Piracetam attenuates cyclophosphamide-evoked pulmonary injury in rats; the role of AMPK/NF-κB/NLRP3/caspase-1 and caspase-3 mediated apoptosis signaling cascades

Abstract Cyclophosphamide (CP) is often employed in the treatment of numerous malignancies and autoimmune diseases, although it is accompanied by numerous side effects. Piracetam (PIRA) is used as a nootropic agent and reported to possess antioxidant, anti-inflammatory, and anti-apoptotic properties in addition to its established cognitive-enhancing effects. This study aimed to investigate the potential protective effects of PIRA against CP-induced lung damage in rats. CP was utilized to provoke pulmonary damage. Molecular docking was performed to predict the binding affinity of piracetam for NF-κB p65, NLRP3, caspase-1, caspase-3, and AMPK. Arterial blood gas parameters (PaO₂ and PaCO₂) were assessed to evaluate pulmonary gas-exchange function. The lung contents of MDA, GSH, and CAT activity were measured. Levels of lung IL-18, IL-1β, TNF-α, and caspase-1 were evaluated using ELISA. Immunohistochemistry was employed to evaluate NF-κB p65 and caspase-3. The Western blot technique was utilized to evaluate the protein expression of NLRP3 and p-AMPK. Lung Bax and Bcl-2 gene expression was assessed using qRT-PCR. The histological examination of lung tissues was conducted. Molecular docking revealed favorable binding affinities of piracetam. CP caused a notable reduction in PaO₂ and elevation in PaCO₂, alongside a notable increase in lung MDA, IL-18, IL-1β, TNF-α, caspase-1, and Bax levels, with a substantial reduction in GSH, CAT, p-AMPK, and Bcl-2. CP administration also led to the upregulation of NLRP3 protein. Additionally, the immunopositivity of both NF-κB p65 and caspase-3 was elevated in the CP group. PIRA markedly ameliorated all previously described functional, biochemical, and histopathological anomalies. PIRA pretreatment significantly improved CP-induced pulmonary injury, an effect associated with suppression of NF-κB/NLRP3/caspase-1 and caspase-3 signaling and with increased p-AMPK expression.