Ethnopharmacology and the development of natural PAF antagonists as therapeutic agents

Chemistry of ginkgolides: structure–activity relationship as PAF antagonists

“…The main pharmacological actions are antagonist on PAF induced thrombosis, lung anaphylaxis, cardiac anaphylaxis, transplant rejection, immune disorder, etc. [7]. Ginkgolides derive from one of the most complex natural molecular framework.…”

Enantioselective synthesis of (−)-paeonilide

“…14 Due to the medicinal interest in the Ginkgo biloba extracts over 8000 tons of dried leaves are produced each year. 20 Due to the structural similarity between Ginkgolides and Paeonilide (+)- (5), it was tested in bioassays. 11 The results showed a selective inhibition of the platelet aggregation induced by the phospholipide PAF (7) (platelet activating factor, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) with an IC 50 value of 25 M (8 g/mL), but no effect on the platelet aggregation induced by adenoside diphosphate (ADP) (8) or arachidonic acid (AA) (9) (Figure 3).…”

Suppression of lipopolysaccharide-induced expression of inflammatory indicators in RAW 264.7 macrophage cells by extract prepared fromGinkgo bilobacambial meristematic cells

“…Ginkgo nut extract has been used to treat asthma and cough (Smith & Luo, 2004) while extract from the leaves is known to have anticancer (Zhang et al, 2008) and antioxidant (Sener et al, 2007) properties as well as a role in the improvement of blood circulation (Huang et al, 2004). Reports indicate that the administration of ginkgo leaf extract resulted in decreases in platelet aggregation, allergic reaction, general inflammatory response, oxygen radical discharge, and other pro-inflammatory functions of macrophages (Braquet, 1987;Braquet & Hosford, 1991). More importantly, studies suggest increased blood flow and anti-inflammatory effects resulting from ginkgo leaf extract are related to the inhibition of COX and lipoxygenase activity (Houghton, 1994).…”