Flavonoids and phenolic acids from Lablab Flos Alba and their anti-inflammatory activity via NLRP3 inflammasome

The flowers of Dolichos lablab L. (Lablab Flos Alba), a dual-purpose medicinal and dietary plant, exhibit significant nutritional and bioactive properties, though their phytochemical basis remains poorly characterized. To address this, a detailed phytochemical investigation was carried out on it, and twelve new compounds, namely flosdolilabflavonosides A 1 -A 5 , B ( 1 – 6 ), flosdolilabphenosides A, B, C 1 , C 2 , D 1 , D 2 ( 7 – 12 ), along with thirty-two known flavonoids ( 13 – 44 ) were obtained. Twenty-six of the known isolates were reported for the first time in Lablab Flos Alba . And nine constituted new records for the Lablab genus. The effects of compounds 1 – 12 on the NLRP3 inflammasome were further explored by using LPS/Nigericin-stimulated bone marrow-derived macrophages (BMDMs) as in vitro model. Elisa assay revealed that compounds 6 , 8 , and 12 could significantly inhibit the release of interleukin-1 β (IL-1 β ). Mechanistic studies via Western blotting demonstrated their dual regulatory effects: pretreatment with compounds 6 , 8 , and 12 downregulated NLRP3 and pro-IL-1 β expression prior to LPS stimulation, while post-treatment with LPS/nigericin markedly reduced levels of cleaved IL-1 β and cleaved caspase-1. These findings indicate that the anti-inflammatory activity of compounds 6 , 8 , and 12 arises from their interference with both the priming phase and the activation phase of NLRP3 inflammasome signaling. • 44 compounds including 12 new ones were isolated and identified from Lablab Flos Alba . • Elisa assay indicated compounds 6 , 8 and 12 inhibited the release of IL-1 β . • 6 , 8 and 12 exerted anti-inflammatory effect through NLRP3 inflammasome pathway.