Kinase Assay: |
Faseb Journal, 2011, 25(1):772. | Velutin reduces lipopolysaccharide-induced proinflammatory cytokine TNFα and IL-6 production by inhibiting NF-κB activation.[Reference: WebLink] | Five flavonoids, (2S,3S)-dihyrokaempferol 3-O-b-D-glucoside (1) and its isomer (2R,3R)-dihydrokaempferol 3-O-b-D-glucoside (2) , isovitexin (3), Velutin (4) and 5,40-dihydroxy-7,30,50-trimethoxyflavone (5), were isolated from acai (Euterpe oleracea Mart.) pulp. METHODS AND RESULTS: The structures of these compounds were elucidated based upon spectroscopic and chemical analyses. To our knowledge, compounds 1, 2, 4 and 5 were identified from acai pulp for the first time. The in vitro antioxidant activities of these compounds were evaluated by the oxygen radial absorbance capacity (ORAC) assay. The ORAC values varied distinctly (4458.0–22404.5 lmol Trolox equivalent (TE)/g) from 5,40-dihydroxy-7,30,50-trimethoxyflavone (5) to isovitexin (3) and were affected by the numbers/positions of hydroxyl groups, substitute groups, as well as stereo configuration. The anti-inflammatory effects of these compounds were screened by the secreted embryonic alkaline phosphatase (SEAP) reporter assay, which is designed to measure NF-jB activation. Velutin (4) was found to dose-dependently inhibit SEAP secretion in RAW-blue cells induced by LPS, with an IC50 value of 2.0 lM. Velutin (4) also inhibited SEAP secretion induced by oxidised LDL, indicating potential athero-protective effects. |
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