title: Role of hesperetin (a natural flavonoid) and its analogue on apoptosis in HT-29 human colon adenocarcinoma cell line--a comparative study.
abstract: Colon cancer is one of the serious health problems in most developed countries and its incidence rate is increasing in India. Hesperetin (HN) (3',5,7-trihydroxy-4'-methoxyflavonone) and hesperetin analogue (HA) were tested for their apoptosis inducing ability. Methyl thiazolyl tetrazolium assay revealed a dose as well as duration-dependent reduction of HT-29 (colon adenocarcinoma) cellular growth in response to HN and HA treatment. At 24 h 70 μM of HN and 32 μM of HA showed 50% reduction of HT-29 cellular growth. Acridine orange/ethidium bromide staining showed apoptotic features of cell death induced by HN and HA. Rhodamine 123 staining showed significant reduction in mitochondrial membrane potential induced by HN and HA. HN and HA induced DNA damage was confirmed by comet tail formation. Lipid peroxidation markers (TBARS) and protein oxidation marker (PCC) were significantly elevated in HN and HA treated groups. Enzymic antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) were slightly decreased in their activities compared to control (untreated HT-29 cells). Results of Western blot analysis of apoptosis associated genes revealed an increase in cytochrome C, Bax, cleaved caspase-3 expression and a decrease in Bcl-2 expression. These findings indicate that HN and HA induce apoptosis on HT-29 via Bax dependent mitochondrial pathway involving oxidant/antioxidant imbalance.
authors.affiliation: Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar 608 002, Tamilnadu, India.
authors.forename: Gunasekaran
authors.initials: G
authors.lastname: Sivagami
authors.forename: Rajamanickam
authors.initials: R
authors.lastname: Vinothkumar
authors.forename: Roberta
authors.initials: R
authors.lastname: Bernini
authors.forename: Christo Paul
authors.initials: CP
authors.lastname: Preethy
authors.forename: Anvarbatcha
authors.initials: A
authors.lastname: Riyasdeen
authors.forename: Mohammad Abdulkader
authors.initials: MA
authors.lastname: Akbarsha
authors.forename: Venugopal Padmanaban
authors.initials: VP
authors.lastname: Menon
authors.forename: Namasivayam
authors.initials: N
authors.lastname: Nalini
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D017209:Apoptosis / Q000187:drug effects*; D002374:Catalase / Q000378:metabolism; D003110:Colonic Neoplasms / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D004249:DNA Damage; D005979:Glutathione Peroxidase / Q000378:metabolism; D019073:HT29 Cells; D006569:Hesperidin / Q000494:pharmacology*; D006801:Humans; D015227:Lipid Peroxidation; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D006569:Hesperidin; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; C013015:hesperetin