Walnut Green Husk Research Articles

Two new diarylheptanoids from the green walnut husks of Juglans mandshurica Maxim.

Chemical investigation on the 95% ethanol extract of green walnut husks of Juglans mandshurica Maxim. led to the isolation of two new diarylheptanoid compounds, including Juglanin K (1) and Myricananin I (2), together with ten known compounds (3–13). Their structures were elucidated by extensive analyses of comprehensive spectroscopic methods. The isolated compounds were evaluated for their antibacterial activities against Escherichia coli and Staphylococcus aureus. The results showed that compound 2 had moderate antibacterial activity with the MIC values of 0.313 and 0.156 mg/mL, respectively. compounds 1, 3–7 and 13 showed weakly antibacterial activities against Escherichia coli and Staphylococcus aureus with the MIC values of 0.625–2.5 mg/mL.

Phytochemical Composition, Antimicrobial, Anticancer Properties, and Antioxidant Potential of Green Husk from Several Walnut Varieties (Juglans regia L.).

Husk powder was prepared from seven varieties of walnut fruit and their hulling rate, chemical compounds, and total phenolic contents were evaluated. The apolar and polar extracts were prepared, respectively, from hexane and a hydroethanolic solvent, while qualitative and semi-quantitative analyses were performed by GC/MS and UHPLC-PDA-HRMS/MS. The antioxidant, antimicrobial, and antitumor properties of green walnut husk were also evaluated. The total content of phenolic compounds varied between the varieties, ranging from 35.2 ± 0.9 to 58.0 ± 0.0 mg/g gallic acid equivalent of dry husk weight (dw). The apolar extract was found to contain alkanes, tocopherols, sterols, and fatty acids, including oleic, linoleic, and linolenic, while the polar extract showed the presence of phenolics including salicylate glucuronide, taxifolin, catechin, and quercetin isomers. The antioxidant power obtained by the PAOT (total antioxidant power) method for the husk powders ranged from 256.5 ± 5.9 to 746.8 ± 6.9 score/g dw, and seemed consistent with the total phenolic content and the results obtained by the classic antioxidant test with DPPH. The walnut husk also showed an antibacterial effect against Gram-negative and Gram-positive bacteria and cytotoxic potential against HepG2. Among the selected varieties, the green Saman had the highest antioxidant properties, while the Saman with a brown color had the lowest.

Synergism between walnut green husk extract and sodium dodecyl benzene sulfonate on cold rolled steel in 1.0 mol/L H2SO4 solution

Walnut green husk extract (WGHE) was prepared by the reflux method using the agricultural residues of walnut green husk as raw materials. Its synergistic inhibition effect with an anionic surfactant of sodium dodecyl benzene sulfonate (SDBS) on the corrosion of cold rolled steel (CRS) in 1.0 mol/L H2SO4 solution at 20-50 ℃ was investigated using mass loss measurement, electrochemical techniques and surface analysis. Effective components for synergistic inhibition in WGHE were also explored in depth. The results show that individual WGHE or SDBS exhibits moderate inhibition, and the maximum inhibition efficiency of 100 mg/L is below 60%. However, the mixture of WGHE/SDBS has better inhibitive performance, and the maximum inhibition efficiency can reach as high as 95%. The corresponding synergism parameter is higher than 1, and the optimum concentration ratio is 1:1, but decreases at relatively higher temperatures. The adsorption of WGHE follows Freundlich isotherm, while SDBS and WGHE/SDBS obey Langmuir isotherm. Comparing with individual WGHE or SDBS, WGHE/SDBS inhibits both cathodic and anodic reactions simultaneously to more extent, and further increases charge transfer resistance for CRS corrosion. SEM and AFM microphotographs confirm that WGHE/SDBS exhibits greater inhibitive ability on CRS surface than individual inhibitor. XPS analysis confirms the adsorption of inhibitor molecules containing O and N atoms in WGHE on CRS surface. The synergistic inhibited CRS surface has superior hydrophobic properties with a larger obtuse contact angle. There is also a synergism between SDBS and the major components of rutin, quercetin and 1-methylnaphoqinone in WGHE, but their synergistic inhibition degree is a little weaker than WGHE/SDBS.

