bergamottin

Bergamottin is a natural furanocoumarin found in citrus fruits, most notably bergamot (Citrus bergamia) and grapefruit (Citrus × paradisi). It occurs in the peels and juice and is a major constituent of bergamot essential oil. As a member of the psoralen-like furanocoumarins, bergamottin is photoactive when exposed to ultraviolet A light.

Pharmacology and mechanism of action: Bergamottin acts as a potent mechanism-based inhibitor of intestinal cytochrome P450 3A4. After ingestion, it is metabolized to reactive intermediates that inactivate CYP3A4, thereby reducing first-pass metabolism of many orally administered drugs. The inhibition is time-dependent and can persist for 24 to 72 hours or longer, depending on exposure and individual factors.

Clinical significance: The grapefruit juice effect describes increased plasma levels of various medications when taken with grapefruit products containing bergamottin. Drugs commonly affected include certain statins (such as simvastatin and atorvastatin), calcium channel blockers (such as felodipine), and some immunosuppressants, among others. These interactions can raise the risk of adverse effects and may necessitate dose adjustments or avoidance of grapefruit products.

Occurrence and safety: Bergamottin is present in bergamot oil used in flavorings and perfumery, as well as in grapefruit juice. People taking medications metabolized by CYP3A4 should be aware of potential interactions with bergamottin-containing products. In addition, furanocoumarins can cause phototoxic reactions when skin is exposed to sunlight after contact with plant material or juice.