Mitigating the Effects of Oxidative Sperm DNA Damage

Abstract

Sperm DNA damage is correlated with reduced embryo development and increased miscarriage risk, reducing successful conception. Given its links with oxidative stress, antioxidants have been investigated as a potential treatment, yet results are conflicting. Importantly, individual antioxidants are not identical in composition, and some compounds may be more effective than others. We investigated the use of the polyphenol-rich, high-antioxidant-capacity fruit acai as a treatment for elevated sperm DNA fragmentation (>16%), measured by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). Following ≥ 74 days of treatment, we observed a significant decrease in sperm DNA fragmentation (-17.0% ± 2.5%) to 11.9 ± 1.7% (0-37%), with a 68.6% success rate (defined as post-treatment TUNEL < 16%). Post-treatment decreases in DNA fragmentation and success rates were not significantly impacted by low motility and/or concentration, or exceptionally high (> 25%) TUNEL. Treatment significantly reduced concentration in men with normal semen parameters, but 88% remained normal. Overall, successful treatment was not associated with age, semen parameters or TUNEL result at baseline. However, body mass index was significantly higher in nonresponders at baseline. This study provides evidence of a low-cost, effective treatment for elevated sperm DNA damage using acai.

Keywords: DNA damage; acai; antioxidant; polyphenol; sperm.

Figure 1

Percentage of terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL)-positive spermatozoa before (grey circles) and after (open circles) ≥ 74 days of treatment with acai (n = 35). Solid black lines indicate mean and SEM. Red dashed line indicates the clinically relevant cut-off of 16%. * significantly different, p value = 0.00000008.

Figure 2

Percentage of TUNEL-positive spermatozoa before (grey circles) and after (open circles) ≥ 74 days of treatment with acai in men with normal (n = 17) or low (n = 18) baseline semen parameters (‘low’ determined as concentration and/or total motility below WHO lower reference limits (concentration 15 × 10⁶ spermatozoa/mL, total motility 40%). Solid black lines indicate mean and SEM. Red dashed line indicates clinically relevant cut-off of 16%. * significantly different, p values = normal; 0.0002, low; 0.0002.

Figure 3

Percentage of TUNEL-positive spermatozoa before (grey circles) and after (open circles) ≥ 74 days of treatment with acai in men with moderate (16 – 25%, n = 15) or high (> 25%, n = 20) baseline TUNEL results. Solid black lines indicate mean and SEM. Red dashed line indicates clinically relevant cut-off of 16%. * significantly different, p values = moderate; 0.02, high; 0.0000002.