Naringin
A flavonoid glycoside responsible for the bitter taste of grapefruit. Naringen is metabolized to its aglycone (i.e., sugar-free) form, naringenin, in-vivo. Both naringin and naringenin are biologically active and can contribute to the “grapefruit juice effect” on ingested drugs. Unlike grapefruit furanocoumarins, naringin and naringenin have relatively weak effects on “Phase I” drug-metabolizing enzymes; however, naringenin may also affect drug metabolism via esterase inhibition.
Naringin is sometimes added to dietary supplements to enhance the bioavailability of ingested nutrients/nutraceuticals, although specific benefits have not been demonstrated.
In addition to the above, naringin/naringenin have been shown to have antitumor, anxiolytic (anxiety-reducing), anti-inflammatory, antioxidant and anti-osteoporotic effects in cell culture and/or animal experiments.
Chemical name: 4′,5,7-Trihydroxyflavanone-7-rhamnoglucoside