Effects of the antioxidant crocin on frozen-thawed buffalo (Bubalus bubalis) sperm

This work aimed to evaluate the effect of crocin on frozen-thawed sperm quality in buffalo. Spermatozoa were incubated in Tyrode’s Albumin Lactate Pyruvate medium supplemented with 0, 0.5, 1, and 2 mM crocin for 2 h. Sperm motility was evaluated by phase-contrast microscopy, viability and acrosome integrity by Trypan blue Giemsa staining, and membrane functional integrity by the hypoosmotic swelling test. The DNA fragmentation was evaluated by Tunel and ROS levels by spectrofluorometric analysis. The treatment with 2 mM of crocin increased (P <.05) sperm membrane functional integrity compared to the control group (59.1 ± 1.6 vs 53.3 ± 1.5) and reduced sperm DNA fragmentation, compared to the other groups (11.3 ± 1.1, 13.3 ± 1.2, 13.6 ± 1.2 and 6.0 ± 0.7, respectively in 0, 0.5, 1 and 2 mM crocin; P <.01). Finally, a dose-dependent decrease (P <.01) in superoxide anion production in the presence of crocin was observed, as indicated by Dihydroethidium values (922.6 ± 13.0, 596.8 ± 7.4, 498.9 ± 5.3 and 421.4 ± 5.0 a.u., respectively in 0, 0.5, 1 and 2 mM crocin; P <.01). The results of this study demonstrated a positive effect of 2 mM crocin on frozen-thawed buffalo sperm, as indicated by the improvement of sperm membrane integrity and the reduction of DNA fragmentation and ROS levels.