Effect of Morinda citrifolia (Noni) on progressive motility of stallion spermatozoa

Breeding induced endometritis is a major concern for mares susceptible to uterine problems or when frozen semen is used for artificial insemination. Morinda citrifolia (Noni) fruit puree has immunomodulatory, anti-inflammatory, and antioxidant properties in vivo and in vitro, and therefore, has the potential to modulate the uterine response to semen components. The use of Noni at the time of breeding will only be practical if it is safe for the spermatozoa. The objective of this work was to determine the effect of five concentrations of Noni in semen extender (A = 0; B = 0.75; C = 1.5; D = 3; and E = 6%) on progressive motility of stallion spermatozoa over time. Three stallions with different progressive motility percentages were collected four times; aliquots of each ejaculate were diluted 1:3 semen: Noni-extender. Samples for time 0 were evaluated immediately; samples for times 24 and 48h were cooled to 5 ° C and then warmed to 37 ° C for 5 minutes before evaluation. Progressive motility was determined in duplicates for each sample by a CASA system (Hamilton Thorne). There was a significant (p ≤0.05) effect of treatment, stallion, time, and stallion by time interaction. The effect for treatment was mainly due to lower progressive motility for the highest concentration of Noni: A = 32^a; B = 32^a; C = 33^a; D = 32^a; and E = 24^b% (LSM; SEM = 2.4). Percentages of progressive motility for each stallion were: Stallion 1^a: 49; 44; and 30%; Stallion 2^b: 32; 34; and 19%; and Stallion 3^b: 34; 25; and 12% at 0, 24 and 48h respectively (LSM; SEM = 2.2). In conclusion, concentrations of 0.75 to 3% Noni fruit puree in semen extender had no detrimental effect on the progressive motility of stallion spermatozoa over time and could be used as starting concentrations for experimental trials on uterine treatments.

Keywords: Morinda citrifolia (Noni), spermatozoa, progressive motility