Xiao-Dong Wang1, Chen-Yang Li1, Miao-Miao Jiang2, Dong Li2, Ping Wen3, Xun Song1, Jun-Da Chen4, Li-Xuan Guo4, Xiao-Peng Hu1, Guo-Qiang Li5, Jian Zhang1, Chun-Hua Wang6, Zhen-Dan He7. 1. Department of Pharmacy, School of Medicine, Shenzhen University, Shenzhen 518060, Guangdong, PR China; Institute of Biotherapy, Shenzhen University, Shenzhen 518060, Guangdong, PR China; Engineering Laboratory of Shenzhen Natural Micromolecule Innovative Drugs, Shenzhen University, Shenzhen 518060, Guangdong, PR China. 2. Tianjin Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, PR China. 3. Business Technology Department, Shenzhen Institute for Drug Control, Shenzhen 518057, Guangdong, PR China. 4. Department of Pharmacy, School of Medicine, Shenzhen University, Shenzhen 518060, Guangdong, PR China. 5. Experiment and Technology Center, Jinan University, Guangzhou 510632, Guangdong, PR China. 6. Tianjin Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin 300193, PR China. Electronic address: pharmwch@126.com. 7. Department of Pharmacy, School of Medicine, Shenzhen University, Shenzhen 518060, Guangdong, PR China; Institute of Biotherapy, Shenzhen University, Shenzhen 518060, Guangdong, PR China; Engineering Laboratory of Shenzhen Natural Micromolecule Innovative Drugs, Shenzhen University, Shenzhen 518060, Guangdong, PR China. Electronic address: hezhendan@126.com.
Abstract
BACKGROUND: Catharanthus roseus (L.) G. Don consists of a range of dimeric indole alkaloids with significant antitumor activities. These alkaloids have been found to possess apoptosis-inducing activity against tumor cells in vitro and in vivo mediated by nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and c-Jun N-terminal kinase (JNK) pathways, in which DNA damage and mitochondrial dysfunction play important roles. In this study, a unique bisindole alkaloid named cathachunine, along with five known dimeric indole alkaloids, was obtained from C. roseus and investigated in vitro. PURPOSE: The aim of this study was to investigate the antitumor activity of isolated alkaloids and the mechanism through which cathachunine exerts its antitumor effect. STUDY DESIGN AND METHODS: Cell growth inhibition was assessed by WST-1 and lactate dehydrogenase (LDH) assays in HL60, K562 leukemia cells and EA.hy926 umbilical vein cells. Induction of apoptosis in HL60 cells was confirmed by observation of nuclear morphology, a caspase-3 activity assay and annexin V-fluorescein isothiocyanate/propidium iodide (FITC/PI) double staining. The intrinsic apoptotic pathway induced by cathachunine was evidenced by B-cell lymphoma 2/Bcl-2-associated X protein (Bcl-2/Bax) dysregulation, loss of mitochondrial membrane potential, translocation of cytochrome c, and cleavage of caspase-3 and poly-ADP ribose polymerase (PARP). Reactive oxygen species (ROS) production after cathachunine treatment was determined by 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) staining. Cell cycle arrest of the S phase was also observed in HL60 cells after cathachunine treatment. RESULTS: The WST-1 and LDH assays showed that Catharanthus alkaloids were cytotoxic toward human leukemia cells to a greater extent than toward normal human endothelial cells, and the anti-proliferation and pro-apoptosis abilities of cathachunine were much more potent than other previously reported alkaloids. The induction of apoptosis by cathachunine occurred through an ROS-dependent mitochondria-mediated intrinsic pathway rather than an extrinsic pathway, and was regulated by the Bcl-2 protein family. CONCLUSION: An unprecedented bisindole alkaloid cathachunine which lost C-18' and C-19' was isolated from C. roseus. It exerted a potent antitumor effect toward human leukemia cells through the induction of apoptosis via an intrinsic pathway. Thus, this study provides evidence for a new lead compound from a natural source for anti-cancer investigations.
BACKGROUND:Catharanthus roseus (L.) G. Don consists of a range of dimeric indole alkaloids with significant antitumor activities. These alkaloids have been found to possess apoptosis-inducing activity against tumor cells in vitro and in vivo mediated by nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and c-Jun N-terminal kinase (JNK) pathways, in which DNA damage and mitochondrial dysfunction play important roles. In this study, a unique bisindole alkaloid named cathachunine, along with five known dimeric indole alkaloids, was obtained from C. roseus and investigated in vitro. PURPOSE: The aim of this study was to investigate the antitumor activity of isolated alkaloids and the mechanism through which cathachunine exerts its antitumor effect. STUDY DESIGN AND METHODS: Cell growth inhibition was assessed by WST-1 and lactate dehydrogenase (LDH) assays in HL60, K562 leukemia cells and EA.hy926 umbilical vein cells. Induction of apoptosis in HL60 cells was confirmed by observation of nuclear morphology, a caspase-3 activity assay and annexin V-fluorescein isothiocyanate/propidium iodide (FITC/PI) double staining. The intrinsic apoptotic pathway induced by cathachunine was evidenced by B-cell lymphoma 2/Bcl-2-associated X protein (Bcl-2/Bax) dysregulation, loss of mitochondrial membrane potential, translocation of cytochrome c, and cleavage of caspase-3 and poly-ADP ribose polymerase (PARP). Reactive oxygen species (ROS) production after cathachunine treatment was determined by 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) staining. Cell cycle arrest of the S phase was also observed in HL60 cells after cathachunine treatment. RESULTS: The WST-1 and LDH assays showed that Catharanthusalkaloids were cytotoxic toward humanleukemia cells to a greater extent than toward normal human endothelial cells, and the anti-proliferation and pro-apoptosis abilities of cathachunine were much more potent than other previously reported alkaloids. The induction of apoptosis by cathachunine occurred through an ROS-dependent mitochondria-mediated intrinsic pathway rather than an extrinsic pathway, and was regulated by the Bcl-2 protein family. CONCLUSION: An unprecedented bisindole alkaloidcathachunine which lost C-18' and C-19' was isolated from C. roseus. It exerted a potent antitumor effect toward humanleukemia cells through the induction of apoptosis via an intrinsic pathway. Thus, this study provides evidence for a new lead compound from a natural source for anti-cancer investigations.
Authors: René Escobedo-González; Claudia Lucia Vargas-Requena; Edgar Moyers-Montoya; Juan Manuel Aceves-Hernández; María Inés Nicolás-Vázquez; René Miranda-Ruvalcaba Journal: Molecules Date: 2017-06-25 Impact factor: 4.411