Advances in health-promoting effects of natural polysaccharides: Regulation on Nrf2 antioxidant pathway

A decade review on phytochemistry and pharmacological activities of Cynomorium songaricum Rupr.: Insights into metabolic syndrome

BACKGROUND

Cynomorium songaricum Rupr. (CSR), a perennial herb with a rich history in traditional medicine, has demonstrated therapeutic potential against metabolic syndrome (MetS) through its active compounds, including proanthocyanidins, polysaccharides, and triterpenoids. MetS, a global health concern, encompasses interlinked conditions such as obesity, type 2 diabetes mellitus (T2DM), and inflammation. This review synthesizes recent findings on CSR's pharmacological and phytochemical properties, focusing on its role in ameliorating MetS.

METHODS

Following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, relevant studies were retrieved from PubMed, Web of Science, and CNKI databases up to December 2024. Keywords included "Cynomorium Songaricum Rupr.", "Cynomorii Herba", "Suoyang", "Suo Yang", "Metabolic syndrome", "Proanthocyanidins", "Polysaccharides" and "Triterpenoids" and their combinations. Inclusion criteria emphasized studies exploring CSR's impact on MetS, while duplicate, low-quality studies and studies not written in Chinese, English, or unrelated were excluded.

RESULTS

A total of 92 studies were analyzed, revealing that CSR's active components exhibit multi-target effects. Proanthocyanidins reduce glucose absorption and oxidative stress, polysaccharides enhance insulin sensitivity and gut microbiota composition, and triterpenoids mitigate obesity and mitochondria damage. These mechanisms collectively contribute to the beneficial effects of CSR against MetS.

CONCLUSION

CSR presents a promising natural therapy for MetS, utilizing its pharmacologically active compounds to address core metabolic dysfunctions. Future studies should focus on clinical validation and safety assessments to facilitate CSR's integration into modern therapeutic regimens.

Polysaccharides with antioxidant activity: Extraction, beneficial roles, biological mechanisms, structure-function relationships, and future perspectives: A review

Polysaccharides are valuable macromolecules due to their multiple bioactivities, safety, and a wide range of sources. Recently, a series of polysaccharides with antioxidant activity have been intensively reported. In this review, the latest advances in polysaccharides with antioxidant activity have been reviewed, primarily based on the investigations of polysaccharides regarding advanced extraction methods, roles in oxidative stress-related diseases, intracellular signaling pathways associated with antioxidant responses, activating pathways in the gut, structure-function relationships, and methods to improve antioxidant activity. The summarized information highlighted that much work needs to be conducted, from laboratory to industry, to understand and fully utilize the antioxidant potential of polysaccharides. Finally, future perspectives, including scaling-up of advanced extraction methods, standardizing the protocols for assessing and screening polysaccharides, bridging gaps on the biological mechanisms underlying antioxidant activity, performing clinical trials, and elucidating structure-antioxidant relationships, have been addressed. The information present in this review will be helpful to the scientific community when studying on polysaccharides with antioxidant potential and provides research directions for a better understanding of the polysaccharides and promotes their successful applications in functional foods and nutraceuticals.

Optimization of hypobaric and ultrasonic processing of persimmon rhamnogalacturonan-I to enhance drug-digestion interactions

The biological activity of polysaccharides used for nutraceuticals/drug excipients has been a neglected area of study. This work deals with the preparation, optimization, characterization, and evaluation of persimmon (Diospyros kaki Thunb.) fruit by-products and the study of the resultant dietary fiber (DF) interaction with other compounds, using acetaminophen as a model. Processing conditions for persimmon by-products were optimized to enhance antioxidant activity, with hypobaric, ultrasonic, and drying conditions tested at three levels of time and pH. The optimized DF was evaluated through in-vitro and ex-vivo release and permeation studies. Optimal conditions included three cycles of vacuum instantaneous expansion coupled with ultrasound waves (USEX), 42 min of ultrasound assisted extraction (UAE), and a pH of 1.5. After treatments, the antioxidant capacity (AC) increased six-fold, and zeta potential (ζ) analysis indicated polysaccharide aggregation at the optimized pH. The optimized polysaccharides, mainly formed by rhamnogalacturonan-I, displayed nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent activity. In-vitro drug-DF interaction studies showed higher acetaminophen release during digestion. Permeation kinetics adhered to the Korsmeyer-Peppas model in both ex-vivo and in-vitro models, suggesting complex permeation mechanisms. Results suggest that the optimized DF enhances the bioavailability and controlled release of acetaminophen, indicating its potential for use in drug delivery systems and nutraceutical applications.

