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Interactive suppression of aberrant crypt foci induced by azoxymethane in rat colon by phytic acid and green tea 总被引:1,自引:2,他引:1
Several epidemiological studies point to a strong correlation between
nutrient composition of the diet and cancer of the colon. Phytic acid,
present in grains, has been credited with reducing the risk of cancer of
the colon. A number of reports are available indicating the benefits of
green tea consumption in reducing the risk of stomach, lung and skin
cancer, but little data are available on the effect of green tea in
reducing the risk of colon cancer. Also, there are no studies on the
combined effect of these compounds on colon tumorigenesis. Thus the primary
objective of this investigation was to elucidate the combined effects of
green tea and phytic acid on colonic preneoplastic lesions and the Phase II
enzyme glutathione S-transferase. Fisher 344 male weanling rats were
divided into nine groups of 15 rats each and fed the experimental diet for
13 weeks. Rats received two s.c. injections of azoxymethane in saline at 16
mg/kg body wt at 7 and 8 weeks of age. Rats received three levels (0, 1 and
2%) of phytic acid with three levels (0, 1 and 2%) of green tea within each
phytic acid level in a 3 x 3 factorial experiment. Results indicate that
while green tea had a marginal effect (P < 0.14), phytic acid
significantly reduced the incidence of aberrant crypt foci (P < 0.008).
The interaction between green tea and phytic acid was significant (P <
0.029 for distal and < 0.0168 for entire colon) and positive, pointing
to a synergistic effect of green tea and phytic acid.
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Based on 20,713 singleton livebirths at the John Radcliffe Hospital, Oxford, in 1978-1984, we calculated new birthweight and head circumference values for males and females between 24 and 42 weeks of gestation. Among the 803 babies born at or before 34 weeks of gestation, 28% were delivered electively for fetal problems; they were considerably lighter and had smaller heads than infants born after spontaneous preterm labour. As we and others have recommended elsewhere, the electively delivered preterm infants were excluded from the calculation of the new birthweight and head circumference centiles. In our series males were heavier and had larger head circumferences than females at most gestational ages. There were consistent and statistically significant differences in birthweight at all gestational ages from 37 weeks and in head circumference at all gestational ages from 35 weeks. 相似文献
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