Therapeutic use of fisetin and pirfenidone combination in bleomycin-induced pulmonary fibrosis in adult male albino rats

Pulmonary fibrosis is an important health problem; one of the drugs used in its treatment is pirfenidone (PFD). Fisetin (FST) is a flavonoid with antioxidative, anti-inflammatory, and antifibrotic effects. The aim of this study was to induce PF in rats with bleomycin (BLM) and to investigate the combined effect of PFD and FST in the treatment of fibrosis. In the study, 40 male Wistar rats were divided into five groups (n = 8). Sham group was administered saline on day 0 and BLM (5 mg/kg, i.t.) was administered to the other groups; BLM + PFD group: PFD (50 mg/kg) was administered every day between the first and 15th days; BLM + FST group: FST (25 mg/kg) was administered between the first and 15th days; BLM + PFD + FST group: PFD (50 mg/kg) and FST (25 mg/kg) were administered by gavage every day between the first and 15th days. At the end of the 15th day, BAL was performed under anaesthesia and lung tissues were removed. Histopathological, biochemical, and RT-PCR analyses were performed in the lung tissue. In our study, the concomitant use of FST and PFD caused downregulation of NF-κB p65, TGF-β1, and α-SMA expressions; downregulation of TIMP-1, MMP-2, and MMP-9 genes; downregulation of HYP, MPO, and MDA activity; decrease in the number of differential cells in BAL; and upregulation of GSH. This shows that FST and PFD have antifibrotic, antioxidative, and anti-inflammatory effects. Our results show that the combined use of PFD and FST in BLM-induced pulmonary fibrosis reduces extracellular matrix accumulation, downregulates the level of gelatinases and their inhibitors, and provides significant improvements in antioxidative defence parameters.

Hydroxytyrosol Alleviates Methotrexate-Induced Pulmonary Fibrosis in Rats: Involvement of TGF-β1, Tissue Factor, and VEGF

Methotrexate (MTX) is an indispensable drug used for the treatment of many autoimmune and cancerous diseases. However, its clinical use is associated with serious side effects, such as lung fibrosis. The main objective of this study is to test the hypothesis that hydroxytyrosol (HT) can mitigate MTX-induced lung fibrosis in rats while synergizing MTX anticancer effects. Pulmonary fibrosis was induced in the rats using MTX (14 mg/kg/week, per os (p.o.)). The rats were treated with or without HT (10, 20, and 40 mg/kg/d p.o.) or dexamethasone (DEX; 0.5 mg/kg/d, intraperitoneally (i.p.)) for two weeks concomitantly with MTX. Transforming growth factor beta 1 (TGF-β1), interleukin-4 (IL-4), thromboxane A2 (TXA2), vascular endothelial growth factor (VEGF), 8-hydroxy-2-deoxy-guanosine (8-OHdG), tissue factor (TF) and fibrin were assessed using enzyme-linked immunosorbent assay (ELISA), immunofluorescence, and RT-PCR. Pulmonary fibrosis was manifested by an excessive extracellular matrix (ECM) deposition and a marked increase in TGF-β1 and IL-4 in lung tissues. Furthermore, cotreatment with HT or dexamethasone (DEX) significantly attenuated MTX-induced ECM deposition, TGF-β1, and IL-4 expression. Similarly, HT or DEX notably reduced hydroxyproline contents, TXA2, fibrin, and TF expression in lung tissues. Moreover, using HT or DEX downregulated the gene expression of TF. A significant decrease in lung contents of VEGF, IL-8, and 8-OHdG was also observed in HT + MTX- or DEX + MTX -treated animals in a dose-dependent manner. Collectively, the results of our study suggest that HT might represent a potential protective agent against MTX-induced pulmonary fibrosis.

