Studies on curcumin, the principal element of turmeric powder, have demonstrated several biological
actions such as antibacterial activity. Evaluation of new analogs or new compounds of curcumin for their
antibacterial effect is interesting for researchers. In this in vitro study, we attempted to test the
antibacterial activity of indium curcumin (In(CUR)3), indium diacetylcurcumin (In(DAC)3), and
diacetylcurcumin (DAC) in comparison with curcumin. The action of these agents were examined on
Staphylococcus aureus (ATCC 25923), Staphylococcus epidermidis (ATCC 14990), Pseudomonas
aeruginosa (ATCC 27853), and Escerichia coli (ATCC 25922). Curcumin was effective against S. aureus
and S. epidermidis, whereas In(DAC)3 showed activity against S. epidermidis and P. aeruginosa. The
effect of In(DAC)3 on P. aeruginosa is an advantage. Strikingly, In(CUR)3 exhibited antibacterial activity
on all the four mentioned strains. DAC did not show antibacterial effect on any of the four test bacteria.
The minimum inhibitory concentration (MIC) of curcumin was 187.5 μg/ml for S. aureus, and 46.9 μg/ml
for S. epidermidis. However, the MIC of In(CUR)3 was lower for the same bacterial strains (93.8 μg/ml for
S.aureus and 23.4 μg/ml for S. epidermidis). Therefore, In(CUR)3 was found to have more antibacterial
effect than curcumin itself and could be a suitable candidate for further in vivo investigations