title: Investigation of the effects of oral administration of vitamin E and beta-carotene on the chemiluminescence responses and the frequency of sister chromatid exchanges in circulating leukocytes from cigarette smokers.
abstract: Sixty asymptomatic cigarette smokers were randomly allocated into three treatment groups. Smokers in Group 1 received 900 international units of Vitamin E (VE) daily for 6 wk, whereas 40 mg of beta-carotene (BC) daily was administered to those in Group 2 for the same period. Subjects in Group 3 were treated with a matched placebo. Plasma levels of VE and BC as well as circulating leukocyte counts, sister chromatid exchanges (SCEs), and the luminol-enhanced chemiluminescence (LECL) responses of blood phagocytes activated with phorbol myristate acetate (PMA) and FMLP with cytochalasin B (FMLP/CB) were measured prior to the administration of the antioxidant/placebo after 4 and 6 wk of supplementation and 12 wk after cessation of treatment. SCEs and leukocyte counts remained unchanged throughout the trial in all three treatment groups. Administration of VE for 4 wk was accompanied by decreased FMLP/CB-activated (p less than 0.005) and PMA-activated (p less than 0.005) LECL responses. However, with PMA as stimulant, the inhibition of LECL was transient, with partial recovery observed after 6 wk despite continued administration of VE. Administration of BC was associated with progressive inhibition of both FMLP/CB-activated (p less than 0.05 and p less than 0.01 after 4 and 6 wk, respectively) and PMA-activated (p less than 0.025 after 6 wk) LECL. No alterations in LECL responses were observed in Group 3 (placebo). VE appeared to inhibit the generation of oxidants by activated phagocytes, whereas BC scavenged oxidants generated by the myeloperoxidase/H2O2/halide system.
authors.affiliation: Department of Medicine, Coronation Hospital, Transvaal, Republic of South Africa.
authors.forename: G A
authors.initials: GA
authors.lastname: Richards
authors.forename: A J
authors.initials: AJ
authors.lastname: Theron
authors.forename: C E
authors.initials: CE
authors.lastname: Van Rensburg
authors.forename: A J
authors.initials: AJ
authors.lastname: Van Rensburg
authors.forename: C A
authors.initials: CA
authors.lastname: Van der Merwe
authors.forename: J M
authors.initials: JM
authors.lastname: Kuyl
authors.forename: R
authors.initials: R
authors.lastname: Anderson
mesh_terms: D000166:Acridines / Q000494:pharmacology; D000284:Administration, Oral; D000328:Adult; D002338:Carotenoids / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007958:Leukocyte Count / Q000187:drug effects; D007962:Leukocytes / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D008163:Luminescent Measurements; D008165:Luminol / Q000494:pharmacology; D008297:Male; D016032:Randomized Controlled Trials as Topic; D012854:Sister Chromatid Exchange / Q000187:drug effects*; D012907:Smoking / Q000097:blood* / Q000235:genetics; D013481:Superoxides / Q000378:metabolism; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D019207:beta Carotene
chemical_list: D000166:Acridines; D019207:beta Carotene; D013481:Superoxides; D014810:Vitamin E; C033472:10,10'-dimethyl-9,9'-biacridinium; D002338:Carotenoids; D008165:Luminol