ABSTRACT
Ring-C of oleanolic acid was chemically modified by treating with NBS under a variety of experimental conditions. The structures of the synthesized compounds were established by spectral analysis ((1)H &(13)C NMR and Mass). All the compounds were evaluated against a panel of five human cancer cell lines by using MTT assay. Among the tested compounds, 2 and 7 showed significant activity against breast cancer cell line, MCF-7. Most significantly, compound 7 showed several folds enhanced activity against MCF-7 cancer cell lines (IC50: 2.96µM) than that of the parent (1) and the intermediate compound (6). Flow cytometric analysis revealed that these compounds arrested the cell cycle in G0/G1 phase and induced mitochondrial mediated apoptosis.
Subject(s)
Antineoplastic Agents/pharmacology , Oleanolic Acid/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Apoptosis/drug effects , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Membrane Potential, Mitochondrial/drug effects , Mitochondria/drug effects , Mitochondria/metabolism , Molecular Structure , Oleanolic Acid/chemical synthesis , Oleanolic Acid/chemistry , Structure-Activity RelationshipABSTRACT
In our previous studies, benzimidazole-oxindole conjugates were synthesized and evaluated by National Cancer Institute (NCI) for their cytotoxic activity and the new molecules like 5c and 5p were considered as potential leads. These conjugates arrested the cell cycle at G2/M phase and inhibited tubulin polymerization. These observations prompted us to investigate the apoptotic mechanism induced by these lead molecules against human breast cancer cells (MCF-7). Studies like measurement of mitochondrial membrane potential (ΔΨm), generation of reactive oxygen species (ROS) and Annexin V-FITC assay revealed that these compounds induced mitochondrial mediated (intrinsic apoptotic pathway) apoptosis in human breast cancer cells. It was further confirmed by western blot analysis of pro apoptotic protein Bax, anti apoptotic protein Bcl-2, cytochrome c release, caspase-9 activity and cleavage of PARP.
Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Benzimidazoles/pharmacology , Indoles/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Benzimidazoles/chemistry , Cell Cycle Checkpoints/drug effects , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Humans , Indoles/chemistry , MCF-7 Cells , Membrane Potential, Mitochondrial/drug effects , Molecular Structure , Oxindoles , Reactive Oxygen Species/metabolism , Structure-Activity RelationshipABSTRACT
A series of new molecules have been designed based on a hybridization approach by combining the arylcinnamide and combretastatin pharmacophores. These were synthesized and evaluated for their cytotoxic activity, effect on inhibition of tubulin polymerization and apoptosis inducing ability. Most of the conjugates exhibited significant cytotoxic activity against some representative human cancer cell lines and two of the conjugates 6i and 6p displayed potent cytotoxicity with GI50 values of 56nM and 31nM respectively against the human breast cancer cell line (MCF-7). SAR studies revealed that 3,4-substitution on the phenyl ring of the cinnamide moiety is beneficial for enhanced cytotoxicity. Moreover, G2/M cell cycle arrest was induced by these conjugates (6i and 6p) apart from tubulin polymerization inhibition (IC50 of 1.97µM and 1.05µM respectively). Further, mitochondrial membrane potential, Annexin V-FITC and caspase-9 activation assays suggested that these conjugates induce cell death by apoptosis. Docking studies revealed that these conjugates interact and bind at the colchicine binding site of the tubulin.
