Effects of hypolaetin-8-glucoside and related flavonoids on soybean lipoxygenase and snake venom phospholipase A2.
Hypolaetin-8-glucoside, a novel flavonoid isolated from Sideritis mugronensis and possessing anti-inflammatory and gastroprotective properties in the rat, was compared with the structurally related flavonoids hypolaetin, isoscutellarein, rutin, quercetin and kaempferol for inhibitory effects on the enzymes soybean 15-lipoxygenase and snake venom phospholipase A2. The aglycone flavonoids dose-dependently inhibited snake venom phospholipase A2 but the glycosides hypolaetin-8-glucoside and rutin were inactive. All 6 flavonoids inhibited soybean 15-lipoxygenase with no differences between glycosides and aglycones, although flavonols appeared more active than flavones. The inhibition of these enzyme activities cannot explain the anti-inflammatory action of hypolaetin-8-glucoside, unless a significant proportion of the drug reaches the target tissue as the aglycone, hypolaetin.
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology*; D016859:Lipoxygenase Inhibitors; D010713:Phosphatidylcholines / Q000378:metabolism; D010740:Phospholipases / Q000037:antagonists & inhibitors*; D010741:Phospholipases A / Q000037:antagonists & inhibitors*; D054467:Phospholipases A2; D012910:Snake Venoms / Q000032:analysis; D013025:Glycine max / Q000032:analysis
D001095:Arachidonic Acids; D005419:Flavonoids; D016859:Lipoxygenase Inhibitors; D010713:Phosphatidylcholines; D012910:Snake Venoms; D016718:Arachidonic Acid; C044475:hypolaetin-8-glucoside; D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2