Table 1.

Oral bioavailability of the most common dietary polyphenols, their interactions with different CYP450 isoforms and the effect in terms of modulation of bioavailability of polyphenols exerted by carbohydrates, lipid, proteins, minerals and other nutrients and food minor constituents.

Polyphenol or Polyphenol Class	Oral Bioavailability	Main Cytochrome Interactions	Polyphenol-Polyphenol Interaction	Nutrients Interaction
Anthocyanidins	1–2% [22]	Weak CYP450 inhibitors [60]	Not known	Lipids, carotenoids, digestible carbohydrates, hydrophilic and lipophilic vitamins, alkaloids, P-glycoprotein inhibitors improve flavonoids and curcumin bioavailability Minerals, proteins and dietary fibers decrease flavonoids bioavailability [38]
Curcumin	<1% [61]	CYP3A4 (inhibition) [38]	Not known
Flavan-3-ols	2–15% in green tea; 5–10% in cocoa beans [26,27]	EGCG: inhibition of the activity of CYP1A2 CYP3A4 CYP2E1 [46]	Green, black and oolong tea phenolic complex improve EGCG bioavailability [45]
Hydroxytyrosol	High [62]	Plausible interaction with CYP450 [62]	In olive oil tyrosol is converted in hydroxytyrosol by CYP2A6 and CYP2D6 [42,43]
Isoflavones	High [63]	Genistein: CYP450 ω-hydroxylase subfamily inhibitor [60]	Not known
Quercetin	<1% (up to 17% when ingested as glycoside) [64]	CYP1A2 CYP2A6 (inhibition) [65]	Not known
Resveratrol	<1% [37]	CYP3A4 CYP1B1 CYP1A1 CYP1A2 (inhibition) [31,37,51]	Red wine phenolic complex improves resveratrol bioavailability [35,37] Quercetin improves resveratrol bioavailability [40,41]