Dendrobium huoshanense stem polysaccharide ameliorates alcohol-induced gastric ulcer in rats through Nrf2-mediated strengthening of gastric mucosal barrier

Protection effect of Dioscoreae Rhizoma against ethanol-induced gastric injury in vitro and in vivo: A phytochemical and pharmacological study

ETHNOPHARMACOLOGICAL RELEVANCE

Dioscoreae Rhizoma, a kind of Chinese yam, is a medicinal and edible plant used in China for strengthening the spleen and stomach. However, there is a lack of modern pharmacology studies regarding its anti-gastric injury activity.

AIM OF THE STUDY

This study aimed to investigate the phytochemical composition of Chinese yam aqueous extract (CYW) and evaluate its gastroprotective effects against ethanol-induced gastric injury in vitro and in vivo.

MATERIALS AND METHODS

The active components of CYW were identified using HPLC-QTOF-MS/MS in combination with the GNPS molecular networking and network pharmacology. In vitro studies were performed in the RAW264.7/GES-1 cell coculture system. In vivo study, mice were treated with CYW (0.31, 0.63, and 3.14 g/kg BW, orally) for 14 days, followed by a single oral dose of ethanol (10 mL/kg BW) to induce gastric injury. The biochemical, inflammation and oxidative stress markers were analyzed using commercial kits. Histopathology was used to assess the degree of gastric injury. Gene and protein expressions were studied using RT-qPCR and western blotting, respectively.

RESULTS

CYW significantly restored the levels of SOD, GPx and CAT, and reduced the MDA content. Further analyses showed that CYW significantly alleviated the gastric oxidative stress by inhibiting the inflammation via decreasing p-NF-κB and p-IκB-α expression levels and inhibiting the generation of IL-6, TNF-α, and IL-1β. At the same time, the fraction remarkably upregulated Bcl-2, downregulated Bax and increased growth factor secretion, thereby prevented gastric mucous cell. Besides, The combination of HPLC-QTOF-MS/MS, GNPS molecular networking analysis, and network pharmacology demonstrated that linoleic acid, 3-acetyl-11-keto-beta-boswellic acid, adenosine, aminocaproic acid, tyramine, DL-tryptophan, cycloleucine, lactulose, melibiose, alpha-beta-trehalose, and sucrose would be the main active compounds of CYW against ethanol-induced gastric injury.

CONCLUSION

This study showed that CYW is potentially rich source of anti-oxidant and anti-inflammatory bioactive compounds. It showed efficacy against ethanol-induced gastric injury by inhibiting inflammation, oxidative stress, and apoptosis in the stomach. The results of the current work indicate that Dioscoreae Rhizoma could be utilized as a type of natural resource for production of new medicine and functional foods to prevent and/or ameliorate ethanol-induced gastric injury.

Lamivudine protects mice from gastric ulcer by activating PGK1 to suppress ferroptosis

Gastric ulcer is a highly prevalent digestive tract disease across the world, which is recurrent and hard to cure, sometimes transforming into gastric cancer if left untreated, posing great threat to human health. To develop new medicines for gastric ulcer, we ran a series of screens with ethanol stress model in GES-1 cells, and we uncovered that lamivudine rescued cells from ethanol toxicity. Then, we confirmed this discovery using the well-established ethanol-induced gastric ulcer model in mice and our findings suggest that lamivudine can directly activate phosphoglycerate kinase 1 (PGK1, EC 2.7.2.3), which binds and stimulates superoxide dismutase 1 (SOD1, EC 1.15.1.1) to inhibit ferroptosis and ultimately improve gastric ulcer. Moreover, AAV-PGK1 exhibited comparable gastroprotective effects to lamivudine. The findings are expected to offer novel therapeutic strategies for gastric ulcer, encompassing both lamivudine and AAV-PGK1.

