RÉSUMÉ
BACKGROUND: There is considerable evidence that many patients concurrently administer dietary supplements with conventional drugs, creating a risk for potential drug-supplement interaction. The aim of this study was to determine the effect of Cellgevity® supplement on selected rat liver cytochrome P450 (CYP) enzymes. Also, based on our previous finding, we sought to determine the effect of Cellgevity® on the pharmacokinetics of carbamazepine, a CYP3A4 substrate. METHODS: Male Sprague-Dawley (SD) rats were randomly put into 5 groups and administered either distilled water (negative control), Cellgevity® (3 separate doses), or phenobarbital (positive control), per os. Modulation of liver CYP enzyme activity was evaluated after 30 days of treatment, using probe substrates, spectroscopic, and high-performance liquid chromatographic methods. In the pharmacokinetic study, 12 SD rats were put into 2 groups and administered carbamazepine plus normal saline (group 1) or carbamazepine plus Cellgevity® (group 2), per os, both over a period of 14 days. Blood samples from rats in the same group were collected after treatment. Serum samples were prepared and pooled together at each specific sampling time point. Levels of carbamazepine were determined using a fluorescence polarization immunoassay. RESULTS: Activities of rat liver CYP1A1/2, CYP2C9, and CYP2D6 were significantly increased by Cellgevity® after 30-day treatment. Pharmacokinetic parameters for rats administered carbamazepine with Cellgevity® vis-a-vis carbamazepine with normal saline were as follows: C max; 20 µmol/L vs 11 µmol/L, AUC0â¶24; 347 µmol h/L vs 170 µmol h/L, K e; 0.28 h-1 vs 0.41 h-1, and t 1/2; 2.3 h vs 1.7 h, respectively. CONCLUSIONS: Cellgevity® increased the activity of rat CYP1A1/2, CYP2C9, and CYP2D6 enzymes and was found to alter the pharmacokinetics of carbamazepine in rats.
RÉSUMÉ
Drug interactions are key reasons for adverse drug reactions and attrition from market. Major infectious diseases causing morbidity/mortality in Ghana are malaria, tuberculosis, and HIV/AIDS. In this study, plant medicines commonly used to treat/manage these diseases in Ghana were investigated for their potential to modulate rat cytochrome P450 enzyme activities. Fluorescence and high-performance liquid chromatography-based assays were used to assess effects of antimalarial plant medicines, Fever (FEV), Mal-TF (MAL), and Kantinka terric (KT); anti-TB medicines, Chestico (CHES), CA + ST Pains + HWNT (TF), and Kantinka herbatic (KHB); and anti-HIV/AIDS medicines, Wabco (WAB), AD + T/AD (LIV) and Kantinka BA (KBA) on rat liver microsomal cytochrome P450 enzyme activities. Effects of medicines on rat biochemical and hematological parameters were also assessed. Generally, the medicines altered microsomal CYP1A1/1A2, CYP2B1/2B2, CYP2C9, and CYP2D6 activities. Only KBA elicited an increase (80%) in CYP1A1/1A2 activity. FEV, MAL, CHES, WAB, and LIV strongly inhibited the enzyme activity. All the medicines significantly inhibited CYP2C9 (24%-80%) activity. CYP2D6 activity increased after treatment with MAL, KBA, LIV, and TF. Also, MAL, WAB, LIV, KHB, and CHES increased CYP2B1/2B2 activity, while KT decrease the activity. Generally, the medicines altered liver function in the rats. Cholesterol levels declined after KBA treatment only. White and red blood cell counts, hemoglobin and hematocrit levels were significantly reduced in KT- and KBA-treated rats. Our results suggest that use of the medicines could have implications for drug interactions and safety, particularly if the medicines are administered over prolonged periods. Further investigations are imperative to establish clinical relevance of these results.