Effects of venotonic drugs on the microcirculation: Comparison between Ruscus extract and micronized diosmine1

Background Chronic venous disease of the lower limbs is a common public health problem worldwide with negative impact on quality of life and results with drugs used to treat it are sparse, probably due to lack of good experimental models. Objective In this investigation we have tested the effects of two commonly used venotonic substances, Ruscus extract and micronized diosmine, on the microcirculation in vivo. Methods These substances were given orally, by gavage, during two weeks, twice daily and observations were made using the hamster cheek pouch preparation. Results The drugs elicited a dose-dependent inhibition of (1) macromolecular permeability increase induced by histamine or ischemia followed by reperfusion, being the Ruscus extract more active on both and (2) leukocyte-endothelium interaction, again being the Ruscus extract more effective in the inhibition of the number of adherent and rolling leukocytes. About the duration of the effect after the end of the treatment, both drugs had similar effects but Ruscus extract showed greater permanence of its effect on all observed parameters. Conclusions Our results suggest that both drugs have antioxidant and anti-inflammatory properties being Ruscus extract more active. It should be added that only Ruscus extract showed a significant venular constriction.