Xylooligosaccharides from hardwood and cereal xylans produced by a thermostable xylanase as carbon sources for Lactobacillus brevis and Bifidobacterium adolescentis

To compare xylans from forestry with agricultural origins, hardwood xylan (birch) and cereal arabinoxylan (rye) were hydrolyzed using two variants of the xylanase RmXyn10A, full-length enzyme and catalytic module only, from Rhodothermus marinus . Cultivations of four selected bacterial species, using the xylooligosaccharide (XOS) containing hydrolysates as carbon source, showed selective growth of Lactobacillus brevis DSMZ 1264 and Bifidobacterium adolescentis ATCC 15703. Both strains were confirmed to utilize the XOS fraction (DP 2-5), whereas putative arabinoxylooligosaccharides from the rye arabinoxylan hydrolysate were utilized by only B. adolescentis. Escherichia coli did not grow, despite its capability to grow on the monosaccharides arabinose and xylose. It was also shown that Pediococcus parvulus strain 2.6 utilized neither xylose nor XOS for growth. In summary, RmXyn10A or its catalytic module proved suitable for high-temperature hydrolysis of hardwood xylan and cereal arabinoxylan, producing XOS that could qualify as prebiotics for use in functional food products.

Evaluation of the mechanism of gelation of an oleogel based on a triterpene extract from the outer bark of birch

Oleogels are known for their high physical, chemical, and mechanical stability and good in vivo efficacy, which make them appropriate vehicles for dermal drug delivery and skin care for very dry skin. Modern formulation research focusses on well tolerated and sustainable formulation concepts. This paper deals with an innovative oleogel, which is based on a triterpene dry extract from the outer bark of birch (TE). In this formulation TE does not only act as an excipient but provides interesting pharmacological properties at the same time. The oleogel was formulated using solely Simmondsia Chinensis seed oil (jojoba oil) and TE. Fluorescence microscopy and confocal Raman microscopy showed that suspended TE particles arrange in a three-dimensional gel network. Infrared spectroscopy revealed that the formation of hydrogen bonds between TE particles is responsible for the self-assembly of TE in oil. Moreover, the influence of TE concentration and morphology of the TE particles on the viscoelasticity of the resulting oleogels was analyzed. Gel strength increased with TE concentration and was critical to the specific surface area of the TE particles.

Potential of hot water extraction of birch wood to produce high-purity dissolving pulp after alkaline pulping

The potential of hot water extraction of birch wood to produce highly purified dissolving pulp in a subsequent soda-anthraquinone pulping process was evaluated. After intermediate extraction intensities, pulps with low xylan content (3-5%) and high cellulose yield were successfully produced. Increasing extraction intensity further decreased the xylan content in pulp. However, below a xylan content of 3%, the cellulose yield dramatically decreased. This is believed to be due to cleavage of glycosidic bonds in cellulose during severe hot water extractions, followed by peeling reactions during alkaline pulping. Addition of sodium borohydride as well as increased anthraquinone concentration in the pulping liquor increased the cellulose yield, but had no clear effects on pulp purity and viscosity. The low intrinsic viscosity of pulps produced after severe extraction intensities and soda-anthraquinone pulping corresponded to the viscosity at the leveling-off degree of polymerization, suggesting that nearly all amorphous cellulose had been degraded.

Quantitative structures and thermal properties of birch lignins after ionic liquid pretreatment

The use of ionic liquid (IL) in biomass pretreatment has received considerable attention recently because of its effectiveness in decreasing biomass recalcitrance to subsequent enzymatic hydrolysis. To understand the structural changes of lignin after pretreatment and enzymatic hydrolysis process, ionic liquid lignin (ILL) and subsequent residual lignin (RL) were sequentially isolated from ball-milled birch wood. The quantitative structural features of ILL and RL were compared with the corresponding cellulolytic enzyme lignin (CEL) by nondestructive techniques (e.g., FTIR, GPC, quantitative (13)C, 2D and (31)P NMR). The IL pretreatment caused structural modifications of lignin (cleavage of β-O-4 ether linkages and formation of condensed structures). In addition, lignin fragments with lower S/G ratios were initially extracted, whereas the subsequently extracted lignin is rich in syringyl unit. Moreover, the maximum decomposition temperature (T(M)) was increased in the order ILL < RL < CEL, which was related to the corresponding β-O-4 ether linkage content and molecular weight (M(w)). On the basis of the results observed, a possible separation mechanism of IL lignin was proposed.

