Effects of Quercetin Administration on TNF-α, IL-6, Hydroxyproline, and Ashcroft Scores in Preclinical Study of Pulmonary Fibrosis: A Systematic Review and Meta-Analysis

Abstract

Lung fibrosis, a chronic respiratory diseases which is marked by alveolar fibrosis wall thickening with limited treatment options and progression to respiratory failure. There are molecular pathways of signaling associated with pulmonary fibrosis, namely the transforming growth factor beta (TGF-β)/Smad pathway, WNT/β-catenin pathway, and PI3K/Akt/mTOR pathway. Quercetin is a flavonoid which has demonstrated potential antifibrotic and anti-inflammatory actions. This compound suppressing reactive oxygen species dependent on Smad/β-catenin. These studies were designed to evaluate the potency of quercetin in treating pulmonary fibrosis. The studies were conducted via systematic review and meta-analysis following the PRISMA 2020 protocol. Quercetin was administered at a dose of 5–100 mg/kg for 21–42 days. Meta-analysis resulted in a significant reduction in TNF-α (SMD = −3.63; 95% CI: −6.07 to −1.18; p = 0.0037), IL-6 (SMD = −1.29; 95% CI: −1.90 to −0.68; p < 0.0001), hydroxyproline (SMD = −2.95; 95% CI: −4.16 to −1.74; p < 0.0001), and Ashcroft score (SMD = −5.90; 95% CI: −9.44 to −2.36; p = 0.0011). These findings indicate that quercetin effectively reduces inflammation and severity of fibrosis in a preclinical model of pulmonary fibrosis, highlighting its potential as a therapeutic candidate.