Brij detergents reveal new aspects of membrane microdomain in erythrocytes

Membrane microdomains enriched in cholesterol, sphingolipids (rafts), and specific proteins are involved in important physiological functions. However their structure, size and stability are still controversial. Given that detergent-resistant membranes (DRMs) are in the liquid-ordered state and are rich in raft-like components, they might correspond to rafts at least to some extent. Here we monitor the lateral order of biological membranes by characterizing DRMs from erythrocytes obtained with Brij-98, Brij-58, and TX-100 at 4?°C and 37?°C. All DRMs were enriched in cholesterol and contained the raft markers flotillin-2 and stomatin. However, sphingomyelin (SM) was only found to be enriched in TX-100-DRMs – a detergent that preferentially solubilizes the membrane inner leaflet – while Band 3 was present solely in Brij-DRMs. Electron paramagnetic resonance spectra showed that the acyl chain packing of Brij-DRMs was lower than TX-100-DRMs, providing evidence of their diverse lipid composition. Fatty acid analysis revealed that the SM fraction of the DRMs was enriched in lignoceric acid, which should specifically contribute to the resistance of SM to detergents. These results indicate that lipids from the outer leaflet, particularly SM, are essential for the formation of the liquid-ordered phase of DRMs. At last, the differential solubilization process induced by Brij-98 and TX-100 was monitored using giant unilamellar vesicles. This study suggests that Brij and TX-100-DRMs reflect different degrees of lateral order of the membrane microdomains. Additionally, Brij DRMs are composed by both inner and outer leaflet components, making them more physiologically relevant than TX-100-DRMs to the studies of membrane rafts.     

Development of efficient one-pot three-component assembly of trityl olmesartan medoxomil

We have elaborated a one-pot three-component assembly of trityl olmesartan medoxomil starting from commercially available ethyl 4-(2-hydroxypropan-2-yl)-2-propyl-1H-imidazole-5-carboxylate, 5-(4′-(bromomethyl)-[1,1′-biphenyl]-2-yl)-1-trityl-1H-tetrazole and 4-(chloromethyl)-5-methyl-1,3-dioxol-2-one intermediates. The developed and optimized one-pot process provides 72–75% yield of trityl olmesartan medoxomil over three steps, which represents in average ca. 90% yield per synthetic step, on a 300?g scale. The process is conducted in simple fashion and provides highly pure trityl olmesartan medoxomil (up to 97.5% by HPLC), which can be easily converted to olmesartan medoxomil that fully complies with all ICH requirements. Furthermore, the described process significantly improves the primary process to trityl olmesartan medoxomil by drastic reduction of required unit operations and application of single reaction solvent through the reaction sequence. Moreover, the amount of used organic solvents was notably reduced. The developed process has provided solid bases for industrial production of trityl olmesartan medoxomil.     

Multiple,concentration-dependent effects of sucrose,auxins and cytokinins in explant cultures of kale and tobacco

We describe complex multiple concentration dependencies for the response of isolated pith tissues to plant biologically active substances. Kale and tobacco stem pith explants were cultured on agar media containing combinations of sucrose, cytokinin [kinetin or benzyladenine (BA)] and auxin [indole-3-acetic acid (IAA) or naphthaleneacetic acid (NAA)]. Absorption of these components by explants and their effects on explant mass, contents of soluble proteins, starch and sugars, and activity of ADP-glucose pyrophosphorylase (AGPase) were studied in relation to their concentration. Up to ten pronounced statistically significant maxima (peaks or waves) were repeatedly detected in the dose–response curves over a concentration range of several logarithmic orders. Slight maxima were observed in the corresponding absorption curves. Pronounced maxima of sucrose absorption were induced by IAA and BA, and those of NAA absorption were induced by sucrose. Both types of multiple maxima (in dose–response and absorption curves) may be due to changes in concentration of intracellular solutes (sugars, auxins and cytokinins), thereby affecting metabolic processes that act as sinks for external solutes and elicit feedback appearance of maxima in absorption curves. Good correspondence between external concentrations at which maxima of different compared curves occur in addition to statistical significance of individual maxima and repeatability of experimental results supports the conclusion that the multiple maxima exhibited are genuine. We consider it possibile that the multiple maxima are associated with endopolyploidy or mixoploidy and/or epigenomic diversity of pith cells that show different sensitivities to biologically active solutes.     

DNA methylation changes in triticale due to in vitro culture plant regeneration and consecutive reproduction

Doubled haploids of triticale are of interest for plant breeders due to hybrid breeding programs based on cytoplasmic male sterility Tt phenomenon. However, (epi)mutations appearing during in vitro culture regeneration may lead to a phenotypic variation that makes the uniformity of plant materials questionable. Using RP-HPLC genomic DNA methylation of donor doubled haploid plants utilized as a source of tissues for the in vitro regeneration (via androgenesis and somatic embryogenesis) of triticale cv. Bogo and their consecutive generative progeny was evaluated. It was demonstrated that in vitro cultures induced a decrease of the DNA methylation of the regenerants independently of the approach used for plant regeneration. The decrease in DNA methylation of genomic DNA proceeded up to the first/second successive generations followed by the beginning of its reestablishment. Moreover, somatic embryogenesis resulted in a higher level of genomic DNA demethylation in regenerants than androgenesis and the process of methylation seems to be affected by donor plant. It is being speculated that long term changes in genomic DNA methylation may be a source of off-type individuals that may spontaneously arise during plant breeding.     

