Lymphotonic activity of Ruscus extract, hesperidin methyl chalcone and vitamin C in human lymphatic smooth muscle cells

Besides actions including their venotonic, anti-inflammatory, and anti-oxidant effects, venoactive drugs are expected to act on edema via their action on lymphatics. The objective of this study was to evaluate the effect of the combination of Ruscus, hesperidin methyl chalcone and Vitamin C (Ruscus/HMC/Vit C) on intracellular calcium mobilization and contraction of human lymphatic smooth muscle cells (LSMCs) to better characterize the mechanism of its lymphotonic activity.

Calcium mobilization was evidenced by videomicroscopy analysis of the fluorescence emitted by a specific Ca²⁺ sensitive dye and measured after injection of Ruscus/HMC/Vit C at 0.1, 0.3, 1.0, and 3.0 mg/mL into LSMCs.

Ruscus/HMC/Vit C induced a strong and reproducible concentration-dependent calcium mobilization in LSMCs. On the contrary, another venoactive drug used as comparator, micronized purified flavonoid fraction (MPFF), did not induce calcium mobilization whatever the tested concentration.

Although alternative mechanisms of action may result in potential lymphotonic effects, the efficacy of lymphotonic products is nonetheless related to their stimulating effect on the contractile activity of the smooth muscle cells surrounding lymphatic vessels. In the light of the results obtained in this study, the direct effect of Ruscus/HMC/Vit C on LSMC contraction may partially explain its clinical efficacy on lymphotonic activity, as has been observed in terms of objective signs of edema as reported in the recent guidelines on chronic venous disease.