Polysaccharides from Diaphragma juglandis fructus: Extraction optimization, antitumor, and immune-enhancement effects

Utilization of electron beam irradiation pretreatment for the extraction of pectic polysaccharides from Diaphragma juglandis fructus: Structural, physicochemical, and functional properties

The effects of electron beam irradiation (EBI) pretreatment on the alkaline extraction of pectic polysaccharides from Diaphragma juglandis fructus (DJF) are highly dependent on the irradiation dosage. Comprehensive characterizations encompassing physicochemical, structural, and functional properties were conducted on crude pectic polysaccharide extract from DJF subjected to various EBI doses. EBI pretreatment significantly increased the yields of crude pectic polysaccharides extract (increasing by 41.89 %), also facilitating the extraction of uronic acid, RG-I structure, and protein content, despite causing a decrease in total sugar content. EBI pretreatment induced the degradation of pectin, resulting in decreased molecular weight, particle size, crystallinity, viscosity, thermal stability, and water holding capacity, while enhancing solubility and oil holding capacity. Variations in physicochemical and structural properties induced by different EBI doses influenced the functional activities of DJF pectic polysaccharides. Low-dose EBI (at 5 kGy) pretreatment markedly improved the emulsifying activity/stability (increasing by 20.82/74.10 %) and ABTS/DPPH radical scavenging activity (increasing by 27.91/12.40 %), whereas high-dose EBI pretreatment (50 kGy) greatly enhanced foaming capacity/stability (increasing by 259.99/175.56 %). These findings provide a novel regulatory strategy for the functional activity of pectic polysaccharides.

Regulation of Intestinal Inflammation by Walnut-Derived Bioactive Compounds

Walnuts (Juglans regia L.) have shown promising effects in terms of ameliorating inflammatory bowel disease (IBD), attributed to their abundant bioactive compounds. This review comprehensively illustrates the key mechanisms underlying the therapeutic potential of walnuts in IBD management, including the modulation of intestinal mucosa permeability, the regulation of inflammatory pathways (such as NF-kB, COX/COX2, MAPCK/MAPK, and iNOS/NOS), relieving oxidative stress, and the modulation of gut microbiota. Furthermore, we highlight walnut-derived anti-inflammatory compounds, such as polyunsaturated fatty acids (PUFA; e.g., ω-3 PUFA), tocopherols, phytosterols, sphingolipids, phospholipids, phenolic compounds, flavonoids, and tannins. We also discuss unique anti-inflammatory compounds such as peptides and polysaccharides, including their extraction and preparation methods. Our review provides a theoretical foundation for dietary walnut supplementation in IBD management and provides guidance for academia and industry. In future, research should focus on the targeted isolation and purification of walnut-derived anti-inflammatory compounds or optimizing extraction methods to enhance their yields, thereby helping the food industry to develop dietary supplements or walnut-derived functional foods tailored for IBD patients.

Investigation of natural deep eutectic solvent for the extraction of crude polysaccharide from Polygonatum kingianum and influence of metal elements on its immunomodulatory effects

In this study, natural deep eutectic solvent (NADES) was used to extract Polygonatum kingianum crude polysaccharide (PKCP) and response surface methodology (RSM) was designed to optimize the extraction procedure. The immunomodulatory effect of PKCP and the influence of metal elements on its immunomodulatory effect were further discussed. The optimum conditions for PKCP extraction were obtained by RSM optimization: NADES were synthesized with a 1:2 choline chloride-glycerol molar ratio, then extracted at a liquid-solid ratio of 16.6 mL g-1 and water content of 31.2 % for 60 min at 60 °C. This method was used for the extraction of PKCP, and the extraction efficiency was 29.69 %, which was 2.5 times greater than the conventional method of water extraction. In the concentration range of 200-800 μg mL-1, PKCP could activate macrophages, promoting NO secretion and mRNA expression of interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS) in a dose-dependent way. NO secretion and cytokine expression were not affected when the metal elements were spiked to the equivalent of the metal elements contained in Polygonatum kingianum. When the content of metal elements was higher, the secretion of NO and the gene expression of iNOS were both decreased, which may affect the immunomodulatory effect of Polygonatum kingianum.

