Antibacterial effects of curcumin: An in vitro minimum inhibitory concentration study

Aim: To evaluate the antibacterial effect of curcumin with the minimum inhibitory concentration (MIC) method in standard bacterial strains. Methods: The in vitro antibacterial activity of curcumin was evaluated against methicillin-sensitive Staphylococcus aureus (MSSA) (ATCC 29213), methicillin-resistant Staphylococcus aureus (MRSA) (ATCC 43300), Enterococcus faecalis (ATCC 29212), Bacillus subtilis (ATCC 6633), Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922) and Klebsiella pneumoniae (ATCC 700603) using the macrodilution broth susceptibility test method. After incubation in tubes, the antibacterial activity of curcumin was detected by a lack of turbidity, which indicated the inhibition of bacterial growth. The concentration in the tube with the highest dilution showing no turbidity was defined as the MIC. Results: The curcumin MIC values were 175 mg/ml, 129 mg/ml, 219 mg/ml, 217 mg/ml, 163 mg/ml, 293 mg/ml and 216 mg/ml against P. aeruginosa, B. subtilis, MSSA, MRSA, E. coli, E. faecalis and K. Pneumonia, respectively. Conclusion: This study revealed antibacterial effects of curcumin against standard bacterial strains in high concentrations. Animal experiments have demonstrated that curcumin applied at high doses has strong antibacterial activity. There is a need for further in vivo studies to shed light on antibacterial effects of curcumin with high concentrations.