Induction of apoptosis by Uncaria tomentosa through reactive oxygen species production, cytochrome c release, and caspases activation in human leukemia cells.
Uncaria tomentosa (Wild.) DC., found in the Amazon rain forest in South-America and known commonly as cat's claw, has been used in traditional medicine to prevent and treat inflammation and cancer. Recently, it has been found to possess potent anti-inflammation activities. In this study, we extracted cat's claw using four different solvents of different polarities and compared their relative influence on proliferation in human premyelocytic leukemia HL-60 cell lines. Cat's claw n-hexane extracts (CC-H), ethyl acetate extracts (CC-EA) and n-butanol extracts (CC-B) had a greater anti-cancer effect on HL-60 cells than those extracted with methanol (CC-M). Furthermore, CC-EA induced DNA fragmentation in HL-60 cells in a clearly more a concentration- and time-dependent manner than the other extracts. CC-EA-induced cell death was characterized by cell body shrinkage and chromatin condensation. Further investigating the molecular mechanism behind CC-EA-induced apoptosis, sells treated with CC-EA underwent a rapid loss of mitochondrial transmembrane (DeltaPsi(m)) potential, stimulation of phosphatidylserine flip-flop, release of mitochondrial cytochrome c into cytosol, induction of caspase-3 activity in a time-dependent manner, and induced the cleavage of DNA fragmentation factor (DFF-45) and PARP poly-(ADP-ribose) polymerase (PARP). CC-EA promoted the up-regulation of Fas before the processing and activation of procaspase-8 and cleavage of Bid. In addition, the apoptosis induced by CC-EA was accompanied by up-regulation of Bax, down-regulation of Bcl-X(L) and cleavage of Mcl-1, suggesting that CC-EA may have some compounds that have anti-cancer activities and that further studies using cat's claw extracts need to be pursued. Taken together, the results of our studies show clearly that CC-EA's induction of apoptosis in HL-60 cells may make it very important in the development of medicine that can trigger chemopreventive actions in the body.
Cheng
An-Chin
AC
Department of Nutrition and Health Science, Toko University, Chia-Yi County 613, Taiwan.
Jian
Cheng-Bang
CB
Huang
Yu-Ting
YT
Lai
Ching-Shu
CS
Hsu
Ping-Chi
PC
Pan
Min-Hsiung
MH
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D000975:Antioxidants; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins; D051023:BH3 Interacting Domain Death Agonist Protein; D020169:Caspases / Q000378:metabolism*; D020948:Cat's Claw / Q000737:chemistry*; D002462:Cell Membrane; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D045304:Cytochromes c / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D019254:Genes, bcl-2; D018922:HL-60 Cells; D006801:Humans; D007938:Leukemia / Q000378:metabolism; D010718:Phosphatidylserines; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011065:Poly(ADP-ribose) Polymerases; D011506:Proteins; D017382:Reactive Oxygen Species / Q000378:metabolism*; D019014:fas Receptor
D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; D051017:Apoptosis Regulatory Proteins; D051023:BH3 Interacting Domain Death Agonist Protein; C494814:BID protein, human; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D010718:Phosphatidylserines; D010936:Plant Extracts; D011506:Proteins; D017382:Reactive Oxygen Species; C109664:caspase-activated DNase inhibitor; D019014:fas Receptor; D045304:Cytochromes c; D011065:Poly(ADP-ribose) Polymerases; D020169:Caspases