Affiliations: Laboratório de Pesquisas em Microcirculação, State University of Rio de Janeiro, Brazil | Institut de Recherches Pierre Fabre, Rue Jean Rostand, Labege Innopole, Cedex 31319, France
Abstract: Ruscus aculeatus extract (the active principle of Cyclo 3 Fort) is used to increase venous tone in patients with venous disease. In these experiments, the effects of oral Cyclo 3 Fort on capillary permeability were studied in hamsters with moderate diabetes induced by two intraperitoneal injections of streptozotocin (40 mg/kg). Hamsters were treated with a placebo or Cyclo 3 Fort, 2, 10 or 50 mg/kg/day, for 4 weeks starting 3 days after induction of diabetes. Intravital microscopy of cheek pouch preparations was performed using fluorescein‐labelled dextran (FITC‐dextran) as a marker for plasma exudation (leak formation). Plasma levels of glucose were measured prior to experiments. Following preparation for intravital microscopy, each cheek pouch was subjected to two applications of histamine, 5\times10^{-6} M for 5 min at 30‐minute intervals. Plasma exudation (number of leaks/cm^2) was significantly reduced in animals receiving Cyclo 3 Fort at doses of 10 mg/kg or above. The mean number of leaks was 258\pm17 in the placebo group, compared with 253\pm12, 125\pm7 (p<0.01) and 99\pm7 (p<0.01) in animals receiving Cyclo 3 Fort, 2, 10 or 50 mg/kg, respectively. Blood glucose levels did not differ between groups. Thus, oral Cyclo 3 Fort inhibited histamine‐induced plasma exudation in hamsters with mild diabetes without affecting the glycaemia.
