Inhibition of low density lipoprotein oxidation by myrigalone B, a naturally occurring flavonoid.

The influence of myrigalone B, a flavonoid from the fruit exudate of Myrica gale L. on Cu(2+)-induced oxidation of low density lipoprotein from cholesterol fed rabbits was investigated. Myrigalone B was an effective antioxidant, as shown by its ability to dose-dependently prolong the lag time for the formation of conjugated dienes. A 100% increase in lag time corresponds to a myrigalone B concentration of 1.4 +/- 1.1 microM. For alpha-tocopherol, used as a reference, this effect corresponds to a concentration of 1.9 +/- 1.2 microM. Myrigalone B also dose-dependently reduced the maximum rate of formation of conjugated dienes, 1.4 microM causing a 15 +/- 5% reduction, but it had no influence on the maximal amount of conjugated dienes formed.