Effects of (−)‐Epigallocatechin Gallate on the Motility and Penetrability of Frozen–Thawed Boar Spermatozoa Incubated in the Fertilization Medium

Abstract

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 μm EGCG for 1, 3 and 5 h, supplementation with 50 and 100 μm 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 μm 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 μm 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 μm EGCG, but the effects vary with individual boars.

Antioxidant effect of lemon balm (Melissa officinalis) and mate tea(Ilex paraguensys)on quality, lipid peroxidation and DNA oxidation of cryopreserved boar epididymal spermatozoa

“…produced significant improvement in total motility and reduced the lipoperoxidation on boar spermatozoa (Zhao et al ., ; Malo et al ., ). Epigallocatechin gallate (the major polyphenol in green tea) and rosmarinic acid (the main antioxidant in rosemary) improved the motility and penetrability of frozen–thawed boar spermatozoa (Kaedei et al ., ; Luño et al ., ). Recently, studies showed that essential oil of geranium ( Pelargonium graveolens) prevented testicular oxidative damage by reduced lipoperoxidation and improved total sperm motility, viability and morphology in mice spermatozoa after administration of reprotoxic drug (Slima et al ., ).…”

Epigallocatechin‐3‐Gallate (EGCG) Reduces Rotenone Effect on Stallion Sperm–Zona Pellucida Heterologous Binding

“…When stallion spermatozoa were treated under capacitating condition with 10 and 20 lM EGCG, stallion sperm-ZP binding activity was improved compared with control semen. A positive influence of EGCG addition on both fresh and frozen-thawed spermatozoa during IVF on ZP binding and oocyte penetration was already recorded in pig (Spinaci et al 2008;Kaedei et al 2012), suggesting a modulating action of this polyphenol on sperm capacitation. This effect could be exerted thanks to the antioxidant ability of EGCG that can act on the balance between excessive ROS production, which overwhelms the limited capacity of these cells to protect themselves from oxidative stress, and mild intracellular ROS generation, which stimulates intracellular cAMP generation, inhibits tyrosine phosphatase activity and enhances the formation of oxysterols, thus inducing a physiological capacitation (Aitken et al 2015).…”

“…; Kaedei et al. ), suggesting a modulating action of this polyphenol on sperm capacitation. This effect could be exerted thanks to the antioxidant ability of EGCG that can act on the balance between excessive ROS production, which overwhelms the limited capacity of these cells to protect themselves from oxidative stress, and mild intracellular ROS generation, which stimulates intracellular cAMP generation, inhibits tyrosine phosphatase activity and enhances the formation of oxysterols, thus inducing a physiological capacitation (Aitken et al.…”

Preincubation with green tea polyphenol extract is beneficial for attenuating sperm injury caused by freezing‐thawing in swine

“…Interestingly, Kaedei et al (2012) reported that EGCG (50 μmol/L) has positive effects on sperm penetration rates and sperm motility when frozen-thawed boar spermatozoa are incubated in IVF medium supplemented with various amounts of EGCG. Among them, EGCG is abundantly present.…”