Polysaccharides of Dendrobium officinale Kimura & Migo Leaves Protect Against Ethanol-Induced Gastric Mucosal Injury via the AMPK/mTOR Signaling Pathway in Vitro and vivo

Multi-omics analysis reveals the pre-protective mechanism of Dendrobium flexicaule polysaccharide against alcohol-induced gastric mucosal injury

Dendrobium flexicaule (DF) is an endemic plant primarily found in the mountains of central China with important medicinal and edible values. In traditional Chinese medicine, DF has the effects of nourishing stomach and "Yin", and clearing heat. At present, no studies have explored the mechanisms by which Dendrobium flexicaule polysaccharides (DFP) exert pre-protect effects against alcohol-induced gastric mucosal injury. In this study, DFP (367.478 kDa) was extracted through water extraction and ethanol precipitation, and composed of mannose (79.89 %), glucose (19.05 %), xylose (0.42 %), arabinose (0.33 %), and galactose (0.31 %). A rat model of alcohol-induced gastric mucosal injury was established to evaluate the pre-protective effects of DFP. Histological analysis, using hematoxylin-eosin staining, revealed that DFP alleviated gastric mucosal congestion and redness. Furthermore, DFP downregulated the expression of IL-6, IL-1β, MPO and MDA, while upregulating the expression of PGE2, GSH and SOD. Immunofluorescence analysis demonstrated that DFP upregulated the expression of ZO-1 and Occludin, thereby improving gastric barrier function. Multi-omics analysis revealed its regulation of the complement and coagulation cascade signaling pathway, as well as the propanoate metabolism pathway. Immunohistochemical analysis further confirmed that DFP significantly down-regulated the expression of C3, VTN, F2, Serpind1, CPB2, FGA and VWF. Overall, this study offers novel insights into the pre-protective effects and mechanisms of DFP against alcohol-induced gastric mucosal injury, laying the groundwork for the development of DF based therapeutic resources.

Challenges and Strategies in the Industrial Application of Dendrobium officinale

Dendrobium officinale Kimura & Migo (D. officinale) is a well-recognized traditional Chinese medicinal herb that is both medicinal and edible. Contemporary pharmacological studies have revealed that D. officinale contains abundant bioactive compounds, including polysaccharides, flavonoids, alkaloids, and dendrobine, exhibiting diverse pharmacological properties such as antioxidant, anti-inflammatory, and immunomodulatory effects. However, the industrial application of D. officinale faces many problems, such as the scarcity of wild resources, low natural reproduction rate, and slow growth rate as well as the lack of relevant industrial standards. Nevertheless, substantial advancements, including the exploitation of artificial propagation techniques and breeding of new varieties, have been achieved in recent years. These developments have effectively addressed the challenges associated with its low natural reproduction rate and the scarcity of wild resources. This review summarizes the progress in the industrial development, seedling cultivation, and pharmacological exploration of D. officinale in recent years. Furthermore, it analyzes current research inadequacies and offers strategic solutions to enhance its application in healthcare and medicine.

Research progress on the regulatory and pharmacological mechanism of chemical components of Dendrobium

Dendrobium is a precious Chinese herbal medicine, which belongs to the genus Orchidaceae. Ancient records and modern pharmacological research show that Dendrobium has pharmacological effects such as anti-tumor, antioxidant regulating immunity and blood glucose, and anti-aging. Dendrobium contains polysaccharides, alkaloids, bibenzyl, sesquiterpenes, phenanthrene, polyphenols and other types of chemicals. Its pharmacological activity is closely related to these chemical components. For example, dendrobium extracts can achieve anti-tumor effects by inhibiting tumor cell proliferation and metastasis, promoting cell apoptosis and ferroptosis, or increasing cell sensitivity to chemotherapy drugs. It enhances immunity by regulating immune cell activity or cytokine release. In addition, it can alleviate neurodegenerative diseases by protecting nerve cells from apoptotic damage. In recent years, research reports on biologically active compounds in Dendrobium have shown a blowout growth, which makes us realize that it is meaningful to continuously update the research progress on the components and pharmacological regulatory mechanism of this traditional Chinese medicine. By classifying the collected chemical components according to different chemical structures and summarizing their pharmacological mechanisms, we investigated the current research progress of Dendrobium and provide a more comprehensive scientific foundation for the further development and clinical transformation of Dendrobium in the future.

Variations in Cold Resistance and Contents of Bioactive Compounds among Dendrobium officinale Kimura et Migo Strains

Dendrobium officinale is a valuable traditional Chinese herbal plant that is both medicinal and edible. However, the yield of wild Dendrobium officinale is limited. Adverse stress affects the growth, development, and yield of plants, among which low temperature is the primary limiting factor for introducing Dendrobium officinale to high-latitude areas and expanding the planting area. Therefore, this study aims to explore the variations in growth ability, cold resistance, and contents of bioactive compounds among different Dendrobium officinale strains. Four strains of Dendrobium officinale were selected as experimental materials and were subjected to low-temperature stress (4 °C). The agronomic traits, physiological indices, as well as the expressions of cold resistance-related genes (HSP70, DcPP2C5, DoCDPK1, and DoCDPK6) in the roots and leaves of Dendrobium officinale, were determined. The contents of bioactive compounds, including polysaccharides, flavonoids, and phenols were also measured. Compared with the other strains, Xianju had the highest seed germination and transplantation-related survival rates. Under low-temperature stress, Xianju exhibited the strongest cold resistance ability, as revealed by the changes in water contents, chlorophyll levels, electrical conductivities, enzyme activities, and expressions of the cold resistance-related genes. Additionally, the polysaccharide content of Xianju increased the most, while the stem flavonoid and leaf phenol contents were elevated in all four strains under cold treatment. Therefore, selecting excellent performing strains is expected to expand the planting area, improve the yield, and increase the economic benefits of Dendrobium officinale in high latitude areas with lower temperatures.

Boric Acid Alleviates Gastric Ulcer by Regulating Oxidative Stress and Inflammation-Related Multiple Signaling Pathways

Oxidative stress and inflammation have pivotal roles in gastric ulcer development caused by alcohol consumption. Trace element boric acid taken into the human and animal body from dietary sources displays strong antioxidant and anti-inflammatory functions. However, the mechanisms underlying these actions of boric acid remain unclear, and its effectiveness in preventing gastric lesions is unknown. Therefore, the present study was undertaken to evaluate the protective effects of boric acid in alcohol-induced gastric ulcer and elucidate its potential mechanisms. Gastric ulcer was induced by 75% oral ethanol administration in rats, and the effectiveness of prophylactic boric acid treatment at 100 mg/kg concentration was assessed by histopathological examination, ELISA assay and qRT-PCR. Gross macroscopic and histopathological evaluations revealed that boric acid alleviated gastric mucosal lesions. Boric acid decreased reactive oxygen species (ROS) and malondialdehyde (MDA) concentration and the overall oxidation state of the body while improving antioxidant status. It reduced the concentration of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). The mRNA expression of JAK2 and STAT3 was decreased while the expression of AMPK was increased with boric acid pretreatment. Moreover, Sema3A and PlexinA1 levels were elevated upon boric acid pretreatment, and homocysteine levels were reduced. Our results demonstrated that boric acid protects gastric mucosa from ethanol-induced damage by regulating oxidative and inflammatory responses. In addition, our findings suggested that the gastroprotective activity of boric acid could be attributed to its regulatory function in the IL-6/JAK2/STAT3 signaling modulated by AMPK and that Sema3A/PlxnA1 axis and homocysteine are potentially involved in this process.

