| Horse chestnut extract (HCE), containing 70% escin, is the main
active component of Veinotonyl 75. The aim of this work was to
investigate pharmacological properties attempting to elucidate the
efficacy of HCE in chronic venous insufficiency. Veinotonic and
lymphagogue properties: HCE dose dependently contracts the canine
saphenous isolated vein (cumulative doses 5 x 10(-8) to 5 x 10(-4)
g/ml). Its action lasts more than 5 h. In the perfused canine
saphenous vein, HCE (25-50 mg in bolus) increases the venous pressure
of the normal vein and the pathological vein stenosed 8 days before,
and the contractile response to noradrenaline is significantly
potentiated. Moreover, during the perfusion in inverse direction of
the blood stream, a clear contracting effect on the valves is also
obtained with HCE. In the anaesthetized dog, HCE in situ improves the
femoral vein compliance and opposes the venous distension obtained
during clamping in a carotido-femoral perfusion with constant flow.
In other respects, HCE significantly increases femoral venous
pressure and flow, together with thoracic lymphatic flow, while
respecting the arterial parameters (2.5 and 5 mg/kg i.v.).
Vasculotropic action: HCE dose dependently diminishes the cutaneous
capillary hyperpermeability induced either by injections of
phlogistic agents as histamine and serotonin in the rat (100 to 400
mg/kg p.o.), or by an irritative agent (chloroform) application in
the rabbit (50 to 300 mg/kg p.o. and 2.5 to 5 mg/kg i.v.). It
significantly increases the vascular resistance in the guinea pig fed
a scorbutigenic diet as measured by the petechia method (50 to 400
mg/kg p.o.). Antiedema and antiinflammatory properties: HCE decreases
the formation of edemas induced in the rat's hind paw, one of
lymphatic origin, the other of inflammatory origin (200 to 400 mg/kg
p.o.). In an experimental model of pleurisy in the rat HCE suppresses
plasmatic extravasation and leucocytes emigration into the pleural
cavity (200 to 400 mg/kg p.o.; 1 to 10 mg/kg i.v.). It decreases the
connective tissue formation in the subchronic model of inflammatory
granuloma in the rat (400 mg/kg p.o. and 5-10 mg/kg s.c.).
Antiradical mechanism of action both in vitro and in vivo: HCE dose
dependently inhibits both enzymatic and non-enzymatic in vitro lipid
peroxidation (5 x 10(-6) to 5 x 10(-4) g/ml).(ABSTRACT TRUNCATED AT
400 WORDS)
|