Grapefruit by it's action on enzymes in the digestive system and liver has complex effects. There is enchanced release of CCK with grapefruit and CCK is an appetite suppresant. The main interest in grapefruit as some of you have pointed out,is it's ability to alter druig metabolism,again this relates to it's influence on liver and intestinal enzymes.
To my knowlege it is not a fat "burner" in the way we think of drugs like ephedra alkaloids,but will enhance other drugs and suppress appetite.
Here's a brief abstract explaining some of the enzymatic interactions and complex effects.
Grapefruit juice and drugs: a hazardous combination?
A single glass of grapefruit juice can improve the oral bioavailability of a drug thus either increasing its efficacy or enhancing its adverse effects particularly if the therapeutic index is narrow. Grapefruit juice acts by inhibiting presystemic drug metabolism mediated by CYP P450 3A4 in the small bowel and this interaction would appear to be more relevant if the CYP 3A4 content is high and the drug has a strong first pass degradation. Intestinal P-glycoprotein may also be affected by grapefruit juice. The compounds responsible for this food-drug interaction have not as yet been identified but this phenomenon could result from a complex synergy between flavonoids (naringin, naringenin), furanocoumarins (6',7'-dihydroxybergamottin, bergamottin) and sesquiterpen (nootkatone). In our study, we report the mechanisms of action of grapefruit juice and the interactions between grapefruit juice and 42 drugs; to date.
[Jus de pamplemousse et medicaments: une association a surveiller?]
Therapie 2002 Sep-Oct;57(5):432-45 (ISSN: 0040-5957)
Lohezic-Le Devehat F; Marigny K; Doucet M; Javaudin L
Centre Hospitalier Regional et Universitaire de Rennes, Hopital de Pontchaillou, Service Pharmaceutique, Rennes, France.
[email protected].