Camellia japonica oil suppressed asthma occurrence via GATA-3 & IL-4 pathway and its effective and major component is oleic acid

Background: In December 2016, WHO released a report stating that in 2015 there were 383,000 deaths caused by asthma and 235 million people suffering from asthma. As there are many adverse effects associated with the currently-used asthma drugs, new anti-asthmatic drugs need to be developed. Purpose: In order to find new drug candidates with safe and low side effects, the anti-asthmatic function and mechanism of C. japonica oil were evaluated, and its active ingredients were analyzed for use in an ovalbumin asthma murine model. Study design and methods: The study consisted of six groups: control; ovalbumin group; and dexamethasone group as a positive control; and 10, 100, and 500 mg/kg C. japonica oil treatment groups. In order to measure the anti-asthmatic effect of C. japonica oil, WBC and differential cell count in BALF, IgE in serum, morphological changes in pulmonary system, and gene and protein levels such as IFN-gamma, IL-12p40, IL-4, IL-5, IL-6, TNF-alpha, and IL-6 were all evaluated. Results: C. japonica oil had an anti-asthmatic effect and significantly controlled eosinophil in BALF, Th2-related factors such as GATA-3 that is Th2 cell transcription factor, IL-4, IL-5, and IL-13, and TNF-alpha in the lung. It also dose-dependently modulated inflammatory cells, T-bet, IL-12p40, and IL-6. Oleci acid was the major gradient (52.89%) in C. japonica oil and also had anti-asthmatic effects such as the downregulation of inflammatory cells, WBC, and eosinophil in BALF, IgE in serum, and morphological changes in the lung. Conclusion: We concluded that C. japonica oil is a new anti-asthmatic drug candidate and that oleic acid is the major anti-asthmatic ingredient in C. japonica oil.