title: Synergistic anticancer activity of dietary tea polyphenols and bleomycin hydrochloride in human cervical cancer cell: Caspase-dependent and independent apoptotic pathways.
abstract: Bleomycin is a chemotherapeutic agent that is frequently used in the treatment of various cancers. Bleomycin causes serious adverse effects via antioxidant defense abnormalities against reactive oxygen species (ROS). However, the current cervical cancer monodrug therapy strategy has failed to produce the expected outcomes; hence, combinational therapies are gaining great interest. Tea polyphenols are also effective antioxidative and chemo-preventive agents. However, the combined effect of tea polyphenol (TPP) and bleomycin (BLM) against cervical cancer remains unknown. In this study, we focused on the potential of TPP on BLM anticancer activity against cervical cancer cells. Cervical cancer cells (SiHa) were treated with various concentrations of TPP, BLM and TPP combined with BLM (TPP-BLM), and their effects on cell growth, intracellular reactive oxygen species, poly-caspase activity, early apoptosis and the expression of caspase-3, caspase-8 and caspase-9, Bcl-2 and p53 were assessed. The MTT assay revealed that the SiHa cells were less sensitive to growth inhibition by TPP treatment compared with both BLM and the combination therapy. Nuclear staining indicated that exposure to TPP-BLM increased the percentage of apoptotic nuclei compared with a mono-agent treatment. Caspase activation assay demonstrated that proportion of early and late apoptotic/secondary necrotic cells was higher in the cells treated with the combination therapy than in those treated with either TPP or BLM alone. The TPP-BLM treatment synergistically induced apoptosis through caspase-3, caspase-8 and caspase-9 activation, Bcl-2 upregulation and p53 overexpression. This study suggests that TPP-BLM may be used as an efficient antioxidant-based combination therapy for cervical cancer.
authors.affiliation: Nanobiotechnology and Molecular Biology Research Lab, Department of Food Science and Nutrition, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia. Electronic address: nano.alshatwi@gmail.com.
authors.forename: Ali A
authors.initials: AA
authors.lastname: Alshatwi
authors.affiliation: Nanobiotechnology and Molecular Biology Research Lab, Department of Food Science and Nutrition, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Vaiyapuri Subbarayan
authors.initials: VS
authors.lastname: Periasamy
authors.affiliation: Nanobiotechnology and Molecular Biology Research Lab, Department of Food Science and Nutrition, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Jegan
authors.initials: J
authors.lastname: Athinarayanan
authors.affiliation: Nanobiotechnology and Molecular Biology Research Lab, Department of Food Science and Nutrition, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Ramesh
authors.initials: R
authors.lastname: Elango
mesh_terms: D018906:Antineoplastic Agents, Alkylating / Q000008:administration & dosage / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001761:Bleomycin / Q000008:administration & dosage / Q000494:pharmacology*; D020169:Caspases / Q000378:metabolism*; D045744:Cell Line, Tumor; D004357:Drug Synergism; D004789:Enzyme Activation; D005260:Female; D015870:Gene Expression; D006801:Humans; D016133:Polymerase Chain Reaction; D059808:Polyphenols / Q000008:administration & dosage / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D002583:Uterine Cervical Neoplasms / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*
chemical_list: D018906:Antineoplastic Agents, Alkylating; D059808:Polyphenols; D017382:Reactive Oxygen Species; D001761:Bleomycin; D020169:Caspases
keywords: Apoptosis; Bleomycin; Cervical cancer; Synergistic effect; Tea polyphenols