Effect of flavonoids on protease activities in human skeletal muscle tissue in vitro

The effect of a representative range of flavonoid compounds on the activiti es of a range of proteolytic enzyme types in human skeletal muscle tissue w as determined in vitro. All of the proteases showed some degree of inhibiti on by all of the flavonoid compounds investigated, with IC50 values (concen tration of flavonoid required to inhibit initial activity of muscle proteas es by 50%) for various enzyme/flavonoid combinations ranging from approx. 5 0 mu mol/l to 2 mmol/l. These data demonstrate that in addition to their we ll described antioxidant characteristics, flavonoids also possess novel ant iproteolytic inhibitory activity in vitro, which may in part explain some o f the beneficial effects of these plant derived compounds in vivo. (C) 1999 Elsevier Science BN. All rights reserved.