ABSTRACT
BACKGROUND: Lycopene (LYC) is a natural carotenoid with powerful reactive oxygen species (ROS) scavenging activities. The aim of this study was to investigate if lycopene has the ability to reverse ROS-mediated alterations to the motility, viability and intracellular antioxidant profile of bovine spermatozoa subjected to ferrous ascorbate (FeAA). Spermatozoa were washed out of fresh bovine semen, suspended in 2.9 % sodium citrate and subjected to LYC treatment (0.25, 0.5, 1 or 2 mmol/L) in the presence or absence of FeAA (150 µmol/L FeSO4 and 750 µmol/L ascorbic acid) during a 6 h in vitro culture. Spermatozoa motion characteristics were assessed using the SpermVision™ computer-aided sperm analysis (CASA) system. Cell viability was examined with the metabolic activity (MTT) assay, ROS generation was quantified via luminometry and the nitroblue-tetrazolium (NBT) test was applied to quantify the intracellular superoxide formation. Cell lysates were prepared at the end of the in vitro culture to investigate the intracellular activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) as well as the concentrations of glutathione (GSH) and malondialdehyde (MDA). RESULTS: FeAA treatment led to a reduced spermatozoa motility (P < 0.001), viability (P < 0.001) and a decline of the antioxidant capacity of spermatozoa (P < 0.001) but increased the ROS generation (P < 0.001), superoxide production (P < 0.001) and lipid peroxidation (P < 0.001). LYC administration resulted in a preservation of the spermatozoa motion parameters (P < 0.001), mitochondrial activity (P < 0.001) and antioxidant characteristics (P < 0.001 with respect to SOD; P < 0.01 in relation to CAT; P < 0.05 as for GPx and GSH) with a concentration range of 1 and 2 mmol/L LYC revealed to be the most effective. CONCLUSIONS: Our results suggest that LYC exhibits significant ROS-scavenging and antioxidant properties which may prevent spermatozoa alterations caused by oxidative stress, and preserve the functionality of male reproductive cells.
ABSTRACT
Over the past decades, there has been an emphasis on assessment of the use of natural compounds in the prevention or repair of oxidative injury to spermatozoa. Curcumin (CUR) is a natural phenol with powerful antioxidant properties. The aim of the present study was to examine if CUR could reverse reactive oxygen species (ROS)-mediated alterations to the motility, viability and intracellular antioxidant profile of bull spermatozoa subjected to a prooxidant (i.e., ferrous ascorbate - FeAA). Spermatozoa were washed from recently collected semen samples, suspended in 2.9% sodium citrate and subjected to CUR treatment (5, 10, 25 and 50µmol/L) in the presence or absence of FeAA (150µmol/L FeSO4 and 750µmol/L ascorbic acid) during a 6h in vitro culture. Spermatozoa motility characteristics were assessed using the SpermVision computer-aided spermatozoa analysis (CASA) system. Cell viability was examined with the metabolic activity (MTT) assay, ROS generation was quantified using luminometry and the nitroblue-tetrazolium (NBT) test was used to quantify the intracellular superoxide formation. Cell lysates were prepared at the end of the culture to assess the intracellular activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) as well as the concentrations of glutathione (GSH) and malondialdehyde (MDA). Treatment with FeAA led to a reduced spermatozoa motility (P<0.001), viability (P<0.001) and decreased the antioxidant characteristics of the samples (P<0.001) but increased the ROS generation (P<0.001), superoxide production (P<0.001) and lipid peroxidation (P<0.001). The CUR treatment led to a preservation of spermatozoa motion (P<0.001), mitochondrial activity (P<0.001) and antioxidant characteristics (P<0.05 with SOD and GSH; P<0.01 with CAT and GPx), revealing the concentration range of 25-50µmol/L CUR to be the most effective for sustaining spermatozoa viability. Data from the present study suggest that CUR exhibits significant protective and ROS-scavenging characteristics which may prevent oxidative insults to spermatozoa and thus preserve the functional activity of male gametes.