Inhibitory kinetics and mechanism of active compounds in green walnut husk against α-glucosidase: Spectroscopy and molecular docking analyses

Inhibiting the activity of α-glucosidase is considered an effective strategy to regulate blood sugar levels and manage food-linked hyperglycemia. Green walnut husk (GWH) is the main processing by-product of walnut, still rich in natural bioactive compounds with α-glucosidase inhibition. The objective of this study was to screen the specific components in GWH responsible for the α-glucosidase inhibitory effects and investigate the mechanisms through enzyme kinetic analysis, multi-spectroscopic techniques, and molecular docking analysis. Affinity ultrafiltration-liquid-chromatography-mass spectrometry was employed to rapidly screen and identify the bioactive compounds with α-glucosidase inhibition. Catechin, hyperoside, and quercetin exhibited significant α-glucosidase inhibitory activities with IC50 values of 12.78, 77.24, and 92.87 μg/mL, respectively. The inhibition kinetic analysis indicated that catechin and quercetin were competitive inhibitors, while hyperoside was an uncompetitive inhibitor. UV spectra, Fourier-transform infrared spectroscopy, and fluorescence quenching demonstrated that these inhibitions led to the conformational changes of α-glucosidase. Circular dichroism spectra suggested that α-glucosidase secondary structures were induced by inhibitors. The molecular docking analysis illustrated that the interaction forces between inhibitors and α-glucosidase were hydrogen bonds and hydrophobic interactions, with the binding energy of −8.3, −9.5, and −9.5 kcal/mol, respectively. Therefore, GWH provided a potential source for developing natural α-glucosidase inhibitors.

Antibacterial Efficacy of Walnut Green Husk (WGH) Extract with Zinc Oxide Nanoparticles on Streptococcus Mutans.

Chemical agents, such as Chlorhexidine are used as one of dental plaque control strategy. Researchers are looking for a natural and economic substitute with same antibacterial efficacy and less complications. The aim of this study was to evaluate the antimicrobial efficacy of the Khorasan Razavi walnut green husk (WGH) extract with and without adding ZnO nanoparticles (nZnO) on Streptococcus mutans (S. mutans). In this in vitro study, antimicrobial effect of the Hydro-ethanolic extract of WGH, was evaluated against S. mutans. Broth Dilution and Agar diffusion methods were used with 90 tubes containing different dilutions of WGH extract (100 to 0.006 mg/ml). ZnO nanoparticles (nZnO) were added to 45 tubes. Streptococcus mutans was exposed to 15 different serial concentrations of study extracts, from 100 mg/ml to 0.006 mg/ml. Minimum inhibitory concentration (MIC) of the study extracts were determined and zone of inhibition diameter was compared to positive controls (chlorhexidine 0.2%, nZnO), and negative control (sterile distilled water). The differences between the mean diameters, were analyzed by independent sample T- teS. Minimum inhibitory concentration (MIC) of study extract was found to be 50mg/mL, with adding nZnO, MIC was reduced to 3.12mg/mL. Mean diameter of inhibition zone at 3.12 mg/ml with and without adding ZnO nanoparticles were 17.67±0.57 mm and 8±0.001 mm, respectively, (p-value< 0.001). Adding nZnO could be enhanced antimicrobial efficacy of the WGH extract against S. mutants, while it was still less effective than chlorhexidine.

Resource efficiency and environmental impact of juglone in Pericarpium Juglandis: A review

Black walnut (Juglans nigra) is considered one of the most valuable plants, with a global production of 3.5 million tons of dried fruit yearly. Throughout the past two millennia, its allelopathic effects have been widely recognized. Black walnuts produce a natural naphthoquinone called juglone, which occurs naturally in all parts of the tree, particularly the green husk, and contributes significantly to the allelopathic effects of black walnut. Except for the fruit’s edible nature, the walnut green husk (Pericarpium Juglandis) has been used for centuries to make wine, natural dyes, and traditional medicines to cure certain diseases. Within the extracts of walnut green husk, 1,4-naphthoquinones, gallic acid, caffeic acid, and quercitrin were separated and characterized. Among these compounds, the major active ingredient with a good application prospect is juglone, which has proven to be a natural chemical compound with anticancer, antitumor, antibacterial, and antiviral activities, especially the strong anticancer activity. Juglone is also an environmentally friendly biological pesticide and herbicide. Certainly, the environmental impact of juglone also needs to be considered. Significant quantities of walnut green husk are currently produced as a byproduct of walnut production; however, its value has not been fully utilized and explored, which raises environmental concerns. This review attempts to: 1) summarize the origin and historical use of walnut and walnut green husk; 2) introduce the structure, biosynthesis pathway, extraction method, biological activity, and potential applications of juglone, as well as its environmental impact assessment.

