Anti-inflammatory activities of fractions from Geranium nepalense and related polyphenols

Geranium nepalense Sweet is a common Chinese herbal medicine and has been used as influenza, dysentery, antiphlogistic and analgesic tonic, hemostatic, stomachic, and antidiabetic drugs. The anti-inflammatory effects of G. nepalense on tetradecanoyl phorbol acetate (TPA)-induced mouse ear edema were studied in this work. The results showed that ethyl acetate fraction of the water extract of G. nepalense possessed significant activity at 2.5 g/kg (p < 0.01) with aspirin as a positive control (0.6 g/kg). Six polyphenolic compounds, including three flavonoids, i.e. kaempferol, kaempferol-7-O-β-D-glucopyranoside, and quercetin-7-O-α-rhamnopyranoside, and two tannins, i.e. pyrogallol and gallic acid, and one lignin, i.e. epipinoresinol, were isolated and characterized from ethyl acetate fraction. The isolation of polyphenols provides a clue for beneficial effects of G. nepalense in the demonstrated anti-inflammatory activity.