Avaliação da toxicidade de solvente de extratos vegetais com ação antiviral em sêmen caprino refrigerado / Evaluation of solvent toxicity of plant extract with antiviral action in refrigerated goat semen

ABSTRACT

Background: Caprine Arthritis Encephalitis Virus have been detected in sperm of breeding goats causing economic losses. In order to control the virus, researches aiming to identify natural extracts with potential antiviral effects are performed. However, aqueous or ethanolic extracts must be diluted in dimethyl sulfoxide (DMSO), which is a substance with unknown effects in sperm quality when present in diluting media. Therefore, this study aimed to evaluate sperm viability of refrigerated caprine semen diluted in media containing DMSO. This was performed to provide data that aid in researches involving the use of this component with natural extracts that may inactivate the caprine lentivirus in sperm.Materials, Methods & Results: The experiment was performed at the Laboratory of Seminal Technology in Embrapa Goats and Sheep in the city of Sobral, Brazil. Sperm viability was assessed in caprine semen refrigerated in two dilution media with crescent concentrations of DMSO. Sperm samples of five goats seronegative for the caprine lentivirus were pooled and diluted in minimal essential medium (MEM) enriched with glucose at 0.01 M added of crescent concentrations of DMSO (0%, 1.5%, 1.75%, 2.0%, 2.25% and 2.5%). The same breeders provided the pool of sperm to test Tris added 2.5% of egg yolk and the same concentrations of DMSO previously mentioned. Treatments were refrigerated at 7°C and evaluated up until four h after DMSO addition. Individual progressive motility (MIP), sperm vigor (V), percentage of spermatozoa reactive to hypoosmotic test (HO) and morphologically normal (NOR) were evaluated. IPM, vigor and NOR remained within normal standards for the caprine species in all treatments test. Percentage results of spermatozoa reactive to hypoosmotic was higher in Tris yolk with values ranging between 34.66% to 46.33%. Sperm vigor was positively correlated (r = 0.85) with IPM in the MEM diluted pool of sperm.[...]