| Summary: | 博士 === 國立中興大學 === 食品科學系 === 85 === ABSTRACTA Chinese medicinal plant－psoralea fruit (Psoralea
corylifolia L.), which physiological functionality including
antimutagenicity, anti-genetic toxicity, and antioxidative
protection in primary rat hepatocytes was investigated. As for
the Ames test, water extract and bakuchiol both from psoralea
fruit exhibited antimutagenic activities on indirect mutagens.
The gel-filtrated fractionⅣhad the most antimutagenic activity
in water extract from psoralea fruit, with a melecular weight
about 14,000. In addition,Studies using primary rat hepatocytes
showed that 0.125 mM bakuchiol and 0.6 mg/ml water extract from
psoralea fruit were able to increase cell viability, lower lipid
peroxidation and LDH leakage of hepatocytes by inducing more
reduced glutathione levels (P<0.05) and increase the activities
of antioxidative and detoxification enzymes including
glutathione peroxidase (GSH Px), glutathione reductase GSH Rd)
and glutathione S-transferase (GST).Bakuchiol and water extract
from psoralea fruit were then tested for protection of
hepatocytes against DNA damage and cell death induced by 0.01 mM
AFB1. The result showed that 0.125 mM bakuchiol and 0.6 mg/ml
water extract from psoralea fruit inhibited unscheduled DNA
synthesis of hepatocytes induced by AFB1. The results implied
that bakuchiol and water extract from psoralea fruit could
inhibit genetic toxicity induced by AFB1, possibly by elevation
of hepatic GST activity which promoted detoxification andStudies
on oxidative stress of hepatocytes induced by glucose and
glucose oxidase showed that both bakuchiol and water extrcat
from psoralea fruit inhibited the decrease of cell viability and
lipid peroxidation. Bakuchiol and water extract from psoralea
fruit also scavenged hydroxyl radical, singlet oxygen, hydrogen
peroxide, superoxide anion, lipid radical, and chelated Fe2+ ion
to decrease the oxidative stress of hepatocytes. In addition,
compounds of psoralea fruit maintained and even elevated GSH
levelsBeside curing diseases, Chinese medicated diet were useful
for elevating resistance of organism under disadvantageously
exogenic stress. Thus, hepatocytes were first orientated in
bakuchiol or water extract from psoralea fruit to increase
antioxidant and detoxification system of the cells, and then
subjected to in vitro oxidative stress. The result revealed that
the orientated hepatocytes were more resistant to loss of cell
viability, possibly through significant elevation of GSH levels
and antioxidative and detoxification enzyme activities.
Apparently, the hepatocytes orientated in bakuchiol and water
extract from psoralea fruit effectively protected themself from
the damage by oxidative stress.
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