Antibacterial Activity of Ethanolic Extract of Cinnamon Bark, Honey, and Their Combination Effects against Acne-Causing Bacteria

Abstract

<i>Propionibacterium acnes</i> and <i>Staphylococcus epidermidis</i> are the major skin bacteria that cause the formation of acne. The present study was conducted to investigate antibacterial activity of ethanolic extract of cinnamon bark, honey, and their combination against acne bacteria. The antibacterial activity of extract of cinnamon bark and honey were investigated against <i>P. acnes</i> and <i>S. epidermidis</i> using disc diffusion. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were attained using Clinical and Laboratory Standard Institute (CLSI) methods. The interaction between cinnamon bark extract and honey was determined using a checkerboards method. The results showed that the MICs of cinnamon bark extract and honey against <i>P. acne</i> were 256 µg/mL and 50% <i>v</i>/<i>v</i>, respectively, while those against <i>S. epidermidis</i> were 1024 µg/mL and 50% <i>v</i>/<i>v</i>, respectively. The MBC of cinnamon bark extract against <i>P. acnes</i> and <i>S. epidermidis</i> were more than 2048 µg/mL, whereas the MBC for honey against <i>P. acnes</i> and <i>S. epidermidis</i> were 100%. The combination of cinnamon bark extract and honey against <i>P. acnes</i> and <i>S. epidermidis</i> showed additive activity with a fractional inhibitory concentration index (FICI) value of 0.625. Therefore, the combination of cinnamon bark extract and honey has potential activity against acne-causing bacteria.