Abstract

Background:
Male infertility is closely linked to testicular damage caused by environmental chemicals. Carbon tetrachloride (CCl₄), widely used in manufacturing chlorinated chemicals, is highly toxic to the liver, testes, and other organs. Its testicular toxicity involves oxidative stress, apoptosis, and hyperlipidemia. Plant-derived proteins such as soybeans, with phytoestrogenic properties, have gained attention for their potential health benefits.

Aim:
This study investigated the protective effect of soybean on CCl₄-induced testicular damage.

Methods:
Twenty-eight male albino rats were divided into four groups: control, CCl₄-treated (1.0 ml/kg intraperitoneally, thrice weekly for three weeks), CCl₄-treated plus 10% soybean diet, and CCl₄-treated plus 30% soybean diet (as a schematic cartoon in Figure 1). After seven weeks, serum lipoproteins, testicular malondialdehyde (MDA), and glutathione peroxidase (GPx) were measured; histopathological, histochemical, and immunohistochemical analyses were performed, including cleaved caspase-3 expression.

Results:
CCl₄ exposure significantly reduced HDL, increased LDL, elevated MDA, altered GPx activity, intensified caspase-3 staining, and caused marked testicular structural deterioration. Soybean supplementation ameliorated these effects, restoring lipid profiles, reducing oxidative markers, preserving testicular architecture, improving spermatogenesis, and mitigating caspase-3 expression.

Conclusion:
Overall, soybean exerts antioxidant and immunoprotective effects against CCl₄-induced testicular damage, suggesting a potential dietary strategy to counteract reproductive toxicity.

Key words: CCl4; Soybean; Testes; Histomorphology; GPx, caspase 3.