Naringin (NRG)

Naringin is a flavanone glycoside. It is a major flavonoid in grapefruit and gives the grapefruit juice its bitter taste. It is metabolized to the flavanone naringenin in humans. Both naringenin and hesperetin, which are the aglycones of naringin and hesperidin, occur naturally in citrus fruits. In commercial grapefruit juice production, the enzyme naringinase is used to remove the bitterness created by naringin. Naringin inhibits some drug-metabolizing cytochrome P450 enzymes, including CYP3A4 and CYP1A2, which may result in drug-drug interactions. Ingestion of naringin and related flavonoids can also affect the intestinal absorption of certain drugs, leading to either an increase or decrease in circulating drug levels. To avoid interference with drug absorption and metabolism, the consumption of citrus (especially grapefruit) and other juices with medications is contraindicated.