Preliminary study of the genotoxic potential of homocysteine in human lymphocytes in vitro

dc.contributor.authorCrott, J.
dc.contributor.authorFenech, M.
dc.date.issued2001
dc.description.abstractHomocysteine (Hcy), an immediate precursor of methionine (Met), is considered a risk factor for cardiovascular disease, Alzheimer's disease and neural tube defects. Hcy concentration is also reported to correlate positively with the micronucleus index in lymphocytes in vivo, a marker of chromosome damage. However, it is unclear whether Hcy is genotoxic or simply a biomarker of folate deficiency, a known cause of chromosome damage. We investigated whether high concentrations of Hcy are genotoxic to human lymphocytes in vitro using the cytokinesis-block micronucleus assay. Eighteen lymphocyte cultures were initiated in Met-free and serum-free RPMI 1640 medium for each of four male volunteers aged 22-23 years. At 0, 24, 44 and 72 h, cultures were spiked with L-Hcy or L-Met to achieve concentrations ranging between 50 and 400 microM. The concentration of Hcy at 96 h ranged from 19.45 +/- 2.34 to 149.02 +/- 28.16 microM in Hcy cultures and 0.91 +/- 0.17 to 2.15 +/- 0.9 microM in Met cultures spiked with 50 and 400 microM of metabolite, respectively. Forty-four hours after mitogen stimulation, cytokinesis was inhibited with cytochalasin B. After 96 h, cells were transferred to microscope slides and the frequency of micronucleated-binucleate and necrotic cells was scored. Neither Hcy (P = 0.24) nor Met (P = 0.93) had an apparent dose effect on micronucleus frequency. However, when data were pooled, micronucleus frequency was moderately higher (50.1%) in Hcy- than in Met-spiked cultures (P = 0.04; paired t-test). Hcy concentration was positively correlated with necrosis (P < 0.0005; r(2)= 0.276), however, when data were pooled, levels of necrosis were higher in Met- than in Hcy-spiked cultures (P= 0.01; paired t-test). Further research is required to define more clearly the genotoxic and cytotoxic potential of homocysteine and its metabolites.
dc.description.statementofresponsibilityCrott, Jimmy ; Fenech, Michael
dc.identifier.citationMutagenesis, 2001; 16(3):213-217
dc.identifier.doi10.1093/mutage/16.3.213
dc.identifier.issn0267-8357
dc.identifier.issn1464-3804
dc.identifier.orcidFenech, M. [0000-0002-8466-0991]
dc.identifier.urihttp://hdl.handle.net/2440/14518
dc.language.isoen
dc.publisherOxford Univ Press
dc.source.urihttps://doi.org/10.1093/mutage/16.3.213
dc.subjectLymphocytes
dc.subjectCells, Cultured
dc.subjectHumans
dc.subjectNecrosis
dc.subjectCytochalasin B
dc.subjectMethionine
dc.subjectHomocysteine
dc.subjectMutagens
dc.subjectAnalysis of Variance
dc.subjectMicronucleus Tests
dc.subjectDose-Response Relationship, Drug
dc.subjectModels, Chemical
dc.subjectTime Factors
dc.subjectAdult
dc.subjectMale
dc.titlePreliminary study of the genotoxic potential of homocysteine in human lymphocytes in vitro
dc.typeJournal article
pubs.publication-statusPublished

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