title: Endocannabinoids as biomarkers of human reproduction.
abstract: BACKGROUND
  Infertility is a condition of the reproductive system that affects ∼10-15% of couples attempting to conceive a baby. More than half of all cases of infertility are a result of female conditions, while the remaining cases can be attributed to male factors, or to a combination of both. The search for suitable biomarkers of pregnancy outcome is a challenging issue in human reproduction, aimed at identifying molecules with predictive significance of the reproductive potential of male and female gametes. Among the various candidates, endocannabinoids (eCBs), and in particular anandamide (AEA), represent potential biomarkers of human fertility disturbances. Any perturbation of the balance between synthesis and degradation of eCBs will result in local changes of their tone in human female and male reproductive tracts, which in turn regulates various pathophysiological processes, oocyte and sperm maturation included.
  
  
  METHODS
  PubMed and Web of Science databases were searched for papers using relevant keywords like 'biomarker', 'endocannabinoid', 'infertility', 'pregnancy' and 'reproduction'.
  
  
  RESULTS
  In this review, we discuss different studies on the measurements of AEA and related eCBs in human reproductive cells, tissues and fluids, where the local contribution of these bioactive lipids could be critical in ensuring normal sperm fertilizing ability and pregnancy.
  
  
  CONCLUSIONS
  Based on the available data, we suggest that the AEA tone has the potential to be exploited as a novel diagnostic biomarker of infertility, to be used in association with assays of conventional hormones (e.g. progesterone, β-chorionic gonadotrophin) and semen analysis. However further quantitative research of its predictive capacity is required.
authors: Faculty of Veterinary Medicine, University of Teramo, Teramo, Italy StemTeCh Group, Chieti, Italy.
authors: Cinzia
authors: C
authors: Rapino
authors: Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy European Center for Brain Research/IRCCS Santa Lucia Foundation, Rome, Italy.
authors: Natalia
authors: N
authors: Battista
authors: European Center for Brain Research/IRCCS Santa Lucia Foundation, Rome, Italy Department of Experimental Medicine and Surgery, Tor Vergata University of Rome, Rome, Italy.
authors: Monica
authors: M
authors: Bari
authors: European Center for Brain Research/IRCCS Santa Lucia Foundation, Rome, Italy Center of Integrated Research, Campus Bio-Medico University of Rome, Rome, Italy m.maccarrone@unicampus.it.
authors: Mauro
authors: M
authors: Maccarrone
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D063388:Endocannabinoids / Q000378:metabolism* / Q000502:physiology; D005321:Extraembryonic Membranes / Q000378:metabolism; D005260:Female; D005836:Genitalia, Female / Q000378:metabolism; D005837:Genitalia, Male / Q000378:metabolism; D006801:Humans; D007246:Infertility / Q000175:diagnosis*; D008297:Male; D009865:Oocytes / Q000502:physiology; D010920:Placenta / Q000378:metabolism; D053284:Polyunsaturated Alkamides / Q000378:metabolism; D011247:Pregnancy; D011256:Pregnancy Outcome; D012098:Reproduction / Q000502:physiology*; D013094:Spermatozoa / Q000378:metabolism
chemical_list: D001095:Arachidonic Acids; D015415:Biomarkers; D063388:Endocannabinoids; D053284:Polyunsaturated Alkamides; C078814:anandamide
keywords: biomarkers; endocannabinoids; human reproduction; infertility; pregnancy