The flavonoids of Trichosanthis Fructus in improving ALI mice based on AUF-MS-SPR.

OBJECTIVES

To investigate the anti-inflammatory mechanism and potential bioactive compounds of the flavonoids of Trichosanthis Fructus (TF) in LPS-induced acute lung injury (ALI) mice.

METHODS

The active fraction of TF was screened based on nitric oxide (NO) levels in RAW264.7 cells, and its antioxidant capacity was evaluated in BEAS-2B cells. Balb/c mice were intratracheally instilled with LPS (3 mg/kg), and the levels of Interleukin-1β (IL-1β), IL-6, and Tumor necrosis factor alpha (TNF-α) in serum and lung were measured. The targets of TF intervention in ALI were predicted using Western blotting. The compounds that bind specifically to the targets were identified by affinity ultrafiltration mass spectrometry, and then validated the binding specificity using surface plasmon resonance technology.

KEY FINDINGS: The NO level in LPS-induced RAW264.7 was significantly reduced by the ethyl acetate fraction of TF (TF-EA), and the reactive oxygen species level in H2O2-induced BEAS-2B cells was also decreased. Subsequently, TF-EA may significantly improve LPS-induced ALI in mice by EGFR and TLR4-mediated PI3K/Akt signaling pathway. The flavonoids especially rutin, luteolin-7-O-glucoside, apigenin-7-O-glucoside, and diosmetin-7-O-glucoside had better binding with Epidermal growth factor receptor (EGFR) and Toll-like receptor 4 (TLR4).

CONCLUSIONS

The TF-EA may reduce the release of inflammatory factors by affecting the PI3K/Akt signaling pathway mediated by EGFR and TLR4.