Abstract:
This study examined the biological activities including antioxidant activity, tyrosinase inhibitory activity, collagenase inhibitory activity, elastase inhibitory activity, antibacterial activity, and cytotoxicity activity of cinnamon essential oil from Cinnamomum zeylanicum. The antioxidant activity was determined using DPPH and ABTS assays. The results showed that cinnamon essential oil could inhibit free radicals in DPPH and ABTS assays with percent inhibition ranging from 4.91 - 28.74 % and 4.96 - 50.17 %, respectively. In addition, cinnamon essential oil inhibited the tyrosinase activity, collagenase activity, and elastase activity with percent inhibition ranging from 61.68 - 93.12 %, 2.83 - 30.28 %, and 4.37 - 33.92 %, respectively. The antibacterial activity of the essential oil against Methicilin Resistant Staphylococcus aureus (MRSA), Methicillin sensitive Staphylococcus aureus (MSSA), Staphylococcus epidermidis, and Pseudomonas aeruginosa was investigated using the agar diffusion method. The results showed that the undiluted cinnamon essential oil exhibited antibacterial activity against all test bacteria. The results from MIC and MBC determination showed that cinnamon essential oil at concentration of 31.125 ug/mL could inhibit gram-positive bacteria including Methicilin Resistant Staphylococcus aureus (MRSA), Methicillin sensitive Staphylococcus aureus (MSSA), and Staphylococcus epidermidis. Furthermore, cinnamon essential oil with a concentration of 125 ug/mL could inhibit gram-negative bacteria Pseudomonas aeruginosa while essential oil with a concentration of 500 ug/mL could kill all tested bacteria. The diphenyltetrazolium (MTT) assay was used to determine cell viability. The result from cell viability assay in human fibroblast cells showed that cinnamon essential oil with a concentration less than 100 ug/mL did not exhibit cytotoxicity on this cell. However, it was found that the percentage of cell viability decreased to a concentration of more than 150 ug/mL. The results demonstrate that cinnamon essential oil had antioxidant activity, tyrosinase inhibitory activity, collagenase inhibitory activity, elastase inbibitory activity, and antibacterial activity. In addition, cinnamon essential oil with different effective concentrations did not show toxicity activity to the normal human fibroblast cell. Therefore, cinnamon essential oil with such biological properties found in this research could be a potential candidate for cosmetic and pharmaceutical industries