A Novel Water-Soluble Polysaccharide from Daylily (Hemerocallis citrina Baroni): Isolation, Structure Analysis, and Probiotics Adhesion Promotion Effect

The daylily (Hemerocallis citrina Baroni) flower is a traditional raw food material that is rich in a variety of nutrients. In particular, the content of polysaccharides in daylily is abundant and has been widely used as a functional component in food, cosmetics, medicine, and other industries. However, studies on the structure-effective relationship of daylily flower polysaccharides are still lacking. In view of this, daylily flower polysaccharides were isolated and purified, and their physical and chemical properties, structure, antioxidant activity, and adhesion-promoting effect on probiotics were evaluated. The results showed that a novel water-soluble polysaccharide (DPW) with an average molecular weight (Mw) of 2.224 kDa could be successfully isolated using column chromatography. Monosaccharide composition analysis showed that DPW only comprised glucose and fructose, with a molar ratio of 0.242:0.758. Through methylation and nuclear magnetic resonance (NMR) analysis, it was inferred that DPW belonged to the fructans group with a structure of α-D-Glcp-1→2-β-D-Fruf-1→(2-β-D-Fruf-1)n→. Antioxidant analysis showed that DPW showed strong 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-Oxide (PTIO-scavenging activity with IC50 of 1.54 mg/mL. DPW of 1.25 to 5 mg/mL could significantly increase the adhesion rate of Lactobacillus acidophilu, Lactobacillus casei, Bifidobacterium adolescentis, and Lactobacillus plantarum on Caco-2 cells. Considering the above results, the present study provides a theoretical basis and practical support for the development and application of daylily polysaccharides as a functional active ingredient.

A Review on Extracts, Chemical Composition and Product Development of Walnut Diaphragma Juglandis Fructus

Walnuts are one of the world's most important nut species and are popular for their high nutritional value, but the processing of walnuts produces numerous by-products. Among them, Diaphragma Juglandis Fructus has attracted the attention of researchers due to its complex chemical composition and diverse bioactivities. However, comprehensive reviews of extract activity and mechanistic studies, chemical composition functionality, and product types are scarce. Therefore, the aim of this review is to analyze the extracts, chemical composition, and product development of Diaphragma Juglandis Fructus. Conclusions: For extracts, the biological activities of aqueous and ethanol extracts have been studied more extensively than those of methanol extracts, but almost all of the studies have been based on crude extracts, with fewer explorations of their mechanisms. For chemical composition, the bioactivities of polyphenols and polysaccharides were more intensively studied, while other chemical constituents were at the stage of content determination. For product development, walnuts are mainly used in food and medicine, but the product range is limited. In the future, research on the bioactivity and related mechanisms of Diaphragma Juglandis Fructus can be further expanded to improve its value as a potential natural plant resource applied in multiple industries.

Traditional uses, chemical composition, and pharmacological effects of diaphragma juglandis fructus: A review

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Uyghur medicine, diaphragma juglandis fructus (DJF) has been conventionally used in treating insomnia and nourishing the kidneys. According to traditional Chinese medicine, DJF can boosts kidney and astringent essence, strengthen the spleen and kidney, exert diuretic effect, clear heat, stop eructation, and treat vomiting.

AIM OF THE REVIEW

Research on DJF has increased gradually in recent years, but reviews of its traditional uses, chemical composition, and pharmacological activities are scarce. The purpose of this review is to analyze the traditional uses, chemical composition, and pharmacological activities of DJF and provide an overview of the findings for further research and development of DJF resources.

MATERIALS AND METHODS

Data on DJF were obtained from different databases, including Scifinder, PubMed, Web of Science, Science Direct, Springer, Wiley, ACS, CNKI, Baidu Scholar, and Google Scholar; books; and Ph.D. and MSc theses.

RESULTS

According to traditional Chinese medicine, DJF has astringent properties, inhibits bleeding and banding, strengthens the spleen and kidneys, acts as a sleeping aid by reducing anxiety, and relieves dysentery due to heat exposure. The components of DJF include flavonoids, phenolic acids, quinones, steroids, lignans, and volatile oils, which exhibit good antioxidant, antitumor, antidiabetic, antibacterial, anti-inflammatory, and sedative-hypnotic properties, and present therapeutic potential for kidney diseases.

