Flavonoids as inhibitors of lens aldose reductase.

Flavonoids are effective inhibitors of lens aldose reductase. Quercetin, quercitrin, and myricitrin are significantly more potent than the previously known aldose reductase inhibitors. The inhibitory activity is of the noncompetitive type. In addition, quercitrin effectively blocks polyol accumulation in intact rat lenses incubated in medium containing high concentration of sugars.