Several compounds have been shown to induce the mixed function
oxidase enzyme system of animals, and also to inhibit tumor formation.
Included in this category are several vegetables and isolated
vegetable components from the Cruciferae family. In this
study rainbow trout were fed blanched freeze-dried cauliflower,
broccoli, or Brussel sprouts at the 20% supplemental level for two
months, or 500 ppm benzyl or phenethyl isothiocyanate. At this time
the livers were removed and hepatic microsomal enzymes were studied.
This treatment did not cause any increases in the metabolism of
p-nitroanisole or benzo(a)pyrene and cytochrome P-450 levels were
not elevated. On the contrary, benzo(a)pyrene monooxygenase,
7-ethoxycoumarin 0-dealkylase, resorufin 0-dealkylase, p-nitroanisole
0-demethylase, and cytochrome P-450 levels were increased in trout
treated orally and intraperitoneally with β-napthoflavone. For all
parameters studied, a greater increase in activity was seen in the
trout treated intraperitoneally. The vegetable and isothiocyanate
supplemented diets also did not inhibit tumor formation in trout
challenged with 20 ppb aflatoxin B₁ for one month.
A study with rats showed that both blanched freeze-dried cauliflower
and air-dried cauliflower cause significant increases in
p-nitroanisole 0-demethylase activity and benzo(a)pyrene monooxygenase
activity and increased cytochrome P-450 levels in rat hepatic microsomes
when fed at the 20% supplemental level for 25 days.
It was concluded that the null effects seen with the trout fed
the vegetables and isothiocyanates were not due to the heat treatment
of the vegetables since rats fed blanched freeze-dried cauliflower
had significant increases in enzymatic activity and increased cytochrome
P-450 levels over controls.
The results of the β-napthoflavone experiment verified the
validity and reliability of the experimental assays and conditions
and showed that trout hepatic microsomal enzymes can be induced by
orally administered compounds. / Graduation date: 1981
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27484 |
| Date | 23 May 1980 |
| Creators | Haight, Lynn Ellen |
| Contributors | Nixon, Joseph E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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