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We have investigated the antioxidant properties of curcumin
(CC) in detail. The studies showed that CC is a potent scavenger for hydroxyl radical,
superoxide anion, singlet oxygen and DPPH, a stable free radical. From pulse
radiolysis,
the rate for scavenging hydroxyl radical was found to be 4.76 x 10 Ms which is
comparable to many potent antioxidants like vitamin-E. Lipid peroxidation
induced by radiation and iron or its chelates was strongly inhibited by CC.
Increase in the lipid peroxidation
during post-irradiation period was also inhibited by CC. Further, it also inhibited the
oxidation of human LDL. CC protected plasmid pBR322 DNA against single strand breaks induced by singlet
oxygen a reactive oxygen species with potential genotoxic and mutagenic properties. CC was
more active than beta-carotene, vitamin-E, lipoic acid etc. CC was found to protect
hemoglobin against
nitrite induced oxidation.
Further studies showed that the protection is due to its ability
to scavenge nitrogen dioxide, an important reactive intermediate. We have compared the antioxidant
properties of CC with other related compounds like desmethoxycurcumin,
bisdesmethoxycurcumin,
acetylcurcumin and feruloyl methane, a simpler analog of curcumin. SAR studies showed that
the phenolic, the methoxyl, the 1,3-diketone system and the enolisable styryl ketone make significant
contributions to the antioxidant properties of cc.
RECENT DEVELOPMENT IN THE USE OF CURCUMIN AS A POTENTIAL
DRUG
H.H.Tonnesen and J. Karlsen
Department of Pharmaceutics Institute of Pharmacy, University of Oslo
The rhizomes of the plant Curcuma longa L. have been used
for more than 2000 years in the treatment of rheumatic symptoms. The pharmacological
activity has been attributed to curcumin and the curcuminoids present in the plant
material. The chemistry, stability, photochemical properties and analysis of curcumin have
previously been investigated.
A broad spectrum of biological activity is ascribed to
curcumin. Screening of curcumin in various test systems have been carried out,
and effects on cell systems, enzymes, etc. are documented. Curcumin has recently been discussed as a
potential drug or drug model in the treatment of broad spectrum of disease, e.g. cancer,
HIV infections, thalassemia, and psoriasis. Curcumin seems to play an important role in red-ox and
radical reactions, and the various mechanism of action under investigation. The lecture will discuss the recent development in the
use of curcumin as a potential drug or drug model with emphasis on antioxidant effects.
The distance
from a naturally occurring compound with some postulated pharmacological effects to a modern drug
is long, and the possibilities for the use of curcumin as a drug compound will be valuated with
respect to pharmacological, toxicological and
chemical properties.
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