Triterpene and
steroid saponins and
sapogenins of medicinal plants (Aesculus hippocastanum L., Hedera helix L., Ruscus aculeatus L.) are claimed to be effective for the treatment/prevention of
venous insufficiency. In this work we evaluated the inhibitory effects of these plant constituents on the activity of
elastase and
hyaluronidase, the
enzyme systems involved in the turnover of the main components of the perivascular amorphous substance. The results evidence that for Hedera helix L., the
sapogenins only non-competitively inhibit
hyaluronidase activity in a dose-dependent fashion, showing comparable IC50 values (
hederagenin IC50 = 280.4 microM;
oleanolic acid IC50 = 300.2 microM); both the
saponins hederacoside C and
alpha-hederin are very weak inhibitors. The same behaviour is observed for
serine protease porcine
pancreatic elastase: the
glycosides are devoid of inhibitory action, while genins are potent competitive inhibitors (
oleanolic acid IC50 = 5.1 microM;
hederagenin IC50 = 40.6 microM). Constituents from Aesculus hippocastanum L. show inhibitory effects only on
hyaluronidase, and this activity is mainly linked to the
saponin escin (IC50 = 149.9 microM), less to its genin escinol (IC50 = 1.65 mM). By contrast, ruscogenins from Ruscus aculeatus L., ineffective on
hyaluronidase activity, exhibit remarkable anti-
elastase activity (IC50 = 119.9 microM; competitive inhibition). The mechanism of
elastase inhibition by
triterpene and
steroid aglycones, with a nitroanilide derivative as substrate, is discussed.