Analysis of metabolic differences between Jiaosu fermented from dendrobium flowers and stems based on untargeted metabolomics

Dendrobium officinale is an important traditional Chinese medicinal herb containing bioactive polysaccharides and alkaloids. This study characterized metabolite differences between jiaosu (fermented plant product) from Dendrobium flowers versus stems using untargeted metabolomics. The jiaosu was fermented by mixed fermentation of Saccharomyces cerevisiae, Lactobacillus bulgaricus and Streptococcus thermophilus. Liquid chromatography-mass spectrometry analysis identified 476 differentially expressed metabolites between the two Jiaosu products. Key results showed downregulation of flavonoid metabolism in Dendrobium Stems Edible Plant Jiaosu (SEP) but increased flavonoid synthesis in Dendrobium Flowers Edible Plant Jiaosu (FEP), likely an antioxidant response. SEP displayed upregulation of lignin metabolites with potential antioxidant properties. The findings demonstrate significant metabolite profile differences between SEP and FEP, providing the basis for developing functional jiaosu products targeting specific health benefits.

Anti H. pylori, anti-secretory and gastroprotective effects of Thymus vulgaris on ethanol-induced gastric ulcer in Sprague Dawley rats

The objectives of the present study were to evaluate the acute toxicity, gastroprotective, therapeutic, anti-inflammatory and anti H. pylori activities of T. vulgaris total plant extract against ethanol-induced gastric ulcers in Sprague Dawley rats. Animals were divided into five groups i.e G-1 (Normal Control), Group 2 (ulcer control) were administered orally with 0.5% Carboxymethylcellulose (CMC), Group 3 (omeprazole treated) was administered orally with 20 mg/kg of omeprazole and Groups 4 and 5 (Low dose and High dose of the extract) were administered orally with 250, and 500 mg/ kg of Thymus vulgaris extract, respectively. After 1 hour, the normal group was orally administered with 0.5% CMC (5 ml/kg), whereas absolute alcohol (5ml/ kg) was orally administered to the ulcer control group, omeprazole group, and experimental groups. Stomachs were examined macroscopically and microscopically. Grossly, rats pre-treated with T. vulgaris demonstrated significantly decreased ulcer area and an increase in mucus secretion and pH of gastric content compared with the ulcer control group. Microscopy of gastric mucosa in the ulcer control group showed severe damage to gastric mucosa with edema and leukocytes infiltration of the submucosal layer. However, rats pretreated with omeprazole or Thyme vulgaris exhibited a mild to moderate disruption of the surface epithelium and lower level of edema and leukocyte infiltration of the submucosal layer. The T. vulgaris extract caused up-regulation of Hsp70 protein, down-regulation of Bax protein, and intense periodic acid Schiff uptake of the glandular portion of the stomach. Gastric mucosal homogenate of rats pre-treated with T. vulgaris exhibited significantly increased superoxide dismutase (SOD) and catalase (CAT) activities while malondialdehyde (MDA) level was significantly decreased. Based on the results showed in this study, Thymus vulgaris extract can be proposed as the safe medicinal plants for use and it has considerable gastroprotective potential via stomach epithelium protection against gastric ulcers and stomach lesions.

Dendrobium officinale Kimura & Migo polysaccharide and its multilayer emulsion protect skin photoaging

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium officinale Kimura & Migo is traditionally used to treat skin diseases, gastrointestinal diseases, and other diseases. Dendrobium officinale polysaccharides (DOP) are the main component of Dendrobium officinale that accounts for its bioactivity, which shows a variety of effects such as moisturizing, antioxidant and anti-fatigue. However, there is no comprehensive study on the effect of DOP on skin photoaging combined with in vitro and in vivo models, and its specific mechanism is still unclear.

AIM OF THE STUDY

Our study aimed to explore the effect and underlying mechanism of DOP on skin photoaging, as well as to improve the stability and transdermal absorption of DOP.

MATERIALS AND METHODS

DOP was extracted, purified and structurally characterized. In vitro HaCaT cell photoaging model was used to examine the photoprotection effect of DOP. Cell viability was detected by CCK-8; Intracellular reactive oxygen species were determined by DCFH-DA; DNA damage, cell apoptosis and cell cycle arrest were examined by flow cytocytometry. For autophagy flux detection, the adenovirus loaded with mRFP-GFP-LC3 was introduced into cells. Further, to enhance the stability and absorption of DOP, we designed and prepared the W/O/W type DOP multilayer emulsions (ME) by a two-step emulsification method. The emulsion stability, drug loading and encapsulation rate, DOP stability and DOP transdermal rate were detected. In vivo photoaging animal model was applied to compare the difference of photoaging protection effect between DOP solution and DOP ME. Specifically, skin appearance, histological change, antioxidant system, proinflammatory indicators, matrix metalloproteinases and autophagy level of skin tissues were examined and compared.

RESULTS

The results showed that DOP achieve photoaging protection by inhibiting oxidative stress, alleviating cell cycle arrest and apoptosis, and enhancing autophagy flux in photoaged HaCaT cells. The W/O/W type DOP multilayer emulsion (ME) with high encapsulation rate and strong stability was found to significantly improve the stability and transdermal absorption of DOP. In addition, our results showed that DOP (ME) remarkably improved skin condition of photoaged mice. Specifically, DOP (ME) enhanced the expression of antioxidant enzymes and autophagy and decreased the levels of pro-inflammatory factors and matrix metalloproteinases in the skin of photoaged mice as compared with DOP solution.

CONCLUSIONS

In conclusion, DOP was effective in improving skin photoaging, and the DOP multilayer emulsion we designed enhanced the stability and skin absorption of DOP, boosting DOP's protective effect against photoaging.

