Lonicerae japonicae flos Polyphenols Attenuate Inflammation-Related Ferroptosis and Gut Microbiota Dysbiosis in LPS-Induced Acute Lung Injury in Mice.

Background/

Objectives

Acute lung injury (ALI) currently lacks safe and effective therapeutic strategies with low toxicity. Lonicerae japonicae flos, a traditional herb and functional food, contains polyphenols as its principal active components. This study investigated whether Lonicerae japonicae flos polyphenols (LJP) could exert protective effects against lipopolysaccharide (LPS)-induced ALI in mice.

Methods

Eighty-four male C57BL/6J mice were randomly divided into seven groups and treated daily for 7 days with LJP (200, 100, or 50 mg/kg), liproxstatin-1 (10 mg/kg), dexamethasone (5 mg/kg), or saline (control and model groups). Subsequently, another thirty-six mice were used for the fecal microbiota transplantation (FMT) experiment. All groups except the control group received intratracheal instillation of LPS (5 mg/kg) to induce ALI.

Results

LJP treatment significantly ameliorated lung histopathological damage and gut microbiota dysbiosis. Lung proteomics analysis revealed the enrichment of the NF-κB and ferroptosis pathways. Mechanistically, LJP downregulated pro-inflammatory factors (IL-6, TNF-α, and IL-1β) by suppressing activation of the TLR4/MyD88/NF-κB pathway. Meanwhile, LJP upregulated SOD and GSH levels, thereby suppressing the accumulation of ROS, GSSG, Fe2+, and MDA, which were closely related to the activation of the Nrf2/HO-1 and Sirt3/Nrf2/GPX4 pathways. Furthermore, LJP modulated the gut microbiota and promoted short-chain fatty acid (SCFA) production by elevating the relative abundance of Akkermansia muciniphila and Faecalibaculum. Intriguingly, FMT results confirmed that the LJP-derived gut microbiota markedly alleviated lung tissue injury and intestinal barrier damage in ALI mice.

Conclusions

This study demonstrated that LJP could reshape the gut microbiota to enhance the production of SCFAs and inhibit inflammation-related ferroptosis in ALI mice.