Kinetics and tissue distribution on 14C labeled grape polyphenol fractions

Grape polyphenols have antioxidant properties which have potential health benefits including prevention of neurodegenerative diseases such as Alzheimer’s. 14 C‐labeled grape polyphenols were biosynthesized by grape cell suspension cultures, co‐incubated with radioisotopically‐labeled sucrose, and fractionated to separate polyphenol classes. The kinetics and tissue distribution grape polyphenols were determined by tracking the 14 C label. Sprague‐Dawley rats were implanted with jugular catheters and subcutaneous ultrafiltration probes, and dosed orally. Serum, interstitial fluid, urine and feces were collected for 24 h. Brains were removed and sectioned. The blood peak 14 C concentration of the fractions ranged from 15 minutes to 8 h with some fractions showing multiple peaks. Per cent of label accumulated in the brain at 24 h ranged from .006 to .1%. With all fractions there were measurable amounts of 14 C remaining in the blood at 24 hrs. Smaller amounts were found in subcutaneous ultrafiltrate. 14 C label found in the brain indicated that grape polyphenols or their metabolites are able to cross the blood‐brain barrier. Supported by NIH, 2 P50 AT000477 ‐06.