SYNERGISTIC BACTERIOSTATIC EFFECT OF TERPINEN-4-OL AND α-BISABOLOL ON STAPHYLOCOCCUS AUREUS AND CUTIBACTERIUM ACNES

Abstract

Objective To investigate the synergistic bacteriostatic effect of terpinen-4-ol (T4O) and α-bisabolol (Bis) on Staphylococcus aureus (S.aureus) and Cutibacterium acnes (C.acnes). Methods The microdilution checkerboard technique was used to determine the minimum inhibitory concentration (MIC) of T4O combined with Bis on the two etu perimental bacteria, and fractional inhibitory concentration index (FICI) was calculated. An MIC group (T4O and Bis at a concentration of MIC), a 2×MIC group (T4O and Bis at a concentration of 2×MIC), and a negative control group (no T4O or Bis added) were set up for each experimental bacterium; the time-bactericidal curve was plotted for each experimental bacterium after the addition of both T4O and Bis; each group of the two experimental bacteria was measured in terms of Zeta potential (ZP) on the surface of the strain, leakage of intracellular nucleic acid and protein, damage of bacterial biofilm, and respiratory chain dehydrogenase activity in S.aureus after the addition of both T4O and Bis; a transmission electron microscope was used to observe the influence of T4O combined with Bis on the morphology of the two experimental bacteria. Results The combination of T4O and Bis for S.aureus and C.acnes had an FICI of <0.5, and T4O had an MIC of 0.31 g/L for C.acnes and 0.62 g/L for S.aureus. The time-bactericidal curve showed that the combination of T4O and Bis significantly inhibited the growth of both bacteria. Compared with the negative control group, the combination group had a significant reduction in ZP, a significant increase in the leakage of intracellular nucleic acid and protein, loss of the normal morphology of bacterial body, damage of bacterial biofilm, and a reduction in respiratory chain dehydrogenase activity in S.aureus. Conclusion T4O and Bis have a synergistic bacteriostatic effect on S.aureus and C.acnes, and the combination of T4O and Bis may become an effective component of antibacterial products.

Keywords

• terpinen-4-ol|α-bisabolol|staphylococcus aureus| propionibacterium acnes|acne vulgaris|anti-bacterial agents|drug synergism