Georg Kretzschmar

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Plant natural products derived from phenylalanine and the phenylpropanoid pathway are impressive in their chemical diversity and are the result of plant evolution, which has selected for the acquisition of large repertoires of pigments, structural and defensive compounds, all derived from a phenylpropanoid backbone via the plant-specific phenylpropanoid(More)
Estrogen-like effects of the heavy metal cadmium have been reported in both in vitro and in vivo studies. Yet, the molecular mechanisms involved in the hormonal activity of cadmium ions have not been fully elucidated. There are extensive data on cross-talk between aryl hydrocarbon receptor (AhR) and estrogen receptor (ER). Recently, 17β-estradiol (E2) was(More)
Several authors have investigated the role of aryl hydrocarbon receptor (AHR) in the reproductive tract, but there are no data available whether 17beta-estradiol (E2) regulates expression of members of the AHR pathway in the uterus. We therefore examined the mRNA expression of Ahr as well as the genes of the AHR dimerization partners ARNT1 and ARNT2 and the(More)
Many flavonoids, a major group of phenolic plant-derived secondary metabolites, are known to possess estrogen-like bioactivities. However, little is known about their estrogenic properties in the central nervous system due to the lack of suitable cellular models expressing sufficient amounts of functional estrogen receptor beta (ERbeta). To overcome this(More)
Plant natural products derived from phenylalanine and the phenylpropanoid pathways are impressive in their chemical diversity and are the result of plant evolution, which has selected for the acquisition of large repertoires of pigments, structural and defensive compounds, all derived from a phenylpropanoid backbone via the plant-specific phenylpropanoid(More)
Dominant and territorial behaviour are known social phenomena in cichlids and social stress influences reproduction and growth. The gonadotropic hormones trigger spermatogenesis and subordinate males have typically lower levels of gonadotropins than dominant males. In this study, we compared testis morphology and gene expression of dominant and subordinate(More)
Erythrina poeppigiana is a medicinal plant which is widely used in Asia, Latin America, and Africa in traditional remedies for gynecological complications and maladies. In continuation of studies for the discovery of novel phytoestrogens, four erythroidine alkaloids, namely α-erythroidine, β-erythroidine, and their oxo-derivatives 8-oxo-α-erythroidine and(More)
8-Prenylnaringenin (8-PN) and naringenin (Nar) are phytoestrogens found in food items and nutritional supplements, while 6-(1.1-dimethylallyl)naringenin (6-DMAN) is a component of an African plant. Besides their assumed beneficial effects they may promote mammary and endometrial cancer. We therefore assessed their proliferative and estrogenic potential on(More)
The aryl hydrocarbon receptor (AHR) is known to mediate the cellular response to numerous xenobiotics including dioxin. Surprisingly AHR knockout mice provide evidence for the involvement of the AHR signalling cascade in estrogen regulated physiological functions of the female reproductive system. Several studies already aimed to investigate the impact of(More)