Anti-inflammatory effects of chemical components from Ginkgo biloba L. male flowers on lipopolysaccharide-stimulated RAW264.7 macrophages.

Ginkgo biloba L., well known as living fossil, have various pharmacological activities. Eighteen compounds were isolated from Ginkgo male flowers including a novel matsutake alcohol glycoside, Ginkgoside A (1), and 17 known compounds-calaliukiuenoside (2), benzylalcohol O-α-l-arabinopyranosyl-(1 → 6)-β-d-glucopyranoside (3), amentoflavone (4), sciadopitysin (5), bilobetin (6), isoginkgetin (7), olivil 4-O-β-d-glucopyranoside (8), dihydrodehydrodiconiferyl alcohol-4-O-β-d-glucoside (9), (+)-cyclo-olivil-6-O-β-d-glucopyranoside (10), (-)-isolariciresinol 4-O-β-d-glucopyranoside (11), coniferin (12), trans-cinnamic acid-4-O-β-d-glucopyranoside (13), p-coumaryl alchol glucoside (14), stroside B (15), methylconiferin (16), cis-p-coumaric acid 4-O-β-d-glucopyranoside (17), and cis-coniferin (18). Thirteen of these compounds had not previously found in Ginkgo. All extractive fractions and isolated compounds were evaluated for their anti-inflammatory ability in the lipopolysaccharide-induced RAW264.7 macrophages. The ethanol extract of Ginkgo flowers and the chloroform and ethyl acetate fractions can significantly decrease nitric oxide (NO), interleukin-6 (IL-6), and prostaglandin E₂ (PGE₂ ) production at 100 μg/ml. The most effective compounds, bilobetin (6) and isoginkgetin (7), elevated the NO inhibition ratios to 80.19% and 82.37% at 50 μM, respectively. They also exhibited significant dose-dependent inhibitory effects on tumor necrosis factor-α, IL-6, PGE₂ , inducible NO synthase mRNA, and cyclooxygenase-2 mRNA levels. So they can be promising candidates for the development of new anti-inflammatory agents.