Natural neuro-inflammatory inhibitors from Caragana turfanensis

Abstract Because of the critical role of over-activated microglia in the progress of neurodegenerative diseases, it has been selected as a potential therapeutic target for drug discovery. In order to find natural neuroinflammatory inhibitors, we carried out a bioactivity-oriented phytochemical research of Caragana turfanensis Kom. (Krassn.), which is a folk medicine widely distributed in Xinjiang. As a result, a new coumarin lactone caraganolide A ( 1 ) and 35 known components were characterized from the effective extract of C. turfanensis . Furthermore, their anti-neuroinflammatory effects were evaluated in LPS-induced BV2 microglial cells using Griess assay to determine the release of nitric oxide (NO). Compounds 1 , 2 , 4 – 6 , 9 , 13 – 15 , 20 , 29 and 30 exhibited significant inhibitory activities and no obvious cytotoxicities were observed at their effective concentrations. It is noteworthy, the new compound caraganolide A ( 1 ) (IC 50 1.01 ± 1.57 µM) and 3′,7,8-trihydroxy-4′-methoxyisoflavone ( 5 ) (IC 50 6.87 ± 2.23 µM) exhibited more excellent action than that of positive control minocycline (IC 50 9.07 ± 0.86 μM).