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concentration and time-dependent way (5). The action of Curcumin observed in
our current study is in agreement to results published by Guo and coworkers (24)
who treated human colorectal carcinoma cells with 0–30 µg/mL curcumin and
observed significant concentration-dependent inhibition of cell viability and
growth, as well as induction of apoptosis. It is worth mentioning that low doses of
curcumin (0.02 µM for 24 h) exert different actions than high doses, which can
have cytotoxic effects on 3T3-L1 cells (22).
Figure 4.- Western blot analysis showed that curcumin (40 mM) treated 3T3L1 cells at the
indicated time induced AMPK phosphorylation (p-AMPK) and inhibited phosphorylated
CREB (p-CREB) and also phosphorylated AKt (p-Akt) to a lesser extent . Adiponectin
expression increased with time increasing in compartion with control. The expression
of AMPK and CREB were still detected and didn’t differ post curcumin (40µM) treatment in
indicated time, β – actin used as control for protein loading
Furthermore, flow cytometry analysis of cells treated with curcumin
revealed an accumulation of apoptotic cells and suggested a clear and gradual
increase in cell death compared with control (Figure 3). The results were in
agreement with those published by Kim et al (38); We hypothesize that this delay
in cell growth may be attributable to re-regulation of the expression of some
essential proteins required in cell cycle (39) and to the modulation in apoptotic
factors (24). Curcumin has shown apoptotic effects in many cell lines in a
concentration- and time-dependent manner (6).
