M Muenzner1, N Tappenbeck2,3, F Gembardt2,4, R Rülke1, J Furkert1, M F Melzig5, W-E Siems1, G A Brockmann6, T Walther3,7,8. 1. Leibnizinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany. 2. Department Cardiac Pathobiology, Excellence Cluster Cardio-Pulmonary System, Justus-Liebig-Universität, Gießen, Germany. 3. Medical Faculty Mannheim, University Heidelberg, Institute of Experimental and Clinical Pharmacology and Toxicology, Mannheim, Germany. 4. Department of Internal Medicine III - Division of Nephrology, University Hospital Carl Gustav Carus at the Technische Universität Dresden, Dresden, Germany. 5. Institut für Pharmazie/Dahlem, Centre of Plant Sciences (DCPS), Freie Universität Berlin, Berlin, Germany. 6. Department for Crop and Animal Sciences, Animal Breeding and Molecular Genetics, Humboldt-Universität Berlin, Berlin, Germany. 7. Department of Obstetrics and Clinic of Paediatric Surgery, University Leipzig, Leipzig, Germany. 8. Department of Pharmacology and Therapeutics, School of Medicine and School of Pharmacy, University College Cork, Cork, Ireland.
Abstract
BACKGROUND/ OBJECTIVE: Consumption of green tea has become increasingly popular, particularly because of claimed reduction in body weight. We recently reported that animals with pharmacological inhibition (by candoxatril) or genetic absence of the endopeptidase neprilysin (NEP) develop an obese phenotype. We now investigated the effect of green tea extract (in drinking water) on body weight and body composition and the mediating role of NEP. SUBJECTS/ METHODS: To elucidate the role of NEP in mediating the beneficial effects of green tea extract, 'Berlin fat mice' or NEP-deficient mice and their age- and gender-matched wild-type controls received the extract in two different doses (300 or 600 mg kg-1 body weight per day) in the drinking water. RESULTS: In 'Berlin fat mice', 51 days of green tea treatment did not only prevent fat accumulation (control: day 0: 30.5% fat, day 51: 33.1%; NS) but also reduced significant body fat (green tea: day 0: 27.8%, day 51: 20.9%, P<0.01) and body weight below the initial levels. Green tea reduced food intake. This was paralleled by a selective increase in peripheral (in kidney 17%, in intestine 92%), but not central NEP expression and activity, leading to downregulation of orexigens (like galanin and neuropeptide Y (NPY)) known to be physiological substrates of NEP. Consequently, in NEP-knockout mice, green tea extract failed to reduce body fat/weight. CONCLUSIONS: Our data generate experimental proof for the assumed effects of green tea on body weight and the key role for NEP in such process, and thus open a new avenue for the treatment of obesity.
BACKGROUND/ OBJECTIVE: Consumption of green tea has become increasingly popular, particularly because of claimed reduction in body weight. We recently reported that animals with pharmacological inhibition (by candoxatril) or genetic absence of the endopeptidase neprilysin (NEP) develop an obese phenotype. We now investigated the effect of green tea extract (in drinking water) on body weight and body composition and the mediating role of NEP. SUBJECTS/ METHODS: To elucidate the role of NEP in mediating the beneficial effects of green tea extract, 'Berlin fat mice' or NEP-deficient mice and their age- and gender-matched wild-type controls received the extract in two different doses (300 or 600 mg kg-1 body weight per day) in the drinking water. RESULTS: In 'Berlin fat mice', 51 days of green tea treatment did not only prevent fat accumulation (control: day 0: 30.5% fat, day 51: 33.1%; NS) but also reduced significant body fat (green tea: day 0: 27.8%, day 51: 20.9%, P<0.01) and body weight below the initial levels. Green tea reduced food intake. This was paralleled by a selective increase in peripheral (in kidney 17%, in intestine 92%), but not central NEP expression and activity, leading to downregulation of orexigens (like galanin and neuropeptide Y (NPY)) known to be physiological substrates of NEP. Consequently, in NEP-knockout mice, green tea extract failed to reduce body fat/weight. CONCLUSIONS: Our data generate experimental proof for the assumed effects of green tea on body weight and the key role for NEP in such process, and thus open a new avenue for the treatment of obesity.
Authors: Ngozi Erondu; Ira Gantz; Bret Musser; Shailaja Suryawanshi; Madhuja Mallick; Carol Addy; Josee Cote; George Bray; Ken Fujioka; Harold Bays; Priscilla Hollander; Sandra M Sanabria-Bohórquez; WaiSi Eng; Bengt Långström; Richard J Hargreaves; H Donald Burns; Akio Kanatani; Takehiro Fukami; Douglas J MacNeil; Keith M Gottesdiener; John M Amatruda; Keith D Kaufman; Steven B Heymsfield Journal: Cell Metab Date: 2006-10 Impact factor: 27.287
Authors: Asja Wagener; Armin O Schmitt; Soner Aksu; Werner Schlote; Christina Neuschl; Gudrun A Brockmann Journal: Physiol Genomics Date: 2006-08-15 Impact factor: 3.107