• Journal of the Korean Society of Food Culture
• /
• v.37 no.6
• /
• pp.503-509
• /
• 2022

Methylglyoxal is a highly reactive precursor which forms advanced glycation end products (AGEs). AGEs and methylglyoxal are known to induce various diseases such as diabetes, vascular disorders, Diabetes Mellitus (DM), and neuronal disorders. Juglans regia L is an important food commonly used worldwide, having nutritious components, including phenolic compounds. Since ancient times, Juglans regia L have been differently applied by various countries for health and in diverse diseases, including arthritis, asthma, skin disorders, cancer, and diabetes mellitus. However, the effect of diabetes-induced renal damage against AGEs remains unclear. This study evaluates the anti-glycation and renal protective effects of ethanol extract of Juglans regia L against methylglyoxal-induced renal tubular epithelial cell death. Exposure to methylglyoxal resulted in reduced cell viability in NRK-52E cells, but co-treatment with Juglans regia L extracts significantly increased the cell viability. In addition, we examined the anti-glycation effect of Juglans regia L extracts. Compared to the positive control aminoguanidine and Alagebrium, treatment with Juglans regia L extracts significantly inhibited the formation of AGEs, collagen cross-linking, and breaking collagen cross-linking. Taken together, our results indicate that Juglans regia L is a potential therapeutic agent for regulating diabetic complications by exerting anti-glycation and renal protective activities.

• Journal of Plant Biology
• /
• v.34 no.2
• /
• pp.93-100
• /
• 1991

Walnut (Juglans regia L.) is a common cultivated and wild deciduous tree in the temperate regions of Pakistan and elsewhere. A bare or poor understorey of wild or cultivated species is frequently observed beneath and around it. Soil analysis indicated insignificant differences in nutrient status of soils taken from areas with or without walnut influence. Field investigations revealed that the height, shoot, fresh and dry weight of potato, turnip, corn and bean significantly decreased in the walnut-influenced parts of the field compared to their counter-parts in the same field but without walnut influence. Aqueous extracts from various parts, shoot litter, natural rain leachates and soil collected from beneath walnut significantly reduced the germination, early seedling growth, fresh and dry weight, and moisture contents of corn, turnip and bean in various laboratory experiments. Ferulic, p-coumaric, caffeic, vanillic, jJ-hydroxybenzoic, chlorogenic and gallic acid were identified as the possible allelopathic substances in the aquous extracts and rain leachates of the walnut tree. The findings suggest that the observed poor growth of crops is due to allelopathic effects of walnut.walnut.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.33 no.3
• /
• pp.169-174
• /
• 2019

The purpose of this study was to evaluate the inhibitory effects of Juglans regia complex extract(JCE) consisted of Juglans regia, Eucommia ulmoides, Eleutherococcus senticosus and Zingiber officinale on osteoclast differentiation. Cell toxicity test by using CCK-8, TRAP activity and TRAP positive multi-nucleated cell counting were performed to evaluate inhibitory effect on differentiation of osteoclast from bone marrow derived macrophages(BMMs) induced by receptor activator of nuclear $factor-{\kappa}B$ ligand(RANKL). As a result, JCE inhibited RANKL-induced osteoclast differentiation in BMMs dose-dependently without cytotoxicity. These results suggest that JCE may have a potential role for treating bone lytic diseases such as osteoporosis.

• Biomedical Science Letters
• /
• v.24 no.4
• /
• pp.365-371
• /
• 2018

In this study, antioxidant and anti-neuroinflammatory of ethanol extracts from walnuts's (Juglans regia L.) shell were investigated in vitro. Radical-scavenging activities of the walnuts's shell ethanol extracts (WSE) were examined by using ABTS radicals and ${\alpha},{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) radicals assay. In the ABTS and DPPH radical scavenging activity, $RC_{50}$ of WSE were measured as 15.74 and $40.13{\mu}g/mL$, respectively. Also, to evaluate the anti-neuroinflammatory effects of WSE in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. The production of proinflammatory cytokines NO were examined by LPS in BV-2 cell. BV-2 cells activated with LPS were treated with various doses (10, 25, 50, $100{\mu}g/mL$) of WSE. Supernatants were analyzed for the production of NO using Griess reagent. WSE up to $10{\mu}g/mL$ still required to inhibit NO induced by LPS. These results showed that walnuts's (Juglans regia L.) shell can be used as an easily accessible source of natural anti-neuroinflammatory and natural antioxidants.