Progress of plant-derived non-starch polysaccharides and their challenges and applications in future foods

The development of future food is devoted not only to obtaining a sustainable food supply but also to providing high-quality foods for humans. Plant-derived non-starch polysaccharides (PNPs) are widely available, biocompatible, and nontoxic and have been largely applied to the food industry owing to their mechanical properties and biological activities. PNPs are considered excellent biomaterials and food ingredients contributing to future food development. However, a comprehensive review of the potential applications of PNPs in future food has not been reported. This review summarized the physicochemical and biological activities of PNPs and then discussed the structure-activity relationships of PNPs. Latest studies of PNPs on future foods including cell-cultured meat, food for special medical purposes (FSMPs), and three-dimensional-printed foods were reviewed. The challenges and prospects of PNPs applied to future food were critically proposed. PNPs with strong thermal stability are considered good thickeners, emulsifiers, and gelatinizers that greatly improve the processing adaptability of foods. The mechanical properties of PNPs and decellularized plant-based PNPs make them desirable scaffolds for cultured meat manufacturing. In addition, the biological activities of PNPs exhibit multiple health-promoting effects; therefore, PNPs can act as food ingredients producing FSMP to promote human health. Three-dimensional printing technology enhances food structures and biological activities of functional foods, which is in favor of expanding the application scopes of PNPs in future food. PNPs are promising in future food manufacturing, and more efforts need to be made to realize their commercial applications.

The relationship between polysaccharide structure and its antioxidant activity needs to be systematically elucidated

Polysaccharides have a wide range of applications due to their excellent antioxidant activity. However, the low purity and unclear structure of polysaccharides have led some researchers to be skeptical about the antioxidant activity of polysaccharides. The current reports on the structure-activity relationship of polysaccharides are sporadic, so there is an urgent need to systematically summarize the antioxidant effects of polysaccharides with clear structures and the relationships between the structures to provide a scientific basis for the development and application of polysaccharides. This paper will systematically elucidate the structure-activity relationship of antioxidant polysaccharides, including the molecular weight, monosaccharide composition, glycosidic linkage, degree of branching, advanced conformation and chemical modification. For the first time, the antioxidant activity of polysaccharides is related to their chemical structure through histogram and radar map, and further studies using principal component analysis and cluster analysis. We critically discussed how the source, chemical structure and chemically modified groups of polysaccharides significantly contribute to their antioxidant activity and summarized the current research status and shortcomings of the structure-activity relationship of antioxidant polysaccharides. This review provides a theoretical basis and new perspective for further research on the structure-activity relationship of antioxidant polysaccharides and the development of natural antioxidants.

Insights into the molecular mechanisms, structure-activity relationships and application prospects of polysaccharides by regulating Nrf2-mediated antioxidant response

The occurrence and development of many diseases are closely related to oxidative stress. In this context, accumulating evidence suggests that Nrf2, as the master switch of cellular antioxidant signaling, plays a central role in controlling the expression of antioxidant genes. The core molecular mechanism of polysaccharides treatment of oxidative stress-induced diseases is to activate Keap1/Nrf2/ARE signaling pathway, promote nuclear translocation of Nrf2, and up-regulate the expression of antioxidant enzymes. However, recent studies have shown that other signaling pathways in which polysaccharides exert antioxidant effects, such as PI3K/Akt/GSK3β, JNK/Nrf2 and NF-κB, have complex crosstalk with Keap1/Nrf2/ARE, may have direct effects on the nuclear translocation of Nrf2. This suggests a new strategy for designing polysaccharides as modulators of Nrf2-dependent pathways to target the antioxidant response. Therefore, in this work, we investigate the crosstalk between Keap1/Nrf2/ARE and other antioxidant signaling pathways of polysaccharides by regulating Nrf2-mediated antioxidant response. For the first time, the structural-activity relationship of polysaccharides, including molecular weight, monosaccharide composition, and glycosidic linkage, is systematically elucidated using principal component analysis and cluster analysis. This review also summarizes the application of antioxidant polysaccharides in food, animal production, cosmetics and biomaterials. The paper has significant reference value for screening antioxidant polysaccharides targeting Nrf2.

Integrated Approaches Revealed the Therapeutic Mechanisms of Zuojin Pill Against Gastric Mucosa Injury in a Rat Model with Chronic Atrophic Gastritis

Background

The Zuojin Pill (ZJP) is widely used for treating chronic atrophic gastritis (CAG) in clinical practice, effectively ameliorating symptoms such as vomiting, pain, and abdominal distension in patients. However, the underlying mechanisms of ZJP in treating CAG has not been fully elucidated.

Purpose

This study aimed to clarify the characteristic function of ZJP in the treatment of CAG and its potential mechanism.

