A polysaccharide of Dendrobium officinale ameliorates H2O2-induced apoptosis in H9c2 cardiomyocytes via PI3K/AKT and MAPK pathways

5(S)-5-Carboxystrictosidine from the Root of Mappianthus iodoides Ameliorates H2O2-induced Apoptosis in H9c2 Cardiomyocytes via PI3K/AKT and ERK Pathways

5(S)-5-carboxystrictosidine (5-CS) is a compound found in the root of Mappianthus iodoides, a traditional Chinese medicine used for the treatment of coronary artery disease. The aim of the present study was to investigate the protective effect of 5-CS against oxidative stress-induced apoptosis in H9c2 cardiomyocytes and the underlying mechanisms. 5-CS pretreatment significantly protected against H2O2-induced cell death, LDH leakage, and malondialdehyde (MDA) production, which are indicators for oxidative stress injury. 5-CS also enhanced the activity of SOD and CAT. In addition, 5-CS pretreatment significantly inhibited H2O2-induced apoptosis, as determined by flow cytometer, suppressed the activity of caspase-3 and caspase-9, and attenuated the activation of cleaved caspase-3 and caspase-9. 5-CS also increased Akt and ERK activation altered by H2O2 using Western blot analysis. The PI3K-specific inhibitor LY294002 abolished 5-CS-induced Akt activation. The ERK-specific inhibitor PD98059 abolished 5-CS-induced ERK activation. Both LY294002 and PD98059 attenuated the protective effect of 5-CS on H9c2 cardiomyocytes against H2O2-induced apoptosis and cell death. Taken together, these results demonstrate that 5-CS prevents H2O2-induced oxidative stress injury in H9c2 cells by enhancing the activity of the endogenous antioxidant enzymes, inhibiting apoptosis, and modulating PI3K/Akt and ERK signaling pathways.

Critical review on the research of chemical structure, bioactivities, and mechanism of actions of Dendrobium officinale polysaccharide

Dendrobium officinale (Tie-Pi-Shi-Hu) is a precious traditional Chinese medicine (TCM). The principal active components are polysaccharides (DOP), which have a high potency in therapeutic applications. However, limitations in structure analysis and underlying mechanism investigation impede its further research. This review systemically and critically summarises current understanding in both areas, and points out the influence of starch impurities and the role of gut microbiota in DOP research. As challenges faced in studying natural polysaccharide investigations are common, this review contributes to a broader understanding of polysaccharides beyond DOP.

Dendrobium officinale polysaccharide decreases podocyte injury in diabetic nephropathy by regulating IRS-1/AKT signal and promoting mitophagy

BACKGROUNDS

High glucose (HG) caused oxidative stress and mitochondrial dysfunction, resulting in insulin resistance in podocytes, a key mechanism of diabetic nephropathy. Dendrobium officinale polysaccharide (DOP) was able to improve insulin resistance and antioxidant capability.

OBJECTIVE

The purpose of this study is to explore the mechanism by which DOP decreases the podocyte injury induced by HG.

METHODS

MPC5 cells were treated with HG, DOP, and IRS-1/2 inhibitor NT157. Afterwards, glucose consumption, generations of ROS and MDA were measured using the detection kits. Mitophagy was monitored using both MtphagTracyker and LysoTracker. The mitochondrial membrane potential was evaluated by JC-1 staining. DOP was also used in a mouse model of diabetes, with the measurements of urine albumin, blood creatinine and blood urea nitrogen.

RESULTS

Treatment with DOP suppressed the HG-induced reduction of glucose consumption, the phosphorylation of IRS-1 (phospho Y632), AKT (phospho Ser473 and Thr308) and Nephrin. In addition, HG-induced augment of ROS and MDA, formation of γ-H2A.X foci and translocation of AKT to nucleus were inhibited by DOP. DOP enhanced mitophagy, which was associated with decreased mitochondrial membrane potential and ROS production. DOP conferred protective effect on podocyte in the diabetic mouse by reducing the albumin/creatinine ratio and blood urea nitrogen, and restoring Nephrin expression in podocytes.

CONCLUSIONS

DOP alleviates HG-induced podocyte injuryby regulating IRS-1/AKT signal and promoting mitophagy.

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.

