Anti-Inflammatory Activity of Cajanin, an Isoflavonoid Derivative Isolated from Canavalia lineata Pods.

The bioactive components of Canavalia lineata (Thunb.) DC pods were investigated using bioactivity-guided isolation, and the chemical structures of flavonoids 1 - 3 , isoflavonoid derivatives 4 - 11 , and phenolic compounds 12 and 13 were identified by comparing NMR, MS, and CD spectral data with previously reported spectroscopic data. Compounds 1 - 13 were evaluated for their anti-inflammatory effects on LPS-stimulated RAW264.7 macrophages. Among these compounds, the isoflavonoid derivative cajanin ( 7 ) exhibited the most potent anti-inflammatory activity (IC 50 of NO = 19.38 ± 0.05 µM; IC 50 of IL-6 = 7.78 ± 0.04 µM; IC 50 of TNF-α = 26.82 ± 0.11 µM), exerting its anti-inflammatory effects by suppressing the activation and nuclear translocation of the transcription factor NF-κB by phosphorylating IκB and p65. These results suggested that cajanin ( 7 ) may be a potential candidate for improving the treatment of inflammatory diseases.