At IRSET (Research Institute for Environmental and Occupational Health) – UMR_S 1085, researchers from EHESP School of Public Health and Inserm study the effects of cannabinoids on the development of the human foetal testis. In an article* published in BMC Medicine on 11 July 2023, they show that the substances present in cannabis, Δ9‑trans‑tetrahydrocannabinol (THC) and cannabidiol (CBD), have deleterious effects on testicular tissue cells.

While cannabis use among pregnant women increases worldwide, there is a need to study the effects of the substances it contains on the exposed fetus. The Inserm team entitled ‘Physiology and Physiopathology of Urogenital Tractus’ within Irset, to which Aurore Gely-Pernot (EHESP Conferences Master), Nathalie Dejucq-Rainsford (Research Director Inserm, Team Leader) and Juliette Dochez-Arnault (under doctoral contract at EHESP) belong, conducted a study on human fetal testicular tissues. These were exposed to the two main substances found in cannabis, THC and CBD, at similar  concentrations to those that could be found in the plasma of adults using cannabis. Deleterious effects on testicular tissues were observed as early as 72h of exposure to these cannabinoids.

Cannabis acts in the human body through the endocannabinoid system (ECS). It is a signalling system that regulates biological processes such as metabolism, pain, neuronal activity or immune function. Its expression is well known in the brain, but unknown in the developing human testicle.

“Our study is the first to evidence the presence of ECS in the human fetal testis and to highlight the potential adverse effect of cannabis consumption by pregnant women onto the development of the male gonad.” says Aurore Gely-Pernot.

In the context of ongoing debates on cannabis legalisation, this study calls for addressing this societal issue with a public health approach, looking at the use of the most vulnerable populations, particularly pregnant women. There is now a need for large-scale, long-term studies of mothers and children, to investigate the potential impacts of maternal cannabis use on male reproductive development, and to determine whether it is associated with lifetime reproductive disorders or testicular cancer.

Title of the article
“Expression of the endocannabinoid system and response to cannabinoid components by the human fetal testis”

Dochez-Arnault1, C. Desdoits-Lethimonier1, I. Matias2, B. Evrard1, M. Lagarrigue1, M. Toupin, A. Lardenois1, F. Chalmel1, S. Mazaud-Guittot1, N. Dejucq-Rainsford1#, A. Gely-Pernot1#* (#Co-last Authors)

1Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) – UMR_S 1085, F-35000 Rennes, France.
2Neurocentre Magendie – Inserm U1215 – Bordeaux, France.

Published on 17 July 2023