[Anthocyanosides and the walls of the microvessels: further aspects of the mechanism of action of their protective effect in syndromes due to abnormal capillary fragility]. / Antocianosidi e parete dei microvasi nuovi aspetti sul modo d'azione dell'effetto protettivo nelle sindromi da abnorme fragilità capillare.

On the basis of previous biochemical observations, which have demonstrated the formation of complexes between anthocyanosides and some phospholipids, the AA. investigate the modifications induced by local and general administration of anthocyanosides 1) on the foreign body granuloma and 2) on the composition of the protein fractions in the exudate from the capillaries of the granulation tissue, growing on post-thromboflebitic or varicose leg ulcerations. The biochemical and histochemical data may show that the anthocyanosides protect the altered capillary walls with a double mechanism: a) increasing the endothelium barrier-effect through a stabilisation of the membrane phospholipids and b) increasing the biosynthetic processes of the acid mucopolysaccharides of the connective ground substance, by restoring the altered mucopolysaccharidic pericapillary sheat. This last effect may explain the marked increase of new-formed capillaries and collagen fibrils induced by the anthocyanosides.

Studies on Vaccinium myrtillus anthocyanosides. I. Vasoprotective and antiinflammatory activity.

A Vaccinium myrtillus anthocyanosides preparation (equivalent to 25% of anthocyanidins) demonstrated significant vasoprotective and antioedema properties in exerimental animals. In rabbits, the skin capillary permeability increase, due to chloroform, was reduced both after i.p. (25--100 mg/kg) and oral administration (200--400 mg/kg) of anthocyanosides. Their activity was more lasting in comparison to rutin or mepyramine and this did not seem to be due to a specific antagonism towards inflammatory process mediators such as histamine or bradykinin. Experiments carried out in rats demonstrated that Vacinium myrtillus anthocyanosides were effective both in skin capillary permeability test as well as on vascular resistance of rats fed a P factor deficient diet. In the former test effective doses were in the range of 25--100 mg/kg (by oral route). In both the animal species investigated, anthocyanosides were two-fold more active when compared to the flavonoid rutin. Vaccinium myrtillus anthocyanosides by oral route inhibited carrageein paw oedema in rats showing a dose-response relationship. An antioedema activity was detected also after i.v. or topical application.

Studies on Vaccinium myrtillus anthocyanosides. II. Aspects of anthocyanins pharmacokinetics in the rat.

Vaccinium myrtillus anthocyanins adminstered by i.v. or i.p. route to the rat undergo a rapid body distribution and in part also are easily eliminated such as to fit a three-compartments pharmacokinetic model. The anthocyanins elimination occurs mostly through urine and bile. The slight difference between the amount of anthocyanins eliminated after i.v. and after i.p. application shows a modest liver extracion of these substances. Vaccinium myrtillus anthocyanins possess a greater affinity for some tissues, namely kidneys and skin rather than for plasma. This fact could explain the long-lasting activity of anthocyanins on capillary resistance which is still elevated when plasma levels of these substances are no more detectable.