Flavonoids with anti-inflammatory activities from Daphne giraldii

Abstract

The stem and root barks of Daphne giraldii Nitsche, also known as “Zushima”, is a traditional Chinese medicine with a long history of treating a variety of diseases such as rheumatism arthralgia, quadriplegia, headache, stomachache, waistache, and bruises. Chromatographic fractionation of the EtOH extracts of “Zushima” has led to the isolation of 26 flavonoids, including ten flavonols (1, 2, and 4–11), one flavone (12), two dihydroflavones (13 and 14), a dihydroflavonol (15), six flavans (3 and 16–20), three chalcones (21–23), and three 1,3-diarylpropanes (24–26). Daphgiflavones A−C (1–3) were new flavonoids. Their structures were elucidated by spectroscopic analysis. All compounds were evaluated for anti-inflammatory properties by testing their inhibitory activities against nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated murine RAW264.7 macrophages. Compounds 8, 11, 21, and 23 exhibited significant inhibition on NO production with IC50 values ranging from 2.26 to 6.88 μM, being more active than the positive control quercetin (IC50: 14.16 μM).

Keywords

• Daphne giraldii
• Thymelaeaceae
• Flavonoids
• Anti-inflammation