Psoralen and Isopsoralen Activate Nuclear Factor Erythroid 2-Related Factor 2 Through Interaction With Kelch-Like ECH-Associated Protein 1

As natural furocoumarins, psoralen and its isomer isopsoralen are widely distributed in various fruits including Ficus carica L., vegetables including celery, and medicinal herbs including Psoralea corylifolia L. Although psoralen and isopsoralen have been used as dietary supplements because of their bioactivities such as antibacterial and anti-inflammatory properties; however, the potential mechanisms underlying the antioxidant activities of these two furocoumarins still need to be explored. Hence, the aims of this work were to examine the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) by psoralen and isopsoralen, as well as the binding interaction of Kelch-like ECH-associated protein 1 (Keap1) with these two furocoumarins. Interestingly, both psoralen and isopsoralen induced Nrf2 nuclear translocation in a dose-dependent manner in HEK293T cells. These two furanocoumarins also activated antioxidant response element (ARE)-driven luciferase activity. The mRNA expression of GCLM, HO-1, and NQO1 genes was significantly upregulated by treatment of HEK293T cells with psoralen and isopsoralen, respectively. Similarly, the expression of proteins can be promoted. Both psoralen and isopsoralen were located in the top of the central pocket of the Keap1 Kelch domain, suggesting that they were natural ligands of Keap1. In conclusion, both psoralen and isopsoralen activate Nrf2 through interaction with Keap1, thereby serving as natural antioxidants.

Anti-Aging Effect of Traditional Plant-Based Food: An Overview

Aging is a complex process that involves many physiological mechanisms that gradually impair normal cellular and tissue function and make us more susceptible to diseases and death. It is influenced by intrinsic factors like cellular function and extrinsic factors like pollution and UV radiation. Recent scientific studies show that traditional plant-based foods and supplements can help mitigate the effects of aging. Nutraceuticals, which are dietary supplements with medicinal properties, have gained attention for their ability to prevent chronic and age-related diseases. Antioxidants like flavonoids, carotenoids, ascorbic acid, terpenes, tannins, saponins, alkaloids, minerals, etc. found in plants are key to managing oxidative stress, which is a major cause of aging. Well-known plant-based supplements from Bacopa monnieri, Curcuma longa, Emblica officinalis, Ginkgo biloba, Glycyrrhiza glabra, and Panax ginseng have been found to possess medicinal properties. These supplements have been shown to improve cognitive function, reduce oxidative stress, improve overall health, and potentially extend life and enhance the excellence of life. The obtained benefits from these plant species are due to the presence of their bioactive secondary metabolites, such as bacosides in Bacopa monnieri, curcumin in Curcuma longa, ginsenosides in Panax ginseng, and many more. These compounds not only protect against free radical damage but also modulate key biological pathways of aging. Also, traditional fermented foods (tempeh and kimchi), which are rich in probiotics and bioactive compounds, support gut health, boost immune function, and have anti-aging properties. The molecular mechanisms behind these benefits are the activation of nutrient-sensing pathways like AMPK, SIRT/NAD+, and mTOR, which are important for cellular homeostasis and longevity. This review shows the potential of traditional plant-based foods and dietary supplements for healthy aging, and more studies are needed to prove their efficacy and safety in humans. Incorporating these natural products into our diet may be a practical and effective way to counteract the effects of aging and overall well-being. The foremost goal of this review is to emphasize the importance of supporting the body's antioxidant system by consuming the right balance of natural ingredients in the diet.

