Urinary excretion of cyanidin glycosides

Anthocyanins, which are natural plant pigments from the flavonoid family, represent substantial constituents of the human diet. Several fruits (blackcurrant, blue berries, red grape and elderberry) are rich sources of these efficient antioxidant compounds. The present study was designed to determine the potential bioavailability in humans of the anthocyanins of elderberry, mainly cyanidin-3-glucoside and cyanidin-3-sambubioside, and the influence of the simultaneous ingestion of sucrose on the absorption of anthocyanins. Urinary samples from 16 healthy volunteers--8 women and 8 men--were collected before and over a period of 6 h with intervals of 1 h after the ingestion of 11 g elderberry concentrate (containing 1.9 g of anthocyanins equivalent to 235 ml of fresh juice) 1 day diluted with water, the other day with 30 g sucrose. Using high-performance liquid chromatography, it was possible to quantify the two main anthocyanins of elderberry excreted unchanged in the urine (0.003-0.012% of the oral dose). The ingestion of sucrose led to a reduced excretion of anthocyanins.