Effect of different steam explosion conditions on methane potential and enzymatic saccharification of birch

Birch (Betula pubescens) was steam exploded at 13 different conditions with temperatures ranging from 170 to 230 °C and residence times ranging from 5 to 15 min. Increasing severity in the pretreatment led to degradation of xylan and formation of pseudo-lignin. The effect of the pretreatments was evaluated by running enzymatic saccharification and anaerobic digestion followed by analysis of sugar and methane yields, respectively. Enzymatically released glucose increased with pretreatment severity up to 220 °C for 10 min and levels of solubilized glucose reached 97% of the theoretical maximum. The highest methane yield (369 mL gVS(-1)) was obtained at a severity factor of 4.5 and this yield was 1.8 times higher than the yield from untreated birch. Enzymatic glucose yields and methane yields were generally correlated. The results indicate that steam-exploded birch can be effectively converted to either glucose or methane.

Reactions of airway epithelial cells to birch pollen grains previously exposed to in situ atmospheric Pb concentrations: a preliminary assay of allergenicity

A growing body of evidence suggests that interactions between pollen grains and environmental pollutants, especially air pollutants, could be of critical importance with regard to the increase in allergic responses observed in the past decades. Using birch pollen grains (BPG), a major allergy source in European countries, and lead (Pb), a highly toxic metal trace element (MTE) present in urban areas, the immune response of human epithelial cells exposed to BPG or to Pb-associated BPG was compared. The cellular response after exposure either to BPG, BPG exposed to 30 mg/L of Pb (BPG-30), or BPG exposed to 60 mg/L of Pb (BPG-60) was evaluated after two time lapses (2 and 6 h) by measuring mRNA levels of four mediators, including two inflammatory (interleukin-8 and interleukin-6) and two allergic (interleukin-5 [IL-5] and interleukin-13) cytokines. After 2 h of exposure, significant upregulation of the IL-5 gene was observed after exposure to BPG-60 in comparison with exposure to BPG and BPG-30 (N (IL-5) = 1.9, Mann-Whitney test, p = 0.003). After 6 h of exposure, significant upregulation of the IL-5 gene was observed after exposure to BPG-30 with N (IL-5) = 1.8 and to BPG-60 with N (IL-5) = 2.3 (Mann-Whitney test, p = 0.0029) in comparison with exposure to BPG. This first attempt to investigate the influence of pollution by MTE on pollen grain showed a dose-time-dependent increase in IL-5 gene expression after exposure to BPG combined to Pb.

Cognition-enhancing and neuroprotective activities of the standardized extract of Betula platyphylla bark and its major diarylheptanoids

Diarylheptanoids have been the center of the intensive research efforts for Alzheimer's disease and other neurodegenerative diseases. The present study aimed to determine the effect of the standardized extract of B. platyphylla bark and its major diarylheptanoids in scopolamine-induced amnesic mice through cyclic AMP response element-binding protein (CREB) activation. Oral administration of the standardized extract of B. platyphylla bark (100mg/kg body weight), aceroside VIII (1mg/kg body weight) and platyphylloside (1 or 2mg/kg body weight) significantly ameliorated scopolamine-induced amnesia in passive avoidance test. CREB phosphorylation and brain-derived neurotrophic factor (BDNF) expression in the cortex and hippocampus of the scopolamine-treated mice were markedly increased by the treatment of the standardized extract of B. platyphylla bark and platyphylloside. The standardized extract of B. platyphylla bark and its major diarylheptanoids also significantly protected HT22 cells against neurotoxicity induced by glutamate insult. The standardized extract of B. platyphylla bark and platyphylloside may ameliorate memory deficits by activating the CREB-BDNF pathway and prevent a neurodegeneration by inhibiting neuronal cell death.

