Revisiting cadmium-induced toxicity in the male reproductive system: an update

Heavy metals like cadmium (Cd) are one of the main environmental pollutants, with no biological role in the human body. Cd has been well-documented to have disastrous effects on both plants and animals. It is known to accumulate in kidneys, lungs, liver, and testes and is thought to affect these organs' function over time, which is linked to a very long biological half-life and a very poor rate of elimination. According to recent researches, the testes are extremely vulnerable to cadmium. The disruption of the blood–testis barrier, seminiferous tubules, Sertoli cells, and Leydig cells caused by cadmium leads to the loss of sperm through various mechanisms, such as oxidative stress, spermatogenic cell death, testicular swelling, dysfunction in androgen-producing cells, interference with gene regulation, disruption of ionic homeostasis, and damage to the vascular endothelium. Additionally, through epigenetic control, cadmium disrupts the function of germ cells and somatic cells, resulting in infertile or subfertile males. A full grasp of the mechanisms underlying testicular toxicity caused by Cd is very important to develop suitable strategies to ameliorate male fertility. Therefore, this review article outlines cadmium’s impact on growth and functions of the testicles, reviews therapeutic approaches and protective mechanisms, considers recent research findings, and identifies future research directions.