Metabolomics-Based Analysis of the Effects of Different Cultivation Strategies on Metabolites of Dendrobium officinale Kimura et Migo

Dendrobium officinale Kimura et Migo is a famous plant with a high medicinal value which has been recorded in the Chinese Pharmacopoeia (2020 Edition). The medicinal properties of D. officinale are based on its chemical composition. However, there are no reports on how different cultivation methods affect its chemical composition. In order to reveal this issue, samples of the D. officinale were collected in this study through tree epiphytic cultivation, stone epiphytic cultivation, and greenhouse cultivation. Polysaccharides were determined by phenol sulfuric acid method and secondary metabolites were detected by the UPLC-MS technique. In addition, with regards to metabolomics, we used multivariate analyses including principal component analysis (PCA) and orthogonal partial least squares analysis (OPLS-DA) to screen for differential metabolites which met the conditions of variable importance projection values >1, fold change >4, and p < 0.05. The differential metabolites were taken further for metabolic pathway enrichment analysis, which was based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and validated by antioxidant activity. Comparing the three groups of samples according to the standards of the ChP (2020 edition), the results showed that the polysaccharide content of the samples from stony epiphytic cultivation and greenhouse cultivation was significantly higher than that of the samples from live tree epiphytic cultivation. Metabolomic analysis revealed that there were 185 differential metabolites among the 3 cultivation methods, with 99 of the differential metabolites being highest in the stone epiphytic cultivation. The results of the metabolic pathway enrichment analysis showed that the different cultivation strategies mainly effected four carbohydrate metabolic pathways, five secondary metabolite synthesis pathways, six amino acid metabolic pathways, one nucleotide metabolism pathway, three cofactor and vitamin metabolism pathways, and one translation pathway in genetic information processing. Furthermore, D. officinale from stone epiphytic cultivation which had the best antioxidant activity was implicated in differential metabolite production. This study revealed the effects of different cultivation methods on the chemical composition of D. officinale and also provided a reference for establishing the quality control standards to aid its development and utilization.

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.

Cardioprotective effect of crude polysaccharide fermented by Trametes Sanguinea Lyoyd on doxorubicin-induced myocardial injury mice

Doxorubicin (DOX) is a broad-spectrum anti-tumor drug, but its clinical application is greatly limited because of the cardiotoxicity. Thus, exploration of effective therapies against DOX-induced cardiotoxicity is necessary. The aim of this study is to investigate the effects and possible mechanisms of Trametes Sanguinea Lyoyd fermented crude polysaccharide (TSLFACP) against DOX-induced cardiotoxicity. We investigated the protective effects of TSLFACP on myocardial injury and its possible mechanisms using two in vitro cells of DOX-treated cardiomyocytes H9C2 and embryonic myocardial cell line CCC-HEH-2 and a in vivo mouse model of DOX-induced myocardial injury. We found that TSLFACP could reverse DOX-induced toxicity in H9C2 and CCC-HEH-2 cells. Similarly, we found that when pretreatment with TSLFACP (200 mg/kg, i.g.) daily for 6 days, DOX-induced myocardial damage was attenuated, including the decrease in serum myocardial injury index, and the amelioration in cardiac histopathological morphology. Additionally, immunohistochemistry and western blotting were used to identify the underlying and possible signal pathways. We found that TSLFACP attenuated the expression of LC3-II, Beclin-1 and PRAP induced by DOX. In conclusion, our results demonstrated that TSLFACP could protect against DOX-induced cardiotoxicity by inhibiting autophagy and apoptosis.

Bioactivities and Mechanism of Actions of Dendrobium officinale: A Comprehensive Review

Dendrobium officinale has a long history of being consumed as a functional food and medicinal herb for preventing and managing diseases. The phytochemical studies revealed that Dendrobium officinale contained abundant bioactive compounds, such as bibenzyls, polysaccharides, flavonoids, and alkaloids. The experimental studies showed that Dendrobium officinale and its bioactive compounds exerted multiple biological properties like antioxidant, anti-inflammatory, and immune-regulatory activities and showed various health benefits like anticancer, antidiabetes, cardiovascular protective, gastrointestinal modulatory, hepatoprotective, lung protective, and neuroprotective effects. In this review, we summarize the phytochemical studies, bioactivities, and the mechanism of actions of Dendrobium officinale, and the safety and current challenges are also discussed, which might provide new perspectives for its development of drug and functional food as well as clinical applications.