Antimicrobial and antioxidant activity of phenolic extracts from walnut (Juglans regia L.) green husk by using pressure-driven membrane process.

The online version contains supplementary material available at 10.1007/s13197-022-05588-w.

Potential of nanochitosan coating combined with walnut green husk to improve the preservation of rainbow trout (Oncorhynchus mykiss) during refrigerated storage

The present study evaluated the potential of nanochitosan coating enriched with ethanol-water extract of the walnut green husk (WGHE) on spoilage and rancidity of rainbow trout (Oncorhynchus mykiss) during six-day refrigerated storage. Hence, we have considered fresh trout fillets without any treatment as control (C), immersed in 2% solution of chitosan nanoparticles (CN), combination with 1.5% and 3% WGHE with nanochitosan coating (CN + WGHE 1.5 and CN + WGHE3), for physicochemical, microbial and sensorial assays. The highest levels and total volatile nitrogen were observed after day 6 in C, while the lowest was found in CN + WGHE3 groups. Thiobarbituric acid reactive substance (TBARS) and peroxide value of untreated fillets on day 6 of the study were significantly higher than NC + WGHE3 with 0.08 mg/g and 3.27 mEq/kg, respectively. The total microbial population was: C ˃ CN ˃ CN + WGHE 1.5 > CN + WGHE3, which expresses the effect of the extract on the total microbial population. Overall, the combination of WGHE with CN increased the extract's efficiency in reducing peroxide value, TBARS, and total volatile nitrogen and delayed the pH increase, improving the overall acceptability of rainbow trout fillets stored in refrigerated conditions.

Decolorizing shellac incorporated with natural antibacterial juglone from walnut green husk extract for preserving the postharvest quality of Wichita pecans (Carya illinoinensis [Wangenh.] K. Koch) during storage

The effects of treatment with edible coatings containing decolorizing shellac incorporated with natural antibacterial juglone from walnut green husk extract (WGHE) on the postharvest quality of dried Wichita pecans during 180 days at 4℃ were investigated. WGHE with a high yield of juglone was obtained by Soxhlet extraction in orthogonal test and mixed with main film former of decolorizing shellac to prepare edible coatings. The present results showed that the edible coating preserver NO. 4 (CP4) group had better waterproof performance and could coat pecan nuts in a natural color, decrease the pure kernel yield and the fat content, but the acid value, the peroxide value, and the soluble protein content were increased compared with the blank (BL) group. Moreover, the changing trends of the pure kernel yield were consistent with the fat content but had an opposite relationship to the acid value, as the heat map and correlation coefficients of different indexes after treatment of CP4. Besides, WGHE enhanced the antibacterial activity of CP4, meanwhile, Wichita pecans had a good overall taste in the determination of sensory evaluation, indicating CP4 minimized the hydrolysis and oxidation of internal fats, especially their auto-oxidation, maximized the stability of their functional unsaturated fatty acids and antioxidant functional components. In conclusion, CP4 treatment is a potential method in delaying significantly the oxidation process of pecans for maintaining the pecan nutrition and quality under low temperature during long-term storage.

Development and characterization of chitosan/guar gum active packaging containing walnut green husk extract and its application on fresh-cut apple preservation

The aim of this work was to develop active packaging film by using chitosan/guar gum (CG) film matrix and walnut green husk extract (WE), for preservation of fresh-cut apple. WE was used as cross-linking agent to improve physicochemical properties, and as active substances to enhance antioxidant activity of CG films. Fourier transform infrared spectroscopy and scanning electron microscopy results showed WE formed intermolecular hydrogen bond interactions with the film matrix, and microstructures of the film were more compact. With the increase of WE content (0–4 wt%), the mechanical properties of composite films were significantly enhanced, while permeability of water vapor and oxygen was significantly decreased (p < 0.05). When the amount of extract reached 4 wt%, the DPPH radical scavenging activity of composite film was significantly increased to 94.59%. CG-WE and CG films were used as active packaging materials to preserve fresh-cut apple. When stored at 4 °C for 10 days, CG-WE films showed better performance in reducing firmness, weight loss, total soluble solids and inhibiting browning and microbial growth of fresh-cut apples. Therefore, as a new type of active food packaging material, CG-WE films have good physical properties, and great potential in ensuring food quality and extending shelf life.

