Some Semen Characteristics and Oxidant/Antioxidant Markers of Chilled Diluted Rabbit Semen in Tris-Based Extender Supplemented with Wheat Germ Extracts

Abstract

HEAT germ(WG) was a rich source in antioxidants, and had antimicrobial effects also it proved to have anticold-shock effect in preservation of diluted semen. This study aimed to clarify how various types of wheat germ extracts (including oil, hydroethanolic, and water extracts) in combination with egg yolk contribute to the preservation of buck semen when subjected to the cooling procedure. WG was extracted with petroleum ether (for oil extract), hydroethanol extract and water extract. Chemical analysis of WG extracts was performed by Gas Chromatography to detect saturated and unsaturated fatty acids. Additionally, the antioxidant capacity and metal chelation and reducing power of the hydroethanolic extracts were determined. A pilot experiment was designed to choose the optimum best concentration among 5 concentrations (100-500 µg/ml increament). The concentrations of 200, 300 and 400 µg/ml tris-base were chosen for the study. Diluted semen samples were cooled at 4°C for 48 hours. Sperm motility, viability, abnormality, membrane and acrosome integrity were evaluated in chilled semen during the chilling period. The Malondialdehyde (MDA, nmol/ml) and Catalase (CAT, U/L), in diluted semen, were assessed after 48 hours of chilling. The best extract that conserved a high motile viable sperm with low lipid peroxidation and oxidative stress was the WG oil extract at a concentration of 200 and 300 µg/ml, with egg yolk addition. The WG oil extract was the best in most characteristics specially live sperm (86.33%), acrosome integrity (65.55%), hyperosmotic swelling test (HOST, 56.00%) and CAT (413.12 U/L), while, decrease in abnormal sperm (19.78%) and MDA (35.45 nmol/ml). In conclusion, the use of wheat germ oil extract (200 to 300 µg/ml with less than 5% egg yolk) is suitable for preserving diluted rabbit buck semen for a period of 48 hours during the cooling process.

Effect of black cumin (Nigella sativa) seeds extract in tris egg yolk citrate extender on sperm motility of cryopreserved Surti buck semen

“…The findings of present study showed that 4% Black cumin (Nigella sativa) seeds aqueous extract supplementation in tris egg yolk citrate extender could prolong the individual sperm motility (%) at pre-freeze (69.38±1.64) and post-thaw (46.56±1.35) stage. In accordance to this finding Awan et al (2018) [8] in buffalo; Miah et al (2018) [14] in ovine; Nasiri et al (2022) [12] in human; El-Battawy and Riad (2011) [15] in rabbit; Inanc et al (2021) [16] in ram; Al-Saaidi et al (2009) [17] , Mohammad et al (2009) [18] and Mansour et al (2013) [9] in rats, El-Nattat et al (2019) [19] in rabbit also reported higher sperm motility in lower concentration of Nigella sativa supplemented groups as compared to control group. The highest pre-freeze and post-thaw motility (%) found in T3 (4% Nigella sativa aqueous extract) group followed by T2 (3% Nigella sativa aqueous extract) group in present study, which was compliance with Awan et al (2018) [8] , who also found significantly (p<0.05) higher sperm motility in postcooling and post-thaw semen in 4% Nigella sativa extract group as compared to control group followed by 3% Nigella sativa extract supplemented group in buffalo semen.…”

“…They concluded that higher motility was due to positive effect of thymoquinone on aerobic respiration with oxidative phosphorylation enzyme and eliminating free radicals contributing higher motility. El-Battawy and Riad (2011) [15] found that at 200 µl/ml of Nigella sativa supplemented in tris-based extender could preserve sperm motility (%) significantly (p<0.05) higher as compared to control group at 2 nd day of incubation (5°C). They concluded that this positive effect on motility was due to antioxidant property and rich source of calcium, sodium potassium, iron that are essential for co-enzyme that protects sperm form cryo-damage.…”