CONCLUSIONS

Based on its traditional use, chemical composition, and pharmacological activities, DJF is a promising source of natural medicine in the development of functional foods, drugs, and cosmetics.

Phytochemicals and Biological Activities of Walnut Septum: A Systematic Review

In the last few decades, scientific evidence has stressed the importance of plants in the prevention and/or supportive treatment of a plethora of diseases, many of them chronic, age-associated disorders. Juglans regia L. is a traditional plant that has been integrated into traditional medicine since ancient times. Due to the presence of biologically active compounds, walnut was used in the treatment of various maladies. Recently, investigations have focused on the walnut by-products and waste products, with research on their valuable constituents and active properties. Among these secondary products, walnut septum was analyzed in several studies, its phytochemical profile described, and some of the biological activities examined. However, compared to other walnut by-products, no comprehensive review to gather all the pertinent scientific knowledge was found in the literature. Therefore, the aim of this study was to critically assess the information furnished by peer-reviewed articles regarding the walnut septum chemical composition and the related biological activities, including antioxidant activities, anti-inflammatory effects, antimicrobial properties, antidiabetic activities, anti-tumor properties, and anti-aging potential. In conclusion, as these preclinical studies showed that walnut septum metabolites were responsible for a wide range of preventive and therapeutic uses, further research should confirm the beneficial outcomes in clinical trials.

Physicochemical and Functional Changes in Lotus Root Polysaccharide Associated with Noncovalent Binding of Polyphenols

To promote the functional applications of lotus root polysaccharides (LRPs), the effects of noncovalent polyphenol binding on their physicochemical properties, as well as antioxidant and immunomodulatory activities, were investigated. Ferulic acid (FA) and chlorogenic acid (CHA) were spontaneously bound to the LRP to prepare the complexes LRP-FA₁, LRP-FA₂, LRP-FA₃, LRP-CHA₁, LRP-CHA₂ and LRP-CHA₃, and their mass ratios of polyphenol to LRP were, respectively, 121.57, 61.18, 34.79, 2359.58, 1276.71 and 545.08 mg/g. Using the physical mixture of the LRP and polyphenols as a control, the noncovalent interaction between them in the complexes was confirmed by ultraviolet and Fourier-transform infrared spectroscopy. The interaction increased their average molecular weights by 1.11~2.27 times compared to the LRP. The polyphenols enhanced the antioxidant capacity and macrophage-stimulating activity of the LRP depending on their binding amount. Particularly, the DPPH radical scavenging activity and FRAP antioxidant ability were positively related to the FA binding amount but negatively related to the CHA binding amount. The NO production of the macrophages stimulated by the LRP was inhibited by the co-incubation with free polyphenols; however, the inhibition was eliminated by the noncovalent binding. The complexes could stimulate the NO production and tumor necrosis factor-α secretion more effectively than the LRP. The noncovalent binding of polyphenols may be an innovative strategy for the structural and functional modification of natural polysaccharides.

Techno-functional properties and immunomodulatory potential of exopolysaccharide from Lactiplantibacillus plantarum MM89 isolated from human breast milk

An exopolysaccharide, designated as MM89-EPS, was isolated from Lactiplantibacillus plantarum MM89. It was comprised of glucose and mannose molecules with an average molecular weight of 138 kDa. FTIR and NMR spectra showed that MM89-EPS had characteristic polysaccharide functional groups. MM89-EPS displayed excellent water solubility and capacities to retain water and oil due to its porous structure. MM89-EPS exhibited no significant cytotoxicity on RAW264.7 cells and showed strong immunomodulatory activity by increasing phagocytosis, acid phosphatase activity, and cytokine production in RAW264.7 cells. Furthermore, an in vivo study revealed that splenic indices, intestinal IgA levels, serum cytokine levels, and lymphocyte proliferation were increased in an MM89-EPS-treated cyclophosphamide-induced immunosuppressed mouse model. To summarize, our results indicate that MM89-EPS can efficiently enhance the immunostimulatory activity of immune cells and an immunosuppressed mouse model. Hence, MM89-EPS may be use as a potential source of immunomodulatory agent in various food products.

