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Biphasic modifying effect of indole-3-carbinol on diethylnitrosamine-induced preneoplastic glutathione S-transferase placental form-positive liver cell foci in Sprague-Dawley rats.
- Source :
-
Japanese journal of cancer research : Gann [Jpn J Cancer Res] 1994 Jun; Vol. 85 (6), pp. 578-83. - Publication Year :
- 1994
-
Abstract
- The biphasic modifying effects of indole-3-carbinol (I3C), a naturally occurring constituent of edible cruciferous vegetables, on the development of glutathione S-transferase placental form (GST-P)-positive liver cell foci were investigated by using a medium-term liver bioassay system and a newborn rat hepatocarcinogenesis system. In Experiment 1, a total of 65 male Sprague-Dawley (SD) rats were divided into 5 groups. Animals were given a single intraperitoneal (i.p.) injection of 200 mg/kg diethylnitrosamine (DEN) dissolved in saline for groups 1, 2, and 3 or a single i.p. injection of saline for groups 4 and 5. Group 1 was given the diet containing 0.25% I3C for 2 weeks prior to DEN initiation and then basal diet for 8 weeks. Group 2 was given basal diet for 4 weeks prior to and after DEN initiation and then the diet containing 0.25% I3C for 6 weeks. The rats of group 3 were placed on basal diet during the experiment. Animals of groups 4 and 5 were treated in the same manner as those of groups 1 and 2 except for injection with saline instead of DEN solution. All rats were subjected to two-thirds partial hepatectomy at week 3 and were killed at week 8 after DEN or saline injection. In Experiment 2, a total of 45 female SD rats were dosed with DEN (100 mg/kg, i.p.) or saline at 24 h after birth. After weaning at week 3, the rats were fed diet containing 0.25% I3C for 9 weeks and then were killed at week 12. In Experiment 1, preinitiation exposure to 0.25% I3C caused a significant decrease in numbers of GST-P-positive liver cell foci (P < 0.05), while postinitiation exposure to 0.25% I3C caused significant increases in both number (No./cm2) and area (mm2/cm2) of GST-P-positive liver cell foci (P < 0.05 or 0.01). In Experiment 2, the relative liver weight in the DEN + I3C group was significantly increased (P < 0.001). The numbers and areas of GST-P-positive liver cell foci in the DEN + I3C group were significantly increased as compared to the values of the DEN-alone group (P < 0.001). These results clearly demonstrated that I3C exerts a promoting effect on the postinitiation stage as well as an inhibitory effect on the preinitiation stage in the medium-term liver bioassay.
- Subjects :
- Animals
Biomarkers, Tumor analysis
Body Weight drug effects
Diethylnitrosamine
Enzyme Induction
Female
Glutathione Transferase drug effects
In Vitro Techniques
Isoenzymes drug effects
Liver anatomy & histology
Liver drug effects
Liver Neoplasms, Experimental chemically induced
Male
Organ Size drug effects
Placenta enzymology
Precancerous Conditions chemically induced
Rats
Rats, Sprague-Dawley
Anticarcinogenic Agents therapeutic use
Biomarkers, Tumor biosynthesis
Glutathione Transferase biosynthesis
Indoles therapeutic use
Isoenzymes biosynthesis
Liver Neoplasms, Experimental enzymology
Liver Neoplasms, Experimental prevention & control
Precancerous Conditions enzymology
Precancerous Conditions prevention & control
Subjects
Details
- Language :
- English
- ISSN :
- 0910-5050
- Volume :
- 85
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Japanese journal of cancer research : Gann
- Publication Type :
- Academic Journal
- Accession number :
- 8063610
- Full Text :
- https://doi.org/10.1111/j.1349-7006.1994.tb02399.x