低温保存中のルテオリン添加による羊精液質の改善

The present experiment aimed to investigate the probable protective role of luteolin (Lut) in ram spermatozoa kinematics and the oxidative/anti-oxidative/nitrosative status of semen during cold storage. Ejaculates were collected from five Qezel rams twice a week. Ejaculates were pooled, diluted with Tris-egg yolk extender (negative control) or supplemented with 0 (control; received the solvent of luteolin), 4, 8 and 16  $\mu$ m Lut. Kinematics parameters, viability and membrane functionality of spermatozoa were assessed. Furthermore, amounts of malondialdehyde (MDA) and anti-oxidant activity (AOA), superoxide dismutase activity (SOD) and total nitrate nitrite (TNN) were evaluated in the medium (diluent) and spermatozoa, separately, at 0, 24, 48 and 72 h after storage at 4 °C. Percentages of forward progressive motility and membrane integrity were significantly higher in 8 and 16  $\mu$ m groups compared to control groups at 72 h ( $P<0.05$ ). No significant differences were observed in viability among groups during the study ( $P>0.05$ ). Lower MDA contents were observed in medium and spermatozoa of 8 and 16  $\mu$ m treated groups compared to controls at 72 h ( $P<0.05$ ). In addition, higher AOA levels were observed in the medium of Lut-treated groups compared to controls at 48 and 72 h ( $P<0.05$ ). The activity of SOD was improved by luteolin addition. Luteolin enrichment did not affect TNN amounts. It seems that luteolin (at 8 and 16  $\mu$ m) as a flavonoid protects the ram semen by its anti-oxidative properties and by reduction of lipid peroxidation following 48 and 72 h storage.