FROM:
Mutat Res 1998 (Jun 18); 402 (1–2): 159–163
Nishino H
Department of Biochemistry,
Kyoto Prefectural University of Medicine,
Kawaramachi-Hirokoji,
Kamigyoku, Kyoto 602, Japan
Epidemiological investigations have shown that
cancer risk is inversely related to the consumption of green and
yellow vegetables and fruits. Since beta-carotene is present in
abundance in these vegetables and fruits, it has been
investigated
extensively as a possible cancer- preventive agent. However,
various carotenoids have also anti- carcinogenic activity. And we
found that some of them, such as alpha- carotene, showed higher
potency than beta-carotene to suppress carcinogenesis in animal
experiments. Thus, we have carried out more extended studies on
the
cancer-preventive activities of natural carotenoids. For example,
lutein, zeaxanthin, lycopene, phytoene, fucoxanthin, peridinin
and
astaxanthin seem to be promising. In the present study, we
confirmed the anti-carcinogenic activities of fucoxanthin and
peridinin. Among natural carotenoids, phytoene has not been
evaluated precisely since it becomes unstable when it is
purified. Here, the cancer-preventive activity of phytoene was demonstrated
using new a biotechnological method; i.e., establishment of
mammalian cells producing phytoene was followed by the
introduction of crtB gene which encodes phytoene synthase, and these cells
were proven to acquire the resistance against transformation imposed
by transfection of activated oncogenes. Further studies on various
natural carotenoids, besides beta- carotene, should be continued
to get proper information regarding natural carotenoids in the field
of cancer prevention.