RESUMO
The addition of antioxidants in boar semen is an alternative to mitigate the reduction of sperm quality during preservation. To evaluate the effect of carvacrol on cooling of boar semen. Fifteen ejaculates from five boars were extended in MR-A® with 0, 5, 10, 15, 15, 20, 25 and 30 µM of carvacrol (C) and were cooled for 5 days at 16°C. Sperm motility and kinetics were evaluated with computer-assisted semen analysis (CASA). At 0 and 96 h, membrane functionality was determined by hypoosmotic test; reactive oxygen species (ROS) production and total antioxidant capacity (TAC) by spectrofluorimetry and mitochondrial membrane potential (Δ¥M) by flow cytometry. Linear models, regression analysis and comparison of means by Duncan test, were conducted. The addition of carvacrol did not influence sperm motility, but at low concentrations decreased ROS production, whereas 30 µM C reduced the membrane functionality and 25 µM C decreased Δ¥M. In addition, regression coefficients showed that C produced a lower rate of decrease in different parameters of sperm motility and kinetics. During cooling there is a reduction in sperm quality due to the excessive production of ROS, generating oxidative stress and affecting cell permeability and functionality. In this study, it was possible to demonstrate the protective activity of C as a molecule capable of neutralizing free radicals. In addition, it has been proposed that C is also capable of reducing peroxyl radicals, superoxide radicals, hydrogen peroxide and nitric oxide. Carvacrol can mitigate the reduction of boar semen quality during the storage period under cooling conditions. Likewise, it can reduce ROS production and modulate the mitochondrial activity of porcine sperm.
Assuntos
Preservação do Sêmen , Sêmen , Suínos , Masculino , Animais , Análise do Sêmen/veterinária , Espécies Reativas de Oxigênio , Motilidade dos Espermatozoides , Espermatozoides , Antioxidantes , Preservação do Sêmen/veterinária , Criopreservação/veterináriaRESUMO
Spermatozoa experience oxidative, osmotic, chemical, and thermal stresses when cooled, which degrade the quality and fertilizing capacity of the cells. Adding antioxidants to the sperm extender mitigates these alterations. This study evaluated the effect of isoespintanol (ISO) on boar semen subjected to cooling. Fifteen ejaculates from five boars (Susscrofadomestica) were extended in Beltsville thawing solution (BTS) supplemented with 0 µM (control), 5 µM (ISO5), 10 µM (ISO10), 15 µM (ISO15), 20 µM (ISO20), 25 µM (ISO25), and 30 µM (ISO30) of ISO, which were then cooled for five days at 16 °C. Sperm kinetics, total motility (TM), and progressive motility (PM) were evaluated every 24 h using an IVOS computer-assisted sperm analysis (CASA) system. On day 1 and day 5 of cooling, a hypoosmotic test, spectrofluorometry, and flow cytometry were performed to evaluate the following: membrane functionality, measured as a function of hypoosmotic swelling (HOS); total antioxidant capacity (TAC); reactive oxygen species (ROS); and mitochondrial membrane potential (Δ¥M). Regression analysis and comparison of means using the Duncan test were performed. The ISO added had a slight impact on sperm motility, as evidenced by a reduction in TM at 24 h of cooling (but not prior) with the addition of 20 µM of ISO. Similarly, no effect of the ISO on the kinetics and functional integrity of the sperm membrane was observed at 96 h of cooling; however, the regression coefficients indicated that the ISO lowered the rate of decrease in sperm motility and the proportion of rapid spermatozoa relative to the concentration of ISO used. The ISO did not affect the TAC of the cooled semen; however, different concentrations of ISO lowered ROS production in the semen after 96 h of cooling. ISO also impacted the Δ¥M of the spermatozoa at 0 h of cooling, increasing the proportion of low Δ¥M cells and decreasing the proportion of high Δ¥M cells. In conclusion, ISO can reduce the loss of quality and oxidative stress occurring in boar semen during cooling and can modulate the mitochondrial activity of sperm.
Durante a refrigeração, os espermatozoides sofrem estresse oxidativo, osmótico, químico e térmico, que diminuem sua qualidade e afetam sua capacidade de fertilização. A adição de antioxidantes ao diluente espermático é uma alternativa para mitigar essas alterações. O objetivo desta pesquisa foi avaliar o efeito do isospintanol (ISO) na refrigeração do sêmen suíno. Quinze ejaculados de cinco varrascos (Sus scrofa domestica) foram diluídos em BTS suplementado com ISO a 0 (controle), 5 (ISO5), 10 (ISO10), 15 (ISO15), 20 (ISO20), 25 (ISO25) e 30 (ISO30) µM e foram refrigerados por cinco dias a 16 °C. A motilidade total (MT), motilidade progressiva (MP) e cinética dos espermatozóides foram avaliadas a cada 24 h com um sistema CASA IVOS. Nos dias um e cinco de refrigeração, foram avaliadas a funcionalidade da membrana, a capacidade antioxidante total (CAT), as espécies reativas de oxigênio (ROS) e o potencial de membrana mitocondrial (Δ¥M), através do teste hiposmótico (HOS), espectrofluorimetría e citometria de fluxo. Foram realizadas análises de regressão e comparação de médias, pelo teste de Duncan. A adição de ISO teve pouca influência na motilidade espermática, apresentando apenas redução na MT em 24 h de refrigeração, devido à adição de 20 µM. Da mesma forma, não foi observada influência de ISO na cinética e integridade funcional da membrana em 96 horas de refrigeração; porém, os coeficientes de regressão mostraram que ISO produziu menor taxa de diminuição da motilidade e proporção de espermatozoides rápidos dependendo da concentração utilizada. ISO não influenciou significativamente na CAT do sêmen refrigerado; entretanto, diferentes concentrações de ISO reduziram a produção de EROs a partir do sêmen após de 96 h de refrigeração. ISO também influenciou o Δ¥M dos espermatozóides em 0 h de refrigeração, com aumento das células de baixo Δ¥M e diminuição das células de alto Δ¥M. Em conclusão, o isospintanol pode reduzir a perda da qualidade e o estresse oxidativo do sêmen suíno durante a refrigeração e pode modular a atividade mitocondrial do esperma.