title: Preincubation with green tea polyphenol extract is beneficial for attenuating sperm injury caused by freezing-thawing in swine.
abstract: Polyphenols (PFs) extracted from green tea, known to be potent anti-oxidants, have been reported to be effective in increasing the motility and viability of mammalian sperm, preserved in a liquid form. Therefore, we tested whether PFs might also be effective for maintaining the integrity of frozen-thawed boar spermatozoa. Ejaculates, collected from Clawn miniature pigs, were diluted in a semen extender containing various amounts of PFs (0, 0.01, 0.05, 0.1 and 0.2% w/v) and then stored at 15°C overnight. The semen samples were processed, using the straw freezing procedure, and then frozen in liquid nitrogen. After rapid thawing at 40°C, the spermatozoa were subjected to several assays to evaluate semen quality. Spermatozoa frozen in a medium containing 0.01% w/v PFs exhibited significantly (P < 0.05) higher degrees of post-thawed viability and acrosomal integrity than those stored in the absence of PFs. However, no change in the mitochondrial activity was noted between the two groups. The inclusion of 0.01% PFs in the semen extender was significantly (P < 0.05) effective in increasing both the rates of monospermic oocyte formation and of blastocyst formation. These findings indicate that preincubation with the semen extender, containing 0.01% PFs prior to freezing, exerts a protective effect on boar sperm by preventing injuries associated with freezing-thawing.
authors.affiliation: Laboratory of Animal Reproduction, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Kitaji
authors.affiliation: Laboratory of Animal Reproduction, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Ookutsu
authors.affiliation: Section of Gene Expression Regulation, Frontier Science Research Center, Kagoshima University, Kagoshima, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sato
authors.affiliation: Laboratory of Animal Reproduction, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan.
authors.forename: Kazuchika
authors.initials: K
authors.lastname: Miyoshi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D018929:Cell Culture Techniques / Q000379:methods*; D002470:Cell Survival / Q000187:drug effects*; D015925:Cryopreservation / Q000379:methods*; D005615:Freezing / Q000009:adverse effects*; D008297:Male; D059808:Polyphenols / Q000302:isolation & purification / Q000494:pharmacology*; D013094:Spermatozoa / Q000473:pathology; D013552:Swine; D013556:Swine, Miniature; D013662:Tea / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D059808:Polyphenols; D013662:Tea
keywords: anti-oxidants; boar; cryopreservation; polyphenol; sperm quality