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 E 2 (PGE 2 ) 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, PGE 2 , inducible NO synthase mRNA, and cyclooxygenase‐2 mRNA levels. So they can be promising candidates for the development of new anti‐inflammatory agents.