MODULATION OF CYP1A1 ACTIVITY IN RAT MICROSOMES BY CITRUS L. FRUIT JUICES

Objectives: Juices prepared from citrus fruits make up almost two-thirds of the worldwide market for juice, which makes them one of the most common beverages in the diet. The simultaneous consumption of fruit juices and medicinal drugs poses a risk of herb-drug interactions. Previous studies have noted that Citrus paradisi Macfad., Citrus aurantifolia Linn., Citrus maxima (Burm) Merrill, and Citrus sinensis (L.) Osbeck juices affect cytochrome (CYP) 1A1 activity. Studies testing the effects of Citrus australasica F. Muell., Citrus limon (L.) Osbeck, Citrus reticulata Blanco× Citrus sinensis (L.) Osbeck, and Citrus japonica Thunb. fruit juices on CYP1A1 activity are lacking. Material and Methods: This study evaluate the CYP1A1 activity of Citrus fruit juices on rat liver tissues using the 7-ethoxyresorufin O-deethylase (EROD) assay. Result and Discussion: Among the six fruit juices studied, C. sinensis, C. japonica and C. australasica were found to inhibit CYP1A1 activity by 50%, 50% and 60%, respectively. These juices should be used with caution when taking medicines metabolized by the CYP1A1 isoenzyme.