Effect of clove oil (Eugenia Caryophyllus) on drone semen quality after cryopreservation

Clove oil, primarily extracted from the flower buds of the clove plant, is widely used in food, cosmetics, and traditional medicine due to its rich composition of phenolic acids and flavonoids, with eugenol being a major component. This essential oil exhibits numerous biological activities, including antibacterial, antifungal, and anti-inflammatory properties. In the context of drone semen cryopreservation, challenges such as ice crystal formation, and oxidative stress hinder fertility outcomes. To address these issues, the study explores the effects of commercial clove oil preparation on the post-cryopreservation quality of drone semen, its antioxidant and antibacterial qualities.

The collected semen samples were pooled and divided among semen extenders containing different concentrations of clove oil (C-10, C-20, C-25) and a control extender containing no clove oil. Motility, plasma membrane integrity, acrosomal integrity, and mitochondrial membrane potential were evaluated using microscopic and flow-cytometric methods. Malondialdehyde and glutathione concentrations and catalase activity were also assessed. In addition, the minimum inhibitory concentration and antimicrobial effect of clove oil were evaluated.

At the post-thaw stage, the highest motility was observed in the C-25 group; the C-20 group also showed a significant advantage compared with the control. The C-20 and C-25 groups provided a similar level of membrane integrity protection but better than the control. Acrosomal integrity protection was highest in C-25, and C-20 was also significantly higher than the Control group. The highest mitochondrial membrane potential values were observed in C-20 and C-25. Malondialdehyde concentration was highest in the Control group and lowest in the C-25 group; C-20 and C-25 remained similar to each other. Higher glutathione concentrations and catalase activity were observed in the C-25 group compared with the Control. Catalase activity in the C-20 group did not differ significantly from that in the C-10 or Control groups. The microbiological examination revealed no growth in any of the groups.

The findings indicate that supplementation with a commercial clove oil preparation at the tested doses may improve post-thaw drone semen quality.