Xylans inhibit enzymatic hydrolysis of lignocellulosic materials by cellulases

Hemicelluloses have been found to be physical barriers in the hydrolysis of cellulose, and prevent the access of enzymes to cellulose surface. In addition, soluble hemicelluloses may strongly inhibit the cellulase activity. In this work, birchwood xylan clearly inhibited the enzymatic hydrolysis of wheat straw, Avicel and nanocellulose by cellulases. Hydrolysis efficiencies of cellobiohydrolase I (CBHI, from Thermoascus aurantiacus), cellobiohydrolase II (CBHII, from Trichoderma reesei) and endoglucanase II (from T. aurantiacus) were clearly inhibited by birchwood xylan, respectively. The strongest inhibitory effect of birchwood xylan was observed on the hydrolysis of Avicel by CBHI and CBHII, as a dramatically decreased formation of the main product, cellobiose. After additions of soluble and insoluble oat spelt xylan, cleaved cellobiose units by CBHI from cellulose chain decreased from 8 to 4 and 6, respectively. The results in this work demonstrated that xylans clearly inhibited the hydrolysis efficiencies of both endoglucanase and cellobiohydrolase.

Extraction of betulin, trimyristin, eugenol and carnosic acid using water-organic solvent mixtures

A solvent system consisting of ethyl acetate, ethyl alcohol and water, in the volume ratio of 4.5:4.5:1, was developed and used to extract, at room temperature, betulin from white birch bark and antioxidants from spices (rosemary, thyme, sage, and oregano) and white oak chips. In addition, under reflux conditions, trimyristin was extracted from nutmeg using the same solvent system, and eugenol from olives was extracted using a mixture of salt water and ethyl acetate. The protocol demonstrates the use of water in organic solvents to extract natural products from plants. Measurement of the free-radical scavenging activity using by 2,2-diphenyl-1-picrylhydrazyl (DPPH) indicated that the extraction of plant material using ethyl acetate, ethyl alcohol and water (4.5:4.5:1, v/v/v) was exhaustive when carried out at room temperature for 96 h.

Effects of a catalytic converter on PCDD/F, chlorophenol and PAH emissions in residential wood combustion

Catalytic converters can be used to decrease carbon monoxide, organic compounds and soot from small-scale wood-fired appliances. The reduction is based on the oxidation of gaseous and particulate pollutants promoted by catalytic transition metal surfaces. However, many transition metals have also strong catalytic effect on PCDD/F formation. In this study birch logs were burned in a wood-fired stove (18 kW) with and without a catalytic converter with palladium and platinum as catalysts. PCDD/F, chlorophenol and PAH concentrations were analyzed from three phases of combustion (ignition, pyrolysis and burnout) and from the whole combustion cycle. PCDD/F emissions without the catalytic converter were at a level previously measured for wood combustion (0.15-0.74 ng N m(-3)). PAH emissions without the catalytic converter were high (47-85 mg N m(-3)) which is typical for batch combustion of wood logs. Total PAH concentrations were lower (on average 0.8-fold), and chlorophenol and PCDD/F levels were substantially higher (4.3-fold and 8.7-fold, respectively) when the catalytic converter was used. Increase in the chlorophenol and PCDD/F concentrations was most likely due to the catalytic effect of the platinum and palladium. Platinum and palladium may catalyze chlorination of PCDD/Fs via the Deacon reaction or an oxidation process. The influence of emissions from wood combustion to human health and the environment is a sum of effects caused by different compounds formed in the combustion. Therefore, the usage of platinum and palladium based catalytic converters to reduce emissions from residential wood combustion should be critically evaluated before wide-range utilization of the technology.

