Search Results (75)

The wood of Cryptomeria japonica (Japanese cedar or sugi) is widely used in building and adornment. This study aims to identify the composition of the volatile oils (VOs) extracted from C. japonica solid wood boards by gas chromatography–mass spectroscopy, and to investigate their antimicrobial, anti-inflammatory, and potential neuroprotective activities. A total of 58 volatile organic compounds (VOCs) were identified in the VOs from C. japonica solid wood boards with tree ages of 40, 50, and 60 years (VO-40, 50, and 60), with sandaracopimarinol (13.74–17.59%), ferruginol (10.23–11.29%), abieta-7,13-diene (8.20–13.66%), (+)-δ-cadinene (7.15–9.27%), cis-cubenol (4.36–6.36%), and sandaracopimarinal (3.23–6.04%) as major compounds. The VOs exhibited antifungal potential, especially VO-50 against Aspergillus fumigatus (MIC = 0.312 mg/mL), and VO-60 against Gloeophyllum trabeum (MIC = 1.25 mg/mL). However, VOs exhibited weak antibacterial activity (MIC > 10 mg/mL). Additionally, VOs (10 μg/mL) exhibited anti-inflammatory and potential neuroprotective activities, with VO-60 demonstrating the strongest inhibition of NO (25.79% reduction), TNF-α (52.24% reduction), and IL-6 (27.10% reduction) production in lipopolysaccharide-induced RAW264.7 cells, while increasing cell viability by 70.36% and reducing lactate dehydrogenase release by 41.10% in corticosterone-induced PC12 cells. Correlation and docking analyses revealed that sandaracopimarinal, sandaracopimarinol, β-eudesmol, and ferruginol were the potential active compounds. The results demonstrated that the volatile components from C. japonica solid wood boards not only enhance the board’s decay resistance, but also exhibit therapeutic potential for inflammatory disorders and neuropathic diseases. Full article

Cry j 7 is a 7 kDa cysteine-rich gibberellin regulatory protein (GRP) with six disulfide bonds. It was isolated from Japanese cedar as the pollen allergen in this study. It exhibits cross-reactivity with food allergens such as Pru p 7 from peach and causes pollen-food allergy syndrome (PFAS). In this work, recombinant Cry j 7 and Pru p 7 were successfully overexpressed using Pichia pastoris in a high-cell-density fermentation culture, and pure proteins were purified by reverse-phase HPLC. The characterization of Cry j 7 and Pru p 7 were performed by MS, CD, and ¹H-NMR experiments to confirm the correct native conformation of Cry j 7 as well as Pru p 7. When compared, the results showed that Cry j 7 exhibits excellent stability in disulfide linkages and preserves its original structure up to 90 °C in various pH buffers in comparison to Pru p 7. Notably, NMR analyses indicated the greater mobility in the α-helix and loop regions of S38-C47 in Pru p 7 compared to those of Cry j 7. Furthermore, our results showed that the sensitivity of Cry j 7 to enzyme digestion differed from that of Pru p 7: Cry j 7 was more susceptible to proteolysis, while Pru p 7 displayed better resistance in the gastrointestinal tract. These variations in structural stability and sensitivity to proteolysis provide valuable insights into the allergenicity within the GRP family. Full article

