EFFECT OF SEVEN-DAY TREATMENT OF SWEDISH BITTERS ON SELECTED RAT CYTOCHROME P450 ENZYME ACTIVITY AND OTHER BIOLOGICAL PARAMETERS

Earlier reports have shown that herbal preparations could modulate drug-metabolizing enzymes and other biological parameters in humans. The current study was aimed at determining the effect of Swedish bitters on liver cytochrome P450 (CYP) enzyme activity, blood biochemical and hematological parameters; as well as hepatic antioxidant levels in a rat model. Sprague-Dawley (SD) rats were treated for 7 days with Swedish bitters at 5,10, and 20 mL/kg/day (low, medium and high doses, respectfully). Microsomal and cytosolic fractions were prepared from the rat livers. Fluorimetric and High-Performance Liquid Chromatography-based assays were used to determine CYP activities with specific probe substrates. Hematological and biochemistry assays were conducted on the rat blood samples. Antioxidant activities including glutathione (GSH), superoxide dismutase (SOD), catalase, and lipid peroxidation were assayed using the cytosolic fraction with standard protocols. Results from this study showed that Swedish bitters increased the activities of rat CYP2C9 (3-fold) and CYP2D6 (2-fold) compared to the untreated, with the former being significantly increased (p<0.01). There were no significant changes in GSH and SOD levels and Lipid peroxidation of treated rats. Catalase activity significantly declined after a high-dose treatment with Swedish bitters (p<0.05). Generally, there were no significant changes in the hematological and biochemical parameters of treated compared to untreated rats. Our results suggest a potential for CYP2C9-mediated drug interactions if Swedish bitters is taken chronically with conventional drugs metabolized by these enzymes.