Hemicelluloses prior to aspen chemithermomechanical pulping: pre-extraction, separation, and characterization

A portion of hemicelluloses and acetic acid can be pre-extracted with dilute sulfuric acid prior to the aspen chemithermomechanical pulp process. The streams collected from the second press-impregnation stage after acid pre-extraction contain a significant amount of acid pre-extracted hemicelluloses. Most of the total sugars obtained from the pressate were xylan, in which xylan was further hydrolyzed to sugar monomers under the acid pre-extraction condition. To fully understand the characteristics of hemicelluloses yielded prior to pulping, the pre-extracted hemicelluloses were separated and characterized by FT-IR, (1)H NMR, and thermogravimetric analysis in this study. Most of the FT-IR bonds from the hemicelluloses agreed well with the other two spectra of birch xylan and CA0050 xylan, except a new absorption at 1734 cm(-1) contributed to acetyl groups. The hemicelluloses obtained from acid pre-extraction began to decompose significantly at about 225 °C, slightly lower in comparison with organosolv and alkaline hemicelluloses reported in the literature.

Procyanidin xylosides from the bark of Betula pendula

A procyanidin dimer xyloside, catechin-(4α→8)-7-O-β-xylopyranosyl-catechin, was isolated from the inner bark of Betula pendula and its structure was determined using 1D and 2D NMR, CD and high-resolution ESIMS. Interestingly, the 7-O-β-xylopyranose unit was found to be present in the lower terminal unit of the dimer. In addition to this procyanidin dimer xyloside, an entire series of oligomeric and polymeric procyanidin xylosides was detected. Their structures were investigated by hydrophilic interaction HPLC-HRESIMS. Procyanidin glycosides are still rarely found in nature.

Detection and analysis of unusual features in the structural model and structure-factor data of a birch pollen allergen

Physically improbable features in the model of the birch pollen structure Bet v 1d (PDB entry 3k78) are faithfully reproduced in electron density generated with the deposited structure factors, but these structure factors themselves exhibit properties that are characteristic of data calculated from a simple model and are inconsistent with the data and error model obtained through experimental measurements. The refinement of the 3k78 model against these structure factors leads to an isomorphous structure different from the deposited model with an implausibly small R value (0.019). The abnormal refinement is compared with normal refinement of an isomorphous variant structure of Bet v 1l (PDB entry 1fm4). A variety of analytical tools, including the application of Diederichs plots, Rσ plots and bulk-solvent analysis are discussed as promising aids in validation. The examination of the Bet v 1d structure also cautions against the practice of indicating poorly defined protein chain residues through zero occupancies. The recommendation to preserve diffraction images is amplified.

Test of tree core sampling for screening of toxic elements in soils from a Norwegian site

Tree core samples have been used to delineate organic subsurface plumes. In 2009 and 2010, samples were taken at trees growing on a former dump site in Norway and analyzed for arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and zinc (Zn). Concentrations in wood were in averages (dw) 30 mg/kg for Zn, 2 mg/kg for Cu, and < 1 mg/kg for Cd, Cr, As and Ni. The concentrations in wood samples from the polluted test site were compared to those derived from a reference site. For all except one case, mean concentrations from the test site were higher than those from the reference site, but the difference was small and not always significant. Differences between tree species were usually higher than differences between reference and test site. Furthermore, all these elements occur naturally, and Cu, Ni, and Zn are essential minerals. Thus, all trees will have a natural background of these elements, and the occurrence alone does not indicate soil pollution. For the interpretation of the results, a comparison to wood samples from an unpolluted reference site with same species and similar soil conditions is required. This makes the tree core screening method less reliable for heavy metals than, e.g., for chlorinated solvents.

Sesquiterpenes from the inner bark of the silver birch and the paper birch

The compositions of the mixtures of sesquiterpenoids, largely hydrocarbons that were found in the inner bark of the silver birch, Betula pendula Roth and the paper birch, Betulapapyrifera Marshall, grown in New Zealand were analyzed by SPME-GCMS. The major components of the volatile oil from the inner bark of B. pendula were trans alpha-bergamotene (31%) and alpha-santalene (19%). This composition was quite different from that of the oil from the branches, buds and leaves of the same species from Turkey, but was very similar to that of the oil from the bark of B. pubescens from Russia. The major components of the oil from the inner bark of B. papyrifera were trans alpha-bergamotene (18%), ar-curcumene (12%), E-beta-farnesene (12%), Z-beta-farnesene (10%) and cis-alpha-bergamotene (8%).

