Hysodricanin-A,Mauritin-H,Scutianin-F und Aralionin-C,vier weitere cyclopeptidalkaloide aus Ziziphus,Scutia und Araliorhamnus

From the bark extracts of Ziziphus hysodrica, Z. mauritiana, Scutia buxifolia and Araliorhamnus vaginata, in addition to known peptide alka     

Modulation of the Gut Microbiome and Obesity Biomarkers by Lactobacillus Plantarum KC28 in a Diet-Induced Obesity Murine Model

Probiotics and Antimicrobial Proteins - Lactobacillus plantarum KC28 showed a beneficial (anti-obesity) effect in a diet-induced obese (DIO) C57BL/6 murine model receiving an intermediate high-fat...     

Commentary regarding: “Activity determination of FAD‐dependent glucose dehydrogenase immobilized in PEDOT: PSS‐PVA composite films for biosensor applications”

In the light of continuous improvement and optimization, recent experiments that the authors conducted give new insights into the applied evaluation method of Riegel et al. [1]: Thorough investigations of the previous results regarding the usage of the Lowry Assay showed discrepancies in the determination of the released amount of protein in the analysis solution. The accurate quantification of this parameter is crucial as it directly influences the calculation of the residual enzymatic activity. In concrete terms, this finding has a major impact on the presented and discussed results in the article “Activity determination of FAD‐dependent glucose dehydrogenase immobilized in PEDOT: PSS‐PVA composite films for biosensor applications” [1]. Thus, this commentary addresses the new insights concerning the applied evaluation method, explains necessary revisions and discusses new conclusions derived from the adjusted evaluation method.     

Role of flavonoids in controlling the phototoxicity of Hypericum perforatum extracts.

Hypericum perforatum extracts are used mainly as oral antidepressants. Depending on source the extracts contain various amounts of phenylpropanes, flavonol derivates, biflavones, proathocyanidines, xanthones, phloroglucinoles, some amino acids, naphtodianthrones (hypericines) and essential oil constituents. The therapeutic use of Hypericum perforatum extracts however is limited by their phototoxic potential. It was the aim of the present study to investigate the phototoxic potential of 3 Hypericum perforatum extracts from different sources as well as some of its main constituents. In order to systematically study the phototoxic potential we established a modified neutral red assay utilizing an immortalized human keratinocyte cell line (HaCaT cells) as substrate and UVA irradiation. This modified neutral red assay was found to be a simple and reliable method for detecting phototoxic effects of reference agents and plant extracts. The validity of this method was demonstrated with known phototoxic compounds like chloropromazine and psoralenes like 5-MOP. Hypericum perforatum extracts demonstrated cytotoxicity and photocytotoxicity in a dose and UVA-dose dependent manner. Hypericine itself also evoked severe phototoxic effects and was thus identified as the main phototoxic constituent. Among the tested flavonoids quercitrin was found to be cytotoxic, while rutin unexpectedly demonstrated phototoxicity whereas quercitrin was effective to control the phototoxic activity of Hypericum perforatum extracts.     

Cell cycle analysis of fetal germ cells during sex differentiation in mice

Background information. Primordial germ cells in developing male and female gonads are responsive to somatic cell cues that direct their sex‐specific differentiation into functional gametes. The first divergence of the male and female pathways is a change in cell cycle state observed from 12.5 dpc (days post coitum) in mice. At this time XY and XX germ cells cease mitotic division and enter G₁/G₀ arrest and meiosis prophase I respectively. Aberrant cell cycle regulation at this time can lead to disrupted ovarian development, germ cell apoptosis, reduced fertility and/or the formation of germ cell tumours. Results. In order to unravel the mechanisms utilized by germ cells to achieve and maintain the correct cell cycle states, we analysed the expression of a large number of cell cycle genes in purified germ cells across the crucial time of sex differentiation. Our results revealed common signalling for both XX and XY germ cell survival involving calcium signalling. A robust mechanism for apoptosis and checkpoint control was observed in XY germ cells, characterized by p53 and Atm (ataxia telangiectasia mutated) expression. Additionally, a member of the retinoblastoma family and p21 were identified, linking these factors to XY germ cell G₁/G₀ arrest. Lastly, in XX germ cells we observed a down‐regulation of genes involved in both G₁‐ and G₂‐phases of the cell cycle consistent with their entry into meiosis. Conclusion. The present study has provided a detailed analysis of cell cycle gene expression during fetal germ cell development and identified candidate factors warranting further investigation in order to understand cases of aberrant cell cycle control in these specialized cells.     

Regulation of flowering time by Arabidopsis MSI1

The transition to flowering is tightly controlled by endogenous programs and environmental signals. We found that MSI1 is a novel flowering-time gene in Arabidopsis. Both partially complemented msi1 mutants and MSI1 antisense plants were late flowering, whereas ectopic expression of MSI1 accelerated flowering. Physiological experiments revealed that MSI1 is similar to genes from the autonomous promotion of flowering pathway. Expression of most known flowering-time genes did not depend on MSI1, but the induction of SOC1 was delayed in partially complemented msi1 mutants. Delayed activation of SOC1 is often caused by increased expression of the floral repressor FLC. However, MSI1 function is independent of FLC. MSI1 is needed to establish epigenetic H3K4 di-methylation and H3K9 acetylation marks in SOC1 chromatin. The presence of these modifications correlates with the high levels of SOC1 expression that induce flowering in Arabidopsis. Together, the control of flowering time depends on epigenetic mechanisms for the correct expression of not only the floral repressor FLC, but also the floral activator SOC1.     

Morphological,Biometric, and Morphogenetic Comparison of Two Closely Related Species,Stylonychia vorax and S. pustulata (Ciliophora: Oxytrichidae)1

Differences in the morphology of Stylonychia vorax Stokes, 1885 and S. pustulata (Müller, 1786) Ehrenberg, 1838 recognizable in vivo are the shape, the ventral cirral pattern, the caudal cirri, and the mode of moving. The dorsal-bristle complexes are distinguishable by the length of dorsal kinety four and the spaces among the pairs of basal bodies. When the ranges of variation of different populations and clones are compared by biometric analyses, S. vorax shows a relatively stable cortical pattern whereas in S. pustulata the cortical elements are regulated depending on the size of the body and the number of adoral membranelles. In S. vorax morphogenesis begins with a proliferation of basal bodies close to the transverse cirri. In contrast, in S. pustulata, the oral primordium appears de novo between the left marginal row and the postoral cirri. All other morphogenetic events are the same for both species. In proters and opisthes the six anlagen of the frontal-ventral-transverse cirri are of different origin and evolve independently. Three anlagen of the opisthe separate from the oral primordium, two originate from the right, and one from the left postoral cirrus. Three anlagen of the proter evolve from the posteriormost cirrus in the frontal area, one from the parental undulating membranes, one from the buccal cirrus, and one from the cirrus below the buccal cirrus. The anlagen one to six generate one, three, three, three, four, and four cirri. The characteristic arrangement of the undulating membranes and the participation of only two postoral cirri in the formation of primordia provide features that distinguish between the often confused genera Oxytricha and Stylonychia.