Preparation of Self-microemulsion Solids of Kaempferia galanga (L.) Volatile Oil and Its Effect on Rats with Gastric Ulcer

Kaempferia galanga volatile oil (KVO), the main effective component of the medicinal plant Kaempferia galanga L., possesses a variety of pharmacological activities such as anti-inflammatory, antioxidant, and anti-angiogenic activities and has therapeutic potential for gastric ulcer (GU). However, poor solubility as well as instability limits the clinical application of KVO. In this study, K. galanga volatile oil self-microemulsion solids (KVO-SSMEDDS) were prepared to improve its bioavailability and stability, and the therapeutic effects were evaluated in a rat model with GU. The ratio of oil phase, emulsifier, and co-emulsifier in the KVO-SMEDDS prescription were optimized by plotting the pseudo-ternary phase diagram with the star point design-response surface method. Based on the optimal prescription, self-microemulsifying drug delivery system (SMEDDS) was prepared as solid particles (S-SMEDDS). The prepared KVO-SSMEDDS had a rounded and non-adhesive appearance, formed an O/W emulsion after dissolution in water, and had a uniform particle size distribution with good stability and solubility. It was administered to GU model animals, and the results showed that a certain dose of KVO-SSMEDDS solution could increase the content of gastric mucosal protective factors PGE2, TGF-α, and EGF in gastric tissues and serum, and the expression of inflammatory factors IL-8 and TNF-α was downregulated. Meanwhile, the expression of the NF-κB/COX-2 pathway proteins was inhibited. In conclusion, the prepared KVO-SSMEDDS has good dispersion, solubility, and stability and has a therapeutic effect on rats with GU.

Dietary supplementation with Dendrobium officinale leaves improves growth, antioxidant status, immune function, and gut health in broilers

Background

The Dendrobium officinale leaves (DOL) is an underutilized by-product with a large biomass, which have been shown to exhibit immunomodulatory and antioxidant functions. The purpose of this research was to investigate the effects of DOL on broiler growth performance, antioxidant status, immune function, and gut health.

Methods

One hundred and ninety-two 1-day-old chicks were selected and divided into 4 groups at random, 6 replicates for each group and 8 in each. Chicks were given a basal diet supplemented with different amounts of DOL: 0% (control group, NC), 1% (LD), 5% (MD), or 10% (HD). During the feeding trial (70 days), broiler body weight, feed intake, and residual feeding were recorded. On d 70, 12 broilers from each group were sampled for serum antioxidant and immune indexes measurement, intestinal morphological analysis, as well as 16S rRNA sequencing of cecal contents and short-chain fatty acid (SCFA) determination.

Results

In comparison to the NC group, the LD group had greater final body weight and average daily gain, and a lower feed conversion ratio (p < 0.05, d 1 to 70). However, in MD group, no significant change of growth performance occurred (p > 0.05). Furthermore, DOL supplementation significantly improved the levels of serum total antioxidant capacity, glutathione peroxidase, superoxide dismutase, and catalase, but reduced the level of malondialdehyde (p < 0.05). Higher serum immunoglobulin A (IgA) content and lower cytokine interleukin-2 (IL-2) and IL-6 contents were observed in DOL-fed broilers than in control chickens (p <0.05). Compared to the NC group, duodenal villus height (VH) and villus height-to-crypt depth (VH:CD) ratio were considerably higher in three DOL supplementation groups (p < 0.05). Further, 16S rRNA sequencing analysis revealed that DOL increased the diversity and the relative abundance of cecal bacteria, particularly helpful microbes like Faecalibacterium, Lactobacillus, and Oscillospira, which improved the production of SCFA in cecal content. According to Spearman correlation analysis, the increased butyric acid and acetic acid concentrations were positively related to serum antioxidant enzyme activities (T-AOC and GSH-Px) and immunoglobulin M (IgM) level (p < 0.05).

Conclusion

Overall, the current study demonstrated that supplementing the dies with DOL in appropriate doses could enhance growth performance, antioxidant capacity, and immune response, as well as gut health by promoting intestinal integrity and modulating the cecal microbiota in broilers. Our research may serve as a preliminary foundation for the future development and application of DOL as feed additive in broiler chicken diets.

Dangshen Huangjiu prevents gastric mucosal injury and inhibits Akt/NF-κB pathway

One of the top ten tonic herbs, Dangshen is frequently found in Chinese functional foods. With the inclusion of Dangshen in the list of food and medicine substances in 2020, the Dangshen Huangjiu (DHJ) emerged. In the Bencao, it is written that Huangjiu can "open up the curved veins and thicken the stomach and intestines". Furthermore, increasing investigations have verified the protective effect of Dangshen on the gastric mucosa. Therefore, we propose the hypothesis that the stomach mucosa might be protected by the DHJ. To demonstrate that the effect of solids in Dangshen Huangjiu (DHJG) on damaged human gastric mucosal epithelial cells (GES-1) was reversed, the study used ethanol to induce injury to GES-1 and then used protein immunoblotting (western blotting) to determine the expression levels of p-Akt, p-NF-κB-p65, and NF-κB-p65 proteins in the cells. 0.04 mol L-1 MNNG (5 mL kg-1 body weight) mixed with eating disorders(2 d satiety, l d starvation, 3 d cycle) was used to further establish a chronic non-atrophic gastritis (CNAG) model in Wistar rats, at the same time, the experimental rats were given DHJ and DHJG gavage. Cellular assays confirmed that DHJG (25-100 μg mL-1) dose-dependently increased the viability of ethanol-injured GES-1 and lowered p-Akt and p-NF-κB-p65/NF-κB-p65 protein expression. Animal experiments revealed that 10 mL kg-1 and 20 mL kg-1 DHJ had no significant effect on the basic activity and gastric tissues and related biochemical indices of healthy rats; DHJ (10 mL kg-1, 20 mL kg-1) and DHJG (2.8 g kg-1, 11.4 g kg-1) resulted in some improvement in weight loss and significant improvement in gastric mucosal pathology in CNAG rats with damage. Particularly, DHJ and DHJG significantly decreased the expression of p-Akt, p-NF-κB-p65/NF-κB-p65 and Bcl-2/Bax proteins and Akt, IKKβ, IκBα and NF-κB mRNA in the gastric tissues of CNAG rats. These results showed that DHJG ameliorates ethanol-induced GES-1 cell injury; both DHJ and DHJG alleviate CNAG, and the mechanisms by which they do so may be related to DHJ and DHJG increasing the antioxidant capacity (elevating SOD, decreasing MDA), attenuating inflammatory responses (decreasing IL-1β, IL-6, and TNF-α), reversing apoptosis (reducing the Bcl-2/Bax ratio) and down-regulating gastric tissue p-Akt and p-NF-κB-p65/NF-κB-p65 protein expression as well as Akt, IKKβ, IκBα and NF-κB mRNA expression. This study indicates that the interventional effects of DHJ and DHJG in CNAG may act through the Akt/NF-κB signaling pathway.

