Protective effect of vitamin C and lycopene on the in vitro fertilization capacity of sex-sorted bull sperm by inhibiting the oxidative stress

The fertilization capacity of sex-sorted sperms is seriously decreased, which inhibits its wide application. However, little information is still available about the effect of vitamin C (VC) and lycopene (Lyc) on the fertilization capacity of sex-sorted bull sperm. In this study, the washing medium and fertilization medium of sex-sorted sperm from three bull individuals were supplemented with different concentrations of VC (0, 1 × 10^–3, 1 × 10^–4, 1 × 10^–5, 1 × 10^–6 M) or Lyc (0, 1 × 10^–4, 1 × 10^–5, 1 × 10^–6, 1 × 10^–7). After washing twice and incubation for 1.5 hr, the malondialdehyde (MDA) level, phosphatidylserine (PS) translocation, membrane potential (Δψm) and IVF (in vitro fertilization) ability of sex-sorted sperm were investigated. For the sex-sorted sperm of bulls A, B and C, 1 × 10^–3 M VC or 1 × 10^–4 M Lyc treatment significantly decreased their MDA levels and PS translocation and increased their Δψm levels and cleavage rates after IVF. When blastocysts were concerned, 1 × 10^–4 M Lyc significantly improved the blastocyst rates and their IFN-tau expression of bulls A and C. In conclusion, supplementation of 1 × 10^–3 M VC or 1 × 10^–4 M Lyc in washing and fertilization medium contributed greatly to improving the fertilization capacity of sex-sorted bull sperm during IVF procedure.