Proanthocyanidins attenuates ferroptosis against influenza-induced acute lung injury in mice by reducing IFN-γ.

BACKGROUND: Acute lung injury (ALI) is associated with high morbidity and mortality and is partly driven promoted by ferroptosis. Proanthocyanidins (PAs) is a natural bioactive flavonoid with anti-inflammatory and antioxidant activities. PAs can also significantly protect against acute lung inflammation and ferroptosis in alveolar epithelial cells. However, it is unclear whether PAs can alleviate ALI by reducing ferroptosis. This study aimed to evaluate the protective effects of PAs and the potential mechanisms against Influenza A virus (IAV)-induced ALI. METHODS: Mice were inoculated nasally with IAV to induce ALI. IAV-induced pulmonary inflammation and ferroptosis was tested by measuring the levels of malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11) and acyl-CoA synthetase long-chain family member (ACSL4) in lung tissue. The potential targets that PAs protect against IAV-induced ALI were determined via a systemic pharmacological analysis. The molecular mechanism of PAs in ALI treatment was investigated by assessing the level of inflammation and ferroptosis markers using Western Blot and quantitative real-time PCR. RESULTS: Systemic pharmacological analysis suggested that PAs protect against IAV-induced pneumonia thorough TGF-ß1 and its relative signaling pathway. PAs effectively alleviated histopathological lung injury, reduced inflammatory cytokines and chemokines secretion, which were increased in IAV-infected mice. Meanwhile, PAs further prevented mouse airway inflammation in ALI, concomitant with the decreased expression TGF-ß1, smad2/3, p-Smad2, p-Smad3 and ferroptosis mediator IFN-γ. Furthermore，IFN-γ promotes cell lipid peroxidation and ferroptosis，PAs significantly reduced MDA and ACSL4 levels and upregulated GSH, GPX4, and SLC7A11. CONCLUSION: Overall, PAs can attenuate ferroptosis against IAV-induced ALI via the TGF-ß1/Smad2/3 pathway and is a promising novel therapeutic candidate for ALI.

Protective effect of paeoniflorin on H2O2 induced Schwann cells injury based on network pharmacology and experimental validation.

This study was to investigate the protective effect of paeoniflorin (PF) on hydrogen peroxide-induced injury. Firstly, "SMILES" of PF was searched in Pubchem and further was used for reverse molecular docking in Swiss Target Prediction database to obtain potential targets. Injury-related molecules were obtained from GeenCards database, and the predicted targets of PF for injury treatment were selected by Wayne diagram. For mechanism analysis, the protein-protein interactions were constructed by String, and the KEGG analysis was conducted in Webgestalt. Then, cell viability and cytotoxicity assay were established by CCK8 assay. Also, the experimental cells were allocated to control, model (200 µmol·L-1 H2O2), SB203580 10 µmol·L-1 (200 µmol·L-1 H2O2+ SB203580 10 µmol·L-1), PF 50 µmol·L-1 (200 µmol·L-1 H2O2+ PF 50 µmol·L-1), and PF 100 µmol·L-1 (200 µmol·L-1 H2O2+ PF 100 µmol·L-1) groups. We measured the intracellular ROS, Hoechst 33258 staining, cell apoptosis, the levels of Bcl-xl, Bcl-2, Caspase-3, Cleaved-caspase3, Cleaved-caspase7, TRPA1, TRPV1, and the phosphorylation expression of p38MAPK. There are 96 potential targets that may be associated with PF for injury treatment. Then, we chose the "Inflammatory mediator regulation of TRP channels" pathway for the experimental verification from the first 10 KEGG pathway. In experimental verification, H2O2 decreased the cell viability moderately (P < 0.05), and 100 µmol·L -1 PF increased the cell viability significantly (P < 0.05). Depending on the difference of intracellular ROS fluorescence intensity, PF inhibited H 2O2-induced reactive oxygen species production in Schwann cells. In Hoechst 33258 staining, PF reversed the condensed chromatin and apoptotic nuclei following H2O2 treatment. Moreover, Flow cytometry results showed that PF could substantially inhibit H2O2 induced apoptosis (P < 0.05). Pretreatment with PF obviously reduced the levels of Caspase3, Cleaved-caspase3, Cleaved-caspase7, TRPA1, TRPV1, and the phosphorylation expression of p38MAPK after H 2O2 treatment (P < 0.05), increased the levels of Bcl-2, and Bcl-xl ( P < 0.05). PF inhibited Schwann cell injury and apoptosis induced by hydrogen peroxide, which mechanism was linked to the inhibition of phosphorylation of p38MAPK.