# Improvement of ram semen quality by luteolin enrichment during cold preservation

## TL;DR

Adding luteolin to ram semen during cold storage improves sperm quality by reducing oxidative stress and preserving motility.

## Contribution

Luteolin at 8 and 16 µm improves ram semen quality during cold storage by reducing lipid peroxidation and enhancing antioxidant activity.

## Key findings

- Luteolin at 8 and 16 µm increased forward progressive motility and membrane integrity in ram sperm after 72 h storage.
- Luteolin reduced malondialdehyde levels in both the medium and spermatozoa, indicating reduced lipid peroxidation.
- Luteolin increased antioxidant activity in the medium at 48 and 72 h storage.

## Abstract

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 
µ
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 
µ
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 
µ
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 
µ
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.