The Chemical Constituents of Diaphragma Juglandis Fructus and Their Inhibitory Effect on α-Glucosidase Activity

In our current investigation, 37 constituents (1-37), including 11 megastigmanes (1-11), 17 flavonoids (12-28) and 9 phenylpropanoids (29-37), were isolated from a 70%-EtOH extract of Diaphragma juglandis Fructus. Among them, compounds 1-3, 12 and 29 were new compounds and their structures were elucidated on the basis of physicochemical evidence and meticulous spectroscopic analysis (NMR, HRESIMS and CD). Compounds 13, 16, 21 and 28 showed moderate inhibitory effect on α-glycosidase inhibitory activities, with IC50 values being in the range of 29.47-54.82 µM and stronger than the positive control (acarbose, 60.01 ± 4.82 µM).

Current emerging trends in antitumor activities of polysaccharides extracted by microwave- and ultrasound-assisted methods

This overview highlighted the in vitro and in vivo antitumor effects of polysaccharides extracted by ultrasound- and microwave-assisted solvent extraction methods. The polysaccharide fragments with stronger antiproliferation, antitumoral, and anticarcinoma effects can be identified through purification, fractionation, and bio-analytical assessments. Most of the extracted glucan-based polysaccharides in a dose-dependent manner inhibited the growth of human cancer cell types with cell death-associated morphological changes. Glucans, glucogalactans, and pectins without any cytotoxicity on normal cells showed the antitumor potential by the apoptosis induction and the inhibition of their tumorigenesis, metastasis, and transformation. There is a significantly high association among antiproliferative activities, structural features (e.g., molecular weight, monosaccharide compositions, and contents of sulfate, selenium, and uronic acid), and other bio-functionalities (e.g., antiradical and antioxidant) of isolated polysaccharides. The evaluation of structure-activity relationships of antitumor polysaccharides is an intriguing step forward to develop highly potent anticancer pharmaceuticals and foods without any side effects.

A Validated Ultrasound-Assisted Extraction Coupled with SPE-HPLC-DAD for the Determination of Flavonoids in By-Products of Plant Origin: An Application Study for the Valorization of the Walnut Septum Membrane

Walnut byproducts have been shown to exert functional properties, but the literature on their bioactive content is still scarce. Among walnut byproducts, walnut septum is a dry ligneous diaphragm tissue that divides the two halves of the kernel, exhibiting nutritional and medicinal properties. These functional properties are owing to its flavonoid content, and in order to explore the flavonoid fraction, an ultrasound-assisted (UAE) protocol was combined with solid phase extraction (SPE) and coupled to high-performance liquid chromatography with diode array detection (HPLC-DAD) for the determination of flavonoids in Greek walnut septa membranes belonging to Chandler, Vina, and Franquette varieties. The proposed UAE-SPE-HPLC-DAD method was validated and the relative standard deviations (RSD%) of the within-day and between-day assays were lower than 6.2 and 8.5, respectively, showing good precision, and high accuracy ranging from 90.8 (apigenin) to 97.5% (catechin) for within-day assay, and from 88.5 (myricetin) to 96.2% (catechin) for between-day assay. Overall, seven flavonoids were determined (catechin, rutin, myricetin, luteolin, quercetin, apigenin, and kaempferol) suggesting that the walnut septum is a rich source of bioactive constituents. The quantification results were further processed using ANOVA analysis to examine if there are statistically significant differences between the concentration of each flavonoid and the variety of the walnut septum.