Interactive 360° video to “Polyphenolic extracts of walnut (Juglans regia) green husk containing juglone inhibit the growth of HL-60 cells and induce apoptosis”

BackgroundJuglone is a naphthoquinone currently obtained by chemical synthesis with biological activities including antitumor activity. Additionally, juglone is present in the green husk of walnut, which suggests evaluating the effect of GH extracts on carcinogenic cell lines. ResultsWalnut green husk ethanolic extract was obtained as 169.1 mg juglone/100 g Green Husk and antioxidant activity (ORAC) of 44,920 μmol Trolox Equivalent/100 g DW Green Husk. At 1 μM juglone in HL-60 cell culture, green husk extract showed an antiproliferative effect, but pure juglone did not; under these conditions, normal fibroblast cells were not affected. A dose-dependent effect on mitochondrial membrane potential loss was observed. Apoptosis of HL-60 was detected at 10 μM juglone. Despite high ORAC values, neither purified juglone nor the extract showed protective effects on HL-60 cells under oxidative conditions. ConclusionsGreen husk extract generates an antiproliferative effect in HL-60 cells, which is related to an induction of the early stages of apoptosis and a loss of mitochondrial membrane potential. The normal cells were not affected when juglone is present at concentrations of 1 μM, while at higher concentrations, there is loss of viability of both cancerous and healthy cells.How to cite: Soto-Maldonado C, Vergara-Castro M, Jara-Quezada J, et al. Interactive 360° video to: Polyphenolic extracts of walnut (Juglans regia) green husk containing juglone inhibit the growth of HL-60 cells and induce apoptosis. Electron J Biotechnol 2022;57. https://doi.org/10.1016/j.ejbt.2022.04.002.

Green synthesis of phenolic capping Ag NPs by green walnut husk extract and its application for colorimetric detection of Cd2+ and Ni2+ ions in environmental samples

This study assessed the green synthesis of phenolic capping silver nanoparticles (PC-Ag NPs) using the green walnut husk (GWH) extract of Juglans regia (J. Regia) as reducing and stabilizing agents. The synthesized nanoparticles were evaluated in terms of optical and chemical properties. The results of the analysis confirmed that the PC-Ag NPs formed successfully. Next, the prepared nanoparticles were applied as a colorimetric sensor for spectra and naked-eye detection of Cd2+ and Ni2+ ions. Owing to the reaction of functional groups of GWH extract, including hydroxyl and carboxyl on the surface of detector nanoparticles with Cd2+ and Ni2+ ions, aggregation and sedimentation occurred. These reactions suggest the formation of chelate complexes through polyphenol capabilities to chelate metals. Under optimized conditions (pH = 6, reaction time = 75 min), the introduced nanosensor exhibited good selectivity, sensitivity, and linearity (with R2 = 0.9899 and 0.9922 for Cd2+ and Ni2+, respectively). The detection limit of the reported method was 0.2 nM. Further, the synthesized nanosensor was utilized to determine target analytes in environmental samples, whereby satisfactory recoveries were achieved within 90.57 to 113.61%.

Investigation of antibacterial activity of one-dimensional electrospun Walnut green husk extract-PVP nanofibers

Investigation of antibacterial activity of one-dimensional electrospun Walnut green husk extract-PVP nanofibers

Microemulsion as solvent for naphthoquinones extraction from walnut (Juglans mandshurica Maxim) green husk using high voltage electrical discharge

• An efficient method for obtaining naphthoquinones from walnut husk was developed. • High voltage electric discharge extraction with microemulsion was explored. • The effects of microemulsion formula and discharge conditions were investigated. • High voltage electric discharge with microemulsion shows favorable superiority. Walnut green husks are a good source of natural naphthoquinones (NQs). In this study, a novel extraction strategy combining microemulsion and high voltage electric discharge (HVED) was proposed to extract the NQs from walnut green husks and maximize the value of this agro-byproduct. Firstly, the optimum microemulsion formula (ME8) for NQs extraction was determined among 17 microemulsions prepared with various contents ratios. Then the single factor experiments were conducted to explore the effect of discharge parameters (voltage, treatment time, liquid-solid ratio) on NQs yield. These parameters were further optimized by response surface methodology with Box-Behnken design, and the highest yield of NQs (67.1 ± 0.3 mg/g) was obtained under the predicted optimal conditions. The combination of HVED and microemulsion showed favorable synergistic preponderance and the NQs yield was 1.52 times higher than heating reflux extraction. Moreover, this strategy presented a competitive option to extract hydrophobic compounds in a less-organics-consumption way.

