Volume 73, Issue 7-8

Pulsed-field gel electrophoresis (PFGE) is a highly discriminative molecular typing method that is used for epidemiological studies and investigation of outbreaks caused by different pathogens, including phytopathogenic Xanthomonas species. Bacterial spot (BS) is the most common and one of the most destructive diseases of tomato and pepper plants in Bulgaria. Several Xanthomonas species are known to cause BS, but the global distribution and genetic diversity of these species are not well understood. A collection of 100 BS-causing strains, isolated during the period of 1985–2012 from different tomato cultivars and weeds associated with tomato production areas from 11 geographic regions in Bulgaria, were screened for genetic diversity by genomic DNA restriction with rare-cutting endonucleases ( Xba I and Spe I) subsequently resolved by PFGE. Two haplotypes for Xanthomonas vesicatoria and one haplotype for Xanthomonas gardneri strains were found.

There is substantial evidence regarding enhanced antitumor cytotoxicity of selected chemotherapeutic agents by appropriate heat exposure (40–44°C). Based upon these results, the integration of hyperthermia as an additional treatment modality given simultaneously with systemic chemotherapy is currently of considerable interest. Hyperthermia can be induced by alternating magnetic field and magnetic nanoparticles. Thus, we have used thermosensitive magnetoliposomes that contained superparamagnetic iron oxide nanoparticles and doxorubicin for in vitro and in vivo therapy of rat glioma C6. The results showed that magnetoliposomes can be specifically heated to 43°C (phase transition temperature of a used lipid composition) in a few minutes, and during this, the encapsulated doxorubicin is released in a controllable manner. The in vitro experiments showed that the cell viability decreased to 79.2% after heat treatment alone and to 47.4% for doxorubicin-loaded magnetoliposomes without application of alternating magnetic field, while the combined treatment resulted in 17.3% cell viability. Also, in vivo results demonstrated that magnetic drug targeting has a strong antiglioma effect with a tumor volume growth inhibition and complete regression. Such targeted delivery and controlled release of anticancer agents would provide clinical advantages compared with currently available methods.

The Arctic flora hosts a limited number of species due to its extreme environmental conditions which also yield novel and unique secondary metabolites from withstanding plants. Considering a lack of research on bioactivity potential of Arctic flora, Ranunculus hyperboreus , an Arctic plant, was studied for its anti-inflammatory potential as a part of ongoing research on discovering novel natural bioactive products. Solvent-based fractions (H 2 O, n- BuOH, 85% aq. MeOH, n- hexane) from R. hyperboreus extract were observed to decrease the elevated nitrate amount during the inflammatory response of lipopolysaccharide-induced mouse macrophage RAW264.7 cells. To some extent, treatment with fractions was able to regulate the expression and protein levels of inflammation-related enzymes, iNOS and COX-2, and pro-inflammatory cytokines, TNF-α, IL-1β, and IL-6. The most active fractions, H 2 O and 85% aq. MeOH, were suggested to exert their effect through suppressed activation of MAPK pathways, especially JNK. Based on the studies of same species, phenolic glycosides were suggested to be the main active ingredients. To our knowledge, this is the first report of any bioactivity of R. hyperboreus which could be a valuable source of natural bioactive agents against inflammation.

Exposure to high levels of glucose may cause glucotoxicity, leading to pancreatic β cell dysfunction, including cell apoptosis and impaired glucose-stimulated insulin secretion. The aim of this study was to explore the effect of cyanidin-3-rutinoside (C3R), a derivative of anthocyanin, on glucotoxicity-induced apoptosis in INS-1 pancreatic β cells. Glucose (30 mM) treatment induced INS-1 pancreatic β cell death, but glucotoxicity and apoptosis significantly decreased in cells treated with 50 μM C3R compared to that observed in 30 mM glucose-treated cells. Furthermore, hyperglycemia increased intracellular reactive oxygen species (ROS), lipid peroxidation, and nitric oxide (NO) levels, while C3R treatment reduced these in a dose-dependent manner. C3R also increased the activity of antioxidant enzymes, markedly reduced the expression of pro-apoptotic proteins (such as Bax, cytochrome c , caspase 9 and caspase 3), and increased the expression of the anti-apoptotic protein, Bcl-2, in hyperglycemia-exposed cells. Finally, cell death was examined using annexin V/propidium iodide staining, which revealed that C3R significantly reduced high glucose-induced apoptosis. In conclusion, C3R may have therapeutic effects against hyperglycemia-induced β cell damage in diabetes.

