A single-blind, placebo-controlled, randomized study was performed on the effects of different doses of the total triterpenic fraction of Centella asiatica (TTFCA) in patients with venous hypertensive microangiopathy. A combined microcirculatory model that considers laser Doppler flowmetry (LDF) and transcutaneous oxygen (PO2), transcutaneous carbon dioxide tension (PCO2) measurements was combined with the symptom evaluation. LDF tests included the baseline resting flow, the venoarteriolar reflex, and the variation of flow related to the temperature increase. All tests provided a significant difference between drug-treated groups and the placebo group, thereby allowing a distinction to be made between the higher (120 mg daily) and the lower (60 mg daily) dose of TTFCA. Transcutaneous PO2-PCO2 measurements were significantly modified by drug treatments, while no variation could be detected in the placebo group. Important Symptomatologic effects (evaluated by subjective scores) followed TTFCA administration, especially at the higher dose level, while no effect was obtained with placebo. The trend of symptom evaluation paralleled the results of objective tests of our microcirculatory model, providing evidence that this model can reveal effects of venoactive drugs on venous hypertensive microangiopathy. TTFCA displays a significant activity. Doses as high as 120 mg daily may be safely used in venous hypertension.