Methods

The CAG model was established by alternant administrations of ammonia solution and sodium deoxycholate, as well as an irregular diet. Therapeutic effects of ZJP on body weight, serum biochemical indexes and general condition were analyzed. HE staining and AB-PAS staining were analyzed to characterize the mucosal injury and the thickness of gastric mucosa. Furthermore, network pharmacology and molecular docking were used to predict the regulatory mechanism and main active components of ZJP in CAG treatment. RT-PCR, immunohistochemistry, immunofluorescence and Western blotting were used to measure the expression levels of apoptosis-related proteins, gastric mucosal barrier-associated proteins and PI3K/Akt signaling pathway proteins.

Results

The results demonstrated that ZJP significantly improved the general state of CAG rats, alleviated weight loss and gastric histological damage and reduced the serum biochemical indicators. Network pharmacology and molecular docking found that ZJP in treating CAG by inhibiting inflammation, suppressing apoptosis, and protecting the gastric mucosal barrier via the PI3K/Akt signaling pathway. Further experiments confirmed that ZJP obviously modulated the expression of key proteins involved in gastric mucosal cell apoptosis, such as Bax, Bad, Apaf-1, cleaved-caspase-3, cleaved-caspase-9, Cytochrome C, Bcl-2, and Bcl-xl. Moreover, ZJP significantly reversed the protein expression of Occludin, ZO-1, Claudin-4 and E-cadherin.

Conclusion

Our study revealed that ZJP treats CAG by inhibiting the PI3K/Akt signaling pathway. This research provided a scientific basis for the rational use of ZJP in clinical practice.

Licorice flavonoid ameliorates ethanol-induced gastric ulcer in rats by suppressing apoptosis via PI3K/AKT signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice is the dry roots and rhizomes of Glycyrrhiza uralensis Fisch., Glycyrrhiza glabra L. and Glycyrrhiza inflata Bat., which was first recorded in Shengnong's herbal classic. Licorice flavonoid (LF) is the main compound isolated from licorice with an indispensable action in treating gastric ulcer (GU). However, the underlying mechanisms need to be further explored.

AIM OF THE STUDY

This study aimed to investigate and further elucidate the mechanisms of LF against ethanol-induced GU using an integrated approach.

MATERIALS AND METHODS

The anti-GU effects of LF were evaluated in an ethanol-induced gastric injury rat model. Then, the metabolomics approach was applied to explore the specific metabolites and metabolic pathways. Next, the network pharmacology combined with metabolomics strategy was employed to predict the targets and pathways of LF for GU. Finally, these predictions were validated by molecular docking, RT-qPCR, and western blotting.

RESULTS

LF had a positive impact on gastric injury and regulated the expression of GU-related factors. Upon serum metabolomics analysis, 25 metabolic biomarkers of LF in GU treatment were identified, which were primarily involved in amino acid metabolism, carbohydrate metabolism, and other related processes. Subsequently, a "components-targets-metabolites" network was constructed, revealing six key targets (HSP90AA1, AKT1, MAPK1, EGFR, ESR1, PIK3CA) that may be associated with GU treatment. More importantly, KEGG analysis highlighted the importance of the PI3K/AKT pathway including key targets, as a critical route through which LF exerted its anti-GU effects. Molecular docking analyses confirmed that the core components of LF exhibited a strong affinity for key targets. Furthermore, RT-qPCR and western blotting results indicated that LF could reverse the expression of these targets, activate the PI3K/AKT pathway, and ultimately reduce apoptosis.

CONCLUSION

LF exerted a gastroprotective effect against gastric ulcer induced by ethanol, and the therapeutic mechanism may involve improving metabolism and suppressing apoptosis through the PI3K-AKT pathway.

Dendrobium huoshanense in the treatment of ulcerative colitis: Network pharmacology and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium huoshanense C. Z. Tang et S. J. Cheng (DH) is a traditional medicinal herb with a long history of medicinal use. DH has been recorded as protecting the gastrointestinal function. Modern pharmacology research shows that DH regulates intestinal flora, intestinal mucosal immunity, gastrointestinal peristalsis and secretion of digestive juices. At the same time, some studies have shown that DH has a good therapeutic effect on ulcerative colitis, but its mechanism of action has not been fully elucidated.

AIMS OF THIS STUDY

To investigate the mechanism and effect of Dendrobium huoshanense C. Z. Tang et S. J. Cheng (DH) in the treatment of ulcerative colitis (UC) by combining network pharmacology and in vivo experimental validation.

METHODS

A network pharmacology approach was used to perform component screening, target prediction, PPI network interaction analysis, GO and KEGG enrichment analysis to initially predict the mechanism of DH treatment for UC. Then, the mechanism was validated with the UC mouse model induced by 3% DSS.

