P-237 - The effects of tea tree oil on ROS production and mechanisms in human neutrophils

Abstract

Purpose Many studies have shown that it is very important to keep oral cavity health to prevent lifestyle diseases. Neutrophils (PMN) that sterilize bacteria by producing reactive oxygen species (ROS) and HOCl, play an important role in keeping the oral cavity health. Tea Tree Oil (TTO), one of the essential oils, has been reported to improve immune function. In this study, we investigated the effect of TTO on ROS productive capacity of PMN. Method PMN was separated from heparinized blood by dextran sedimentation and density centrifugation. When oral PMN (OPMN) in its priming state, stimulants-related ROS production is low. To mimic the situation of OPMN, PMN was incubated at 37 °C for 1 hour to ensure low level of ROS production. TTO (0.01%) was added 60 s after the addition of each ROS inhibitor and chemiluminescent L-012. ROS production was measured by L-012 dependent chemiluminescence for a total 300 s time. Result and Discussion Compare to normal state of PMN, the incubated PMN reduced ROS production with time, and PMN with TTO increased ROS production. TTO mainly increased production of both superoxide from mitochondria and MPO-derived HOCl. These results suggest TTO may enhance sterilization by increasing the ROS productive ability from PMN in the oral cavity.