Clastogenic effect by recreative exposure to marijuana in individuals from the Estado de Mexico: Pilot study

Cannabis sativa is the most trafficked illicit substance in the world, 147 million people consume it recreationally. This plant contains more than 100 phytocannabinoids, the most important being 1-delta-9- tetrahydrocannabinol (THC). The genotoxic effect of cannabinoids has been proven in vitro and in vivo models, where damage to nuclear DNA and chromosomal aberrations (CA) was observed. This shows the clastogenic potential of this drug. In this research, we study genotoxic damage in Mexican individuals recreationally exposed to marijuana. The study of chromosomal aberrations was performed in 48 hour lymphocyte cultures of 30 exposed and 30 no exposed individuals. 100 metaphases were analyzed per sample. The type of CA was identified and counted. The number of CAs identified in the exposed group was 344 with a median of 9.5; the no exposed group had 218 CAs, with a median of 6.5. The statistical analysis showed a significant difference between both groups, p=0.013. Chromatid and chromosomal breaks were the most frequent aberrations. Comparing the exposure time vs. frequency of CA in the exposed group, we did not find a significant difference between sub-groups from 1 to 5 and 6 to 11 years. Similarly, in the analysis of the last exposure date vs CA, no significant differences were observed between the subgroups <1 week and >1 week. Our results show an increase in the frequency of the number of CAs in the individuals recreationally exposed. These results show evidence of the genotoxic potential of marijuana.