Antioxidant effects of the essential oil of Syzygium aromaticum on bovine epididymal spermatozoa

Focusing on its application in reproductive biotechnology, we evaluated the effects of the essential oil of Syzygium aromaticum (EOSA) on bovine epididymal sperm quality variables, including morphology, membrane functional integrity, membrane structural integrity, mitochondrial activity, metabolic activity, motility and oxidative stress by reactive oxygen species (ROS) levels. Bovine spermatozoa from eight males were incubated into the following groups: EOSA0 (without EOSA), EOSA10 (10 mug/ml of EOSA), EOSA15 (15 mug/ml of EOSA) and EOSA20 (20 mug/ml of EOSA); the incubation time with and without the EOSA was 1 or 6 hr. None of the sperm quality variables presented difference among the EOSA concentrations. However, the incubation time had a significant effect on the membrane functional integrity, membrane structural integrity, mitochondrial activity, progressive motility and some kinetic parameters. The effect of interaction among EOSA and incubation time was significant only on ROS levels. Spermatozoa incubated in the presence of 15 mug/ml of the EOSA for 1 hr had significantly reduced ROS levels compared with all other groups in the same time. In conclusion, the EOSA at a concentration of 15 microg/ml has antioxidant effects and protects bovine epididymal spermatozoa; hence, the EOSA may potentially be used in the field of reproductive biotechnology.