Water-extractable magnesium, manganese and copper in leaves and herbs of medicinal plants

Since herbal teas, infusions and decoctions prepared from medicinal plants are popular remedies, it remains a topical question whether these herbal drugs can be treated as sources of essential elements for humans, who often use them in their everyday diet. Therefore, total and water-extractable contents of Mg, Mn and Cu were determined in 41 leaves originating from four botanical species of Plantago lanceolata, Arctostaphyllos uva-ursi, Rubus fruticosus and Betula sp., as well as in 33 samples of herbs represented by three species of Urtica dioica, Hypericum perforatum and Achillea millefolium. The highest level was determined in the case of Mg (in a range from 2.0 to 7.0 mg/g of dry mass [d.m.]), followed by Mn (from 50.0 to 1300.0 mg/kg d.m.), and lowest of all, Cu (from 3.5 to 19.5 mg/kg d.m.). Student's t-test showed that a statistically significant difference exists between samples originating from different plant species regarding the total content and water-extractable forms of Mg, Mn and Cu. By analysis of the relations between elements, it was observed that total level of Cu correlated with total levels of Mg and Mn, which indicates a synergistic interaction between the essential elements under study. With regard to Dietary Reference Intakes (DRIs), the leaves of Rubus fruticosus contained the highest amounts of a water-extractable bioavailable form of Mn, which guarantees from 160 to 200% of the daily requirement of Mn for women and men, respectively. On the other hand, the extract obtained from Urticae folium gave water-extractable Mg in the amount of 76 mg/500 mL, which constitutes about 20% of daily requirement. The plant material richest in water-extractable Cu was Hyperici herba, containing 154.5 microg/500 mL, or 17% of DRI for both sexes.

[A multicenter comparative observation on the effectiveness and the rapidness of the effect of Cystostop Rapid versus antibiotic therapy in patients with uncomplicated cystitis]

The currently available treatment for uncomplicated urinary tract infections includes only antibiotics and chemotherapeutic agents. Experience in the management of acute uncomplicated infections using non-antibiotic products is very limited. The aim of this observation was to study to what extent the response to Cystostop Rapid would be more rapid and more effective compared to antibiotic therapy in patients with acute uncomplicated urinary bladder infections. The secondary objective was to determine the time to improvement of cystitis symptoms following the start of treatment, as well as the duration of patients' disablement. A total of 158 female subjects were included, assessed microbiologically, and evaluated for incidence and severity of symptoms, before the start of treatment and after completion of treatment. A visual analogue scale was used for patient self-assessment of the severity of symptoms, the improvement of symptoms, as well as the time to improvement of symptoms.

RESULTS

158 females, eligible according to the inclusion criteria of the study, were allocated to one of the two groups according to time of enrollment: Group A included 86 subjects: assigned to Cystostop Rapid for 3 days and administered according to the manufacturer's recommended regimen; and Group B included 72 women: assigned to ciprofloxacin 500 mg twice daily for 3 days according to the Product Registration File with the BDA. The clinical and microbiological effectiveness of Cystostop Rapid was comparable to that of ciprofloxacin, providing a two-fold more rapid improvement of cystitis symptoms, at a mean time to improvement of 24 hours (p < 0.02) versus 46 hours for ciprofloxacin. Clinical improvement within 48 hours of Cystostop Rapid regimen occurred in 97% (p < 0.02) of patients, vs. 65.3% of patients on ciprofloxacin. Improvement of symptoms within 12 hours was reported in 36% of patients on Cystostop Rapid vs. 5.5% of patients in the ciprofloxacin group (p < 0.02). No adverse events or intolerability to the therapy were reported throughout the course of the study.

