New biflavonoids isolated from Xylia kerrii leaves extract with selective cytotoxicity against MH7A human rheumatoid arthritis synovial fibroblast cells

Abstract

Three new biflavonoids (1–3) and two known flavonoids (4, 5) were isolated from Xylia kerrii collected in Thailand. Compounds 1–5 showed selective cytotoxicity against the rheumatoid fibroblast-like synovial MH7A cell line, and these compounds showed weak cytotoxicity against the human lung synovial fibroblast WI-38 VA13 sub 2 RA cell line. Notably, compound 1 was highly selective toward MH7A cells with an IC₅₀ value of 6.9 μM, whereas the IC₅₀ value for WI-38 VA13 sub 2 RA cells was > 100 μM. The western blotting analysis of MH7A cells treated with compound 1 showed increased CDKN2A /p16INK4A and caspase-8 levels.

Graphical abstract