This work presents investigations of biologically active metabolites of Usnea barbata lichen. Extraction conditions for usnic acid and other biologically active phytocomponents using various solvent systems were chosen. Modern analytical techniques were used to study composition of the obtained extracts; usnic acid and phenolic compound contents were estimated. Antioxidant activity and antimicrobial properties of lichen dry extract against bacteria Bacillus subtilis and Pseudomonas fluorescens were studied.

The antibacterial activity of zinc oxide (ZnO) nanoflowers has been investigated and presented in this article. Classic three-dimensional nanoflowers have been prepared by hydrothermal method using zinc acetate dihydrate Zn(CH 3 COO) 2 ·2H 2 O as the sole precursor. The X-ray diffraction and Fourier transform infrared spectra confirm the formation of ZnO crystals. Consequently, on the basis of morphological and chemical observations, the chemical reaction mechanism of ZnO nanoflowers was also proposed. Antibacterial activity was carried out against food-borne pathogen, Escherichia coli , which is ubiquitous in distribution among food-laden wastes. The experimental procedures for the antibacterial test included a spectroscopic method with different concentrations (5–20 μg/mL) of ZnO nanoflowers to unearth the minimum inhibitory concentration. Our investigation suggests that the lowest concentration of ZnO nanoflower solution that can hamper the growth of this microbial strain was 5 μg/mL.

The present study aims at assessing the efficacies of olivetoric acid (OA) and physodic acid (PA) isolated from Pseudevernia furfuracea (L.) Zopf (Parmeliaceae) in human lymphocytes (HLs) in vitro. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays were performed to establish cytotoxicity in HLs. Besides, oxidative stress and genotoxicity were monitored by estimating the changes of total oxidative stress (TOS) and 8-hydroxy-2′-deoxyguanosine (8-OH-dG) levels, respectively, in HLs. At the same time, OA- and PA-induced total antioxidant capacity (TAC) levels in HLs were determined. Although especially low concentrations of OA (IC 50 =109.94 mg/L) and PA (IC 50 =665.49 mg/L) did not show cytotoxic effect at high levels in HLs, it was revealed that cytotoxicity was significantly (p<0.05) associated with oxidative stress and genotoxicity via correlation analysis. While TOS level in HLs did not statistically (p>0.05) increase in the presence of all treatments (0.5–100 mg/L) of PA, TAC level was increased by PA applications in certain concentrations (0.5–10 mg/L). Overall, the obtained data indicate that OA and especially PA as lichen compounds that do not cause oxidative stress can be a new resource of therapeutics as recognized in the present study with their high antioxidant features.

The objective of the present paper was the assessment of the chemical composition of the essential oils from four Asteraceae species with a considerable food, medicinal, and agricultural value, collected in Egypt, together with their in vitro inhibitory activity against molds and yeasts. The essential oil of Launaea cornuta flowers was also evaluated for the first time, but because of its very low yield (<0.01%), no antifungal test was performed.

The ability of the fungus Aureobasidium pullulans ATCC 42023 to produce pullulan from yeast extract-supplemented xylan hydrolysates of the prairie grass prairie cordgrass was examined relative to polysaccharide and cell biomass production, yield, and pullulan content of the polysaccharide. A pullulan concentration of 11.2 g L −1 and yield of 0.79 g g −1 was produced by ATCC 42023 when grown for 168 h at 30°C on the phosphate-buffered hydrolysate supplemented with yeast extract. The highest biomass level being 8.8 g L −1 was produced by ATCC 42023 after 168 h on a yeast extract-supplemented, hydrolysate-containing complete medium lacking sodium chloride. The highest pullulan content of the polysaccharide produced by ATCC 42023 after 168 h on the hydrolysate medium supplemented with yeast extract and ammonium sulfate was 70%. The findings indicate that a polysaccharide with a high pullulan content can be produced at a relatively high yield by the fungus grown on a yeast extract-supplemented xylan hydrolysate, suggesting that pullulan could be produced using a biomass-based process.