New insight into oxidative stress and inflammatory responses to kidney stones: Potential therapeutic strategies with natural active ingredients

Kidney stones, a prevalent urological disorder, are closely associated with oxidative stress (OS) and the inflammatory response. Recent research in the field of kidney stone treatment has indicated the potential of natural active ingredients to modulate OS targets and the inflammatory response in kidney stones. Oxidative stress can occur through various pathways, increasing the risk of stone formation, while the inflammatory response generated during kidney stone formation further exacerbates OS, forming a detrimental cycle. Both antioxidant systems related to OS and inflammatory mediators associated with inflammation play roles in the pathogenesis of kidney stones. Natural active ingredients, abundant in resources and possessing antioxidative and anti-inflammatory properties, have the ability to decrease the risk of stone formation and improve prognosis by reducing OS and suppressing pro-inflammatory cytokine expression or pathways. Currently, numerous developed natural active ingredients have been clinically applied and demonstrated satisfactory therapeutic efficacy. This review aims to provide novel insights into OS and inflammation targets in kidney stones as well as summarize research progress on potential therapeutic strategies involving natural active ingredients. Future studies should delve deeper into exploring efficacy and mechanisms of action of diverse natural active ingredients, proposing innovative treatment strategies for kidney stones, and continuously uncovering their potential applications.

Ganoderma lucidum polysaccharide promotes broiler health by regulating lipid metabolism, antioxidants, and intestinal microflora

Ganoderma lucidum polysaccharides (GLP) are the primary bioactive macromolecular compounds of Ganoderma lucidum, possessing antioxidant and immunomodulatory effects. Hot water extract of Juncao-substrate Ganoderma Lucidum residue (HWE-JGLR) is abundant in GLP. There are few research reports on the application of HWE-JGLR in animal husbandry. Therefore, this study aims to investigate the effects of HWE-JGLR supplementation on growth performance, serum biochemistry, the antioxidant function of serum and liver, and the intestinal microbiota of yellow-feathered broilers. The control group was fed a corn-soybean meal basal diet, while the HJ I, II, and III groups received diets supplemented with 0.25 %, 0.5 %, and 1 % of HWE-JGLR, respectively. Results showed that HWE-JGLR increased the serum HDL-C content and decreased the TG content in broilers. Moreover, HWE-JGLR enhanced the antioxidant function by the Keap1-Nrf2/ARE signaling pathway and the antioxidative enzyme in broilers. In addition, the cecum of the metagenomic analysis of 16S rRNA showed that the relative abundance of no-rank Ruminococcacea was increased in the HJ I group. Our findings indicate that HWE-JGLR has strong potential for development as a green feed additive based on its functions of lipid-lowering, antioxidation, and the modulation of gut microbiota composition.

Interactions between Gut Microbiota and Natural Bioactive Polysaccharides in Metabolic Diseases: Review

The gut microbiota constitutes a complex ecosystem, comprising trillions of microbes that have co-evolved with their host over hundreds of millions of years. Over the past decade, a growing body of knowledge has underscored the intricate connections among diet, gut microbiota, and human health. Bioactive polysaccharides (BPs) from natural sources like medicinal plants, seaweeds, and fungi have diverse biological functions including antioxidant, immunoregulatory, and metabolic activities. Their effects are closely tied to the gut microbiota, which metabolizes BPs into health-influencing compounds. Understanding how BPs and gut microbiota interact is critical for harnessing their potential health benefits. This review provides an overview of the human gut microbiota, focusing on its role in metabolic diseases like obesity, type II diabetes mellitus, non-alcoholic fatty liver disease, and cardiovascular diseases. It explores the basic characteristics of several BPs and their impact on gut microbiota. Given their significance for human health, we summarize the biological functions of these BPs, particularly in terms of immunoregulatory activities, blood sugar, and hypolipidemic effect, thus providing a valuable reference for understanding the potential benefits of natural BPs in treating metabolic diseases. These properties make BPs promising agents for preventing and treating metabolic diseases. The comprehensive understanding of the mechanisms by which BPs exert their effects through gut microbiota opens new avenues for developing targeted therapies to improve metabolic health.

Ultrasonic-assisted extraction of polysaccharide from Paeoniae Radix alba: Extraction optimization, structural characterization and antioxidant mechanism in vitro

