Effects of marijuana and tobacco on male fertility and their relationship to genetic variation of mitochondrial cytochrome C oxidase genes

Although tobacco smoking declined among men at reproductive age, the use of cannabis increased. The aim of our study was to determine the impact of tobacco and cannabis on sperm quality, sperm DNA integrity tested by Chromomycin A3 (CMA3) and acridine orange (AO) and their association to genetic variants in the Cytochrome C Oxidase 1, 2 and 3 genes (MT-CO1, MT-CO2, and MT-CO3). Semen samples were collected and divided into 37 non-smokers (NS), 39 tobacco smokers (TS), and 37 cannabis smokers (CS). MT-CO1, MT-CO2 and MT-CO3 genes were amplified by PCR and sequenced by Sanger. The results showed reductions in normal sperm morphology and non-progressive motility in TS and CS compared to NS (p < 0.001). However, immotile sperm, AO+, and CMA3 + scores were higher in the CS compared to TS and NS (p < 0.001). Twenty-three nucleotide substitutions (SNPs) detected in the MT-CO1 gene, 15 SNPs detected in the MT-CO2 gene, and 30 SNPs detected in the MT-CO3 gene. None of these SNPs was different between the three groups. Tobacco and cannabis smoking altered the motility and morphology of the spermatozoa and sperm DNA integrity but was not associated with genetic variants in the MT-CO1, MT-CO2 and MT-CO3 genes.