title: [Protective effect of lycopene on human spermatozoa during cryopreservation and its mechanism].
abstract: OBJECTIVE
  To investigate the protective effect of lycopene against cryopreservation injury of post-thawing human sperm and its mechanism.
  
  
  METHODS
  Semen samples were collected from 25 volunteers, each sample equally divided into four parts to be cryopreserved with cryoprotectant only (Ly0 control) or cryoprotectant + lycopene at the concentrations of 2 (Ly2), 5 (Ly5), and 10 µmol/L (Ly10), respectively. Before and after thawing, the semen samples were subjected to computer-assisted semen analysis ( CASA) for sperm kinematics, flow cytometry for sperm apoptosis, thiobarbituric acid assay for malondialdehyde (MDA) concentration, and JC-1 fluorescent staining for the sperm mitochondrial membrane potential (MMP).
  
  
  RESULTS
  After cryopreservation, sperm motility was markedly decreased in all the groups (P < 0.01). The rate of sperm apoptosis was significantly lower in the Ly5 group than in the Ly0 control ([25.68 ± 4.36]% vs [33.26 ± 4.78]%, P < 0.05), while sperm MMP remarkably higher in the former than in the latter ([66.18 ± 14.23]% vs [55.24 ± 12.31]%, P < 0.05). The Ly2, Ly5 and Ly10 groups showed no statistically significance differences in the MDA level from the Ly0 control (P > 0.05).
  
  
  CONCLUSIONS
  Addition of lycopene at a proper concentration to cryoprotectant may reduce oxidative damage to sperm mitochondria in the freezing-thawing process, attenuate oxidative stress injury induced by reactive oxygen species to sperm plasma membrane, and improve the anti-apoptosis ability of sperm.
authors.forename: Zuo-wen
authors.initials: ZW
authors.lastname: Liang
authors.forename: Kai-min
authors.initials: KM
authors.lastname: Guo
authors.forename: Xiao-fan
authors.initials: XF
authors.lastname: Dai
authors.forename: Ling-yun
authors.initials: LY
authors.lastname: Liu
authors.forename: Sheng-qi
authors.initials: SQ
authors.lastname: Xu
authors.forename: Li-jing
authors.initials: LJ
authors.lastname: Zhao
authors.forename: Fu-biao
authors.initials: FB
authors.lastname: Li
authors.forename: Hong-liang
authors.initials: HL
authors.lastname: Wang
mesh_terms: D017209:Apoptosis; D002338:Carotenoids / Q000494:pharmacology*; D015925:Cryopreservation; D003451:Cryoprotective Agents / Q000494:pharmacology; D005434:Flow Cytometry; D006801:Humans; D000077276:Lycopene; D008297:Male; D008315:Malondialdehyde / Q000032:analysis; D018384:Oxidative Stress; D017382:Reactive Oxygen Species; D055101:Semen Analysis; D012662:Semen Preservation / Q000009:adverse effects / Q000379:methods*; D013081:Sperm Motility; D013094:Spermatozoa / Q000187:drug effects* / Q000502:physiology
chemical_list: D003451:Cryoprotective Agents; D017382:Reactive Oxygen Species; D002338:Carotenoids; D008315:Malondialdehyde; D000077276:Lycopene