Isolation, Structural Characteristics Analysis of a Vigna unguiculata Polysaccharide VUP80-3 and Its Protective Effect on GES-1 Cells In Vitro

Cowpea (Vigna unguiculata) is one of the main edible legume vegetables in China, and it can improve spleen and stomach function. A polysaccharide component (VUP80-3) has been isolated from V. unguiculata in this study. The average molecular weight of VUP80-3 is 6.43 × 10⁴ Da, and the main monosaccharide group is glucose. The mass ratio of monosaccharide groups in the polysaccharide was glucose:galactose:arabinose:rhamnose:xylose:mannose:fucose = 152.36:24.50:16.53:8.13:1.26:0.97:0.82. NMR analysis showed that VUP80-3 has →4)-α-D-Galp (1→ and →4)-α-D-Glcp(1→ main chain and →3,4)-β-D-Glcp(1→, →4,6)-α-D-Glcp(1→ branch chains, and the terminal sugar is α-D-Glcp(1→. Biological activity test results showed that VUP80-3 at 1000 μg·mL^-1 significantly increased the activity of ethanol injured GES-1 cells (p < 0.01) and significantly reduced reactive oxygen species (ROS) in ethanol injured GES-1 cells and inflammatory factors (IL-8, IL-1β and TNF-α,) in GES-1 cells. This compound also reduced the apoptosis rate (p < 0.05), thereby significantly reducing the oxidative damage caused by ethanol in GES-1 cells. Therefore, VUP80-3 is a potential drug to protect the gastric mucosa from damage.

Traditional uses, chemical compositions and pharmacological activities of Dendrobium: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium is a kind of medicine food homology plant. Dendrobium has long been used to strengthen "Yin" and tonify five viscera.

AIM OF THIS REVIEW

This paper presents a systematic review of the folk usage, chemical composition and pharmacological activity of Dendrobium, aiming to provide a reference for subsequent in-depth understanding and better exploitation of health food, medicine, and natural products.

MATERIALS AND METHODS

Available information about the genus Dendrobium was collected via Web of Science, PubMed, Science Direct, Scopus, APA-Psy Articles, Google Scholar, Connected Papers, Springer Search, and KNCI. The keywords for this article are Dendrobium, traditional use, chemical diversity and pharmacological activity. Use the "Dictionary of Chinese Ethnic Medicine" to provide 23 kinds of Dendrobium with medicinal value, the Latin name of Dendrobium is verified by the Flora of China (www.iplant.cn), and its species distribution and related information are collected.

RESULTS

There are 78 species of Dendrobium in China, 14 of which are endemic to China. At present, 450 compounds including sesquiterpenoids, lignans compounds, phenolic compounds, phenanthrene compounds, bibenzyls, polysaccharides and flavonoids have been isolated and identified from at least 50 species of Dendrobium. Among them, bibenzyls and polysaccharides are the main active components, phenolics and lignans are widely distributed, sesquiterpenes are the most common chemical constituents in genus Dendrobium plants. The most popular research objects are Dendrobium officinale and Dendrobium huoshanense.

CONCLUSIONS

Based on traditional folk uses, chemical composition and pharmacological studies, Dendrobium is considered a promising medicinal and edible plant with multiple pharmacological activities. In addition, a large number of clinical applications and further studies on single chemical components based on the diversity of chemical structures should be conducted, which will lay the foundation for the scientific utilization of genus Dendrobium.

Dendrobium as a new natural source of bioactive for the prevention and treatment of digestive tract diseases: A comprehensive review with future perspectives

BACKGROUND

The incidence of diseases related to the digestive tract is on the rise, with many types of complex etiologies. Dendrobium nobile Lindl. is a famous Traditional Chinese Medicine (TCM) rich in many bioactives proven to be beneficial in several health diseases related to inflammation and oxidative stress.

PURPOSE

At present, despite the availability of various therapeutic clinical drugs used for the treatment of digestive tract diseases, resistance emergence and existence of several side effects warrant for the developing of novel drugs for improved effects on digestive tract diseases.

METHODS

"Orchidaceae", "Dendrobium", "inflammation", "digestive tract", and "polysaccharide" were used as search terms to screen the literature. The therapeutic use of Dendrobium related to digestive tract diseases relative to known polysaccharides and other bioactive compounds were derived from online databases, including Web of Science, PubMed, Elsevier, Science Direct, and China National Knowledge Infrastructure, as well as relevant information on the known pharmacological actions of the listed phytochemicals.

RESULTS

To better capitalize upon Dendrobium for preventing and treating diseases related to digestive tract, this review summarizes bioactives in Dendrobium reported of potential in digestive tract diseases management and their underlying action mechanisms. Studies revealed that Dendrobium encompasses diverse classes including polysaccharides, phenolics, alkaloids, bibenzyls, coumarins, phenanthrene and steroids, with polysaccharide as the major class. Dendrobium exerts various health effects on a variety of disease related to the digestive tract. Action mechanisms involve antioxidant, anti-inflammatory, anti-apoptotic, antioxidant, anticancer, alongside the regulation of some key signaling pathways.

CONCLUSION

Overall, Dendrobium appears as a promising TCM source of bioactives that has the potential to be further developed into nutraceuticals for digestive tract diseases compared to current drug treatments. This review highlights for Dendrobium potential effects with future perspectives for needed future research to maximize the use of bioactive compounds from Dendrobium for digestive tract disease treatment. A compile of Dendrobium bioactives is also presented alongside methods for their extraction and enrichment for potential incorporation in nutraceuticals.

Dendrobium officinale polysaccharide prevents neuronal apoptosis via TET2-dependent DNA demethylation in high-fat diet-induced diabetic mice

Dendrobium officinale polysaccharide (DP) has the potential function to prevent diabetes-induced neuronal apoptosis, whereas the mechanism is not completely clear. Ten eleven translocation dioxygenase 2 (TET2) is one of the most important therapeutic target for repairing neuronal damage in diabetic mice. The aim of the present study was to investigate whether DP could prevent neuronal apoptosis by regulating TET2 in the brain of HFD-induced diabetic mice. C57BL/6J mice were randomly divided into four groups (n = 12), control group (CON), high-fat diet group (HFD, negative control), metformin group (MET, positive control), and DP group (DP). Compared with HFD group, the neuronal apoptosis of brain was significantly lower in the DP group. The levels of TET2 protein, 5-hydroxymethylcytosine (5hmC) and 5-formylcytosine (5fC) were significantly lower in the HFD group than in both the DP and CON groups in the cerebral cortex of mice. The ratio of p-AMPK/AMPK and α-KG/(fumaric acid + succinic acid) were significantly lower in the HFD group than in the other groups. The present study suggests that DP has a preventive effect on diabetes-induced neuronal apoptosis by regulating TET2 function through improving phosphorylate AMPK and mitochondrial function, thus remodeling DNA epigenetics profile of mice brain.

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

This study aimed to explore whether Dendrobium huoshanense stem polysaccharide (cDHPS) ameliorates alcohol-induced gastric ulcer (GU) through the strengthening effect of the gastric mucosal barrier in rats and its potential mechanism. In normal rats, the pretreatment of cDHPS effectively strengthened gastric mucosal barrier by increasing mucus secretion and tight junction protein expression. In GU rats, cDHPS supplementation effectively alleviated alcohol-induced gastric mucosal injury and nuclear factor κB (NF-κB)-driven inflammation by strengthening gastric mucosal barrier. Moreover, cDHPS significantly activated nuclear factor E2-related factor 2 (Nrf2) signaling and promoted antioxidant enzymes activities in both normal and GU rats. These results suggested that the pretreatment of cDHPS could strengthen gastric mucosal barrier to inhibit oxidative stress and NF-κB-driven inflammation induced gastric mucosal injury, which was likely related to the activation of Nrf2 signaling.

