Silymarin Attenuates Nicotine-Associated Testicular Degeneration and Systemic Oxidative and Inflammatory Changes in Mice

Nicotine exposure can disrupt redox homeostasis and damage the male reproductive system. This study evaluated short-term nicotine-associated systemic and testicular changes and examined whether concurrent silymarin treatment attenuated these alterations. Twenty-eight adult male Swiss albino mice were randomized to control, nicotine, silymarin, and nicotine plus silymarin groups (n = 7 each). Nicotine (1.5 mg/kg/day) and silymarin (100 mg/kg/day) were administered intraperitoneally for seven days. Whole-blood glutathione, plasma malondialdehyde, superoxide dismutase, nitric oxide, paraoxonase-1, total sialic acid, lipid profile, caspase-3, and nuclear factor kappa B, testicular redox markers, and testicular histomorphology were assessed. Nicotine was associated with lower blood glutathione and plasma superoxide dismutase and paraoxonase-1 activities, higher plasma malondialdehyde, nitric oxide, total sialic acid, caspase-3, and nuclear factor kappa B values, and an unfavorable testicular redox profile (all p < 0.001). Degenerative changes were also observed in seminiferous tubules and Leydig cells. Concurrent silymarin treatment attenuated most biochemical alterations and was associated with less severe histological injury, although several markers did not fully return to control values. These findings support a partial protective association under the conditions tested; reproductive function was not directly assessed.