Protective effects and mechanism of curcumin in animal models of pulmonary fibrosis: a preclinical systematic review and meta-analysis

Introduction: At present, there is a lack of effective treatment for pulmonary fibrosis (PF), and a number of studies have confirmed that curcumin (CUR) has a good effect on PF. Research Qusetion: Is CUR effective in preclinical trials for PF and what is its mechanism of action? Methods: Animal reports of PF treated with CUR were searched from Pubmed, Embase, Web of Science and Cochrane Library from 1 January 2000 to 19 April 2023 to compare CUR treatment of PF with a no-intervention model group. A previous registration (nsply registration number: INPLASY202360084) of this review protocol was undertaken. Results: The meta-analysis included 27 publications and 29 studies involving 396 animals. CUR significantly improved the degree of fibrosis, levels of inflammation, and oxidative imbalances in lung tissue in animal models of PF. In terms fibrosis, such as HYP content (SMD = -4.96; 95% CI = -6.05 to -3.87; p = 0.000).In terms of inflammatory indicators, such as MPO activity (SMD = -2.12; 95% CI = -4.93 to 0.69; p = 0.000). In terms of oxidation index, such as MDA (SMD = -5.63; 95% CI = -9.66 to -1.6; p = 0.000). Conclusion: CUR significantly improved the degree of fibrosis, levels of inflammation, and oxidative imbalances in lung tissue in animal models of PF. Due to the quantitative and qualitative limitations of current research, more high-quality studies are needed to verify the above conclusion.

Amelioration of Bleomycin and Methotrexate-Induced Pulmonary Toxicity by Serratiopeptidase and Fisetin

Pulmonary toxicity by anticancer drugs often leads to discontinuation of therapy or switching the therapy to alternative drugs. In the present study, serratiopeptidase (SPTD) and fisetin (FST) were evaluated as chemoprotectant to counteract the pulmonary toxicity induced by BLM and MTX. Single dose of MTX (20 mg/kg) by intraperitoneal and BLM (5 mg/kg) by intra-tracheal route was administered on 7^th day of study. SPTD (20 mg/kg), FST (25 mg/kg), and NAC (250 mg/kg) and combinations of SPTD + NAC, SPTD + FST, and FST + NAC were administered through oral gavage for 14 days. SPTD and FST showed significant (p < 0.05) effect in MTX-induced lung toxicity by increasing reduced glutathione (GSH) and decreasing malondialdehyde (MDA), hydroxyproline (HXP), and collagen. SPTD and NAC showed significant (p < 0.05) effect in BLM-induced pulmonary toxicity by increasing GSH and decreasing MDA, HXP, and collagen whereas FST was not much effective. In combination study, SPTD + NAC combination showed significant (p < 0.05) effect in BLM- and MTX- induced lung injury whereas other combinations did not prove to be highly effective. SPTD can be recommended along with BLM and MTX in chemotherapy protocol alone and in combination with NAC.

Airway Redox Homeostasis and Inflammation Gone Awry: From Molecular Pathogenesis to Emerging Therapeutics in Respiratory Pathology

As aerobic organisms, we are continuously and throughout our lifetime subjected to an oxidizing atmosphere and, most often, to environmental threats. The lung is the internal organ most highly exposed to this milieu. Therefore, it has evolved to confront both oxidative stress induced by reactive oxygen species (ROS) and a variety of pollutants, pathogens, and allergens that promote inflammation and can harm the airways to different degrees. Indeed, an excess of ROS, generated intrinsically or from external sources, can imprint direct damage to key structural cell components (nucleic acids, sugars, lipids, and proteins) and indirectly perturb ROS-mediated signaling in lung epithelia, impairing its homeostasis. These early events complemented with efficient recognition of pathogen- or damage-associated recognition patterns by the airway resident cells alert the immune system, which mounts an inflammatory response to remove the hazards, including collateral dead cells and cellular debris, in an attempt to return to homeostatic conditions. Thus, any major or chronic dysregulation of the redox balance, the air-liquid interface, or defects in epithelial proteins impairing mucociliary clearance or other defense systems may lead to airway damage. Here, we review our understanding of the key role of oxidative stress and inflammation in respiratory pathology, and extensively report current and future trends in antioxidant and anti-inflammatory treatments focusing on the following major acute and chronic lung diseases: acute lung injury/respiratory distress syndrome, asthma, chronic obstructive pulmonary disease, pulmonary fibrosis, and cystic fibrosis.