[Interspecific allelopathic effect of different organs' aqueous extracts of Betula platyphylla and Larix olgensis on their seed germination and seedling growth]

In this paper, the Betula platyphylla root-, branch-, and foliage aqueous extracts and Larix olgensis root-, branch-, foliage-, and bark aqueous extracts over a range of concentrations 5.0, 12.5, 25.0, 50.0, and 100.0 mg x mL(-1) were used to study their interspecific allelopathic effect on the seed germination and seedling growth of the two tree species. All the L. olgensis organs' extracts, except its root extracts at concentration 5.0 mg x mL(-1), had inhibition effect on B. platyphylla seed germination rate, which was 54%, 58%, 59%, and 66% under the effects of L. olgensis foliage-, branch-, bark-, and root extracts, respectively, as compared with the control. With increasing concentration, the inhibition effect of L. olgensis root- and branch extracts increased while that of L. olgensis foliage- and bark extracts decreased. The L. olgensis organs' extracts, especially the foliage extracts at concentration 100.0 mg x mL(-1), had strong inhibition effect on B. platyphylla seed radicle- and hypocotyl length growth, with a decrement of 38% and 55% (P < 0.05), respectively. L. olgensis branch- and foliage extracts promoted, but root- and bark extracts inhibited B. platyphylla seedling growth and biomass production. B. platyphylla organs' extracts promoted L. olgensis seed germination, root- and branch extracts promoted hypocotyl length growth, but foliage extracts at 50.0 and 100.0 mg x mL(-1) decreased the hypocotyl length growth by 27% and 28% (P < 0.05), respectively. B. platyphylla organs' extracts mainly promoted L. olgensis seedling growth, with the height- and collar diameter growth and biomass accumulation at B. platyphylla foliage extracts concentration 5.0 mg x mL(-1) increased by 54%, 60%, and 100% (P < 0.05), respectively. Our results suggested that there existed obvious allelopathic effect between B. platyphylla and L. olgensis, and thus, mixed planting B. platyphylla and L. olgensis could have promotion effects on the growth of the two tree species.

Effect of radial directional dependences and rainwater influence on CVOC concentrations in tree core and birch sap samples taken for phytoscreening using HS-SPME-GC/MS

Phytoscreening for chlorinated volatile organic compounds (CVOC) in tree core samples is influenced by many factors. For instance, greater fluctuations are observed for CVOC concentrations in samples taken around the trunk at a fixed height compared to samples taken directly next to each other. To avoid false negatives and inaccurate interpretation of the results, we investigated this radial directional dependence as well as the influence of rainwater on measured concentrations. CVOC analysis was performed by gas chromatography/mass spectrometry (GC/MS) following Solid-Phase-Microextraction (SPME). Phytoscreening was successfully carried out at three sites using this method. In addition, sap samples were taken from white birches during their budding period as a novel phytoscreening approach. Birch sap sampling is shown to be a suitable means of characterizing contaminant distribution within the soil subsurface. Radial directional dependence of CVOC concentrations varies by almost 80% for tree core samples and 50% for birch sap samples. Variations in concentrations measured around the trunk do not, however, provide information on the inflow direction of contaminated groundwater. The weather conditions were shown to have a greater influence so that CVOC concentrations measured from samples taken during colder, rainier weather were, on average, a factor of 100 lower than those taken during a warm and dry period. Nevertheless phytoscreening is adequate for CVOC characterization in the soil subsurface if the campaign is carried out during a dry weather period, the results then can be taken as being semiquantitative.

Degradation kinetics of the main carbohydrates in birch wood during hot water extraction in a batch reactor at elevated temperatures

Hot water extraction of wood at elevated temperatures may be a suitable method to produce hemicellulose-lean pulps and to recover xylan-derived products from the water extract. In this study, water extractions of birch wood were conducted at temperatures between 180 and 240 °C in a batch reactor. Xylan was extensively removed, whereas cellulose was partly degraded only at temperatures above 180 °C. Under severe extraction conditions, acetic acid content in the water extract was higher than the corresponding amount of acetyl groups in wood. In addition to oligo- and monosaccharides, considerable amounts of furfural and 5-hydroxymethylfurfural (HMF) were recovered from the extracts. After reaching a maximum, the furfural yield remained constant with increasing extraction time. This maximum slightly decreased with increasing extraction temperature, suggesting the preferential formation of secondary degradation products from xylose. Kinetic models fitting experimental data are proposed to explain degradation and conversion reactions of xylan and glucan.

