Total flavonoids from the aerial parts of Tetrastigma hemsleyanum prevent LPS-induced ALI by modulating the TLR4/NF-κB pathway in mice.

BACKGROUND: The traditional Chinese medicine Tetrastigma Hemsleyanum (TH) is employed in treating respiratory diseases; however, the aerial parts by which its total flavonoids alleviate acute lung injury (ALI) are still unknown. This study investigated the protective effect and mechanism of Tetrastigma Hemsleyanum flavonoids (THF) in lipopolysaccharide (LPS)-induced ALI in mice.

METHODS: Firstly, the total flavonoids from the above-ground part of TH were extracted. Subsequently, the composition of THF was analyzed using LC-MS. In vivo, the impact of THF on ALI mice was assessed through lung histopathology and the evaluation of various inflammatory factors' expression in mice. After treating RAW264.7 cells with THF in vitro, changes in inflammatory markers were examined upon LPS stimulation, and mRNA expression levels of inflammatory factors were detected using RT-qPCR. Finally, Western blot analysis was performed to determine TLR4/NF-κB pathway-associated proteins expression.

RESULTS: In summary, a total of 24 flavonoids have been identified in THF. In vivo and vitro results show that THF effectively reduces the damage caused by LPS inflammation by blocking the expression and release of inflammatory factors. THF alleviates inflammatory injury by modulating the TLR4/NF-KB pathway.

CONCLUSION: The results suggest that flavonoids exhibit a potent anti-inflammatory effect and effectively mitigate LPS-induced injury both in vivo and in vitro. We suggested that these flavonoids exert their therapeutic effects by modulating the TLR4/NF-KB pathway. In conclusion, the development of THF is anticipated to represent a promising new pharmaceutical for treatingALI.