Modern interpretation of the traditional application of Shihu - A comprehensive review on phytochemistry and pharmacology progress of Dendrobium officinale

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) "Shihu" has a long history of medicinal use in China from some species of Dendrobium. D. officinale is a major source of "Shihu" and is widely cultivated in south of China and listed separately as "Tiepi Shihu" by the Chinese Pharmacopoeia in now time. Traditionally, D. officinale has been widely used in daily health care and the treatment of diabetes and gastrointestinal diseases.

AIM OF THIS REVIEW

In order to better develop and utilize D. officinale, we conducted this systematic review of previous studies, showed clear structure of all isolates from D. officinale together with pharmacological progress, hoping to provide references for further research and utilization. In addition, specific display of the chemical components and the research progress of related activities can help to better understand the traditional records and modern pharmaceutical applications of the plant medicine.

MATERIALS AND METHODS

Information on phytochemistry and pharmacological studies of D. officinale was collected from various scientific databases including Web of Science, SciFinder, ACS, Springer, Scopus, PubMed, ScienceDirect, Google Scholar and CNKI.

RESULTS

More than 180 compounds isolated from D. officinale, including bibenzyls, phenols, phenylpropanoids, lignans, flavonoids and polysaccharides are listed in this review. Furthermore, modern pharmacological researches such as hypoglycemia, immune regulation, antioxidant, cardiovascular regulation and gastrointestinal protection are summarized.

CONCLUSION

Based on the summary of the research work of D. officinale, we systematically show the chemical composition of the plant, and concluded the relationship of those composition with plant habitat together with the relationship between the structure of chemical components and pharmacological activity. Moreover, we suggest that some of small molecule compounds could also be quality control of D. officinale besides polysaccharides.

The protective effect of quinoa on the gastric mucosal injury induced by absolute ethanol

BACKGROUND

Gastric mucosal injury caused by ethanol is a common gastrointestinal disease. Quinoa (Chenopodium quinoa Willd.), as a nutrient-rich grain, plays a significant role in preventing and treating gastric mucosal damage. The present study aimed to explore the protective effect of quinoa on alcohol-induced gastric mucosal damage and its possible mechanism.

RESULTS

The ethanol-induced gastric mucosal injury rat model was used for in vivo experiments and H₂ O₂ -induced GES-1 cells for in vitro experiments to elucidate the protective effect of quinoa. The results show that quinoa water extract can increase the superoxide dismutase level and decrease the malondialdehyde level in vitro and in vivo. Furthermore, quinoa also reduced the bleeding point and bleeding area in rats with ethanol-induced gastric mucosal injury and improved gastric histopathological changes. H₂ O₂ significantly increased the levels of inflammatory factors in GES-1 cells, which were markedly ameliorated by quinoa water extract. Likewise, quinoa water extract regulated the protein expression levels of Nrf2, Keap1, HO-1, p-IKK, and p-NF-κB through Nrf2 and nuclear factor-κB signaling pathways, reducing the production of oxidative stress and inflammation, thereby repairing the damaged gastric mucosa.

CONCLUSION

The findings of this study demonstrated that quinoa shows protective effect against ethanol-induced gastric mucosal injury through its anti-inflammatory and anti-oxidant effects. We propose that our research will provide a reference for quinoa as a functional food. © 2022 Society of Chemical Industry.

Irbesartan reprofiling for the amelioration of ethanol-induced gastric mucosal injury in rats: Role of inflammation, apoptosis, and autophagy

BACKGROUND

Pronounced anti-inflammatory and anti-apoptotic features have been characterized for the angiotensin receptor blocker irbesartan. Yet, its effect on ethanol-induced gastropathy has not been studied. The present work explored the potential modulation of inflammatory, apoptotic, and autophagic events by irbesartan for the attenuation of ethanol-evoked gastric mucosal injury.

METHODOLOGY

Wistar rats were divided into control, control + irbesartan, ethanol, ethanol + irbesartan, and ethanol + omeprazole groups. Macroscopic examination, histopathology, immunohistochemistry, and biochemical assays were applied to examine the gastric tissues.

KEY FINDINGS

Irbesartan administration (50 mg/kg; by gavage) in ethanol-evoked gastropathy improved the gastric pathological manifestations (area of gastric lesion and ulcer index scores), histopathological changes, and microscopic damage scores. These beneficial effects were interceded by suppression of the HMGB1-associated inflammatory events and the linked downregulation of the nuclear NF-κBp65 protein expression. In the meantime, curtailing of the NLRP3 inflammasome by irbesartan was observed with consequent decline of the pro-inflammatory cytokine IL-1β. In tandem, upregulation of the antioxidant Nrf2 and the cytoprotective PPAR-γ were seen. Together, suppression of the pro-inflammatory cues and pro-oxidant signals attenuated the pro-apoptotic events as evidenced by Bcl-2 upregulation, Bax downregulation, and caspase 3 dampened activity. Regarding gastric autophagy signals, irbesartan diminished SQSTM-1/p62 accumulation and upregulated Beclin 1. This was associated with gastric AMPK/mTOR pathway activation evidenced by increased AMPK (Ser487) phosphorylation and lowered mTOR (Ser2448) phosphorylation.

CONCLUSION

Suppression of the inflammatory and apoptotic signals and upregulation of the pro-autophagy events may advocate the promising gastroprotective actions of irbesartan against ethanol-induced gastric injury.

Research progress on extraction, purification, structure and biological activity of Dendrobium officinale polysaccharides

Dendrobium officinale Kimura et Migo (D. officinale) is a traditional medicinal and food homologous plant that has been used for thousands of years in folk medicine and nutritious food. Recent studies have shown that polysaccharide is one of the main biologically active components in D. officinale. D. officinale polysaccharides possess several biological activities, such as anti-oxidant, heptatoprotective, immunomodulatory, gastrointestinal protection, hypoglycemic, and anti-tumor activities. In the past decade, polysaccharides have been isolated from D. officinale by physical and enzymatic methods and have been subjected to structural characterization and activity studies. Progress in extraction, purification, structural characterization, bioactivity, structure-activity relationship, and possible bioactivity mechanism of polysaccharides D. officinale were reviewed. In order to provide reference for the in-depth study of D. officinale polysaccharides and the application in functional food and biomedical research.

