Inhibition of gram negative bacterial growth and biofilm formation by alpha thujone

Abstract

The increasing resistance of microorganism to antibiotics in the last decades, drove microbiologists, botanists, and natural-products chemists to search for phytochemicals that could be used for treatment of infectious diseases. Essential oils, which are derived from plants, such as thujone, have been recognized to display many biological activities many of which needed more exploration. This study was designed to test the ability of alpha thujone to inhibit the growth and biofilm formation of clinical bacterial isolates. The agar dilution method used to detect the antibacterial effect of alpha thujone, revealed that at high concentrations (30 mg/ml and 15 mg/ml) alpha thujone showed some antibacterial activity on some of the Gram-negative isolates tested. It was evident, however, and after using standard tests for detection of the inhibition of biofilm formation, that alpha thujone, at low concentrations (3.8 mg/ml) demonstrated an inhibitory effect on the biofilm formation of most of the different bacterial strains tested. This previously uncovered characteristic of alpha thujone, may prove to be very useful in preventing infections by primary pathogens.