With growing worldwide interest in constructing larger and taller wooden buildings, wood properties, such as the dynamic modulus of elasticity (${MOE}_{dyn}$), have become increasingly important. However, the ${MOE}_{dyn}$ of trees and logs has rarely been considered in forest management because a method for estimating the ${MOE}_{dyn}$ of logs based on standing tree characteristics has been lacking. Herein, we explored the multiple relationships between the ${MOE}_{dyn}$ of logs and standing tree characteristics of Japanese cedar (Cryptomeria japonica) such as tree height, diameter at breast height (DBH), and tree age, including the stress-wave velocity of the tree, which is known to be correlated with the ${MOE}_{dyn}$ of logs. The relationship between the ${MOE}_{dyn}$ of logs and standing tree characteristics was investigated by considering the bucking position. Different trends between the bottom logs and upper logs were found for all characteristics, showing a multiple trend of tree characteristics with the ${MOE}_{dyn}$ of logs based on the bucking position. The top three generalised linear mixed models for the prediction of the ${MOE}_{dyn}$ of logs showed relatively high accuracies when the bucking position was considered as a random effect. Although the contribution of the stress-wave velocity of the tree was relatively high, adding tree age improved the accuracy of the model, and this model was selected as the top model. The model for the bottom log, utilising the stress-wave velocity and age of the tree as explanatory variables, was highly explanatory (R² = 0.70); however, the best model for upper logs was only moderately explanatory (R² = 0.44). In addition, tree height and DBH were selected as explanatory variables along with tree age in the second and third models, which suggested the importance of growth rate rather than tree size. Therefore, adding correlates associated to characteristics related to height growth, such as site index, and DBH growth, such as stand density, is expected to improve model accuracy. Full article

Lignin, the most abundant renewable aromatic polymer, has been shown to suppress the growth of mammalian tumor cells. Despite extensive studies on lignin structure and its engineering, there is little information on the biological activity of lignin in relation to its molecular structure or the molecular mechanisms by which lignin suppresses tumor cells in mammalian species. Here, we prepared microwave-assisted acid-catalyzed solvolysis lignin (MASL) from Japanese cedar and Eucalyptus globulus and assessed its effects on human and mouse tumor cells. SEC indicated that MASL consists of oligomeric aromatics from the woody plants. Our data showed that MASL significantly reduced the viability of tumor cells by modulating apoptotic pathways. MASL treatment upregulated TNF-α, Fas, and FasL expression levels, while suppressing anti-apoptotic NF-κB and mTOR pathways in tumor cells. In vivo experiments were also performed using tumor-bearing mice to confirm the anti-tumor effects of MASL. Repetitive administrations of a MASL (YM CL1T) significantly inhibited tumor growth in mice in association with elevation of caspase 3 expression. These findings strongly suggest the potential usefulness of low-molecular-weight lignin as an effective therapeutic against malignancies. Full article

Wood drying is often accompanied by changes in mechanical properties due to external thermal energy. This study examined the influences of drying temperature on the mechanical properties of Japanese cedar based on the partial compression properties and bending properties. Two types of longitudinal specimens with quarter grain on both lateral surfaces were prepared under green conditions, followed by subsequent drying under each drying temperature (20 °C, 40 °C, 60 °C, 80 °C, and 100 °C). Then, the partial compression and bending tests were performed using the respective specimens. Young’s modulus perpendicular to grain, yield stress, and compressive strength obtained by the partial compressive test were highest for wood dried at 20 °C. It was considered that the decrease in mechanical properties was attributed to the thermal influences during drying at 100 °C and other factors such as compressive residual stress and cell walls collapsing at lower temperatures. The strain energy suggested that the effects of drying temperature became apparent, especially in the plastic region during loading in the direction perpendicular to the wood fiber. Bending properties showed little influence on drying temperatures compared to the partial compressive properties, whereas the fractures found under the loading point of the wood dried at 100 °C suggested a reduction in resistance to shear forces. Full article

Willow is a promising biomass resource for addressing the challenges of securing stable domestic biomass fuels in Japan and utilising abandoned agricultural land. Among the willow species, Salix pet-susu Kimura KKD (known as ezonokinu willow, EW) stands out for its growth, high production, storage stability, production stability, and business stability. Previous studies have investigated fuel characterisation through gasification (co-gasification) of various biomass mixtures to enhance feedstock flexibility for gasifier commercialisation. However, the synergistic effects of co-gasification using fuels containing EW blended with Japanese cedar, a commonly planted forest species in Japan, remain unexplored. Therefore, this study explored CO₂ co-gasification with different blend ratios of EW/cedar blended char and evaluated the fuel characteristics for each blend ratio to elucidate the synergistic effects. The prepared char samples were utilised in the CO₂ gasification test with TG-DTA as the analyser. The results suggest that in the initial stages of the willow/cedar blended char co-gasification reaction, pore size and specific surface area significantly influence the reaction rate. Subsequent stages of the reaction are influenced by the promoting and inhibiting effects of inorganic components, which impact co-gasification. The synergy factor results for the willow/cedar blended char co-gasification suggest a reaction pathway. Full article