AMPK/mTOR-driven autophagy & Nrf2/HO-1 cascade modulation by amentoflavone ameliorates indomethacin-induced gastric ulcer

Gastric ulcer (GU) is a worldwide gastrointestinal disorder associated with NSAID use. Recently, amentoflavone proved to be a potent autophagy modulator, antioxidant, anti-inflammatory, and anti-apoptotic agent. Eight-week-old male Wistar rats received amentoflavone orally for 14 days at 25, 50, or 100 mg/kg/day. On day 14 of treatment, GU was induced by a single oral instillation of 100 mg/kg indomethacin, one hour after the last treatment. Amentoflavone dose-dependently alleviated indomethacin-induced GU, as demonstrated by repression of gastric mucosa pathological manifestations (ulcer index, ulcer surface area, histopathological deviations, and score) and increased ulcer inhibition percentage. These protective effects were due to the enhancement of gastric mucosa autophagy, as demonstrated by increased levels of beclin-1, MAP1LC3B, and CTSD, and reduced expression of p62 (SQSTM1). In addition, amentoflavone modulated the AMPK/mTOR pathway by increasing p-AMPK and reducing mTORC1 levels. Moreover, it hindered the redox aberrations by reducing MDA level and enhancing SOD activity, GSH level, and Nrf2/HO-1 cascade. Furthermore, a decrease in caspase-3 levels, Bax/Bcl-2 ratio and an increase in Bcl-2 expression suggest inhibition of the apoptotic process. Additionally, amentoflavone suppressed gastric mucosal inflammation by decreasing IL-1β, TNF-α, IFN-γ levels, IL-4, IL-6 mRNA expressions and MPO activity, and increasing IL-10 mRNA expresion. Therefore, amentoflavone could consider a promising natural agent protecting against indomethacin-induced GU.

Polydatin attenuates chronic alcohol consumption-induced cardiomyopathy through a SIRT6-dependent mechanism

Polydatin has attracted much attention as a potential cardioprotective agent against ischemic heart disease and diabetic cardiomyopathy. However, the effect and mechanism of polydatin supplementation on alcoholic cardiomyopathy (ACM) are still unknown. This study aimed to determine the therapeutic effect of polydatin against ACM and to explore the molecular mechanisms with a focus on SIRT6-AMP-activated protein kinase (AMPK) signaling and mitochondrial function. The ACM model was established by feeding C57/BL6 mice with an ethanol Lieber-DeCarli diet for 12 weeks. The mice received polydatin (20 mg kg^-1) or vehicle treatment. We showed that polydatin treatment not only improved cardiac function but also reduced myocardial fibrosis and dynamin-related protein 1 (Drp-1)-mediated mitochondrial fission, and enhanced PTEN-induced putative kinase 1 (PINK1)-Parkin-dependent mitophagy in alcohol-treated myocardium. Importantly, these beneficial effects were mimicked by SIRT6 overexpression but abolished by the infection of recombinant serotype 9 adeno-associated virus (AAV9) carrying SIRT6-specific small hairpin RNA. Mechanistically, alcohol consumption induced a gradual decrease in the myocardial SIRT6 level, while polydatin effectively activated SIRT6-AMPK signaling and modulated mitochondrial dynamics and mitophagy, thus reducing oxidative stress damage and preserving mitochondrial function. In summary, these data present new information regarding the therapeutic actions of polydatin, suggesting that the activation of SIRT6 signaling may represent a new approach for tackling ACM-related cardiac dysfunction.

Dendrobium officinale leaf polysaccharides ameliorated hyperglycemia and promoted gut bacterial associated SCFAs to alleviate type 2 diabetes in adult mice

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Fractions of LDOP show the hypoglycemic effect and can restore histological function of T2D mice.

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There is a difference in the anti-T2D effect between LDOP-A and LDOP-B.

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LDOP-A modulated the gut microbiota composition of T2D mice.

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LDOP-A promotes the formation of SCFAs in T2D mice, especially butyric acid.

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Compared with LDOP-B, LDOP-A shows greater potential to ameliorate T2D.

The present study aimed to explore the possible mechanisms underlying Dendrobium officinale leaf polysaccharides of different molecular weight to alleviate glycolipid metabolic abnormalities, organ dysfunction and gut microbiota dysbiosis of T2D mice. An ultrafiltration membrane was employed to separate two fractions from Dendrobium officinale leaf polysaccharide named LDOP-A and LDOP-B. Here, we present data supporting that oral administration of LDOP-A and LDOP-B ameliorated hyperglycemia, inhibited insulin resistance, reduced lipid concentration, improved β-cell function. LDOP-A with lower molecular weight exhibited improved effect on diabetes than LDOP-B, concurrent with increased levels of colonic short-chain fatty acids (SCFAs) i.e., butyrate, decreased ratio of Firmicutes to Bacteroidetes phyla, and increased abundance of the gut beneficial bacteria i.e., Lactobacillus, Bifidobacterium and Akkermansia. These results suggest that LDOP-A possesses a stronger effect in ameliorating T2D than LDOP-B which may be related to the distinct improved SCFAs levels produced by the change of intestinal flora microstructure.

Tricholoma matsutake-Derived Peptides Show Gastroprotective Effects against Ethanol-Induced Acute Gastric Injury

Acute gastric injury caused by ethanol is a frequent disorder of the gastrointestinal tract. In this study, we investigated the potential gastroprotective effects of Tricholoma matsutake-derived peptides against ethanol-triggered acute gastric injury and the associated mechanisms. Peptides SDLKHFPF and SDIKHFPF significantly attenuated the ethanol-induced decrease in GES-1 cell survival (82.39 ± 1.93 and 80.10 ± 1.08% vs 56.58 ± 1.86%), inhibited GES-1 cell apoptosis, and alleviated the ethanol-induced gastric mucosal injury (64.76 ± 3.98 and 49.29 ± 3.25%), ulcer index (3.33 ± 0.47 and 4.67 ± 0.47 vs 6.67 ± 0.47), and histopathological changes in mice. Peptide treatment inhibited the phosphorylation and nuclear translocation of nuclear factor kappa B (NF-κB), the secretion of tumor necrosis factor-α, interleukin-6, and endothelin-1. In addition, T. matsutake peptide pretreatment increased growth factor secretion, upregulated B-cell lymphoma-2, downregulated Bcl-2-associated X (Bax), and cleaved cysteinyl aspartate specific proteinase 3, thereby promoting gastric cell survival. These findings strongly suggest that T. matsutake peptides attenuate ethanol-induced inflammatory responses and apoptosis by suppressing NF-κB signaling activation, thereby enhancing gastric epithelial barrier functions.

Mechanisms of Dendrobium officinale polysaccharides in repairing gastric mucosal injuries based on mitogen-activated protein kinases (MAPK) signaling pathway

The present study aimed to investigate the protective effects and molecular mechanisms of Dendrobium officinale polysaccharides on gastric mucosal injuries. Following one week of continuous intragastric administration, a gastric mucosal injury model was established using intragastric administration of anhydrous ethanol. The area of gastric ulcer was measured, the contents of interleukin- 6 (IL-6), epidermal growth factor receptor (EGFR), and thyroid transcription factor 1 (TFF-1) in serum were detected by enzyme linked immunosorbent assay (ELISA), and the expressions of EGFR, TFF-1, IL-6, Raf-2, MAP kinase kinase 1 (MEK1), MEK2, and ERK1 in the gastric tissue were determined utilizing qPCR, Western blotting and immunohistochemistry. Simultaneously, Dendrobium officinale polysaccharides and anhydrous ethanol were added to the gastric mucosal cells (GES1) cultured in vitro, and the protective effects of Dendrobium officinale polysaccharides on cell viability was detected using Cell Counting Kit (CCK)-8. The addition of Dendrobium officinale polysaccharides markedly improved the gastric epithelial defect, inflammatory cell infiltration, and redness and swelling stemmed from gastric mucosal injuries and greatly reduced the area of gastric ulcer. The inhibition rates of gastric ulcer were 48.12 ± 2.98, 42.95 ± 1.52, and 27.96 ± 2.05% in the high, medium, and low concentration Dendrobium officinale polysaccharide groups, respectively. Dendrobium officinale polysaccharides could increase the expressions of EGFR and TFF-1 and decrease the expressions of IL-6, Raf-2, MEK1, MEK2, and ERK1. Dendrobium officinale polysaccharides could reduce the level of inflammatory factors and protect gastric mucosa by inhibiting the expression of MAPK pathway genes and proteins.

