ABSTRACT
Dihydroflavonol taxifolin and its glycoside, astilbin, from Engelhardtia chrysolepis inhibited rat lens and recombinant human aldose reductase. Taxifolin also inhibited sorbitol accumulation in human red blood cells. Furthermore, this dihydroflavonol aglycone maintained the clarity of rat lens incubated with a high concentration of glucose. These dihydroflavonols may be effective for preventing osmotic stress in hyperglycemia.
Subject(s)
Aldehyde Reductase/metabolism , Flavonoids/pharmacology , Quercetin/analogs & derivatives , Sorbitol/metabolism , Trees/drug effects , Animals , Erythrocytes/drug effects , Erythrocytes/enzymology , Erythrocytes/metabolism , Flavonols , Humans , Lens, Crystalline/drug effects , Lens, Crystalline/enzymology , Lens, Crystalline/metabolism , Quercetin/pharmacology , Rats , Recombinant Proteins/metabolism , Trees/enzymology , Trees/metabolismABSTRACT
Astilbin and neoastilbin, dihydroflavonol rhamnosides from Engelhardtia chrysolepis, showed potent inhibition of lens aldose reductase. Kinetic analysis showed astilbin exhibited uncompetitive inhibition against both dl-glyceraldehyde and NADPH. These taxifolin glycosides were selective inhibitors of aldose reductase with no inhibition of NADH oxidase.
Subject(s)
Aldehyde Reductase/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Flavonoids/pharmacology , Flavonols , Kidney/enzymology , Lens, Crystalline/enzymology , Plants/chemistry , Animals , Cattle , Drugs, Chinese Herbal , Glyceraldehyde/pharmacology , Kinetics , Mitochondria, Liver/enzymology , Multienzyme Complexes/analysis , NADH, NADPH Oxidoreductases/analysis , NADP/pharmacology , Plant Leaves/chemistry , Quercetin/pharmacology , SwineABSTRACT
The sulfated flavonoids in Polygonum hydropiper showed potent inhibiton against lens aldose reductase. Among these flavonoids isorhamnetin 3,7-disulfate (5) was most potent. Kinetic analysis showed that 5 exhibited noncompetitive inhibition against both dl-glyceraldehyde and NADPH.
Subject(s)
Aldehyde Reductase/antagonists & inhibitors , Enzyme Inhibitors/isolation & purification , Flavonoids/isolation & purification , Lens, Crystalline/enzymology , Plants, Medicinal/chemistry , Animals , Cattle , Enzyme Inhibitors/pharmacology , Flavonoids/pharmacology , Kidney/enzymology , Liver/enzymology , Mitochondria, Liver/drug effects , Mitochondria, Liver/enzymology , NADH, NADPH Oxidoreductases/antagonists & inhibitors , SwineABSTRACT
A naturally occurring p-benzoquinone derivative, maesanin, inhibited porcine lens aldose reductase. Systematic investigation of related p-benzoquinone derivatives revealed that 2,5-dihydroxy-p-benzoquinone was a potent inhibitor of aldose reductase and aldehyde reductase but had no effect on NADH oxidase. Kinetic analysis showed this p-benzoquinone exhibited uncompetitive inhibition against DL-glyceraldehyde and noncompetitive inhibition against NADPH.
