Protective effect of polyphenols in an inflammatory process associated with experimental pulmonary fibrosis in mice

Abstract

Polyphenols have been described to have a wide range of biological activities, and many reports, published during recent years, have highlighted the beneficial effects of phenolic compounds, illustrating their promising role as therapeutic tools in several acute and chronic disorders. The purpose of study was to evaluate, in an already-assessed model of lung injury caused by bleomycin (BLM) administration, the role of resveratrol and quercetin, as well as to explore the potential beneficial properties of a mango leaf extract, rich in mangiferin, and a grape leaf extract, rich in dihydroquercetin (DHQ), on the same model. Mice were subjected to intra-tracheal administration of BLM, and polyphenols were administered by oral route immediately after BLM instillation and daily for 7 d. Treatment with resveratrol, mangiferin, quercetin and DHQ inhibited oedema formation and body weight loss, as well as ameliorated polymorphonuclear infiltration into the lung tissue and reduced the number of inflammatory cells in bronchoalveolar lavage fluid. Moreover, polyphenols suppressed inducible nitric oxide synthase expression, and prevented oxidative and nitroxidative lung injury, as shown by the reduced nitrotyrosine and poly (ADP-ribose) polymerase levels. The degree of apoptosis, as evaluated by Bid and Bcl-2 balance, was also suppressed after polyphenol treatment. Finally, these natural products down-regulated cyclo-oxygenase-2, extracellular signal-regulated kinase phosphorylated expression and reduced NF-κBp65 translocation. Our findings confirmed the anti-inflammatory effects of resveratrol and quercetin in BLM-induced lung damage, and highlight, for the first time, the protective properties of exogenous administration of mangiferin and DHQ on experimental pulmonary fibrosis.

Evaluation of antioxidant, antiinflammatory, and gastroprotective properties of Rubus fruticosus L. fruit juice

“…In fact, the inhibition of proinflammatory responses (NO, iNOS, COX‐2, and PGE 2 ) by polyphenols contained in Mexican blackberry ( Rubus spp) extracts has been widely demonstrated, highlighting a significant correlation between antioxidant capacity and NO inhibition (Cuevas‐Rodríguez et al, ). Thus, the antioxidant and antiinflammatory properties of polyphenols, in agreement with previous studies, could be attributed to the reduction of the nitrosative stress and subsequent formation of NO (Impellizzeri et al, , ; Mandalari et al, , ; Paterniti et al, ).…”

Geraniin Inhibits LPS-Induced THP-1 Macrophages Switching to M1 Phenotype via SOCS1/NF-κB Pathway

“…One of the most interesting activities of polyphenolic compounds is their ability to modulate the macrophage immune response [9]. Several studies have demonstrated that polyphenolic compounds have a certain degree of anti-inflammatory activity [10][11][12]. Geraniin is a polyphenolic compound that has a wide range of bioactive properties, including anti-oxidant activity, protecting from infections, exerting immunological effects, and inducing metabolic changes [13].…”

Silica‐induced initiation of circular ZC3H4 RNA/ZC3H4 pathway promotes the pulmonary macrophage activation

“…Recent evidence suggests that AMO polarization and activation have a crucial role in early inflammatory responses associated with fibrosis induced by SiO 2 (29–31). In this study, we examined the expression of F4/80, a macrophage marker, in an in vivo animal model and observed that the expression of F4/80 was significantly increased after 28 d of SiO 2 treatment compared with that in a normal saline (NS) ( Fig.…”