Structural characterization and immunoregulatory activity of polysaccharides from Dendrobium officinale leaves

In this study, two kinds of polysaccharides from leaves of Dendrobium officinale, namely DLP-1 and DLP-2, were obtained by hot water extraction, ethanol sedimentation, and chromatographic separation using DEAE-52 cellulose and Sephadex G-100 columns. They were composed of different monosaccharides and the content of monosaccharides varied significantly while DLP-1 (M_w 1.38 × 10⁶  Da) was mainly composed of mannose (71.69%) and glucose (22.89%), and DLP-2 (M_w 1.93 × 10⁶  Da) was constituted by rhamnose (35.05%), arabinose (24.12%), and galactose (25.65%). A triple-helical conformation was exhibited by both of them. The scanning electron microscope image of DLP-1 showed an irregular and large lamellar shape, as well as a smooth surface and a porous interior, illustrating they had an amorphous structure. In contrast, DLP-2 revealed a rough, loose, and uneven surface consisting of large sponge-like particles. Nuclear magnetic resonance analysis showed that (1→4)-β-D-Manp, (1→4)-β-D-Glcp, and (1→4)-2-O-acetyl-β-D-Manp were the main linkage types of DLP-1, whereas DLP-2 was constituted by a large amount of (1→4)-β-D-Manp, (1→4)-β-D-Glcp, and other residues. Besides, DLP-1 and DLP-2 stimulated the proliferation and phagocytic capacities of RAW 264.7 cells and improved the production of nitric oxide, interleukin-6, TNF-α, and IL-1β. These results proved that both DLP-1 and DLP-2 possessed excellent immunoregulatory bioactivities and could be functional food or adjuvant drug. PRACTICAL APPLICATIONS: The leaf of Dendrobium officinale is a by-product with huge biomass. The lack of systematic research on its chemical composition and pharmacologic effect, leading to a great waste of resources. In order to maximize the value of D. officinale, this study aimed to investigate the structural characteristics and immunologic effects of two polysaccharide fractions (DLP-1 and DLP-2) from D. officinale leaves, showing that DLP-1 and DLP-2 in D. officinale leaves could be used as anti-inflammatory agents to avoid wasting.

Advances in the regulation of natural polysaccharides on human health: The role of apoptosis/autophagy pathway

Due to the multiple biological activities of polysaccharides, their great potential as "natural drugs" for many diseases has been the subject of continuous exploration in the field of food and nutrition. Apoptosis and autophagy play a key role in mammalian growth, development and maintenance of cellular homeostasis. Recent studies suggest that apoptosis/autophagy may be the key regulatory target for the beneficial effects of polysaccharides. However, the regulation of apoptosis and autophagy by polysaccharides is not consistent in different disease models. Therefore, this review outlined the relationship between apoptosis/autophagy and some common human diseases, then discussed the role of apoptosis/autophagy pathway in the regulation of human health by polysaccharides, Furthermore, the application of visualization, imaging and multi-omics techniques was proposed in the future trend. The present review may be beneficial to accelerate our understanding of the anti-disease mechanisms of polysaccharides, and promote the development and utilization of polysaccharides.

Activation of AMPK/mTOR-driven autophagy and inhibition of NLRP3 inflammasome by saxagliptin ameliorate ethanol-induced gastric mucosal damage

AIMS

Saxagliptin, a selective/potent dipeptidyl peptidase-4 inhibitor, has revealed remarkable anti-inflammatory features in murine models of nephrotoxicity, hepatic injury, and neuroinflammation. However, its potential effect on ethanol-induced gastric mucosal injury has not been examined. Hence, the present work investigated the prospect of saxagliptin to attenuate ethanol-evoked gastric injury, with emphasis on the AMPK/mTOR-driven autophagy and NLRP3/ASC/caspase-1 pathway.

MATERIALS AND METHODS

In ethanol-induced gastropathy, the gastric tissues were examined by immunohistochemistry, immunoblotting, histopathology, and ELISA.

KEY FINDINGS

The results demonstrated that saxagliptin (10 mg/kg; by gavage) suppressed the gastric pathological signs (area of gastric ulcer and ulcer index scores), histopathologic aberrations/damage scores, without provoking hypoglycemia in rats. These protective features were attributed to the enhancement of gastric mucosal autophagy flux, as proven with increased expression of LC3-II and Beclin 1, decreased accumulation of p62 SQSTM1, and activation of the autophagy-linked AMPK/mTOR pathway by increasing the expression of p-AMPK/AMPK and decreasing the expression of the autophagy suppressor p-mTOR/mTOR signal. In tandem, saxagliptin counteracted the ethanol-induced pro-apoptotic events by downregulating Bax, upregulating Bcl2 protein, and lowering the Bax/Bcl2 ratio. Equally important, saxagliptin suppressed the NLRP3 inflammasome in the gastric tissue by lowering the expression of NLRP3, ASC, and nuclear NF-κBp65, decreasing the activity of caspase-1, and diminishing the IL-1β levels. In the same regard, saxagliptin suppressed the mucosal oxidative stress by lowering lipid peroxide levels, increasing GSH and GPx antioxidants, and activating Nrf2/HO-1 pathway.

SIGNIFICANCE

Saxagliptin may be a promising intervention against ethanol-evoked gastropathy by activating AMPK/mTOR-driven autophagy and inhibiting NLRP3 inflammasome.

Traditional Uses, Phytochemistry, Pharmacology, and Quality Control of Dendrobium officinale Kimura et. Migo

Dendrobium officinale, a well-known plant used as a medicinal and food homologous product, has been reported to contain various bioactive components, such as polysaccharides, bibenzyls, phenanthrenes, and flavonoids. It is also widely used as a traditional medicine to strengthen “Yin”, nourish heart, tonify five viscera, remove arthralgia, relieve fatigue, thicken stomach, lighten body, and prolong life span. These traditional applications are in consistent with modern pharmacological studies, which have demonstrated that D. officinale exhibits various biological functions, such as cardioprotective, anti-tumor, gastrointestinal protective, anti-diabetes, immunomodulatory, anti-aging, and anti-osteoporosis effects. In this review, we summarize the research progress of D. officinale from November 2016 to May 2021 and aim to better understand the botany, traditional use, phytochemistry, and pharmacology of D. officinale, as well as its quality control and safety. This work presents the development status of D. officinale, analyzes gaps in the current research on D. officinale, and raises the corresponding solutions to provide references and potential directions for further studies of D. officinale.

