To reduce oxidative stress caused by obesity and diabetes,
dietary supplementation of antioxidants has been
proposed. Different studies have shown that curcumin has
antioxidant and anti-hyperglycaemic properties in diabetic
and obese animal models [10-13]. It was reported that theactivity of erythrocyte antioxidant enzymes superoxide
dismutase and catalase were significantly higher (2- and
1.5-fold, respectively), and glutathione peroxidase activity
was significantly lower (0.7 fold) in diabetic db/db mice
than in nondiabetic db/+ mice. In the db/db mice, these
enzyme activities were restored to basal values after curcumin
treatment. Curcumin also significantly decreased
MDA levels from 479.7 to 393.3 nmol/g haemoglobin in
erythrocytes of these mice [12]. Furthermore, in PC12
cells that were exposed to 4-hydroxynonenal, curcumin
treatment prevented changes in glutathione levels as well
as mitochondrial oxidative damage and respiration and
decreased the accumulation of carbonylated proteins and
apoptosis [14].We recently showed that curcumin treatment increased
oxygen consumption and significantly decreased lipid and
protein oxidation levels in liver mitochondria isolated
from HFD-induced obese mice compared with those in
the untreated obese mice [15]. In kidney mitochondria,
curcumin treatment significantly increased oxygen consumption
and decreased lipid and protein peroxidation
levels in HFD-induced obese mice when compared with
those in untreated obese mice. Curcumin treatment neither
had any effect on body weight gain or on mitochondrial
NO synthesis.
Therefore, we testing hypotheses of that dietary supplementation
with curcumin improve indices of lipid
oxidation, oxygen consumption rate, nitric oxide (NO)
synthesis and ATPase activity in the liver and kidneys of
diabetic db/db mice.