Piperine,a Natural Bioenhancer,Nullifies the Antidiabetic and Antioxidant Activities of Curcumin in Streptozotocin-Diabetic Rats

Knowing that curcumin has low bioavailability when administered orally, and that piperine has bioenhancer activity by inhibition of hepatic and intestinal biotransformation processes, the aim of this study was to investigate the antidiabetic and antioxidant activities of curcumin (90 mg/kg) and piperine (20 or 40 mg/kg), alone or co-administered, incorporated in yoghurt, in streptozotocin (STZ)-diabetic rats. The treatment for 45 days of STZ-diabetic rats with curcumin-enriched yoghurt improved all parameters altered in this experimental model of diabetes: the body weight was increased in association with the weight of skeletal muscles and white adipose tissues; the progressive increase in the glycemia levels was avoided, as well as in the glycosuria, urinary urea, dyslipidemia, and markers of liver (alanine and aspartate aminotransferases and alkaline phosphatase) and kidney (urinary protein) dysfunction; the hepatic oxidative stress was decreased, since the activities of the antioxidant enzymes superoxide dismutase, catalase and gluthatione peroxidase were increased, and the levels of malondialdehyde and protein carbonyl groups were reduced. The dose of 20 mg/kg piperine also showed antidiabetic and antioxidant activities. The treatment of STZ-diabetic rats with both curcumin and 20 mg/kg piperine in yoghurt did not change the antidiabetic and antioxidant activities of curcumin; notably, the treatment with both curcumin and 40 mg/kg piperine abrogated the beneficial effects of curcumin. In addition, the alanine aminotransferase levels were further increased in diabetic rats treated with curcumin and 40 mg/kg piperine in comparison with untreated diabetic rats. These findings support that the co-administration of curcumin with a bioenhancer did not bring any advantage to the curcumin effects, at least about the antidiabetic and antioxidant activities, which could be related to changes on its biotransformation.     

Steppe-like grassland as a refuge of the wild edible and medicinal plant species in anthropogenic landscape in northeastern Croatia

Habitat fragmentation and modification have been recognized as the most serious threats to biodiversity. In Croatia, the intensive human activities resulted in the landscape transformation, reduction of grassland areas and loss of species number. Increasingly threatened are the wild edible and medicinal plants which contribute remarkably to the biodiversity of different grassland types. In northeastern Croatia, one of the last remnants of the steppe-like grassland remained preserved in a very complex anthropogenic landscape. We examined the diversity of vascular plants occurring on this small habitat patch. Among the relatively high number of plant taxa (in a total of 177) found during the two years of investigations, most could be used both for human nutrition (28 taxa), and for the treatment of a wide range of diseases (60 taxa), while some taxa have nutritional value for livestock (17 taxa). All 23 recorded taxa with edible and medicinal properties are threatened in Croatia, 21 are threatened across Europe, and two are Red Listed taxa. Our results showed that small and isolated steppe-like grassland represents an important refuge for variety of valuable plant species in intensively used landscapes. Accordingly, such small habitats should be, at least locally, effectively protected.     

Physical training improves thermogenesis and insulin pathway,and induces remodeling in white and brown adipose tissues

Physical training (PT) has been considered as a treatment in metabolic syndrome (MS), since it induces thermogenic activity in brown (BAT) and white (WAT) adipose tissues. We evaluated the therapeutic effect of PT on activity of WAT and BAT in rats with MS induced by high-fat diet (30% lard) for 13 weeks and submitted, for the last 6 weeks, to swimming or kept sedentary (SED) rats. MS-SED rats compared to control diet (CT-SED) rats showed low physical fitness and high levels of glucose, insulin, homeostasis evaluation of insulin resistance (HOMA-IR), homeostasis evaluation of the functional capacity of β-cells (HOMA-β), and blood pressure. The gastrocnemius muscle decreased in peroxisome proliferator-activated receptor gamma coactivator 1-alpha and beta (PGC-1α, PGC-1β), and uncoupled protein 2 and 3 (UCP2 and UCP3) expressions. Both WAT and BAT increased in the adipocyte area and decreased in blood vessels and fibroblast numbers. WAT increased in expression of pro-inflammatory adipokines and decreased in anti-inflammatory adipokine and adiponectin. WAT and gastrocnemius showed impairment in the insulin signaling pathway. In response to PT, MS rats showed increased physical fitness and restoration of certain biometric and biochemical parameters and blood pressure. PT also induced thermogenic modulations in skeletal muscle, WAT and BAT, and also improved the insulin signaling pathway. Collectively, PT was effective in treating MS by inducing improvement in physical fitness and interchangeable effects between skeletal muscle, WAT and BAT, suggesting a development of brown-like adipocyte cells.     

Revision of the Barsine punicea Moore, 1878 species-group,with descriptions of two new species and two new subspecies (Lepidoptera,Erebidae, Arctiinae)

The Barsine puniceaMoore, 1878 species-group is revised. Two new species, Barsine bachma Volynkin & ?erný, sp. nov. (Central Vietnam and Hainan, China) and Barsine sirikitae Volynkin & ?erný, sp. nov. (North Thailand), and two new subspecies, Barsine punicea kachina Volynkin & ?erný, ssp. nov. (North Myanmar) and Barsine bachma bolovena Volynkin & ?erný, ssp. nov. (South Laos) are described. Barsine punicea melanandra ?erný, 2009 is upgraded to the species level: Barsine melanandra ?erný, 2009, stat. nov.Miltochrista rothschildiDraudt, 1914 is synonymized with Barsine punicea and downgraded to the subspecies status: Barsine punicea rothschildi (Draudt, 1914), syn. & stat. nov. The lectotype for Miltochrista coccineaRothschild, 1913 is designated. Adult, male and female genitalia are illustrated.