Bioavailability of furocoumarins after ingestion of grapefruit or grapefruit juice

Abstract

Furocoumarins are photoactive compounds that may cause phytophotodermatitis and are abundant in grapefruit. However, little is known about the distribution of furocoumarins in fresh grapefruit and commercial grapefruit juices. Furthermore, the fate of grapefruit furocoumarins in humans is largely unknown. Thus, seven furocoumarins: bergaptol, psoralen, 8‐methoxypsoralen (8‐MOP), bergapten, 6′,7′‐dihydroxybergamottin (6′,7′‐DHB), epoxybergamottin, and bergamottin in grapefruit (whole, flesh, and peel) and grapefruit juice were measured using UPLC‐MS/MS. We also measured the concentration of furocoumarins from the plasma of 6 healthy young‐adult subjects before and at 90 and 180 min after consumption of grapefruit (600 g, n=3) or grapefruit juice (474 ml, n=3). Six compounds in grapefruit or juice were detected but 8‐MOP was not detectable. Peel contained more furocoumarins than flesh in grapefruit. Bergamottin and 6′,7′‐DHB were predominant compounds in flesh and juice. In plasma, bergamottin and 6′,7′‐DHB were found after grapefruit and grapefruit juice ingestion and absorbed with different rates. The findings indicate that furocoumarins from grapefruit can be absorbed, metabolized and reliably measured in plasma. Since bergamottin derivatives are well‐known UVA‐induced photosensitizer, further research is warranted to examine the association between furocoumarin bioavailability and disease risk. This study was funded by the Warren Alpert Medical School of Brown University.