A multidisciplinary group of experts gathered in Parma Italy for a workshop hosted by the University of Parma, May 16–18, 2014 to address concerns about the potential relationship between environmental metabolic disrupting chemicals, obesity and related metabolic disorders. The objectives of the workshop were to: 1. Review findings related to the role of environmental chemicals, referred to as “metabolic disruptors”, in obesity and metabolic syndrome with special attention to recent discoveries from animal model and epidemiology studies; 2. Identify conclusions that could be drawn with confidence from existing animal and human data; 3. Develop predictions based on current data; and 4. Identify critical knowledge gaps and areas of uncertainty. The consensus statements are intended to aid in expanding understanding of the role of metabolic disruptors in the obesity and metabolic disease epidemics, to move the field forward by assessing the current state of the science and to identify research needs on the role of environmental chemical exposures in these diseases. We propose broadening the definition of obesogens to that of metabolic disruptors, to encompass chemicals that play a role in altered susceptibility to obesity, diabetes and related metabolic disorders including metabolic syndrome.
1 January 2015 in Colloids and Surfaces B: Biointerfaces
Vaginal lactobacilli offer protection against recurrent urinary and vaginal infections. The precise mechanisms underlying the interaction between lactobacilli and the host epithelium remain poorly understood at the molecular level. Deciphering such events can provide valuable information on the mode of action of commensal and probiotic bacteria in the vaginal environment. We investigated the effects exerted by five Lactobacillus strains of vaginal origin (Lactobacillus crispatus BC1 and BC2, Lactobacillus gasseri BC9 and BC11 and Lactobacillus vaginalis BC15) on the physical properties of the plasma membrane in a cervical cell line (HeLa). The interaction of the vaginal lactobacilli with the cervical cells determined two kinds of effects on plasma membrane: (1) modification of the membrane polar lipid organisation and the physical properties (L. crispatus BC1 and L. gasseri BC9); (2) modification of α5β1 integrin organisation (L. crispatus BC2, L. gasseri BC11 and L. vaginalis BC15). These two mechanisms can be at the basis of the protective role of lactobacilli against Candida albicans adhesion. Upon stimulation with all Lactobacillus strains, we observed a reduction of the basal oxidative stress in HeLa cells that could be related to modifications in physical properties and organisation of the plasma membrane. These results confirm the strictly strain-specific peculiarities of Lactobacillus and deepen the understanding of the mechanisms underlying the health-promoting role of this genus within the vaginal ecosystem.
1 January 1992 in Journal of the Chemical Society, Perkin Transactions 2
The first case of enantioselective fluorescence quenching of dansyl(DNS)-amino acids (2) by a chiral complex, bis-(L-phenylalanylamidato)copper(II)(1) in aqueous solution is reported. The nature of the quenching, whether static or dynamic, has been investigated by time-resolved fluorescence techniques. The fluorescence lifetimes of the unquenched D- and L-DNS-phenylalanine were found to be the same as the quenched ones: 90% of the total fluorescence intensity for all samples was due to a 8.9 ns component. Thus, the decrease in the fluorescence intensities was ascribed to ground state interactions between the dansyl moiety and the copper complex (static quenching). From the Stern–Volmer plot it was possible to calculate the formation constants of the ternary diastereometric complexes formed according to a ligand exchange reaction. The difference between the logarithms of the stability constants of these complexes accounts for the enantio-selectivity observed in aqueous solutions. The present results are relevant also for the understanding of the mechanism of chiral recognition in HPLC using chiral copper(II) complexes as additives to the eluent (Chiral Ligand Exchange Chromatography), and must be taken into account for correct quantitative determination.
9-Hydroxystearic acid (9-HSA) is an endogenous cellular lipid that possesses antiproliferative and selective effects against cancer cells. A series of derivatives were synthesized in order to investigate the effect of the substituent in position 9 and on the methyl ester functionality on the biological activity. The two separate enantiomers of methyl 9-hydroxystearate and of methyl 9-aminostearate showed antiproliferative activity against the HT29 cell line. This indicates the importance of position 9 groups being able to make hydrogen bonding with the molecular target. Further, this effect must be preserved when the carboxy group of 9-HSA is esterified. The biological tests showed that the amines, contrarily to methyl esters, resulted in cytotoxicity. A deep investigation on the effect of methyl (R)-9-hydroxystearate on HT29 cells showed an antiproliferative effect acting through the CDKN1A and MYCBP gene expression.