Objective: The effects of essential oils on the formation of superoxide radicals during UVA (365 nm) irradiation were investigated.
Methods: ESR (electron spin resonance) spin-trapping experiments were performed on a reaction mixture containing 15 μM riboflavin, 0.10 M DMPO (5,5-dimethyl-l-pyrroline-N-oxide), 23 mM phosphate buffer (pH 7.4) and 6.3% (v/v) DMSO (dimethyl sulfoxide) (standard reaction mixture) during UVA (365 nm) irradiation.
Results: On addition of various concentrations of tea tree oil (or lavender super oil or grapefruit oil or peppermint oil or wintergreen oil) to the standard reaction mixture, the ESR peak height decreased dose-dependently.
Conclusion: This result shows that antioxidant activities increase as follows: lavender super oil