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Effects of (−)‐Epigallocatechin Gallate on the Motility and Penetrability of Frozen–Thawed Boar Spermatozoa Incubated in the Fertilization Medium
Author(s) -
Kaedei Y,
Naito M,
Naoi H,
Sato Y,
Taniguchi M,
Tanihara F,
Kikuchi K,
Nagai T,
Otoi T
Publication year - 2012
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/j.1439-0531.2012.01984.x
Subject(s) - human fertilization , boar , andrology , incubation , sperm motility , sperm , motility , epigallocatechin gallate , biology , chemistry , antioxidant , anatomy , polyphenol , biochemistry , medicine , genetics
Contents Epigallocatechin gallate (EGCG) is the major polyphenol in green tea ( Camellia sinensis ) and is known for its antioxidant effects. The objective of the present study was to examine the effects of EGCG during in vitro fertilization (IVF) on the sperm quality and penetrability into oocytes. In the first experiment, the effects of concentration and incubation period of EGCG on the motility and penetrability of spermatozoa were examined. When frozen–thawed spermatozoa were incubated in IVF medium supplemented with 0 (control), 1, 50 and 100 μ m EGCG for 1, 3 and 5 h, supplementation with 50 and 100 μ m EGCG improved motility of the spermatozoa (p < 0.05), but not viability, as compared with the control group. When frozen–thawed spermatozoa were co‐incubated with in vitro ‐matured (IVM) oocytes in IVF medium supplemented with 50 and 100 μ m EGCG for 5 h, supplementation of EGCG had positive effects on sperm penetration rates. In the second experiment, the effects of supplementation of EGCG in IVF medium on penetrability of sperm from different boars and development of fertilized oocytes were evaluated. When frozen–thawed spermatozoa from six boars were co‐incubated with IVM oocytes in IVF medium supplemented with 50 μ m EGCG, the effect of EGCG on sperm penetration and development of oocytes after fertilization was found to vary with individual boar. Our results indicate that motility and penetrability of boar spermatozoa are improved by co‐incubation with 50 μ m EGCG, but the effects vary with individual boars.