Upon degranulation, basophils and mast cells secrete an array of inflammatory mediators, including histamine, which leads to not only allergic inflammation but also other inflammatory diseases. We previously reported that an aqueous extract from enzyme-treated, dried sardine inhibits the degranulation of RBL-2H3 cells and attenuates the symptoms of Japanese cedar pollinosis in mice. This study evaluated an antiallergic effect of dipeptides containing acidic amino acid residue in an antigen-induced degranulation assay using RBL-2H3 cells. The result showed that acidic amino acid residue-containing dipeptides inhibit the degranulation of RBL-2H3 cells without cytotoxicity. Additionally, L-histidyl-L-glutamic acid (His-Glu), one of the acidic amino acid residue-containing dipeptides tested in this study, inhibited calcium ionophore-induced degranulation. We also found that His-Glu suppressed microtubule reorganization in RBL-2H3 cells after antigen stimulation. His-Glu slightly, but not significantly, suppressed the elevation of cytosolic calcium ion concentration leading to degranulation. Immunoblot analysis revealed that His-Glu significantly suppressed the phosphorylation of phosphoinositide 3-kinase and Akt, but not that of Syk or phospholipase Cγ. Overall results suggest that acidic amino acid residue-containing dipeptides can be used as food ingredients with an antiallergic effect. Full article

High-temperature vapour-phase acetylation (HTVPA) is a simultaneous acetylation and heat treatment process for wood modification. This study was the first investigation into the impact of HTVPA treatment on the resistance of wood to biological degradation. In the termite resistance test, untreated wood exhibited a mass loss (ML_t) of 20.3%, while HTVPA-modified wood showed a reduced ML_t of 6.6–3.2%, which decreased with an increase in weight percent gain (WPG), and the termite mortality reached 95–100%. Furthermore, after a 12-week decay resistance test against brown-rot fungi (Laetiporus sulfureus and Fomitopsis pinicola), untreated wood exhibited mass loss (ML_d) values of 39.6% and 54.5%, respectively, while HTVPA-modified wood exhibited ML_d values of 0.2–0.9% and −0.2–0.3%, respectively, with no significant influence from WPG. Similar results were observed in decay resistance tests against white-rot fungi (Lenzites betulina and Trametes versicolor). The results of this study demonstrated that HTVPA treatment not only effectively enhanced the decay resistance of wood but also offered superior enhancement relative to separate heat treatment or acetylation processes. In addition, all the HTVPA-modified wood specimens prepared in this study met the requirements of the CNS 6717 wood preservative standard, with an ML_d of less than 3% for decay-resistant materials. Full article

This paper presents a method for applying forging to high-density wood. A cylindrical container was formed using a closed die, and the appropriate conditions for temperature and punch length were evaluated. Ulin, which is a high-density wood, and Japanese cedar, which is a low-density wood and widely used in Japan, were used as test materials. The pressing directions were longitudinal and radial based on wood fiber orientation, and the shape and density of the resulting containers were evaluated. In the case of ulin, cracks decreased by increasing the temperature, while temperature had little effect on Japanese cedar. Containers without cracks were successfully formed by using a punch of appropriate length. The density of the containers was uniform in the punch length l = 20 and 40 mm in the L-directional pressing and l = 20 mm in the R-directional pressing when using ulin, with an average density of 1.34 g/cm³. This result indicates the forging ability of ulin is high compared to that of commonly used low-density woods. In summary, this paper investigated the appropriate parameters for forging with ulin. As a result, products of more uniform density than products made by cutting were obtained. Full article