Walnut green husk ethanol extract improves gut microbiota and their metabolites associated with NLRP3 in non-alcoholic steatohepatitis.

Increasing studies have shown that walnut green husk (WGH) has obvious effects on reducing lipid, resisting oxidation, and protecting the liver. However, the mechanism by which WGH can prevent high-fat diet (HFD)-induced non-alcoholic steatohepatitis (NASH) remains unclear. This study is aimed at investigating the effects of WGH ethanol extract (WGHE) on NLRP3-related biochemical indicators and the diversity and metabolism of gut microbiota in HFD-induced NASH rats. WGHE was administered to HFD-induced NASH rats for 6 weeks. The results showed that WGHE could decrease the levels of blood and liver TC, TG, LDL-C, AST, and ALT and the levels of liver indices, including IL-1β, IL-6, TNF-α, TGF-β, FFA, VLDL, caspase-1, ASC, and NLRP3, while it could increase the levels of HDL-C. The pathological damage to liver tissues was significantly reduced. Moreover, WGHE could reduce the Firmicutes/Bacteroidetes (F/B) ratio and the relative abundances of potentially harmful bacteria, such as Lachnospiraceae and Christensenellaceae, and increase that of potentially beneficial bacteria, such as norank_f__Muribaculaceae. These bacteria were associated with NASH and most of them were significantly associated. A total of 23 gut bacteria and 31 metabolites were significantly altered by HFD, which was reversed by WGHE. The common functional pathways, including lipid metabolism and steroid biosynthesis, were identified through the analysis of KEGG metabolic pathways. In addition, the changes in gut microbiota, such as unclassified_f__Lachnospiraceae, unclassified_g__Blautia, and unclassified_g__Desulfovibrio, were associated with the changes in key intestinal metabolites, such as arachidonoyl amine, xanthine, and 25,26-epoxy-1α-hydroxyvitamin D3. In conclusion, WGHE could mitigate HFD-induced NASH in rats by interfering with the NLRP3-related gut microbiota and their metabolites.

Using Phenol-Rich Agro-Wastes as Substrates for the Cultivation of Hypsizygus ulmarius Mushroom with Enhanced Functional and Nutritional Potential

HIGHLIGHTS Straw-based media are more suitable for Hypsizygus ulmarius cultivation Grape pomace and green walnut husks are useable as alternative supplement materials These harmful wastes are converted into functional foods by mushroom cultivation

Green walnut husk extracts Proliferation and Migration in Gastric Cancer.

Background: In the past few decades, natural products have become an increasingly important source of potential anti-cancer agents. The green walnut husk(GWH) extracts have been reported to inhibit multiple tumor cells and might be a promising chemopreventive agent in human neoplasia. However, it is not clear whether GWH extracts inhibit gastric cancer.Methods: Proliferation, invasion, and migration of gastric cancer cells were assessed by the CCK-8, wound-healing, and Transwell assay. The apoptotic rate was detected by flow cytometry(FCM). The expressions of Bcl-2, Bax, and Caspase-3 proteins were examined by Western blot. Moreover, the growth of gastric cancer cells was assessed using orthotopic xenograft models, and related proteins expressions were evaluated using immunohistochemistry. Finally, the Gene expression profile of gastric cancer treated with GWH extracts was evaluated by using High-throughput RNA sequencing(RNA-seq).Results: GWH extracts effectively inhibited gastric cancer cell growth in vitro and in vivo. In vivo, GWH extracts inhibited the survival of gastric cancer cells in a dose and time-dependent manner, inhibited the migration and invasion of gastric cancer cells, regulated the expressions of apoptosis-related proteins, and induced apoptosis of gastric cancer cells. In vitro, GWH extracts inhibited the growth of mouse xenografted tumors. A total of differentially expressed genes, of which 41 genes were up-regulated, and 610 genes were down-regulated, were identified by RNA-seq. GO, and KEGG analysis showed that these differentially expressed genes might be related to the mechanism of the anti-gastric cancer effect of GWH extracts.Conclusion: GWH extracts played an anti-gastric cancer effect by inducing apoptosis and inhibiting invasion. Secondly, the differential expression of many genes, multiple signal pathways, and metabolic pathways in gastric cancer play an essential role in the anti-gastric cancer effect of GWH extracts. The results suggested that GWH extracts are expected to be a low toxic drug for the treatment of gastric cancer in the future.

