Discovery of anti-inflammatory chemical constituents from Baliospermum calycinum Müll. Arg

To discover anti-inflammatory compounds from Baliospermum calycinum Müll. Arg., a bioactivity-guided approach was employed. The 95% ethanolic extract of the aerial parts was partitioned into petroleum ether, ethyl acetate, n-butanol, and water fractions, which were screened for inhibitory effects on NO production in LPS-stimulated RAW 264.7 macrophages. The ethyl acetate fraction showed the strongest activity and significantly attenuated carrageenan-induced paw edoema and xylene-triggered ear edoema, and this effect was associated with reduced TNF-α and IL-1β levels. Further phytochemical investigation on the active fraction yielded eight compounds (1–8). Compounds 1 and 8 were obtained from the genus Baliospermum for the first time, while 3–5 were firstly reported from B. calycinum. Anti-inflammatory evaluation showed that compound 5 suppressed NO production and significantly downregulated TNF-α and IL-6 levels in LPS-activated RAW 264.7 macrophages. These results provide further evidence for the traditional use of B. calycinum in Dai medicine for managing inflammation-related conditions.