The present study examined the effects of foods containing lipopolysaccharides from Pantoea agglomerans (LPSp) on eye–nose allergic symptoms using a double-blind, placebo-controlled, randomized, parallel-group comparative research design. Sixty-three Japanese individuals aged 20–65 years with eye–nose allergic symptoms were included in this study and assigned to the LPS (480 μg/day)-containing food and placebo groups. Data on the subjective eye–nose allergic symptoms and antiallergic medication during the 8-week period were evaluated. The immunoglobulin E (IgE) and eosinophil counts were measured as indicators that may be correlated with allergy. No significant group differences were found in the change in eye–nose allergic symptoms from baseline. However, the LPS group showed a significantly shorter duration of antiallergic medication use and lower total antiallergic drug score than the placebo group. The corrected nasal allergy score calculated by taking into account the antiallergic drug score at week 8 was predominantly lower in the LPS group. The IgE to house dust and cedar pollen and eosinophil counts tended to be lower in the LPS group, and the total IgE and eosinophil counts were significantly lower in the LPS group at week 4. In conclusion, our results indicate that LPS-containing foods alleviate eye–nose allergic symptoms and consequently lower the use of antiallergic drugs (UMIN000049974). Full article

About 40% of cedar pollinosis patients living in the Yamagata Prefecture showed pollinosis symptoms before the first day of the pollen season, which was determined by Durham samplers, the standard sampler for pollen information in Japan. The amount of Cry j 1 (major cedar pollen allergen) per cedar pollen is reported to be six pg. This amount is difficult to measure using the ELISA method, so we applied the highly sensitive ESR radical immunoassay method to measure the allergen; now we can provide information for sensitive patients. It revealed that Cry j 1 exists in orbicles and tapetum. It is presumed that it is smaller than pollen, so it comes from a place where cedar are already in bloom. It is desirable to obtain real-time information on an hourly basis. Currently, information from automatic cedar pollen monitors is becoming main-stream. However, this monitor may count during snowfalls, Asian dust flying, etc., even when there was no apparent pollen examined with a microscope. This paper describes the current status of automatic cedar pollen monitors, their usefulness, and their advantages and disadvantages in comparison with results obtained by other methods of measurement. Lastly, the paper describes expectations for cedar pollen information in the future. Full article

Breeding long-lived trees is challenging, but it has been shown that genomic information can be used to improve efficiency. In this study, genomic prediction (GP) was tested on selected individuals of a two-generation breeding population of Cryptomeria japonica, the most common plantation tree in Japan. In the 1980s, the second-generation plus trees (101 clones) were selected from about 8500 individuals obtained by cross-mating the first-generation plus trees (47 clones). RAD-seq based on 8664 SNPs was used to perform GP for three important traits in this population: tree height, wood stiffness, and male flower quantity. The association between traits and genotypes was modeled using five Bayesian models whose predictive accuracy was evaluated by cross-validation, revealing that the best model differed for each trait (BRR for tree height, BayesA for wood stiffness, and BayesB for male flower quantity). GP was 1.2–16.0 times more accurate than traditional pedigree-based methods, attributed to its ability to model Mendelian sampling. However, an analysis of the effects of intergenerational kinship showed that parent–offspring relationships reduce the predictive accuracy of GP for traits strongly affected by selection pressure. Overall, these results show that GP could significantly expedite tree breeding when supported by a deep understanding of the targeted population’s genetic background. Full article