RESULTS

Based on the network pharmacological analysis, a comprehensive of 101 active components were identified, with 19 of them potentially serving as the crucial elements in DH's effectiveness against UC treatment. Additionally, the study revealed 314 potential core therapeutic targets along with the top 5 key targets: SRC, STAT3, AKT1, HSP90AA1, and PIK3CA. In experiments conducted on live mice with UC, DH was found to decrease the levels of IL-6 and TNF-α in the blood, while increasing the levels of IL-10 and TGF-β. This led to notable improvements in colon length, injury severity, and an up-regulation of SRC, STAT3, HSP90AA1, PIK3CA, p-AKT1 and PI3K/AKT signaling pathway expression in the colon tissue.

CONCLUSIONS

In this study, the active components and main targets of DH for UC treatment were initially forecasted, and the potential mechanism was investigated through network pharmacology. These findings offer an experimental foundation for the clinical utilization of DH.

Rapid Discovery of Aβ42 Fibril Disintegrators from Ganoderma lucidum via Ligand Fishing and Their Neuroprotective Effects on Alzheimer's Disease

An amyloid-β (Aβ) fibril is a vital pathogenic factor of Alzheimer's disease (AD). Aβ fibril disintegrators possess great potential to be developed into novel anti-AD agents. Here, a ligand fishing method was employed to rapidly discover Aβ42 fibril disintegrators from Ganoderma lucidum using Aβ42 fibril-immobilized magnetic beads, which led to the isolation of six Aβ42 fibril disintegrators including ganodermanontriol, ganoderic acid DM, ganoderiol F, ganoderol B, ganodermenonol, and ergosterol. Neuroprotective evaluation in vitro exhibited that these Aβ42 fibril disintegrators could significantly mitigate Aβ42-induced neurotoxicity. Among these six disintegrators, ergosterol and ganoderic acid DM with stronger protecting activity were further selected to evaluate their neuroprotective effect on AD in vivo. Results showed that ergosterol and ganoderic acid DM could significantly alleviate Aβ42-induced cognitive dysfunction and hippocampus neuron loss in vivo. Moreover, ergosterol and ganoderic acid DM could significantly inhibit Aβ42-induced neuron apoptosis and Nrf2-mediated neuron oxidative stress in vitro and in vivo.

Phytochemical Profile of Alkaloid Extract from Dendrobium huoshanense and Inhibitory Effects against Oxidative Stress in H2 O2 -Induced PC12 Cells

This study aimed to explore the alkaloid profile of Dendrobium huoshanense and determine the potential protective effect against oxidative damage. The crude D. huoshanense alkaloid extract (DHAE) was obtained by 70 % ethanol extraction and liquid-liquid partition. DHAE contained specific alkaloid components with abundant 6-hydroxynobiline (58.15 %) and trace dendrobine (3.23 %) in the preliminary HPLC fingerprint and GC-MS analysis, which was distinguished from D. officinale or D. nobile. Subsequently, six alkaloids including 6-hydroxynobiline, 2-hydroxy dendrobine, nobilonine, dendrobine, Findlayines D and trans-dendrochrysanine were identified in the purified DHAE (namely DHSAE-3, DHSAE-3') via further solid phase extraction coupled with UPLC-MS/MS analysis. Meanwhile, pretreatment with DHAE or DHSAE (0.5, 5 μg/mL) increased cell viability by 14.0-57.4 % compared to that of H2 O2 -induced PC12 Model cells. Among them, 5 μg/mL DHSAE-3-treated cells displayed a pronounced reversion than the positive vitamin E (p<0.01). Furthermore, a clear cellular morphological restoration and 38.4 % reduction in intracellular reactive oxidative species level were achieved. Our findings suggest that D. huoshanense has a characteristic alkaloid profile represented by abundant 6-hydroxynobiline, and DHAEs exhibit obvious protection against oxidative neuronal damage. Overall, this study indicates that DHAEs might be used to inhibit oxidative stress and provide a source to develop novel neuroprotective drugs.

