Diosmin is a derivative of benzopyron. Refers to the group of bioflavonoids, has phlebotonizing and venoprotective action, reduces the permeability of the vascular wall. Reduces the extensibility and increases the tone of the veins, reduces venous congestion in the lower limbs. The venotonic effect of diosmin is dose-dependent. The mechanism of the venotonic action of the diosmin is not fully understood.It is assumed that the drug inhibits the activity of catechol-O-methyltransferase (an enzyme that degrades norepinephrine, which increases the tone of the veins). This hypothesis was confirmed in the course of experimental studies (under the conditions "ex vivo" diosmin intensified the vasoconstrictive effect of epinephrine, norepinephrine and serotonin on isolated fragments of superficial veins of the forearm and a large human saphenous vein. It was also shown that diosmin reduces the content of serum enzymes responsible for the metabolism of mucopolysaccharides in the venous wall.
In clinical trials diosmin reduced the capacity of the venous bed and the volume of venous congestion (according to plethysmography), reduced the average pressure in the deep and superficial veins of the legs (according to ultrasound Doppler ultrasound) and increased systolic and diastolic arterial pressure in patients with postoperative orthostatic hypotension.
Diosmin improves lymphatic drainage, increases the tone and frequency of lymphatic capillary contraction, increases their functional density, and reduces lymphatic pressure.
Diosmin improves microcirculation. In experimental studies diosmin increased the resistance of capillaries (dose-dependent effect) and reduced their permeability in rats and guinea pigs with vitamin P deficiency, and also reduced capillary permeability induced by chloroform, histamine and hyaluronidase.
Diosmin reduces the adhesion of leukocytes to the venous wall and their migration to parainous tissues, improves diffusion of oxygen and perfusion in the skin tissue. In experimental studies diosmin had an anti-inflammatory effect, blocking the production of free radicals, the synthesis of prostaglandins and thromboxane.