Dietary Antioxidants in the Treatment of Male Infertility: Counteracting Oxidative Stress

“…As stated before, obesity can lead to diabetes type 2 which is known to impair male fertility by inter alia reducing sperm quality [53]. In diabetic rats RPO supplementation was shown to elevate the percentage of progressive motile spermatozoa [9].…”

“…Recent data shown that subfertility in dogs is responsible for male fertility impairment in 30% of cases ( 36 , 46 ), consequently optimizing seminal parameters is one of the primary intents of breeding programs. To date, the etiology of suboptimal semen quality has a multifactorial origin ( 47 ) and may result from external factors, such as environment ( 48 ), diet ( 49 , 50 ) and stress ( 51 ), as well as internal factors such as aging ( 52 ), metabolism ( 53 ), nutrient availability ( 54 , 55 ), oxidative status ( 47 , 48 ), endocrine and hormonal disorders, urogenital tract affections ( 56 , 57 ).…”

“…Due to this, in the seminal environment ROS levels are controlled by a specific set of endogenous and exogenous antioxidants ( 81 ), that contribute to avoid ROS overload and preserve semen quality ( 11 ). In particular, the levels of catalase, glutathione peroxidase, and exogenous antioxidants play an important role in sperm maturation, quality parameters, and fertility ( 27 , 48 , 82 ). Hypofertile dogs with poor semen quality showed higher serum ROS levels and lower antioxidant enzymes value than fertile dogs ( 3 , 11 ).…”

“…A randomized clinical trial did not report any significant difference in SDF levels or clinical pregnancy rates after 3 months of antioxidants compared to placebo [ 88 ]. This conflicting evidence highlights the importance of careful patient selection and cautious prescription of antioxidants, as liberal use may shift the subtle balance between oxidants and antioxidants, towards reductive stress (RS) within the reproductive tract, which - similar to OS - can also lead to impaired sperm function and DNA abnormalities [ 89 90 ]. Thus, empiric antioxidant treatment is not devoid of potential adverse effects.…”

“…As stated before, obesity can lead to diabetes type 2 which is known to impair male fertility by inter alia reducing sperm quality [53]. In diabetic rats RPO supplementation was shown to elevate the percentage of progressive motile spermatozoa [9].…”

“…Recent data shown that subfertility in dogs is responsible for male fertility impairment in 30% of cases ( 36 , 46 ), consequently optimizing seminal parameters is one of the primary intents of breeding programs. To date, the etiology of suboptimal semen quality has a multifactorial origin ( 47 ) and may result from external factors, such as environment ( 48 ), diet ( 49 , 50 ) and stress ( 51 ), as well as internal factors such as aging ( 52 ), metabolism ( 53 ), nutrient availability ( 54 , 55 ), oxidative status ( 47 , 48 ), endocrine and hormonal disorders, urogenital tract affections ( 56 , 57 ).…”

“…Due to this, in the seminal environment ROS levels are controlled by a specific set of endogenous and exogenous antioxidants ( 81 ), that contribute to avoid ROS overload and preserve semen quality ( 11 ). In particular, the levels of catalase, glutathione peroxidase, and exogenous antioxidants play an important role in sperm maturation, quality parameters, and fertility ( 27 , 48 , 82 ). Hypofertile dogs with poor semen quality showed higher serum ROS levels and lower antioxidant enzymes value than fertile dogs ( 3 , 11 ).…”

“…A randomized clinical trial did not report any significant difference in SDF levels or clinical pregnancy rates after 3 months of antioxidants compared to placebo [ 88 ]. This conflicting evidence highlights the importance of careful patient selection and cautious prescription of antioxidants, as liberal use may shift the subtle balance between oxidants and antioxidants, towards reductive stress (RS) within the reproductive tract, which - similar to OS - can also lead to impaired sperm function and DNA abnormalities [ 89 90 ]. Thus, empiric antioxidant treatment is not devoid of potential adverse effects.…”

“…As stated before, obesity can lead to diabetes type 2 which is known to impair male fertility by inter alia reducing sperm quality [53]. In diabetic rats RPO supplementation was shown to elevate the percentage of progressive motile spermatozoa [9].…”

“…Recent data shown that subfertility in dogs is responsible for male fertility impairment in 30% of cases ( 36 , 46 ), consequently optimizing seminal parameters is one of the primary intents of breeding programs. To date, the etiology of suboptimal semen quality has a multifactorial origin ( 47 ) and may result from external factors, such as environment ( 48 ), diet ( 49 , 50 ) and stress ( 51 ), as well as internal factors such as aging ( 52 ), metabolism ( 53 ), nutrient availability ( 54 , 55 ), oxidative status ( 47 , 48 ), endocrine and hormonal disorders, urogenital tract affections ( 56 , 57 ).…”

“…Due to this, in the seminal environment ROS levels are controlled by a specific set of endogenous and exogenous antioxidants ( 81 ), that contribute to avoid ROS overload and preserve semen quality ( 11 ). In particular, the levels of catalase, glutathione peroxidase, and exogenous antioxidants play an important role in sperm maturation, quality parameters, and fertility ( 27 , 48 , 82 ). Hypofertile dogs with poor semen quality showed higher serum ROS levels and lower antioxidant enzymes value than fertile dogs ( 3 , 11 ).…”

“…A randomized clinical trial did not report any significant difference in SDF levels or clinical pregnancy rates after 3 months of antioxidants compared to placebo [ 88 ]. This conflicting evidence highlights the importance of careful patient selection and cautious prescription of antioxidants, as liberal use may shift the subtle balance between oxidants and antioxidants, towards reductive stress (RS) within the reproductive tract, which - similar to OS - can also lead to impaired sperm function and DNA abnormalities [ 89 90 ]. Thus, empiric antioxidant treatment is not devoid of potential adverse effects.…”