Aufgaben und Funktionen der ?Senatskommission zur Beurteilung der gesundheitlichen Unbedenklichkeit von Lebensmitteln? der Deutschen Forschungsgemeinschaft

The Senate Commission on Food Safety (SKLM) of the German Research Foundation (DFG) advises authorities and the government on food safety. The risk assessment of foodstuffs, including novel and functional foods, covers the evaluation of food ingredients and additives as well as the evaluation of novel processing methods. In carrying out this task the Commission expresses its opinion primarily on those aspects which are concerned with the safety assessment. In addition, questions relating to the technological need and to nutritional or physiological benefits are also considered. The topics considered may originate from enquiries of the Ministry for Consumer Protection, Nutrition and Agriculture (BMVEL). Other topics may be selected by the Commission on its own initiative, if they are considered to be of particular importance for consumer protection. Within the context of this activity the SKLM also organises symposia and expert discussions, their outcome subsequently being published as resolutions, conclusions or opinions.

Studies on the inhibition of tumor cell growth and microtubule assembly by 3-hydroxy-4-[(E)-(2-furyl)methylidene]methyl-3-cyclopentene-1,2-dione, an intensively coloured Maillard reaction product

Very recently, 3-hydroxy-4-[(E)-(2-furyl)methylidene]methyl-3-cyclopentene-1,2-dione (1) has been successfully identified as an intensively coloured Maillard product formed from glucose and L-proline upon thermal food processing. Using a biomimetic synthetic strategy, reference material of compound 1 was prepared and purified, and then used to study its effect on the growth of human tumor cells. Compound 1 was found to potently inhibit the growth of human tumor cells in vitro. Using a reporter gene assay we could show that in growth inhibitory concentrations compound 1 effectively inhibits the phosphorylation of the transcription factor Elk-1. In addition, 1 was found to affect the microtubule skeleton. The human mammary carcinoma cell line MCF-7 exhibits a decrease of the microtubule organisation when treated for 24 h with 1 (> or =20 microM). At concentrations of 30 microM and above a loss of microtubule integrity is observed after 1 h incubation. In vitro studies demonstrated that the polymerisation and, to a minor extent, also the depolymerisation of tubulin, isolated and purified from bovine brain, is inhibited in a dose-dependent manner at concentrations of 30 microM and above. This is the first time that a non-enzymatically formed browning compound of known structure was reported to effectively inhibit tumor cell growth and microtubule assembly.

The anthocyanidins cyanidin and delphinidin are potent inhibitors of the epidermal growth-factor receptor

The aglycons of the most abundant anthocyanins in food, cyanidin (cy) and delphinidin (del), were found to inhibit the growth of human tumor cells in vitro in the micromolar range, whereas malvidin (mv), a typical anthocyanidin in grapes, was less active. The aglycons preferentially inhibited the growth of the human vulva carcinoma cell line A431, overexpressing the epidermal growth-factor receptor (EGFR). The glycosides cyanidin-3-beta-D-galactoside (cy-3-gal, idaein) and malvidin-3-beta-D-glucoside (mv-3-glc, oenin) did not affect tumor cell growth up to 100 microM. The tyrosine kinase activity of the EGFR, isolated from A431 cells, was potently inhibited by cy and del. Mv and the glycosides cy-3-gal and mv-3-glc were inactive up to 100 microM. In intact cells the influence of anthocyanin treatment on downstream signaling cascades was investigated by measuring the phosphorylation of the transcription factor Elk-1. A431 cells were transiently transfected with a luciferase reporter gene construct whose expression is controlled by MAP kinase pathway dependent phosphorylation of a GAL4-Elk-1 fusion protein. We found that cy and del inhibited the activation of the GAL4-Elk-1 fusion protein in the concentration range where growth inhibition was observed. Thus, the anthocyanidins cy and del are potent inhibitors of the EGFR, shutting off downstream signaling cascades. These effects might contribute substantially to the growth-inhibitory properties of these natural food constituents.