Green Walnut Husk Ameliorating the Adverse Effects Induced by High Fat Diet in Rats

This study was designed to investigate the ameliorating effect of methanolic extract of green walnut husk (GWH) in hypercholesterolemic rats. A total of thirty male Albino Wistar rats (Rattus norvegicus domestica) were divided randomly into six equal groups. Group 1, negative control, fed on a standard rat diet whereas groups 2–6, hypercholesterolemic rats, fed a high-fat diet (1% cholesterol in a standard diet). Group 2, positive control, was left untreated, whereas the groups 3–5 treated orally with methanolic extract of GWH at 200, 400, and 800 mg/kg/day BW, respectively. Group 6, treatment control, received atorvastatin intraperitoneally at a dosage rate of 0.8 mg/kg/day. The treatment lasted for 84 days. Lipid profiles, biomarkers for liver and kidney functions, some hematological parameters, and liver histopathological assessment were performed. No significant variation was observed on lipid profile values after 42 days of GWH intake; while after 84 days, there was significant reduction (P&lt;0.05) in cholesterol, LDL, and triglycerides and significant increase (P&lt;0.05) in HDL. On day 42, the GWH intake revealed no ameliorating effect on ALT, AST, ALP, serum creatinine, and blood urea nitrogen (BUN); while on day 84, the GWH at 400 and 800 mg/kg BW reduced liver injury enzymes and serum creatinine levels but not the BUN. The GWH showed no significant effect on RBC, HGH, HCV, MCH, and MCHC counts; however, the WBCs count of all experimental groups showed significant (P&lt;0.05) increase when compared to negative control. In comparison with other experimental groups, the 800 mg/kg GWH group and the treatment control group exhibited significant decrease (P&lt;0.05) in HCT. The histopathological findings of the liver showed that the 800 mg/kg BW dosage rate of GWH was efficient in ameliorating the adverse tissue changes noticed in the positive control and other experimental groups. It can be inferred that GWH at dosage rate 200, 400, and 800 mg/kg BW have a potential antidyslipidemic effect in dose and period dependent manner. Further investigation to identify the safety of GWH for long standing using against hyperlipidemic patients is required.

Green Husk of Walnuts (Juglans regia L.) from Southern Italy as a Valuable Source for the Recovery of Glucans and Pectins

Walnut green husk is an agricultural waste produced during the walnut (Juglans regia L.) harvest, that could be valued as a source of high-value compounds. In this respect, walnut green husks from two areas of Southern Italy (Montalto Uffugo and Zumpano), with different soil conditions, were investigated. Glucans and pectins were isolated from dry walnut husks by carrying out alkaline and acidic extractions, respectively, and then they were characterized by FT-IR, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The colorimetric method for the enzymatic measurement of α- and β-glucans was performed. The maximum total glucan yield was recovered from Montalto walnut husks (4.6 ± 0.2 g/100 g DM) with a β-glucan percentage (6.3 ± 0.4) higher than that calculated for Zumpano walnut husks (3.6 ± 0.5). Thermal analysis (DSC) confirmed the higher degree of crystallinity of glucans from Zumpano. The pectin content for Montalto husks was found to be 2.6 times that of Zumpano husks, and the esterification degree was more than 65%. The results suggested that J. regia L. green husks could be a source of glucans and pectins, whose content and morphological and thermal characteristics were influenced by different soil and climate conditions.

Polyphenols-rich extracts from walnut green husk prevent non-alcoholic fatty liver disease, vascular endothelial dysfunction and colon tissue damage in rats induced by high-fat diet

This study is aims to evaluate the beneficial effects of polyphenols-rich extracts from walnut green husk (WGHP) on the prevention of obesity, nonalcoholic fatty liver disease (NAFLD), vascular endothelial dysfunction and colon tissue damage in rats fed high fat diet for 8 weeks. HPLC analysis showed that epicatechin, rutin and caffeic acid are the main components of WGHP. Administration of WGHP to HF-fed rats effectively prevented abnormal body weight gain, lipid metabolism disorder, oxidative stress and inflammation. Biochemical analysis and histopathological observation consistently confirmed the protective effects of WGHP on NAFLD, vascular endothelial dysfunction and colon tissue damage in rats caused by HF. In addition, 16S RNA sequencing results showed that WGHP reduced the Firmicutes/Bacteroidetes ratio in HF-fed rats and reversed the relative abundance of Ruminococcaceae-UCG-014 and Fusicatenibacter. These results suggest that WGHP may serve as a nutritional agent for protecting liver, cardiovascular and colon tissue in HF-fed rats.