Iva Boušová1, Petra Matoušková2, Hana Bártíková2, Barbora Szotáková2, Veronika Hanušová3, Veronika Tománková4, Eva Anzenbacherová4, Barbora Lišková4, Pavel Anzenbacher4, Lenka Skálová2. 1. Department of Biochemical Sciences, Faculty of Pharmacy, Charles University in Prague, Heyrovského 1203, 500 05, Hradec Králové, Czech Republic. Iva.Bousova@faf.cuni.cz. 2. Department of Biochemical Sciences, Faculty of Pharmacy, Charles University in Prague, Heyrovského 1203, 500 05, Hradec Králové, Czech Republic. 3. Faculty of Medicine in Hradec Králové, Charles University in Prague, Šimkova 870, 500 38, Hradec Králové, Czech Republic. 4. Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, 775 15, Olomouc, Czech Republic.
Abstract
PURPOSE: Consumption of dietary supplements with green tea extract (GTE) is popular for weight management, but it may be accompanied by various side effects, including interactions with drugs. The aim of the present in vivo study was to evaluate the effect of defined GTE (Polyphenon 60) in three dosage schemes on insulin, leptin and drug-metabolizing enzymes in obese mice. METHODS: Experimental obesity was induced by repeated s.c. application of monosodium glutamate to newborn mice. Green tea extract was administered in three dosage schemes in chow diet. The plasmatic levels of insulin and leptin were assayed using enzyme-linked immunosorbent assay. Enzyme activities and mRNA expressions of drug-metabolizing enzymes (totally 13) were analyzed in liver and small intestine using spectrophotometric and HPLC assays and RT-PCR, respectively. RESULTS: GTE-treatment decreased insulin and leptin levels. Eleven enzymes were significantly affected by GTE-treatment. Long-term administration of 0.01% GTE caused increase in the activity and mRNA level of cytochrome P450 3A4 (CYP3A4) ortholog in the liver as well as in the small intestine. Interestingly, short-term overdose by GTE (0.1%) had more pronounced effects on enzyme activities and mRNA expressions than long-term overdose. CONCLUSIONS: GTE-mediated induction of CYP3A4 ortholog, the main drug-metabolizing enzyme, could result in decreased efficacy of simultaneously or subsequently administered drug in obese individuals.
PURPOSE: Consumption of dietary supplements with green tea extract (GTE) is popular for weight management, but it may be accompanied by various side effects, including interactions with drugs. The aim of the present in vivo study was to evaluate the effect of defined GTE (Polyphenon 60) in three dosage schemes on insulin, leptin and drug-metabolizing enzymes in obesemice. METHODS: Experimental obesity was induced by repeated s.c. application of monosodium glutamate to newborn mice. Green tea extract was administered in three dosage schemes in chow diet. The plasmatic levels of insulin and leptin were assayed using enzyme-linked immunosorbent assay. Enzyme activities and mRNA expressions of drug-metabolizing enzymes (totally 13) were analyzed in liver and small intestine using spectrophotometric and HPLC assays and RT-PCR, respectively. RESULTS:GTE-treatment decreased insulin and leptin levels. Eleven enzymes were significantly affected by GTE-treatment. Long-term administration of 0.01% GTE caused increase in the activity and mRNA level of cytochrome P450 3A4 (CYP3A4) ortholog in the liver as well as in the small intestine. Interestingly, short-term overdose by GTE (0.1%) had more pronounced effects on enzyme activities and mRNA expressions than long-term overdose. CONCLUSIONS:GTE-mediated induction of CYP3A4 ortholog, the main drug-metabolizing enzyme, could result in decreased efficacy of simultaneously or subsequently administered drug in obese individuals.
Entities:
Keywords:
Catechins; Drug-metabolizing enzymes; Green tea extract; Metabolic syndrome; Obesity
Authors: Francisco J Alarcon-Aguilar; Alejandro Zamilpa; Ma Dolores Perez-Garcia; Julio C Almanza-Perez; Eunice Romero-Nuñez; Efrain A Campos-Sepulveda; Laura I Vazquez-Carrillo; Ruben Roman-Ramos Journal: J Ethnopharmacol Date: 2007-07-27 Impact factor: 4.360