title: Tocotrienol-rich fraction prevents cell cycle arrest and elongates telomere length in senescent human diploid fibroblasts.
abstract: This study determined the molecular mechanisms of tocotrienol-rich fraction (TRF) in preventing cellular senescence of human diploid fibroblasts (HDFs). Primary culture of HDFs at various passages were incubated with 0.5 mg/mL TRF for 24 h. Telomere shortening with decreased telomerase activity was observed in senescent HDFs while the levels of damaged DNA and number of cells in G(0)/G(1) phase were increased and S phase cells were decreased. Incubation with TRF reversed the morphology of senescent HDFs to resemble that of young cells with decreased activity of SA-β-gal, damaged DNA, and cells in G(0)/G(1) phase while cells in the S phase were increased. Elongated telomere length and restoration of telomerase activity were observed in TRF-treated senescent HDFs. These findings confirmed the ability of tocotrienol-rich fraction in preventing HDFs cellular ageing by restoring telomere length and telomerase activity, reducing damaged DNA, and reversing cell cycle arrest associated with senescence.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, National University of Malaysia, Jalan Raja Muda Abdul Aziz, Kuala Lumpur, Malaysia. suzanamakpol@yahoo.com
authors.forename: Suzana
authors.initials: S
authors.lastname: Makpol
authors.forename: Lina Wati
authors.initials: LW
authors.lastname: Durani
authors.forename: Kien Hui
authors.initials: KH
authors.lastname: Chua
authors.forename: Yasmin Anum
authors.initials: YA
authors.lastname: Mohd Yusof
authors.forename: Wan Zurinah Wan
authors.initials: WZ
authors.lastname: Ngah
mesh_terms: D002453:Cell Cycle / Q000187:drug effects*; D048430:Cell Shape / Q000187:drug effects; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects*; D005591:Chemical Fractionation; D020552:Comet Assay; D004249:DNA Damage; D004171:Diploidy; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D013194:Staining and Labeling; D019098:Telomerase / Q000378:metabolism; D016615:Telomere / Q000378:metabolism*; D024508:Tocotrienols / Q000494:pharmacology*; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D024508:Tocotrienols; D019098:Telomerase; D001616:beta-Galactosidase