title: Cell cycle arrest and mechanism of apoptosis induction in H400 oral cancer cells in response to Damnacanthal and Nordamnacanthal isolated from Morinda citrifolia.
abstract: Oral cancer is the eleventh most prevalent cancer worldwide. The most prevalent oral cancer is oral squamous cell carcinoma (OSCC). Damnacanthal (DAM) and nordamnacanthal (NDAM), the anthraquinone compounds, are isolated from the root of Morinda citrifolia L. (Noni), which has been used for the treatment of several chronic diseases including cancer. The objectives of this study were to evaluate the cytotoxicity, cell death mode, cell cycle, and the molecular mechanism of apoptosis induced by DAM and NDAM on OSCC. The cytotoxic effects of these compounds against OSCC cell lines were determined by MTT assay. The cell death mode was analysed by DNA laddering and FITC-annexin V/PI flow cytometric assays. In addition, the mechanism of apoptosis induced by DAM and NDAM was detected using mitochondrial membrane potential, Cytochrome c, and caspases assays. Finally, the effect of DAM and NDAM on cell cycle phase distribution of OSCC cells was detected by flow cytometry. In the present study, DAM and NDAM showed cytotoxicity towards OSCC cell lines and the maximum growth inhibition for both compounds was observed in H400 cells with IC50 value of 1.9 and 6.8 μg/ml, respectively, after 72 h treatment. The results also demonstrated the inhibition of H400 OSCC cells proliferation, internucleosomal cleavage of DNA, activation of intrinsic apoptosis pathway, and cell cycle arrest caused by DAM and NDAM. Therefore, these findings suggest that DAM and NDAM can be potentially used as antitumor agents for oral cancer therapy.
authors.affiliation: Department of Oral Biology and Biomedical Sciences, Faculty of Dentistry, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Gohar
authors.initials: G
authors.lastname: Shaghayegh
authors.affiliation: Department of Oral Biology and Biomedical Sciences, Faculty of Dentistry, University of Malaya, 50603, Kuala Lumpur, Malaysia. aied@um.edu.my.|Oral Cancer Research and Coordinating Centre, Faculty of Dentistry, University of Malaya, 50603, Kuala Lumpur, Malaysia. aied@um.edu.my.
authors.forename: Aied M
authors.initials: AM
authors.lastname: Alabsi
authors.affiliation: School of Biotechnology, Faculty of Bioresource and Food Industry, University Sultan Zainal Abidin, 22200, Kuala Terengganu, Terengganu, Malaysia.
authors.forename: Rola
authors.initials: R
authors.lastname: Ali-Saeed
authors.affiliation: School of Biotechnology, Faculty of Bioresource and Food Industry, University Sultan Zainal Abidin, 22200, Kuala Terengganu, Terengganu, Malaysia.
authors.forename: Abdul Manaf
authors.initials: AM
authors.lastname: Ali
authors.affiliation: Oral Cancer Research and Coordinating Centre, Faculty of Dentistry, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Vui King
authors.initials: VK
authors.lastname: Vincent-Chong
authors.affiliation: Oral Cancer Research and Coordinating Centre, Faculty of Dentistry, University of Malaya, 50603, Kuala Lumpur, Malaysia.
authors.forename: Rosnah Binti
authors.initials: RB
authors.lastname: Zain
keywords: Apoptosis; Cytochrome c; Damnacanthal and nordamnacanthal; Human oral squamous cell carcinoma (OSCC); Mitochondrial membrane potential