Evaluation of estrogenic potency of a standardized hops extract on mammary gland biology and on MNU-induced mammary tumor growth in rats

Autor: Günter Vollmer, Shao-Nong Chen, Birgit M. Dietz, Florian Goerl, Dana Macejova, Guido F. Pauli, Judy L. Bolton, Oliver Zierau, Michael H. Muders, Annekathrin Martina Keiler, Richard B. van Breemen, Dejan Nikolic
Rok vydání: 2017
Předmět:
0301 basic medicine
Alkylating Agents
medicine.medical_specialty
medicine.drug_class
Ovariectomy
Endocrinology
Diabetes and Metabolism
medicine.medical_treatment
Clinical Biochemistry
Intraperitoneal injection
Mammary gland
Stimulation
Biology
Humulus
Biochemistry
Article
Rats
Sprague-Dawley
03 medical and health sciences
Chalcones
Mammary Glands
Animal
0302 clinical medicine
Endocrinology
Internal medicine
Progesterone receptor
medicine
Animals
Rats
Wistar
Molecular Biology
Cell Proliferation
Mammary tumor
Plant Extracts
Uterus
Mammary Neoplasms
Experimental
Methylnitrosourea
Organ Size
Cell Biology
biology.organism_classification
030104 developmental biology
medicine.anatomical_structure
Liver
Estrogen
030220 oncology & carcinogenesis
Flavanones
Ovariectomized rat
Molecular Medicine
Female
Zdroj: The Journal of Steroid Biochemistry and Molecular Biology. 174:234-241
ISSN: 0960-0760
DOI: 10.1016/j.jsbmb.2017.09.020
Popis: Supplements with estrogenic activities are intensively investigated as potential alternatives for the treatment of menopausal symptoms. These investigations include studies on their safety regarding potential breast cancer risks. Therefore, the aim of this study was to assess whether or not a standardized hops (Humulus lupulus) extract, containing 0.42% of the estrogenic flavanone, 8-prenylnaringenin, would stimulate growth of methyl-nitrosourea (MNU) induced mammary cancer in ovariectomized (OVX) Sprague-Dawley (SD) rats or would impact on the proliferative activity within the normal mammary gland of Wistar rats. To induce tumorigenesis SD-rats received an intraperitoneal injection of 50 mg/kg body weight of MNU on postnatal days PND 50 and 52. 28 days later animals were OVX or were SHAM operated (positive control) and randomly allocated and maintained for 140 days on either a phytoestrogen-free placebo diet (SHAM and negative control) or on the hops fortified diet. For the investigations in the normal mammary gland young adult Wistar rats were bilaterally OVX and randomly allocated to a control group fed to a phytoestrogen-free diet, or to a diet supplemented either with E2-benzoate or the hops extract. As a major result, the tumor incidence was 15% (3 tumors totally) in OVX controls, whereas it was 85% (39 tumors totally) in SHAM operated positive controls. No tumors were detectable in the hops group. In addition, no estrogenic activity of the hops extract was detectable in uterus and liver of these animals. In investigations on the normal mammary gland, no impact of hops extract on the expression of estrogen dependent proliferation markers or of progesterone receptor became apparent. In conclusion, the lack of growth stimulation of MNU-induced breast cancer in OVX SD-rats and the lack of stimulation proliferative events in the normal mammary gland of OVX Wistar rats by standardized hops extracts provides an important piece of evidence regarding the safety of these extracts in the management of menopausal symptoms.
Databáze: OpenAIRE
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