In recent decades, the quantity of sperm and the quality of semen have decreased, causing an increased incidence of male infertility. The increased exposure to environmental pollutants and metals, including aluminum, is one of the causes. Aluminum is reported to activate the proinflammatory macrophages and the NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome pathway in many organs. Thymoquinone (TQ), the bioactive component of Nigella sativa, possesses immunomodulatory, anti-inflammatory, anti-apoptotic, and antioxidant properties. The purpose of this work is to investigate how thymoquinone affects aluminum chloride (AlCl₃)-induced testicular damage and to study, for the first time, its role in modifying the inflammasome pathway, specifically NLRP3/caspase-1/IL-1β, and in targeting macrophage polarization. Negative control, TQ control (10 mg/kg/d), AlCl₃ group (100 mg/kg/d), and AlCl₃ + TQ group were the rat groups. Serum testosterone, FSH, and LH were measured, along with a seminal analysis, evaluation of testicular oxidative stress markers, and assessment of testicular enzymes LDH, SDH, and ACP. NLRP3, caspase-1, IL-1β, CD68, and CD163 immunohistochemical staining, as well as histological alterations, were evaluated. TQ could lower oxidative stress markers, limit the AlCl₃-induced activation of the NLRP3/caspase-1/IL-1β inflammasome pathway, and induce macrophage polarization toward an M2 anti-inflammatory phenotype, thereby restoring testicular enzymes, histological structure, semen quality, and hormone levels. Thymoquinone attenuates aluminum chloride-induced testicular injury by inhibiting NLRP3/caspase-1/IL-1β inflammasome signaling and polarizing the macrophages toward an anti-inflammatory M2 phenotype.

Background: Acrylamide (ACR), a toxic compound formed during high-temperature cooking of carbohydrate-rich foods, is known to induce multi-organ toxicity, including oxidative and inflammatory lung injury. N-Acetylcysteine (NAC), a precursor of glutathione (GSH), possesses potent antioxidant and anti-inflammatory properties that may counteract ACR-induced pulmonary damage. This study investigated the protective effects of NAC against ACR-mediated lung toxicity, with an emphasis on the GSK-3β/Nrf2/NF-κB signaling axis. Methods: Forty male Wistar rats were allocated into four groups: control, NAC (250 mg/kg/day), ACR (50 mg/kg/day), and NAC + ACR. After 11 days of treatment, lung tissues were examined histopathologically using H&E, PAS, and Masson’s trichrome stains. Oxidative stress biomarkers (MDA, SOD, GPx, CAT, GSH) were quantified biochemically. Immunohistochemistry and qRT PCR assessed expression of Nrf2, NF-κB, IL-1β, and Caspase 3, while ELISA measured TNF α, IL-6, Bax, Bcl 2, and GSK 3β. Results: ACR exposure resulted in severe lung injury characterized by alveolar wall edema, epithelial hyperplasia, leukocytic infiltration, goblet cell hyperplasia, and peribronchiolar collagen deposition. These pathological changes were accompanied by a marked increase in MDA, NF-κB, IL-1β, TNF α, IL-6, Bax, Caspase 3, and GSK 3β, together with significant reductions in antioxidant enzymes and Nrf2/HO 1/NQO1 expression. NAC co-administration significantly ameliorated ACR-induced lung damage, restoring normal histological architecture, reducing fibrosis, and normalizing goblet cell activity. NAC also reversed oxidative stress, enhanced Nrf2 and downstream antioxidant responses, suppressed NF-κB-mediated inflammation, and mitigated apoptosis. Notably, NAC downregulated ACR-induced GSK 3β activation, thereby contributing to balanced redox and inflammatory signaling. Conclusions: NAC confers significant protection against ACR-induced pulmonary toxicity through its antioxidant, anti-inflammatory, and anti-apoptotic activities. These effects are mediated, at least in part, by modulation of the GSK 3β/Nrf2/NF-κB pathway. NAC demonstrates promising therapeutic potential for preventing chemically induced lung injury.