfoxides; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: D051033:Apoptosis Inducing Factor; D004220:Disulfides; D044243:Linoleic Acids, Conjugated; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D013454:Sulfoxides; D051028:bcl-2-Associated X Protein; C496197:trans-10,cis-12-conjugated linoleic acid; D045304:Cytochromes c; C048980:ajoene; D051057:Proto-Oncogene Proteins c-akt; D048031:JNK Mitogen-Activated Protein Kinases; D053148:Caspase 3; D053179:Caspase 7