Spermostatic activity of Eugenia brejoensis and Myroxylon peruiferum essential oils toward human spermatozoa

In this study, the in vitro spermostatic action, hemolytic action in combination of parabens of two essential oils (EOs) from Eugenia brejoensis Mazin (Myrtaceae, EbEO) and Myroxylon peruiferum L. (Fabaceae, MpEO) is reported, in addition to the first chemical characterization of MpEO. The EOs were obtained by hydrodistillation and characterized by gas chromatography-mass spectrometry (GC-MS). Different concentrations of both EOs (25 to 400 µg/mL) were mixed with human ejaculate and sperm motility was assessed after 5, 15 and 30 min. A total of 44 compounds were identified in MpEO; the major components were spathulenol, α-pinene, caryophyllene oxide, limonene and β-elemene. Both EOs exhibited spermostatic action in a dose-dependent manner. The best results were obtained for EbEO at all treatment times, showing IC50 values of 454.75 µg/mL (5 min), 417.68 µg/mL (15 min) and 403.93 µg/mL (30 min). M. peruiferum also showed significant immobilizing potential with IC50 values of 620.39 µg/mL (5 min), 652.70 µg/mL (15 min) and 579.37 µg/mL (30 min). Both oils showed low cytotoxicity against human erythrocytes. This is the first report on human spermostatic action for EOs from E. brejoensis and M. peruiferum which has antimicrobial activity and low cytotoxicity. These results suggest the need for further research on toxicological aspects of both EOs and their components in order to develop new pharmaceutical preparations using them as leader compounds. Key words: Eugenia brejoensis and Myroxylon peruiferum essential oils, spermostatic activity, human spermatozoa.