Objective: To investigate the repairing effect of Yishen Tongluo Prescription (YTP) on sperm DNA fragmentation index (DFI) in male rats exposed to benzo(a)pyrene (BaP) and its possible mechanism.
Methods: Thirty Wistar male rats were equally randomized into a blank control, a BaP-exposure and a YTP intervention group, those in the latter two groups exposed to BaP at 20 mg/kg/d for 60 consecutive days, and those in the YTP intervention group treated intragastrically with YTP from the 31st day of BaP exposure for a total of 30 days. After the last administration, the sperm DFI of the rats was detected by sperm chromatin structure analysis, the levels of FSH, LH and T in the serum and superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO) and adenosine triphosphate (ATP) in the testis were measured by ELISA.
Results: Compared with the blank controls, the rats in the BaP-exposure group showed significantly increased DFI ( ［4.23 ± 1.40］% vs ［12.46 ± 3.07］%, P < 0.05), serum FSH (［1.76 ± 0.31］ vs ［2.53 ± 0.28］ U/L, P < 0.05) and LH (［30.59 ± 2.14］ vs ［39.72 ± 2.80］ U/L, P < 0.05), decreased levels of serum T (［5.33 ± 0.43］ vs ［4.42 ± 0.38］ nmol/L, P < 0.05) and testicular SOD (［166.18 ± 3.74］ vs ［113.23 ± 10.76］ U/ml, P < 0.05) and ATP (［41.23 ± 2.21］ vs ［33.48 ± 2.74］ mol/L, P < 0.05), and elevated contents of MDA (［7.55 ± 0.93］ vs ［10.59 ± 1.17］ nmol/ml, P < 0.05) and NO (［44.23±4.47］ vs ［54.49 ± 3.13］ mol/L, P < 0.05). All the above parameters returned to normal after YTP intervention (DFI: ［5.73 ± 2.46］%, FSH: ［2.07 ± 0.45］ U/L, LH: ［33.94 ± 4.44］ U/L, T: ［4.96 ± 0.24］ nmol/L, SOD: ［135.22 ± 7.26］ U/ml, ATP: ［38.26 ± 2.14］ mol/L, MDA: ［8.37 ± 1.29］ nmol/ml, NO: ［48.36 ± 3.98］ mol/L), with statistically significant difference from those in the BaP-exposure group (all P < 0.05).
Conclusion: Yishen Tongluo Prescription can repair BaP-induced sperm DNA damage in male rats, which may be attributed to its effects of suppressing oxidative damage.
Keywords: male infertility; Yishen Tongluo Prescription; benzo(a)pyrene; oxidative stress; sex hormones.