title: Different starting times of alpha-tocopherol and gamma-tocotrienol supplementation and tumor marker enzyme activities in the rat chemically induced with cancer.
abstract: 1. alpha-Tocopherol (alpha-T) and gamma-tocotrienol (gamma-T) were supplemented continuously for 8 weeks in the diets of normal rats and rats chemically induced with cancer using diethylnitrosamine (DEN), 2-acetylaminofluorene (AAF) and partial hepatectomy. Hepatocarcinogenesis was followed by determining the plasma gamma-glutamyl-transpeptidase (GGT) and alkaline phosphatase (ALP) activities as well as placental glutathione S-transferase (PGST) and GGT activities histochemically, at 4-week intervals. 2. Male Rattus norvegicus were supplemented alpha-T and gamma-T at two different doses of 30 and 300 mg/kg diet. The supplementation was started at three different times: simultaneously with DEN administration; 4 weeks; and 8 weeks after DEN administration. 3. Elevation of plasma GGT activities and formation of PGST and GGT positive foci were attenuated significantly (P < 0.05) when alpha-T and gamma-T were supplemented simultaneously with cancer induction. Supplementation begun 4 and 8 weeks after cancer induction did not affect plasma enzyme activities and formation of enzyme-positive foci. 4. alpha-T was more effective than gamma-T, and a lower dose of 30 mg/kg was found to be more effective in reducing the severity of hepatocarcinogenesis.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia.
authors.forename: S
authors.initials: S
authors.lastname: Makpol
authors.forename: N A
authors.initials: NA
authors.lastname: Shamaan
authors.forename: Z
authors.initials: Z
authors.lastname: Jarien
authors.forename: A G
authors.initials: AG
authors.lastname: Top
authors.forename: B A
authors.initials: BA
authors.lastname: Khalid
authors.forename: W Z
authors.initials: WZ
authors.lastname: Wan Ngah
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood*; D000818:Animals; D016588:Anticarcinogenic Agents / Q000008:administration & dosage*; D014408:Biomarkers, Tumor / Q000097:blood*; D002839:Chromans / Q000008:administration & dosage*; D007150:Immunohistochemistry; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008114:Liver Neoplasms, Experimental / Q000201:enzymology / Q000517:prevention & control*; D008297:Male; D051381:Rats; D014810:Vitamin E / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D016588:Anticarcinogenic Agents; D014408:Biomarkers, Tumor; D002839:Chromans; D014810:Vitamin E; C013649:plastochromanol 8; D005723:gamma-Glutamyltransferase; D000469:Alkaline Phosphatase