title: Ribavirin, but not interferon alpha-2b, is associated with impaired osteoblast proliferation and differentiation in vitro.
abstract: Hepatitis C treatment with interferon alpha-2b (IFN-alpha) and ribavirin has been related to decreased bone mineral density. The aim of this study was to investigate the in vitro effects of different concentrations of ribavirin and IFN-alpha on osteoblast-like cells. Human osteoblast-like cells obtained by the outgrowth of cells from bone chips were exposed to ribavirin (0.1-10 microg/mL) or IFN-alpha (0.1-1000 UI/mL). At regular time-points, cultures were harvested for posterior analysis. Alkaline phosphatase (ALP) activity was determined on days 7 and 14, and cell growth was accessed by C3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and cell count on days 1, 3, 5, and 7. Flow cytometry analysis was used for investigating cell death on days 1, 3, 5, and 7. IFN-alpha affected ALP expression only at the higher concentration (1000 UI/mL) after 7 days (P < 0.05). No effects were detected in cell growth. In ribavirin treated cultures, concentrations higher than 2.5 microg/mL were associated with a decrease in ALP activity within 7 and 14 days (P < 0.01 and P < 0.001, respectively). Furthermore, the reduction in cell growth was dose-dependent and was detected after the fifth day. This decrease can be explained by an increase in the number of dead cells and a decrease in cell proliferation. In conclusion, our experiments demonstrated that ribavirin reduced, in a time- and dose-dependent manner, the number of metabolically active cells through a decrease in proliferation and an increase in cell death, and induced an impairment in osteoblast differentiation. These negative effects of ribavirin on osteblast-like cells might contribute to the bone loss reported in vivo.
authors.affiliation: Division of Endocrinology, Hospital Universitário Clementino Fraga Filho (HUCFF), Rio de Janeiro, Brazil. rom_br@yahoo.com
authors.forename: R O
authors.initials: RO
authors.lastname: Moreira
authors.forename: A
authors.initials: A
authors.lastname: Balduíno
authors.forename: H S L H
authors.initials: HS
authors.lastname: Martins
authors.forename: J S N
authors.initials: JS
authors.lastname: Reis
authors.forename: M E L
authors.initials: ME
authors.lastname: Duarte
authors.forename: M L F
authors.initials: ML
authors.lastname: Farias
authors.forename: R
authors.initials: R
authors.lastname: Borojevic
mesh_terms: D000469:Alkaline Phosphatase / Q000187:drug effects / Q000378:metabolism; D001846:Bone Development / Q000187:drug effects / Q000502:physiology*; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects* / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000009:adverse effects; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010024:Osteoporosis / Q000139:chemically induced* / Q000378:metabolism / Q000503:physiopathology; D011994:Recombinant Proteins; D012254:Ribavirin / Q000633:toxicity*; D013778:Tetrazolium Salts; D013844:Thiazoles; D013997:Time Factors
chemical_list: D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D013778:Tetrazolium Salts; D013844:Thiazoles; D012254:Ribavirin; D000469:Alkaline Phosphatase; C022616:thiazolyl blue