Green tea extract as a cryoprotectant additive to preserve the motility and DNA integrity of human spermatozoa.

Cryopreservation impairs sperm quality and functions, including motility and DNA integrity. Antioxidant additives in sperm freezing media have previously brought improvements in postthawed sperm quality. Green tea extract (GTE) is widely considered as an excellent antioxidant, and its beneficial role has been proven in other human cells. This study aims to evaluate the GTE as a potential additive in cryopreservation media of human spermatozoa. In part one, the semen of 20 normozoospermic men was used to optimize the concentration of GTE that maintains sperm motility and DNA integrity against oxidative stress, induced by hydrogen peroxide (H2O2). Spermatozoa were treated with GTE at different concentrations before incubation with H2O2. In part two, the semen of 45 patients was cryopreserved with or without 1.0 ng ml-1 GTE. After 2 weeks, the semen was thawed, and the effect on sperm motility and DNA fragmentation was observed. Our data showed that GTE significantly protected sperm motility and DNA integrity against oxidative stress induced by H2O2when added at a final concentration of 1.0 ng ml-1. We found that the addition of 1.0 ng ml-1 GTE to cryopreservation media significantly increased sperm motility and DNA integrity (both P < 0.05). More interestingly, patients with high sperm DNA damage benefited similarly from the GTE supplementation. However, there was no significant change in the reactive oxygen species (ROS) level. In conclusion, supplementing sperm freezing media with GTE has a significant protective effect on human sperm motility and DNA integrity, which may be of clinical interest.

Corticotropin-releasing hormone antagonists possess anti-inflammatory effects in the mouse ileum.

BACKGROUND & AIMS: Corticotropin-releasing hormone (CRH) released at local sites of inflammation promotes inflammation in the periphery. We investigated its effects in the intestinal responses caused by toxin A from Clostridium difficile, the causative agent of antibiotic-associated colitis. METHODS: Ileal loops were injected with 10 microg of toxin A, and enterotoxic responses were measured at various time points. RESULTS: Pretreatment of mice with 2.5 microg/kg of the CRH receptor antagonist alpha-helical CRH((9-41)) that blocks both CRH receptor subtypes reduced toxin A-mediated ileal secretion, epithelial cell damage, mucosal edema, neutrophil infiltration, and mucosal content of interleukin 1 beta and tumor necrosis factor alpha. Pretreatment with the specific CRH(1) receptor antagonist antalarmin (20 mg/kg, IP) also inhibited toxin A-induced fluid secretion and toxin A-associated histologic changes. CRH messenger RNA and protein were increased in mouse ileum 30 minutes after intraluminal toxin A administration. In situ hybridization and immunohistochemistry demonstrated that toxin A at 1 hour caused a substantial increase in the expression of both CRH receptor subtypes in the ileal mucosa. CONCLUSIONS: Peripheral CRH may play a proinflammatory role in toxin A-induced intestinal secretion and inflammation and that CRH(1) receptor, at least in part, is important in the mediation of these responses.