Temporal variation in epidermal flavonoids due to altered solar UV radiation is moderated by the leaf position in Betula pendula

The physiological mechanisms controlling plant responses to dynamic changes in ambient solar ultraviolet (UV) radiation are not fully understood: this information is important to further comprehend plant adaptation to their natural habitats. We used the fluorimeter Dualex to estimate in vivo the epidermal flavonoid contents by measuring epidermal UV absorbance (A(375) ) in Betula pendula Roth (silver birch) leaves of different ages under altered UV. Seedlings were grown in a greenhouse for 15 days without UV and transferred outdoors under three UV treatments (UV-0, UV-A and UV-A+B) created by three types of plastic film. After 7 and 13 days, Dualex measurements were taken at adaxial and abaxial epidermis of the first three leaves (L1, L2 and L3) of the seedlings. After 14 days, some of the seedlings were reciprocally swapped amongst the treatments to study the accumulation of epidermal flavonoids in the youngest unfolded leaves (L3) during leaf expansion under changing solar UV environments. A(375) of the leaves responded differently to the UV treatment depending on their position. UV-B increased the A(375) in the leaves independently of leaf position. L3 quickly adjusted A(375) in their epidermis according to the UV they received and these adjustments were affected by previous UV exposure. The initial absence of UV-A+B or UV-A, followed by exposure to UV-A+B, particularly enhanced leaf A(375) . Silver birch leaves modulate their protective pigments in response to changes in the UV environment during their expansion, and their previous UV exposure history affects the epidermal-absorbance achieved during later UV exposure.

Inter- and intra-specific variation in stem phloem phenolics of paper birch (Betula papyrifera) and European white birch (Betula pendula)

Outbreaks of bronze birch borer (BBB) (Agrilus anxius), a wood-boring beetle endemic to North America, have been associated with widespread mortality of birch (Betula spp.). There is substantial inter- and intra-specific variation in birch resistance to BBB. Species endemic to North America, such as paper birch (B. papyrifera), have coevolved with BBB and are more resistant than European and Asian birch species, such as European white birch (B. pendula), which lack an evolutionary history with BBB. Borer larvae feed on stem phloem tissue. Therefore, in search of potential resistance mechanisms against BBB, we compared the constitutive phenolic profile of stem phloem tissue of paper birch with that of European white birch. We also analyzed intraspecific variation in phenolic composition among clones and/or half-siblings of both species. Three phenolics (coumaroylquinic acid, betuloside pentoside A, and a diarylheptanoid hexoside) were detected only in paper birch, and concentrations of six other phenolics were significantly higher in paper birch. These differences may contribute to the high resistance of paper birch to BBB relative to European white birch. There was significant intraspecific variation in four of 17 phenolics found in paper birch and in five of 14 found in European white birch, but clones and half-siblings within each species could not be distinguished by phenolic composition using multivariate analysis.

Black painted pottery, Kildehuse II, Odense County, Denmark

This work aimed at characterization of a black layer covering a Bronze Age (period VI) pot surface. To solve research problems plane polarized light microscopy (PLM), scanning microscopy with X-ray microanalyser (SEM/EDS), Raman and FTIR microspectroscopies were applied. Observation of the black layer under the PLM suggests that we deal with an opaque, isotropic layer, purposely put on leather-hard, burnished surface of a pot. No traces of organic substances that might have modified a pot surface before painting were detected. The black layer coats the pot with a continuous 0.2-0.4 μm thick layer. The black layer must have been applied while warm or hot. It is recognized that the black layer is a true painting layer. Spectroscopic analyses (Raman and FTIR) point that birch tar or a birch-pine tar had been applied. Carbon black should be definitely excluded. The analyzed organic substance is structurally ordered in various degrees, due to varying temperature influence. Some Raman spectra reveal, in second-order region of the spectrum (>2000 cm(-1)), the graphite presence. Scarce points reveal the presence of inorganic admixtures: clay minerals, feldspars and quartz. The next question is: Is it an organic paint or a carbon-based, "mixed" paint? Inorganic admixtures are only casual. Relatively high concentration of alumina is expected to have appeared due to aluminum mobility in acidic environment and this was provided by organic tar/pitch substances. Phosphorus (usually with calcium) mostly concentrates together with clay minerals. Thus, hypothesis on bone powder or ash addition to tar/pitch should be excluded. Some elements may originate not only from inorganic substances but also from wood ashes.

