Antibacterial Activity of Synthetic Curcumin Derivatives: 3,5-Bis(benzylidene)-4-Piperidone (EF24) and EF24-Dimer Linked via Diethylenetriaminepentacetic Acid (EF2DTPA)

Curcumin is well known for its antimicrobial and anti-inflammatory properties. However, since systemic absorption and bioavailability of curcumin from gastrointestinal tract is considerably poor, synthetic curcuminoids are being developed as better alternatives. Two curcumin derivatives: 3,5-bis(benzylidene)-4-piperidone (EF24) and EF24-dimer linked via diethylenetriaminepentacetic acid (EF₂DTPA), were included in this study. We investigated the antibacterial activity of EF24 and EF₂DTPA against Gram-negative (Escherichia coli) and Gram-positive (Enterococcus faecalis, Staphylococcus aureus) bacteria. We also studied the effects of EF24 and EF₂DTPA on uptake and localization of pHrodo-labeled E. coli in the acidic compartments (phagolysosomes) of dendritic cells (DCs) under in vitro conditions. Our results demonstrate that treatment with EF24 and EF₂DTPA directly suppresses the bacterial growth. However, these compounds do not affect the bacterial uptake or localization in the DCs.