Plant/algal polysaccharides extracted by microwave: A review on hypoglycemic, hypolipidemic, prebiotic, and immune-stimulatory effect

Microwave-assisted extraction (MAE) is an emerging technology to obtain polysaccharides with an extensive spectrum of biological characteristics. In this study, the hypoglycemic, hypolipidemic, prebiotic, and immunomodulatory (e.g., antiinflammatory, anticoagulant, and phagocytic) effects of algal- and plant-derived polysaccharides rich in glucose, galactose, and mannose using MAE were comprehensively discussed. The in vitro and in vivo results showed that these bioactive macromolecules with the low digestibility rate could effectively alleviate the fatty acid-induced lipotoxicity, acute hemolysis, and dyslipidemia status. The optimally extracted glucomannan- and glucogalactan-containing polysaccharides revealed significant antidiabetic effects through inhibiting α-amylase and α-glucosidase, improving dynamic insulin sensitivity and secretion, and promoting pancreatic β-cell proliferation. These bioactive macromolecules as prebiotics not only improve the digestibility in gastrointestinal tract but also reduce the survival rate of pathogens and tumor cells by activating macrophages and producing pro-inflammatory biomarkers and cytokines. They can effectively prevent gastrointestinal disorders and microbial infections without any toxicity.

Optimization of ultrasonic-assisted extraction of polysaccharides from Hemerocallis citrina and the antioxidant activity study

The present study discussed the optimization of the ultrasonic-assisted extraction of polysaccharides from daylily polysaccharides (DPs). The extracted crude polysaccharides were further separated and purified, and the antioxidant activities including 1,1-diphenyl-2-111 picrylhydrazyl (DPPH) radical scavenging, 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radical scavenging, hydroxyl radical scavenging, and ferric-reducing antioxidant power (FRAP) activities of the obtained fractions were also evaluated. The results showed that the optimal ultrasonic-assisted extraction parameters with DPs yield of 15.25 ± 1.13% were water to powder ratio of 25 ml/g, extraction power of 694 W, extraction temperature of 71°C, extraction time of 38 min, and three times extraction. By DEAE Sepharose Fast Flow column, four water-soluble polysaccharide fractions (DP-1, DP-2, DP-3, and DP-4) were successfully obtained. Monosaccharide component analysis showed that the four obtained fractions were all hetero-polysaccharides that mainly contained rhamnose, arabinose, fructose, galactose, glucose, galacturonic acid, and glucuronic acid in different molar ratios. All the four DP fractions did show obvious antioxidant activities in vitro, and the DP-3 component had relatively high ABTS free radical scavenging activity. Overall, our research showed that DPs could provide cheap raw materials for the development of natural antioxidants in medicines, functional foods, and even cosmetics. PRACTICAL APPLICATION: This article deals with the optimization of the ultrasonic-assisted extraction of polysaccharides from daylily and its antioxidant activities. The results showed that the optimal ultrasonic-assisted extraction yield of DPs was 15.25 ± 1.13%. By DEAE Sepharose Fast Flow column, four water-soluble polysaccharide fractions were successfully obtained, and all the four DP fractions did show obvious antioxidant activities in vitro. Daylily polysaccharides could provide cheap raw materials for the development of natural antioxidants in medicines, functional foods, and even cosmetics.

Walnut (Juglans regia L.) Septum: Assessment of Bioactive Molecules and In Vitro Biological Effects

Walnut (Juglans regia L.) septum represents an interesting bioactive compound source by-product. In our study, a rich phenolic walnut septum extract, previously selected, was further examined. The tocopherol content determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed higher amounts of α-tocopherol compared to γ- and δ-tocopherols. Moreover, several biological activities were investigated. The in vitro inhibiting assessment against acetylcholinesterase, α-glucosidase, or lipase attested a real management potential in diabetes or obesity. The extract demonstrated very strong antimicrobial potential against Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella enteritidis. It also revealed moderate (36.08%) and strong (43.27%) antimutagenic inhibitory effects against TA 98 and TA 100 strains. The cytotoxicity of the extract was assessed on cancerous (A549, T47D-KBluc, MCF-7) and normal (human gingival fibroblasts (HGF)) cell lines. Flow cytometry measurements confirmed the cytotoxicity of the extract in the cancerous cell lines. Additionally, the extract demonstrated antioxidant activity on all four cell types, as well as anti-inflammatory activity by lowering the inflammatory cytokines (interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-1 β (IL-1β)) evaluated in HGF cells. To the best of our knowledge, most of the cellular model analyses were performed for the first time in this matrix. The results prove that walnut septum may be a potential phytochemical source for pharmaceutical and food industry.

