Impact of Algerian date palm pollen aqueous extract on epididymal and ejaculated rabbit sperm motility during in vitro incubation

Abstract

Date palm pollen (DPP) has been widely tested in vitro in preservation of spermatozoa of different farm animals except in rabbits. The objective of this study was to evaluate the effect of various concentrations (20, 40, 80 mg/mL) of DPP aqueous extract on epididymal and ejaculated rabbit spermatozoa during in vitro incubation at 37 °C during 120 min. NaCl Pollen Extender (NPE) and TRIS Base Extender (TPE) were respectively used in epididymal and ejaculated sperm preservation. Sperm motility parameters were objectively analysed by a Computer Aided Sperm Analyser (CASA). The results revealed that in epididymal sperm at 0 minute, sperm motility showed significant higher values (p ≤ 0.05) for all doses of DPP in comparison to the control group. After 30, 60 and 120 min, the motility rate was higher (p > .05) in all the experimental groups compared to the control. Concerning velocity traits (VCL and VAP), and trajectories parameters (LIN, ALH, BCF), the doses of 40 mg/mL and 80 mg/mL showed the highest values than Control. In ejaculated samples, the motility rate at 0 minute improved only with the dose of 80 mg/mL and DPP showed protective effect at all doses (20, 40, 80 mg/mL) up to 60 min of incubation. DPP enhanced spermatozoa velocity (VCL and VAP) and the trajectory of sperm (LIN, ALH, BCF) even from 20 mg/mL at any points of storage. In conclusion, aqueous extract of date palm pollen is a suitable supplement to the extender for rabbit sperm by protecting and improving sperm motility parameters. HIGHLIGHTS The addition of DPP extract improves the quality of epididymal and ejaculated rabbit sperm. The extender supplemented with 80 mg/mL of DPP in NPE has a beneficial effect on kinetic traits of epididymal sperm. Nevertheless, in TPE extender, 20 mg/mL of DPP was enough to improve sperm motility traits in ejaculated rabbit semen.