French oak wood extract (Robuvit (R)) reduces the wheal and flare response to histamine and decreases capillary filtration in normal subjects

Aim. Objective of the study was to evaluate the effect of supplementation with French oak wood extract (Robuvit (R)) on the cutaneous histamine reaction and capillary permeability in healthy subjects. Methods. 14 female participants in a control group and 16 females in the test group, supplemented daily with 300 mg French oak wood extract (Robuvit (R)) for 3 days and received an intracutaneous injection of histamine After the injection, wheal and redness areas on the skin were evaluated. Time until complete disappearance of flares and skin thickness was measured. Microcirculation flux at the injection site was recorded by Laser Doppler. Capillary filtration in the lower limbs was measured by venous occlusio plethysmography on days 1, 2 and 3 following intake of Robuvit (R). Results. In comparison to controls, the reaction to histamin was reduced in the group supplemented with the French oak wood extract: significantly smaller wheal area (-28%), smaller redness area (-13%), less skin thickness (-18%), lower microcirculation flux (-49%). The capillary filtration in supplemented subjects was significantly lower after 3 days (22%) compared to control. Conclusion. This pilot evaluation indicates an anti-histaminic activity of the French oak wood extract. The reduced capillary filtration suggests a role of Robuvit (R) in edema prevention.