Affiliations: Institutes of Biochemistry, College of Medicine,
National Taiwan University, No.1, Section 1, Jen-ai Road, Taipei, Taiwan,
10018 | Institutes of Toxicology, College of Medicine,
National Taiwan University, No.1, Section 1, Jen-ai Road, Taipei, Taiwan,
10018
Note: [] Institute of Biochemistry, College of Medicine, National Taiwan
University, No.1, Section 1, Jen-ai Road, Taipei, Taiwan. Fax: +886 2 2391
8944; E-mail: jklin@ha.mc.ntu.edu.tw
Abstract: Curcumin is a major component of Curcuma species, which is commonly
used as a yellow coloring and flavoring agent in foods. Curcumin has shown
anti-carcinogenic activity in animals as indicated by its ability to block
colon tumor initiation by azoxymethane and skin tumor promotion induced by
phorbol ester TPA. Curcumin possesses anti-inflammatory activity and is a
potent inhibitor of reactive oxygen-generating enzymes such as
lipoxygenase/cyclooxygenase, xanthine dehydrogenase/oxidase and inducible
nitric oxide synthase. Curcumin is also a potent inhibitor of protein kinase C,
EGF-receptor tyrosine kinase and I\kappaB kinase.
Subsequently, curcumin inhibits the activation of NF\kappaB
and the expressions of c-jun, c-fos, c-myc and iNOS. It is proposed that
curcumin may suppress tumor promotion through blocking signal transduction
pathways in the target cells. Curcumin was first biotransformed to
dihydrocurcumin and tetrahydrocurcumin and that these compounds subsequently
were converted to monoglucuronide conjugates. These results suggest that
curcumin-glucuronide, dihydro-curcumin-glucuronide,
tetrahydrocurcumin-glucuronide and tetrahydrocurcumin are major metabolites of
curcumin in mice.