• Journal of Korean Society of Forest Science
• /
• v.99 no.3
• /
• pp.298-303
• /
• 2010

To explore on the defense strategies against hervivory of Juglans regia and J. mandshurica, morphological characteristics of the leaf, leaf domatia structure and the number, herbivores insects and mites on the leaves, collected from the trees growing in Mt. Chiak, Mt. Cheongtae, Mt. Jungwang, Namyangju-si and Wonju-si, were investigated from May to October, 2009. Domatia of J. mandshurica revealed tuft type, these of J. regia revealed pocket+tuft type. Domatia number per leaflet proved the higher figures, 28.3/leaflet for J. mandshurica, and the lower, 19.6/leaflet for J. regia. Leaf surface trichomes of J. regia revealed stellates only on the domatia structures, and that of J. mandshurica does dense stellates and glandular hairs on the leaf-blade and vein. Predatory mites' number per leaflet proved highly significant differences among tree species, and mean of predatory mites was higher values (4.8/leaflet) in J. mandshurica and lower values (3.5/leaflet) in J. regia. Small amount of nectar are found distal veinparts on the leaf margin of J. mandshurica. Dense glandular hairs on the lower leaf surfaces of J. mandshurica estimates useful strategy against herbivory. It may be possible to breed J. regia for better expression of leaf traits such as dense glandular hairs that increase predator populations and efficacy.

• Research in Plant Disease
• /
• v.17 no.3
• /
• pp.386-390
• /
• 2011

In June 2011, walnuts (Juglans regia) from orchards in Kimcheon and Muan, in southern Korea, were found to exhibit downy mildew-like symptoms of a foliar disease. Whitish polygonal efflorescence was produced on the abaxial surface of affected leaves and discolored light green blotches on the corresponding adaxial surfaces. In the later stage of disease development, diseased tissues collapsed and became necrotic. Based on morphological and cultural characteristics, the causal fungus was identified as Microstroma juglandis. The sequence of ITS rDNA of the present isolate showed 100% similarity with those of M. juglandis obtained from GenBank databases, thus confirming its identity. Pathogenicity tests were conducted on leaves of walnut seedlings, fulfilling Koch's postulates. The disease has been previously reported in North America, Europe, Oceania and some western Asia. This is the first report of downy leaf spot on walnuts in East Asia.

• Clinical Nutrition Research
• /
• v.11 no.2
• /
• pp.120-132
• /
• 2022

Numerous clinical trials have examined the beneficial effects of Juglans regia leaf extract (JRLE) in patients with type 2 diabetes mellitus (T2DM); however, the results of these studies are inconsistent. Therefore, we conducted the current systematic review and meta-analysis to evaluate the effect of JRLE on glycemic control and lipid profile in T2DM patients. We searched online databases including PubMed, Scopus, EMBASE, and Web of Science for randomized controlled clinical trials that examined the effect of JRLE on glycemic and lipid indices in T2DM patients. Data were pooled using both fixed and random-effect models and weighted mean difference (WMD) was considered as the overall effect size. Of the total records, 4 eligible studies, with a total sample size of 195 subjects, were included. The meta-analysis revealed that JRLE supplementation significantly reduces fasting blood glucose (WMD, -18.04; 95% confidence interval [CI], -32.88 mg/dL, -3.21 mg/dL; p = 0.017) and significantly increases fasting insulin level (WMD, 1.93; 95% CI, 0.40 U/L, 3.45 U/L; p = 0.014). Although the overall effect of JRLE supplementation on hemoglobin A1c was not significant, a significant reduction was seen in studies with an intervention duration of > 8 weeks (WMD, -0.64; 95% CI, -1.16%, -0.11%; p = 0.018). Moreover, we also found no significant change in lipid parameters. Our findings revealed a beneficial effect of JRLE supplementation on glycemic indices in T2DM patients, but no significant improvement was found for lipid profile parameters.

