Effect of honey on naringin absorption from a decoction of the pericarps of Citrus grandis.

To measure naringin/naringenin absorption of a decoction prepared from the pericarps of Citrus grandis and to investigate the effect of honey on naringin/naringenin absorption, six healthy males received 200 mL decoctions of untreated and honey-treated Pericarpium Citri Grandis in a randomized crossover design. The absorption was measured by renal recovery of naringenin glucuronides/sulfates over 48 hours. The contents of naringin/naringenin in 200 mL decoctions of untreated and honey-treated Pericarpium Citri Grandis were determined to be 261.5/23.8 mumol and 303.3/11.6 mumol, respectively. The mean cumulated renal excretion of naringenin glucuronides/sulfates after intake of these two decoctions were 74.8 mumol (26.2% of dose) and 49.8 mumol (15.8% of dose), respectively. Paired Student's t-test showed that the difference of the total renal recovery of naringin/naringenin between the two decoctions was significant. The results indicated that honey significantly reduced naringin/naringenin absorption by 33.4% in humans and suggested that honey treatment might alter the efficacy of Pericarpium Citri Grandis.