摘要Objective: To investigate antioxidant potential of pentoxifylline on spermatozoa of small ruminants including rams and bucks. Methods: The levels of hydrogen peroxide (H2O2) production in ram and buck spermatozoa incubated with 0 (control), 4 and 8 mM of pentoxifylline were measured after 45-min incubation. Then, the motility parameters of ram and buck spermatozoa incubated with 0 (control), 1 mM of H2O2, 1 mM of H2O2 plus 4 mM of pentoxifylline, and 1 mM of H2O2 plus 8 mM of pentoxifylline were analysed. H2O2 was estimated using a fluorometric assay and spermatozoa motility characteristics were analyzed using computer aided sperm analyzer. Results: Pentoxifylline significantly decreased the levels of H2O2 produced from both ram and buck spermatozoa (P<0.05), and significant lower rates of H2O2 formation were noted when 8 mM of pentoxifylline was added (P<0.05). The values of all sperm motility parameters for the two species significantly decreased after incubation with H2O2 (P<0.05). In contrast, when the spermatozoa were incubated with both H2O2 and two concentrations of pentoxifylline, the motility values rose significantly compared to those incubated with H2O2 alone (P<0.05). For both ram and buck sperm samples, the rapid and static subpopulation motility parameters were the most affected categories by pentoxifylline addition compared to the medium and slow categories. Conclusions: Pentoxifylline possesses an antioxidant capacity proved by its ability of reducing H2O2 levels as well as by increasing motility values of stressed spermatozoa. Therefore, pentoxifylline could be recommended as antioxidant additive for spermatozoa of small ruminants under stress conditions.