Birch bark extract as therapy for chronic hepatitis C--a pilot study

The hepatoprotective effect of birch bark extract (BBE) in patients with chronic hepatitis C (CHC) was studied. Forty-two patients with serologically confirmed chronic hepatitis C were treated for 12 weeks with 160 mg standardized BBE per day. The primary outcome parameter measured was the rate of alanine aminotransferase (ALT) normalization after 12 weeks. Secondary parameters included the course of ALT, aspartate aminotransferase (AST) levels, quantitative HCV RNA levels, subjective symptoms associated with CHC (fatigue, abdominal discomfort, depression, and dyspepsia), safety and compliance. The qualitative-quantitative analysis of BBE was made using high performance liquid chromatography to confirm the presence of 75% betulin and 3.5% betulinic acid. Significant differences in the mean ALT and HCV RNA levels were observed after 12 weeks of treatment. The level of ALT was decreased in 54.0% and normalized (p=0.046). HCV RNA was reduced in 43.2% (p=0.016). After 12 weeks of treatment, reports of fatigue and abdominal discomfort were reduced by 6-fold (p=0.028) and 3-fold (p=0.05), respectively. Dyspepsia was no longer reported (p=0.042) and the effect was significantly different from baseline. Because this study lacks a control group clinical relevance of the data can only be estimated in future by following controlled clinical trials.

An aqueous birch leaf extract of Betula pendula inhibits the growth and cell division of inflammatory lymphocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Leaf extracts of Betula pendula have been traditionally used for the treatment of patients with rheumatoid arthritis (RA) or osteoarthritis.

AIM OF THE STUDY

We investigated the anti-proliferative capacity of an aqueous leaf extract of Betula pendula (BPE) on human primary lymphocytes in vitro, because activated lymphocytes play a major role in the initiation and maintenance of RA.

MATERIALS AND METHODS

Lymphocyte proliferation and cell division was measured by the activity of mitochondrial dehydrogenases and by using the membrane-permeable dye carboxyfluorescein diacetate succinimidyl ester (CFSE), respectively. Apoptosis was analyzed by surface staining of phosphatidylserine and intracellular activation of effector caspases 3 and 7 in comparison to the drug methotrexate using flow cytometric and photometrical analysis. In addition, the impact of the extract on cell cycle distribution was investigated by propidium iodide staining of DNA. For the bioassays BPE concentrations of 10-160 μg/mL were investigated. A phytochemical analysis, using LC-MS and HPLC, was conducted to identify the polyphenolic constituents of the birch leaf extract.

RESULTS

Leaf extracts of Betula pendula inhibited the growth and cell division (CD8(+): 40 μg/mL: 45%; 80 μg/mL: 60%; 160 μg/mL: 87%) (CD4(+): 40 μg/mL: 33%; 80 μg/mL: 54%; 160 μg/mL: 79%) of activated, but not of resting T lymphocytes in a significant dose-dependent manner. The inhibition of lymphocyte proliferation due to apoptosis induction (compared to untreated control: 40 μg/mL: 163%; 80 μg/mL: 240%; 160 μg/mL: 348%) and cell cycle arrest was comparable to that of methotrexate. LC-MS analyses showed that the extract contains different quercetin-glycosides.

CONCLUSION

Our results give a rational basis for the use of Betula pendula leaf extract for the treatment of immune disorders, like rheumatoid arthritis, by diminishing proliferating inflammatory lymphocytes.