• Journal of Life Science
• /
• v.25 no.4
• /
• pp.433-440
• /
• 2015

Several studies suggest that regular consumption of walnuts may have beneficial effects against oxidative stress-mediated disease such as cancer. The present study reports the total phenolic and flavonoid contents, together with the antioxidant and antibacterial activities of several solvent extracts (methanol, n-hexane, ethyl acetate, n-butanol, and water) obtained from walnut (Juglans regia L.) green husk. MIC (minimal inhibitory concentration) values of the walnut extracts for 8 human pathogenic bacteria strain were determined using agar dilution method. Antioxidant activity of extracts were assessed using DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)) assays, EC₅₀ of DPPH and ABTS scavenging activities, and determination of total phenolic and flavonoid content and its correlation with DPPH and ABTS scavenging capacities. Among the six extracts, ethyl acetate extract (EtOAc Ex) showed the highest antimicrobial activity at 3.2 mg/ml of MICs against Staphylococcus aureus SG511. Total flavonoids and polyphenol contents of EtOAc Ex were 42.48 mg of quercetin equivalents (QE)/g and 223.25 mg of gallic acid equivalents (GAE)/g respectively. The highest antioxidative potential was shown by the sample extracted with EtOAc Ex (EC₅₀=13.43 μg/ml for DPPH and EC₅₀=41.83 μg/ml for ABTS radical scavenging activity assay). These results showed that J. regia green husk extracts can be used as an easily accessible source of natural antibacterial agents and natural antioxidants.

• Korean Journal of Food Science and Technology
• /
• v.36 no.5
• /
• pp.842-846
• /
• 2004

To elucidate quality changes of pine nuts and walnuts coated with green tea extract-containing protein film during storage, pine nuts and walnuts were coated with soy protein isolate (SPI) and zein film containing green tea extract, and stored at $35^{\circ}C$ for 4 weeks. During storage, peroxide, acid, and 2-thiobarbituric acid (TBA) values increased with increasing storage time regardless of treatments. Degrees of lipid oxidation were lowest in protein coating containing green tea extract, followed by protein coating and control. After 4 weeks, for pine nuts, 40, 32, and 21% of peroxide, acid, and TBA values respectively decreased by treatment of zein film coating containing green tea extract compared with control. For walnuts, 29, 24, and 21% of peroxide, acid, and TBA values respectively decreased. With SPI film coating, 41, 36, and 8% of peroxide, acid, and TBA values of pine nuts respectively decreased. For walnuts, 26, 28, and 5% of peroxide, acid, and TBA values respectively decreased by treatment of SPI film coating containing green tea extract.

• Journal of Internet of Things and Convergence
• /
• v.7 no.4
• /
• pp.35-41
• /
• 2021

Natural dyeing has traditionally been used in many countries around the world, and as natural dyes are diversified, the diversity of dyeing patterns is also expanding. This study tried to establish standardization by providing numerical values that could provide quantified information to the Internet of Things by more accurately analyzing the color changes of dyes and mordants for the four natural dyes. The addition of copper acetate, iron II sulfate and potassium dichromate to the dye extracted from Juglans regia Linn changed the original color of brown to other colors of purple, khaki and dark brown, respectively. Except for potassium dichromate added to Sophora japonica L. or Phellodendron amurense Ruprecht, the concentration of other mordants was reduced, but the color difference of the dyed silk was very large. However, although there is a difference in degree, copper acetate and iron sulfate induced color changes of 35% and 15%, respectively. In summary, it was confirmed that the highest color change was induced when 15 grams of copper acetate was added to J. regia Linn, S. japonica L. and P. amurense Ruprecht and 150 grams of iron to Phytolacca americana. The results of this study suggested that the accurate color change by various mordants can be utilized as important information that enables more accurate color induction by dyes and mordants.