Autophagy in Gastric Mucosa: The Dual Role and Potential Therapeutic Target

The incidence of stomach diseases is very high, which has a significant impact on human health. Damaged gastric mucosa is more vulnerable to injury, leading to bleeding and perforation, which eventually aggravates the primary disease. Therefore, the protection of gastric mucosa is crucial. However, existing drugs that protect gastric mucosa can cause nonnegligible side effects, such as hepatic inflammation, nephritis, hypoacidity, impotence, osteoporotic bone fracture, and hypergastrinemia. Autophagy, as a major intracellular lysosome-dependent degradation process, plays a key role in maintaining intracellular homeostasis and resisting environmental pressure, which may be a potential therapeutic target for protecting gastric mucosa. Recent studies have demonstrated that autophagy played a dual role when gastric mucosa exposed to biological and chemical factors. More indepth studies are needed on the protective effect of autophagy in gastric mucosa. In this review, we focus on the mechanisms and the dual role of various biological and chemical factors regulating autophagy, such as Helicobacter pylori, virus, and nonsteroidal anti-inflammatory drugs. And we summarize the pathophysiological properties and pharmacological strategies for the protection of gastric mucosa through autophagy.

Effects of Macroporous Resin Extract of Dendrobium officinale Leaves in Rats with Hyperuricemia Induced by Fructose and Potassium Oxonate

AIM AND OBJECTIVE

Fructose, as a ubiquitous monosaccharide, can promote ATP consumption and elevate circulating uric acid (UA) levels. Our previous studies confirmed that the macroporous resin extract of Dendrobium officinale leaves (DoMRE) could reduce the UA level of rats with hyperuricemia induced by a high-purine diet. This study aimed to investigate whether DoMRE had a UA-lowering effect on rats with hyperuricemia caused by fructose combined with potassium oxonate, so as to further clarify the UA-lowering effect of DoMRE, and to explore the UA-lowering effect of DoMRE on both UA production and excretion.

MATERIALS AND METHODS

Rats with hyperuricemia induced by fructose and potassium oxonate were administered with DoMRE and vehicle control, respectively, to compare the effects of the drugs. At the end of the experiment, the serum uric acid (SUA) and creatinine (Cr) levels were measured using an automatic biochemical analyzer, the activities of xanthine oxidase (XOD) were measured using an assay kit, and the protein expression of urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), and ATP-binding cassette superfamily G member 2 (ABCG2) were assessed using immunohistochemical and western blot analyses. Hematoxylin and eosin staining was used to assess the histological changes in the kidney, liver, and intestine.

RESULTS

Rats with hyperuricemia were induced by fructose and potassiumFructose and potassium induced hyperuricemia in rats. Meanwhile, the activities of XOD were markedly augmented, the expression of URAT1 and GLUT9 was promoted, and the expression of ABCG2 was reduced, which were conducive to the elevation of UA. However, exposure to DoMRE reversed these fructose- and potassium oxonate-induced negative alternations in rats. The activities of XOD were recovered to the normal level, reducing UA formation; the expression of URAT1, ABCG2, and GLUT9 returned to the normal level, resulting in an increase in renal urate excretion.

CONCLUSION

DoMRE reduces UA levels in rats with hyperuricemia induced by fructose combined with potassium oxonate by inhibiting XOD activity and regulating the expression of ABCG2, URAT1, and GLUT9. DoMRE is a potential therapeutic agent for treating hyperuricemia through inhibiting UA formation and promoting UA excretion.

Dendrobium officinale polysaccharide triggers mitochondrial disorder to induce colon cancer cell death via ROS-AMPK-autophagy pathway

The homeostasis between mitochondrial function and autophagy is crucial to the physiological activity of cancer cells, and its mechanism is conducive to the development of anti-tumor drugs. Here, we aimed to explore the effect and mechanism of Dendrobium officinale polysaccharide (DOP) on colon cancer cell line CT26. Our data showed that DOP significantly inhibited the proliferation of CT26 cells and elevated autophagy level. Moreover, DOP disrupted mitochondrial function through increasing reactive oxygen species (ROS) and reducing mitochondrial membrane potential (MMP), thereby impairing ATP biosynthesis, which activated AMPK/mTOR autophagy signaling. Intriguingly, the further experiments demonstrated that DOP-induced cytotoxicity, excessive autophagy and mitochondrial dysfunction were reversed after CT26 cells pretreated with antioxidant (N-acetyl-l-cysteine). Herein, these findings implied that DOP-induced mitochondrial dysfunction and cytotoxic autophagy repressed the propagation of CT26 cells via ROS-ATP-AMPK signaling, providing a new opinion for the study of antineoplastic drugs.

Qihu Preparation Ameliorates Diabetes by Activating the AMPK Signaling Pathway in db/db Mice

PURPOSE

To examine the pharmacological effects of Qihu on type 2 diabetes mellitus using db/db mice.

MATERIALS AND METHODS

Thirty-seven db/db mice were randomly divided into the following 5 groups: diabetes model control group (DM group; n = 7), administered with the adjuvant 0.3% carboxymethyl cellulose-Na; positive control group (Met group; n = 8), administered with metformin (0.13 g/kg bodyweight); Qihu-L group (n = 7), administered with a low dose of Qihu (0.75 g/kg bodyweight), Qihu-M group (n = 7), administered with a medium dose of Qihu (1.5 g/kg bodyweight); Qihu-H group (n = 8), administered with a high dose of Qihu (3.0 g/kg bodyweight). BKS mice (n = 8) were used as the negative control group. The db/db mice were administered with drugs through oral gavage for 28 days. The random blood glucose levels, glucose tolerance test, bodyweight, food intake, and blood lipid levels of the mice were measured during the experimental period. The liver and pancreas tissues were collected for pathological, quantitative real-time polymerase chain reaction, and Western blotting analyses.

RESULTS

Compared with the DM group, the Qihu groups exhibited decreased bodyweight gain. The blood glucose levels in the Qihu-L, Qihu-M, and Qihu-H were 31.46%, 43.73%, and 51.83%, respectively, lower than those in the DM group. The triglyceride levels were significantly downregulated and the swelling and steatosis of the hepatocytes were significantly lower in the Qihu-M and Qihu-H groups than in the DM group. Qihu downregulated the expression of IL-1β, IL-6, and TXNIP and upregulated the AMP-activated protein kinase (AMPK) signaling pathway in the pancreas and liver tissues of db/db mice.

CONCLUSION

The anti-diabetic effects of Qihu are mediated through the activation of the AMPK/Txnip signaling and the downregulation of the secretion of inflammatory factors in db/db mice.