A novel Sagittaria sagittifolia L. polysaccharides mitigate DSS-induced colitis via modulation of gut microbiota and MAPK/NF-κB signaling pathways

Sagittaria sagittifolia L. polysaccharides possess anti-inflammatory, antioxidant, and immune-modulatory properties. In this study, we identified a novel S. sagittifolia L. polysaccharide, named PSSP-1, and evaluated its potential in alleviating dextran sulfate sodium (DSS)-induced colitis in a mouse model. The results demonstrated that administration of PSSP-1 at doses of 100, 200, and 400 mg/kg·bw significantly reduced the disease activity index (DAI) and suppressed the expression of inflammatory cytokines in UC mice. Furthermore, PSSP-1 treatment upregulated the expression levels of claudin-1, occludin, and ZO-1, and promoted the diversity and abundance of beneficial gut microbiota, including Lactobacillus and Candidatus_Saccharimonas, while reducing the levels of Bacteroidetes and Verrucomicrobiota. Particularly, the Lactobacillus_johnsonii species may play a potentially significant role in modulating colitis. Subsequently, there was a significant increase in the levels of short-chain fatty acids (SCFAs). Additionally, the correlation analyses revealed positive associations between PSSP-1 supplementation and Nitrosospira and Dialister, which are implicated in gut inflammation. Mechanistically, PSSP-1 intervention inhibited the protein phosphorylation of key molecules in the MAPK and NF-κB signaling pathways. Collectively, these findings suggest that PSSP-1 mitigates colitis symptoms by repairing the intestinal barrier, promoting microbial metabolism, and regulating the gut microbiota-MAPK/NF-κB signaling pathways.

Optimization of Three Extraction Methods and Their Effect on the Structure and Antioxidant Activity of Polysaccharides in Dendrobium huoshanense

Dendrobium huoshanense is a famous edible and medicinal herb, and polysaccharides are the main bioactive component in it. In this study, response surface methodology (RSM) combined with a Box-Behnken design (BBD) was used to optimize the enzyme-assisted extraction (EAE), ultrasound-microwave-assisted extraction (UMAE), and hot water extraction (HWE) conditions and obtain the polysaccharides named DHP-E, DHP-UM, and DHP-H. The effects of different extraction methods on the physicochemical properties, structure characteristics, and bioactivity of polysaccharides were compared. The differential thermogravimetric curves indicated that DHP-E showed a broader temperature range during thermal degradation compared with DHP-UM and DHP-H. The SEM results showed that DHP-E displayed an irregular granular structure, but DHP-UM and DHP-H were sponge-like. The results of absolute molecular weight indicated that polysaccharides with higher molecular weight detected in DHP-H and DHP-UM did not appear in DHP-E due to enzymatic degradation. The monosaccharide composition showed that DHPs were all composed of Man, Glc, and Gal but with different proportions. Finally, the glycosidic bond types, which have a significant effect on bioactivity, were decoded with methylation analysis. The results showed that DHPs contained four glycosidic bond types, including Glcp-(1→, →4)-Manp-(1→, →4)-Glcp-(1→, and →4,6)-Manp-(1→ with different ratios. Furthermore, DHP-E exhibited better DPPH and ABTS radical scavenging activities. These findings could provide scientific foundations for selecting appropriate extraction methods to obtain desired bioactivities for applications in the pharmaceutical and functional food industries.

The Gastroprotective Effect of Walnut Peptides: Mechanisms and Impact on Ethanol-Induced Acute Gastric Mucosal Injury in Mice

The objective of this research was to explore the protective impact of walnut peptides (WP) against ethanol-induced acute gastric mucosal injury in mice and to investigate the underlying defense mechanisms. Sixty male BALB-c mice were divided into five groups, and they were orally administered distilled water, walnut peptides (200 and 400 mg/kg bw), and omeprazole (20 mg/kg bw) for 24 days. Acute gastric mucosal injury was then induced with 75% ethanol in all groups of mice except the blank control group. Walnut peptides had significant protective and restorative effects on tissue indices of ethanol-induced gastric mucosal damage, with potential gastric anti-ulcer effects. Walnut peptides significantly inhibited the excessive accumulation of alanine aminotransferase (ALT), aspartate transferase (AST), and malondialdehyde (MDA), while promoting the expression of reduced glutathione (GSH), total antioxidant capacity (T-AOC), glutathione disulfide (GSSG), and mouse epidermal growth factor (EGF). Furthermore, the Western blot analysis results revealed that walnut peptides significantly upregulated the expression of HO-1 and NQO1 proteins in the Nrf2 signaling pathway. The defensive impact of walnut peptides on the gastric mucosa may be achieved by mitigating the excessive generation of lipid peroxides and by boosting cellular antioxidant activity.