Curcumin Attenuates Hydrogen Peroxide Induced Oxidative Stress on Semen Characteristics during In Vitro Storage of Boar Semen

Curcumin is a major active component of the food flovour tumeric. It has been used for the treatment of many diseases such as inflammatory and infectious diseases, cancer and other disease due to its antioxidant properties. Curcumin is a powerful scavenger of many free radicals such as superoxide anion, hydroxyl radical and nitric oxide. The objective of this study was to investigate the antioxidative effects of curcumin against hydrogen peroxide on semen quality during in vitro storage of boar semen. The sperm treated with different concentration of curcumin (1, 5 and 10 μM) in the presence or absence of hydrogen peroxide (250 μM H₂O₂) were incubated for 3, 6 and 9 hr at 37℃ and analyzed sperm characteristics such as motility, membrane integrity (MI), lipid peroxidation (LPO), reactive oxygen species (ROS) and DNA fragmentation (DF). The sperm motility and MI in H₂O₂ treated group (47.8%±6.8 and 24.8%±2.2) were significantly decreased when compare to curcumin treated group (79.8%±2.7 and 34.6%±1.0, respectively) irrespective of incubation periods(p less than 0.05). The LPO of spermatozoal plasm membrane was measured by thiobarbituric acid (TBA) reactions for malondialdehyde (MDA), MDA level in control (11.6±0.6 nmol/L×10∨6) and curcumin groups (10.7±0.3 nmol/L×10∨6) were lower than those of curcumin plus H₂O₂ (17.1±0.8 nmol/L×10∨6) or H₂O₂ group (22.5±1.9 nmol/L×10∨6) from 3 to 9 hr incubation periods. The DF by sperm chromatin dispersion (SCD) test and ROS production measured by 2',7'-dichlorofluorescein (DCF) fluorescence intensity were no significantly difference through all experimental groups (p greater than 0.05). Correlation among evaluation methods for sperm quality, motility vs MI and DF vs ROS was positively correlated while motility vs DF and ROS vs LPO were negatively correlated in all treatment groups. These results demonstrate that curcumin can effectively improve the sperm quality during in vitro storage of boar semen through its hydrogen peroxide scavenging mechanism as an antioxidant.