The Effect of Single or Multiple Doses of Grapefruit Juice on the Analgesic Effect of Ibuprofen in Mice

Grapefruit juice (GFJ) is a rich source of nutritional compounds but has been shown to alter the concentrations of several clinically useful drugs. Ibuprofen is a commonly used over-the counter-drug.

Aim: This study aims to examine the effect of a single or multiple dose of GFJ on the analgesic effect of ibuprofen.

Methodology: CD1 male mice were randomly distributed into four equal groups (n=9, each). The first group served as a control, the second group was given ibuprofen (100 mg/Kg) by oral gavage, the third group was given a single dose of GFJ (10 mg/Kg) by oral gavage followed by ibuprofen, and the fourth group was given a single dose of GFJ for five days and on the fifth day was given ibuprofen. The analgesic effect was tested using two methods with different mechanisms: thermal (hot plate) and chemical (acetic acid-induced abdominal constriction) pharmacologic stimuli models.

Results: Both GFJ dosing regimen significantly increased the duration of abdominal constriction test when compared with ibuprofen group and did not exert any significant effect on the hot plate effect. This suggest that GFJ may affect the peripherally modulated analgesic effect of ibuprofen. Conclusion: The observed effect of GFJ on ibuprofen analgesic effect warrants further studies on their impact and clinical significance on humans.