Paeoniae Radix alba is used in Traditional Chinese Medicine for the treatment of gastrointestinal disorders, immunomodulatory, cancer, and other diseases. In the current study, the yield of Paeoniae Radix alba polysaccharide (PRP) was significantly increased with optimal ultrasound-assisted extraction compared to hot water extraction. Further, an acidic polysaccharide (PRP-AP) was isolated from PRP after chromatographic separation and was characterized as a typical pectic polysaccharide with side chains of arabinogalactans types I and II. Moreover, it showed antioxidant effects on LPS-induced damage on IPEC-J2 cells determined by qRT-PCR and ELISA, including decreasing the pro-inflammatory factors' expressions and increasing the antioxidant enzymes activities, which was shown to be related to the Nrf2/Keap1 pathway modulated by PRP-AP. The metabolites change (such as itaconate, cholesterol sulfate, etc.) detected by untargeted metabolomic analysis in cells was also shown to be modulated by PRP-AP, and these metabolites were further utilized and protected cells damaged by LPS. These results revealed the cellular active mechanism of the macromolecular PRP-AP on protecting cells, and supported the hypothesis that PRP-AP has strong benefits as an alternative dietary supplement for the prevention of intestinal oxidative stress by modulating cellular metabolism.

Lichen pectin-containing polysaccharide from Xanthoria elegans and its ability to effectively protect LX-2 cells from H2O2-induced oxidative damage

Xanthoria elegans, a drought-tolerant lichen, is the original plant of the traditional Chinese medicine "Shihua" and effectively treats a variety of liver diseases. However, thus far, the hepatoprotective effects of polysaccharides, the most important chemical constituents of X. elegans, have not been determined. The aim of this study was to screen the polysaccharide fraction for hepatoprotective activity by using free radical scavenging assays and a H2O2-induced Lieming Xu-2 cell (LX-2) oxidative damage model and to elucidate the chemical composition of the bioactive polysaccharide fraction. In the present study, three polysaccharide fractions (XEP-50, XEP-70 and XEP-90) were obtained from X. elegans by hot-water extraction, DEAE-cellulose anion exchange chromatography separation and ethanol gradient precipitation. Among the three polysaccharide fractions, XEP-70 exhibited the best antioxidant activity in free radical scavenging capacity and reducing power assays. Structural studies showed that XEP-70 was a pectin-containing heteropolysaccharide fraction that was composed mainly of (1 → 4)-linked and (1 → 4,6)-linked α-D-Glcp, (1 → 4)-linked α-D-GalpA, (1 → 2)-linked, (1 → 6)-linked and (1 → 2,6)-linked α-D-Manp, and (1 → 6)-linked and (1 → 2,6)-linked β-D-Galf. Furthermore, XEP-70 exhibited effectively protect LX-2 cells against H2O2-induced oxidative damage by enhancing cellular antioxidant capacity by activating the Nrf2/Keap1/ARE signaling pathway. Thus, XEP-70 has good potential to protect hepatic stellate cells against oxidative damage.

A review of the pharmacological action and mechanism of natural plant polysaccharides in depression

Depression is a prevalent mental disorder. However, clinical treatment options primarily based on chemical drugs have demonstrated varying degrees of adverse reactions and drug resistance, including somnolence, nausea, and cognitive impairment. Therefore, the development of novel antidepressant medications that effectively reduce suffering and side effects has become a prominent area of research. Polysaccharides are bioactive compounds extracted from natural plants that possess diverse pharmacological activities and medicinal values. It has been discovered that polysaccharides can effectively mitigate depression symptoms. This paper provides an overview of the pharmacological action and mechanisms, intervention approaches, and experimental models regarding the antidepressant effects of polysaccharides derived from various natural sources. Additionally, we summarize the roles and potential mechanisms through which these polysaccharides prevent depression by regulating neurotransmitters, HPA axis, neurotrophic factors, neuroinflammation, oxidative stress, tryptophan metabolism, and gut microbiota. Natural plant polysaccharides hold promise as adjunctive antidepressants for prevention, reduction, and treatment of depression by exerting their therapeutic effects through multiple pathways and targets. Therefore, this review aims to provide scientific evidence for developing polysaccharide resources as effective antidepressant drugs.

Gentiopicroside ameliorates CCl4-induced liver injury in mice by regulating the PPAR-γ/Nrf2 and NF-κB/IκB signaling pathways

OBJECTIVE

This study explored the mechanisms by which gentiopicroside protects against carbon tetrachloride (CCl4)-induced liver injury.

METHODS

Male mice were randomly assigned to the control; CCl4; bifendate 100 mg/kg; or gentiopicroside 25, 50, or 100 mg/kg groups. Both vehicle and drugs were administered intragastrically for 7 days. Mice were administered CCl4 intraperitoneally 1 hour after the last drug dose. After 24 hours, we collected blood and liver samples for testing.

