Table 5.

Molecular alterations of semen and sperm as a consequence of illicit drug consumption

	Parameters		Illicit drugs			Species	References
Semen	Free radicals	Decreased antioxidant capability	Opioids			Human	Safarinejad et al. (38)
		Increased ROS	Morphine			Human (cell line)	Safarinejad et al. (38), Ma et al. (74)
Sperm plasma membrane	ᵟ ,ᵏ, and µ receptors	Decreased sperm motility		Agonist of µ receptors	Morphine	Human (in vitro)	Agirregoitia et al. (76)
					Heroin	Human	Nazmara et al. (53), Rezaei-Mojaz et al. (70)
				Antagonist of ᵟ receptors	Naltrindole	Human	Agirregoitia et al. (76)
		Increased sperm motility	Antagonist of µ receptors		Naloxone	Human	Agirregoitia et al. (76)
	Enkephalin degrading enzymes	Decreased aminopeptidase N (mRNA, Protein)	Heroin			Human	Rezaei-Mojaz et al. (70)
		Decreased enkephalinase (mRNA)	Heroin			Human	Rezaei-Mojaz et al. (70)
	Decreased expression of CatSper 1 - 4 mRNAs		Iranian Kerack			Mice	Amini et al. (69)
Sperm nucleus	Histone-to-protamine Transition deficiency		Heroin			Human	Nazmara et al. (53)
	Increased DFI %		Opioids			Human	Safarinejad et al. (38)
	Decreased protamine-2 (mRNA and Protein)		Heroin			Human	Nazmara et al. (11)
	Increased HDAC1		Heroin			Human	Nazmara et al. (85)
	Decreased HDAC11		Heroin			Human	Nazmara et al. (85)
	Increased miR-122		Heroin			Human	Nazmara et al. (11)
	Decreased miR-125b-5p		Heroin			Human	Nazmara et al. (11)