| dc.description.abstract | A long-term study, using male Wistar rats, was
initiated to determine whether the effects of dietary
constituents on AFBl -induced liver cancer could be
associated with altered microsomal enzyme activity.
They were maintained on mice pellets mixed with specific
dietary constituents for 7 days and then given a single
carcinogenic dose of AFBl (500ug/rat). After three
months, the dietary constituents were discontinued and
the animals were left on mice pellets and drinking water
only fOr a period of about 20 months. At the end of the
trial period" it was observed that dietary mixtures
containing small quantities of either B-carotene,
ascorbic ,acid, GSH, vitamin E~ s~lenium salt, or uric
acid inhibited the development of AFBl - induced liver .
cancer and induced increased mdcrosomal enzyme activity
at least by 50%.' Where B-carotene and uric acid were
the most -e.f f ect Lve inhibitors, vitamin E as was the least,
yet a significant inhibitor of liver cancer. Hepatic
,
levels of cytochrome P-450, aniline hydroxylase and
chlorpromazine demethylase were significantly induced
(X)
in rats fed fortified food followed by AFBl treatment
than in control animals. The inhibition of liver cancer
by dietary factors was probably due to their ability
to induce the activity of hepatic microsomal enzymes.
Increased enzyme activity could lead to rapid activation
of AFBl metabolites that attack cell components.
Inhbition of liver cancer is therefore associated with
induction of increased microsomal enzyme activity | en |