RESULTS

Gentiopicroside significantly reduced serum alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase activities with corresponding reductions in hepatocyte denaturation and necrosis. Gentiopicroside enhanced superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and glutathione levels and reduced heme oxygenase 1 (HO-1) activity and malondialdehyde levels in the liver, and these effects were attributed to peroxisome proliferator-activated receptor (PPAR)-γ/nuclear factor erythroid 2-related factor 2 (Nrf2) activation. Meanwhile, gentiopicroside significantly downregulated HO-1 and upregulated SOD and GSH-Px at the mRNA level in the liver. Furthermore, gentiopicroside significantly suppressed serum tumor necrosis factor-α and interleukin-1β secretion, which was associated with the inhibition of nuclear factor-kappa B (NF-κB)/inhibitor of NF-κB (IκB).

CONCLUSIONS

Gentiopicroside ameliorated CCl4-induced liver injury in mice via the PPAR-γ/Nrf2 and NF-κB/IκB pathways.

Berberine protects cyclophosphamide and busulfan-induced premature ovarian insufficiency in mouse model

Premature ovarian insufficiency (POI) is a clinical syndrome that declines ovarian function in women. Berberine (BBR) is a compound with anti-inflammatory, antioxidant, and anti-apoptotic activities. However, the role of BBR on POI is still unknown. In this study, we investigated the role of BBR on ovarian function decline by establishing a POI mouse model using cyclophosphamide (CTX) and busulfan (BU). Our results showed that POI was attenuated by BBR, which was evidenced by enhanced body weight and ovarian weight, improved morphology of ovary, increased the number of healthy follicles, decreased the production of atretic follicles and restored serum hormone levels, including estradiol, anti-Müllerian hormone and follicle-stimulating hormone. In addition, we showed that germ cell function markers, mouse vasa homologue (MVH) and octamer-binding transcription factor 4 (OCT4) were enhanced by BBR, at both protein and mRNA levels. Furthermore, our results revealed that BBR inhibited inflammation and oxidative stress by reducing nuclear factor kappa B (NF-κB) and enhancing nuclear factor erythroid 2-related factor 2 (Nrf2) pathways. Taken together, we demonstrate that BBR can effectively improve ovarian function in POI mice, which is mainly mediated by reducing oxidative stress and inflammatory response. Our study also provides new strategy for POI treatment.

Relationship of Gene-Structure-Antioxidant Ability of Exopolysaccharides Derived from Lactic Acid Bacteria: A Review

Polysaccharides derived from lactic acid bacteria (LAB) have widespread industrial applications owing to their excellent safety profile and numerous biological properties. The antioxidant activity of exopolysaccharides (EPS) offers defense against disease conditions caused by oxidative stress. Several genes and gene clusters are involved in the biosynthesis of EPS and the determination of their structures, which play an important role in modulating their antioxidant ability. Under conditions of oxidative stress, EPS are involved in the activation of the nonenzyme (Keap1-Nrf2-ARE) response pathway and enzyme antioxidant system. The antioxidant activity of EPS is further enhanced by the targeted alteration of their structures, as well as by chemical methods. Enzymatic modification is the most commonly used method, though physical and biomolecular methods are also frequently used. A detailed summary of the biosynthetic processes, antioxidant mechanisms, and modifications of LAB-derived EPS is presented in this paper, and their gene-structure-function relationship has also been explored.

Structural characterizations and α-glucosidase inhibitory activities of four Lepidium meyenii polysaccharides with different molecular weights

Four polysaccharides (MCPa, MCPb, MCPc, MCPd) were obtained from Lepidium meyenii Walp. Their structures were characterized by chemical and instrumental methods including total sugar, uronic acid and protein content determination, UV, IR and NMR spectroscopy, as well as monosaccharide composition determination and methylation analyses. Four polysaccharides were a group of glucans with different molecular weights ranging from 3.12 to 14.4 kDa, and shared a similar backbone chain consisting of (1→4)-glucose linkages with branches attached to C-3 and C-6. Furthermore, bioactivity assay showed that MCPs had concentration-dependent inhibitory activity on α-glucosidase. MCPb (Mw = 10.1 kDa) and MCPc (Mw = 5.62 kDa) with moderate molecular weights exhibited higher inhibitory activity compared with MCPa and MCPd.