Phenolic composition and nutritional attributes of diaphragma juglandis fructus and shell of walnut (Juglans regia L.)

Phenolic composition and nutritional attributes of diaphragma juglandis fructus (Djf) and walnut shells (Ws) were investigated. Phenolic acids, hydroxybenzoic acid, isoflavone, and flavone were identified in the free phenolic fractions (FPFs) of both Djf and Ws. Bound phenolic fractions were less than FPFs both in content and diversity. The soluble dietary fiber contents of Djf and Ws were 25.56 g/100 g and 9.5 g/100 g, respectively. The contents of unsaturated fatty acids (1912.28 mg/kg and 9137.56 mg/kg, respectively) were significantly higher than that of saturated fatty acid both in Djf and Ws. The content of essential amino acids in Djf (9.67 mg/g) was significantly higher than that in Ws. More than eight types of monosaccharides were detected in Djf and Ws. The monosaccharide content of Djf (314.16 mg/g) was significantly higher than that of Ws (60.97 mg/g). Trehalose was the predominant component both in Djf (71.2%) and Ws (78.6%).

Identification and Quantification of Bioactive Compounds in Diaphragma juglandis Fructus by UHPLC-Q-Orbitrap HRMS and UHPLC-MS/MS

Diaphragma juglandis fructus is the dry wooden diaphragm inside walnuts and a byproduct in food processing of walnut kernels. The purpose of our research is to enrich the information on compounds in Diaphragma juglandis fructus to further discover and exploit its potential nutritional value. In this study, new quali-quantitative analytical approaches were developed to identify and determine bioactive compounds in Diaphragma juglandis fructus. Two-hundred compounds, including hydrolyzable tannins, flavonoids, phenolic acids, and quinones, were identified by UHPLC-Q-Orbitrap HRMS, more than 150 of which were first discovered in Diaphragma juglandis fructus. Among them, 21 major dietary polyphenols with health-promoting effects were successfully quantified using UHPLC-MS/MS, with total contents of 2.88-6.18 mg/g. This successful characterization and quantification of bioactive compounds in Diaphragma juglandis fructus gives a better understanding of its potential nutritional value and supports efficiently developing and reusing it instead of discarding it as agrofood waste.

Characterisation of phenolics in fruit septum of Juglans regia Linn. by ultra performance liquid chromatography coupled with Orbitrap mass spectrometer

Walnut (Juglans regia L.) is an abundant source of polyphenols. Although phenolic species in the walnut kernel have been studied comprehensively, their compositional profile in the internal fruit septum, a traditional nutraceutical material in China, has been rarely explored. In the current study, the methanolic extract of the walnut septum was analysed by Ultra-performance liquid chromatography coupled with Orbitrap mass spectrometry. Totally seventy-five phenolics belonging to flavonoids, tannins and phenolic acids were identified based on mass spectra, references and literatures. Among them, quercetin-3-O-galactoside, quercetin-rhamnose-pentoside, quercetin-3-O-glucoside, quercetin-rhamnose-hexoside, kaempferol-rhamnoside, and two isomers of quercetin-rhamnoside were reported for the first time in walnut. The total polyphenol content was found to be 122.78 ± 2.55 mg GAE/g dry weight in septum. This study is the first to comprehensively investigate and identify phenolic compounds in the fruit septum of walnut and indicates that the septum to be a rich resource of polyphenols.

Beneficial Effect of Intestinal Fermentation of Natural Polysaccharides

With the rapid development of modern society, many chronic diseases are increasing including diabetes, obesity, cardiovascular diseases, etc., which further cause an increased death rate worldwide. A high caloric diet with reduced natural polysaccharides, typically indigestible polysaccharides, is considered a health risk factor. With solid evidence accumulating that indigestible polysaccharides can effectively prevent and/or ameliorate symptoms of many chronic diseases, we give a narrative review of many natural polysaccharides extracted from various food resources which mainly contribute their health beneficial functions via intestinal fermentation.