In this study, short-term accelerated creep tests were conducted using the stepped isostress method (SSM) to investigate the impact of hydrothermal treatment on the long-term creep behaviour of Japanese cedar wood and to determine optimal hydrothermal treatment conditions. The results showed that SSM can effectively predict the creep behaviour of hydrothermally treated wood. Among the treatment conditions tested, Japanese cedar wood treated hydrothermally at 180 °C for 4 h exhibited higher flexural strength retention (91%) and moisture excluding efficiency (MEE) (44%) and demonstrated superior creep resistance compared to untreated wood. When subjected to a 30% average breaking load (ABL) over 20 years, the specimen’s creep compliance, instantaneous creep compliance, b value, activation volume, and improvement in creep resistance (ICR) were 0.17 GPa⁻¹, 0.139 GPa⁻¹, 0.15, 1.619 nm³, and 4%, respectively. The results indicate that subjecting Japanese cedar wood to hydrothermal treatment at 180 °C for 4 h has a negligible effect on its flexural properties but results in significant improvements in both dimensional stability and creep resistance. Full article

Dihomo-γ-linolenic acid (DGLA) is an n-6 polyunsaturated fatty acid that has been shown to have anti-inflammatory and anti-allergic effects in mice and cell study. To date, however, no human intervention study has examined the effects of DGLA. Therefore, we investigated the effects of DGLA on pollen-induced allergic symptoms in healthy adults. We performed a randomized, double-blind, placebo-controlled, parallel-group study comprising healthy Japanese men and women. Each subject received four 250 mg capsules providing 314 mg DGLA/day (DGLA group, n = 18) or olive oil (placebo group, n = 15) for 15 weeks. The primary outcomes, classification of the severity of allergic rhinitis symptoms (CSARS), and the Japanese Rhino-conjunctivitis Quality of Life Questionnaire (JRQLQ) served as symptom scores during the pollen season. In the DGLA group, the cedar pollen associated symptoms of sneezing and a blocked nose in the CSARS were significantly lower than those in the placebo group (p < 0.05, p < 0.01, respectively). Significant trends were observed the symptoms of runny nose in the CSARS and total symptom score (TSS) in the JRQLQ for cedar pollen (p < 0.1). To our knowledge, this is the first study to report the effects of DGLA in humans, and the results suggest that DGLA is effective in reducing allergic symptoms caused by pollen. Full article

In this study, specimens were prepared from Japanese cedar (Cryptomeria japonica) with different thicknesses to determine the best hot-pressing conditions for wood compression layered structural materials (WCLS) through densification at various temperatures and compressing time conditions. However, residual stress-releasing after densification recovery can cause dimensional instability. To address this issue, the drying set method was combined with the compression-set recovery test to determine the best setting time. As a result, the bending strength and modulus of rupture (MOR) of WCLS increased by 9.98 ± 9.71 to 20.87 ± 13.09% and the modulus of elasticity (MOE) increased by 9.87 ± 11.92 to 22.40 ± 17.97%. The volumetric swelling coefficient (S), water absorption percent (WAP), and equivalent moisture content (EMC) decreased as the drying time increased. The anti-swelling efficiency (ASE) and moisture excluding efficiency (MEE) were found to be the highest at a drying time of 12 h, with values ranging from 13.20 ± 15.11 to 36.46 ± 6.83% and 15.18 ± 1.11 to 19.58 ± 8.31%, respectively. The drying method was found to be effective in increasing dimensional stability. The glass transition temperature (Tg) moved to a lower temperature as the compression-set increased, which was due to plasticization of wood caused by high temperature and pressure. The cell walls of WCLS presented viscous buckling, which provided effective dimensional stability. The thermal conductivity of Japanese cedar and each compression-set WCLS were 0.1863 ± 0.0071, 0.1520 ± 0.0147, 0.1817 ± 0.0106, and 0.1423 ± 0.0137 W/mK, respectively. The thermal conductivity of each WCLS increased with an increase in compression-set, but decreased by 10.67 to 22.52% compared to Japanese cedar. The total electricity energy consumption of each WCLS after 24 h of testing decreased with a trend of 30.50 ± 0.84, 29.83 ± 0.42, 29.57 ± 0.51, and 29.4 ± 0.36 kWH. Full article