Reproductive and immune-related consequences of Achillea fragrantissima (Forssk.) in male rats via modulation of steroidogenesis- and immune-related genes expression

Introduction: (AFG) is known for its medicinal properties, while different Achillea species have shown both beneficial and detrimental impacts on male fertility. This investigation evaluated the effects of AFG oral administration on behavior, steroidogenesis, and immune-related gene expression in Sprague-Dawley male rats. Methods: Forty-five mature rats were randomly grouped into: Control, Low-dose group (AFG-L: 500 mg/kg extract), and High-dose group (AFG-H: 1000 mg/kg extract). The AFG extract was orally administered for 30 days. Behavioral, hematological, reproductive, immune, and oxidative stress-related indices were evaluated. Results: < 0.05) downregulated. The AFG-L group maintained normal testicular architecture with preserved seminiferous tubules and only mild interstitial edema alongside mild splenic sinusoid dilatation with macrophage infiltration. In contrast, the AFG-H group exhibited significant histopathological alterations, including irregular seminiferous tubules, reduced mature sperm, and increased interstitial edema, while the spleen showed preserved lymphoid follicles with congested vasculature. Discussion: extract exerts reproductive and immune-enhancing outcomes in male rats, with the low dose exhibiting greater efficacy than the high dose, indicating a clear dose-dependent response.