Inhibitory effect of Calamintha nepeta subsp glandulosa essential oil on lipoxygenase

Abstract

Objective: Scavenging of free radicals and inhibition of lipoxygenase are important target in the treatment of a variety of inflammatory diseases. Calamintha nepeta (L.) Savi subsp. glandulosa (Req.) P.W. Ball of Lamiaceae was previously reported in the treatment of several diseases in folk medicine. In this study, the essential oil of C. nepeta subsp. glandulosa was investigated for its radical scavenging activity and inhibitory effect on lipoxygenase. Material and Method: The essential oil of Calamintha nepeta (L.) Savi subsp. glandulosa (Req.) P.W. Ball was obtained by hydrodistillation and analyzed by gas chromatography mass spectrometry. Essential oil and its major component of biological activity was determined using an UV-spectrophotometric assay. Results: Oxygenated monoterpenes pulegone (54%) and menthone (16%) were found to be the major constituents of the oil. C. nepeta essential oil demonstrated inhibition on lipoxygenase at IC50 = 69.6 +/- 9.1 mu g/mL, whereas its main component pulegone showed no effect at the same tested concentration. Neither the essential oil nor pulegone displayed radical scavenging activity (> 0.5 mg/mL). Major component pulegone of C. nepeta essential oil showed no inhibitory effect on lipoxygenase activity, but other components besides of their low concentration demonstrated an inhibitory effect on lipoxygenase activity in 1/29 ratio when compared to the standard substance. Conclusion: Data of our study indicated that essential oil of C. nepeta may contain potent lipoxygenase inhibitor substances. Further, investigation of other components except the major constituent pulegone on lipoxygenase activity may result in the identification of effective lipoxygenase inhibitors.