Isolation of ellagitannins from Gei urbani radix cum rhizoma and determination of extract's anti-inflammatory activity

Geum urbanum L. is a plant from Rosaceae family. Extracts from its underground parts are traditionally used in external treatment of different skin and mucosa diseases. Despite its position in folk medicine, the external use does not possess any scientific support.

The aim of the study was to perform phytochemical examination and to isolate dominating compounds, as well as to determine inhibition of elastase, hyaluronidase and lipoxygenase activity by Geum urbanum L.

The structures of ellagitannins isolated using column chromatography and preparative HPLC were determined by NMR analysis. Inhibition of hyaluronidase activity was determined by turbidimetric method [1]. Inhibition of LOX activity was determined by spectrophotometric monitoring of linoleic acid oxidation [2]. Inhibition of elastase activity was determined using stimulated neutrophils isolated from venous blood from healthy volunteers by colorimetric method [3].

Two novel ellagic acid derivatives and five known ellagitannins: pedunculagin, stachyurin, casuarinin, gemin G, and dominating gemin A, not previously reported in Geum urbanum L. were isolated. Inhibitory values for LOX: extract at 10 µg/mL 48.7 ± 2.2%, gemin A at 10µM 87.0 ± 2.5% comparing to indomethacin at 50 µg/mL 30.8 ± 2.7%. The IC₅₀ value for hyaluronidase inhibition: extract 12.9 ± 1.1 µg/mL and gemin A 5.3 ± 0.6µM versus reference agent: heparin 62.1 ± 7.51 µg/mL. Elastase release from stimulated neutrophils was inhibited in 30.4 ± 4.8% by aqueous extract at concentration of 10 µg/mL versus quercetin with 44.8 ± 6.6% at 10µM.

These observations can support the traditional use of extracts from Geum urbanum L. in external treatment of skin and mucosa pathologies with inflammatory background.

References:

[1] Piwowarski JP, Kiss AK, Kozłowska-Wojciechowska M, J. Ethnopharm. 2011, 137, 937 – 941

[2] Ling SK, Tanaka T, Kuono I, Biol. Pharm. Bull. 2003, 26, 352 – 356

[3] Kiss AK, Bazylko A, Filipek A, et al., Phytomed. 2011, 18, 557 – 560