Alogliptin/Amentoflavone Combination Mitigates Bleomycin-Induced Lung Fibrosis: The Role of Oxidative Stress, TXNIP-Mediated Pyroptosis, and Autophagy/Apoptosis Balance

Background/Objectives: Bleomycin is an antineoplastic antibiotic used in the management of various malignancies. Nevertheless, its benefits are constrained by the development of pulmonary fibrosis. Amentoflavone, a biflavonoid, exhibits diverse pharmacological activities, including anti-inflammatory, antiviral, antioxidant, and antitumor effects, whereas alogliptin possesses antioxidant and anti-inflammatory properties. This study aimed to assess the potential protective effects of alogliptin and/or amentoflavone in a murine model of bleomycin-induced pulmonary fibrosis and to clarify the underlying mechanisms. Methods: Fifty male C57BL/6 mice were randomly divided into 5 equal groups: control, bleomycin, bleomycin + alogliptin, bleomycin + amentoflavone, and bleomycin + alogliptin + amentoflavone. The assessed endpoints included lung weight/body weight index, lung tissue fibrotic mediators, oxidative stress parameters, proinflammatory cytokines, and pyroptotic and autophagy mediators. Also, the bronchoalveolar lavage fluid (BALF) was evaluated for total and differential leukocytic counts and lactate dehydrogenase (LDH) activity. Moreover, vascular responses to potassium chloride, phenylephrine, and carbachol, together with tracheal responses to carbachol were determined. Lung tissues were further examined histopathologically and immunohistochemically. Results: Treatment with alogliptin and/or amentoflavone significantly decreased the lung weight/body weight index and BALF LDH activity, concomitant with mitigation of lung tissue oxidative stress parameters, fibrotic mediators, apoptosis, and pyroptosis with a significant augmentation of autophagy signals, alongside marked improvement in the lung architecture and vascular and airway reactivity compared with the bleomycin group. These effects were most pronounced with animals treated with the alogliptin/amentoflavone combination. Conclusions: These findings suggest that combined alogliptin and amentoflavone may constitute a promising strategy to prevent bleomycin-induced lung fibrosis.