OP16 - Investigations on the oral bioavailability of trans-resveratrol and trans-ε-viniferin from native and micellar Vineatrol®30 grapevine-shoot extract in healthy volunteers.

Vineatrol ® 30 grapevine-shoot extract contains the stilbenes trans-resveratrol as well as considerable amounts of the resveratrol dimer trans-ε-viniferin. Resveratrol is a potent antioxidant, anti-inflammatory, and chemopreventive agent in vitro and in vivo, and is thought to be cardio- and neuroprotective. The bioavailability of these stilbene compounds in humans is low (ca. 1-2%). The aim of our project was therefore to enhance the oral bioavailability and thus potentially the biological activity of trans-resveratrol and trans-ε-viniferin from Vineatrol ® 30, and to assess its safety in humans. We performed a single-blind crossover trial with twelve healthy volunteers, with the two study arms separated by ≥1-week washout periods. All participants orally ingested in random order capsules with a single dose of 500 mg Vineatrol ® 30 as native powder or liquid micelles. Blood samples were collected before (0 h) and after (0.5, 1, 2, 4, 6, 8 and 24 h) Vineatrol ® 30 intake. Urine samples were collected before (0 h) and 1-6, 6-12 and 12-24 h after intervention. Liver and kidney function parameters were quantified in serum samples before as well as 4 and 24 h after intake of Vineatrol ® 30. Blood and urine samples are currently being analysed for total trans-resveratrol and trans-ε-viniferin by HPLC and serum samples for the activity of liver enzymes and further safety parameters. The pharmacokinetics of native and micellar stilbenes as well as the tolerability and safety of the native and micellar formulations will be presented. [ABSTRACT FROM AUTHOR]