Water-soluble non-starch polysaccharides of wild-simulated Dendrobium catenatum Lindley plantings on rocks and bark of pear trees

•

NSPs with antioxidant activity derived from wild-simulated D. catenatum were analyzed.

•

NSP contents depended on the cultured modes and growth periods.

•

Facility cultivation provide best growth condition but produce highest ratio of starch.

•

While wild-simulated cultivation harvest higher ratio of NSPs, especially in September.

The total water-soluble polysaccharide (TP) of Dendrobium catenatum is composed of starch and active non-starch polysaccharides (NSPs) with glucomannan as the main structural type. Although the TP content has been used as a quality assessment indicator for many years, the NSPs content in samples from different environments and growth seasons have not been reported. In this study, we found that NSPs had stronger antioxidant activity than TP. The NSPs content was higher in wild-simulated environments including rocks and trees compared to plantings grown in greenhouse. The culture mode and growth period affected the ratio of NSPs and starch. Facility cultivation provided optimal growth conditions but produced more starch, whereas wild-simulated cultivation resulted in a higher ratio of NSPs, particularly in September. Therefore, cultivation by lithophytation and epiphytation may be preferable to facility plantings, which is expected to be enormously useful for the current production and quality control of D. catenatum.

A Systematic Review on Polysaccharides from Dendrobium Genus: Recent Advances in the Preparation, Structural Characterization, Bioactive Molecular Mechanisms, and Applications

Dendrobium polysaccharides (DPSs) have aroused people's increasing attention in recent years as a result of their outstanding edible and medicinal values and non-toxic property. This review systematically summarized recent progress in the different preparation techniques, structural characteristics, modification, various pharmacological activities and molecular mechanisms, structure-activity relationships, and current industrial applications in the medicinal, food, and cosmetics fields of DPSs. Additionally, some recommendations for future investigations were provided. A variety of methods were applied for the extraction and purification of DPSs. They possessed primary structures (e.g., glucomannan, rhamnogalacturonan I type pectin, heteroxylan, and galactoglucan) and conformational structures (e.g., random coil, rod, globular, and a slight triple-helical). And different molecular weights, monosaccharide compositions, linkage types, and modifications could largely affect DPSs' bioactivities (e.g., immunomodulatory, anti-diabetic, hepatoprotective, gastrointestinal protective, antitumor, anti-inflammatory, and anti-oxidant activities). It was worth mentioning that DPSs were significant pharmaceutical remedies and therapeutic supplements especially due to their strong immunity enhancement abilities. We hope that this review will lay a solid foundation for further development and applications of Dendrobium polysaccharides.

Preparation, Structural Features and in vitro Immunostimulatory Activity of a Glucomannan From Fresh Dendrobium catenatum Stems

Dendrobium catenatum polysaccharides (DCPs) have attracted attention due to their multiple physiological activities and health benefits. In this study, a novel water-soluble DCP was obtained from fresh D. catenatum stems through three-phase partitioning and ethanol precipitation at room temperature. Its structural characteristics, rheological property, and in vitro immunostimulatory activity were evaluated. Results demonstrated that DCP was a homogenous polysaccharide with a carbohydrate content of 92.75% and a weight-average molecular weight of 2.21 × 10⁵ Da. This polysaccharide is an O-acetylated glucomannan comprised by glucose, mannose, and galacturonic acid in a molar ratio of 30.2:69.5:0.3 and mainly comprises (1→4)-β-D-mannopyranosyl (Manp), 2-O-acetyl-(1→4)-β-D-Manp, (1→6)-α-D-glucopyranosyl (Glcp), and (1→4)-α-D-Glcp residues. DCP exhibits an extended rigid chain in an aqueous solution and favorable steady shear fluid and dynamic viscoelastic behaviors. In vitro immunostimulating assays indicated that DCP activates RAW264.7 cells, thus markedly promoting macrophage proliferation and phagocytosis and increasing the levels of nitric oxide, interferon-γ, interleukin-6, and interleukin-1β. Moreover, the presence of O-acetyl group and high M_w in DCP might be responsible for its potent immunostimulatory activity in vitro. Therefore, our data suggested that DCP could be developed as a promising immunostimulant in functional food and pharmaceutical industries.

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.

Dendrobium officinale polysaccharide-induced neuron-like cells from bone marrow mesenchymal stem cells improve neuronal function a rat stroke model

Various methods have been used to induce the neuronal differentiation of marrow mesenchymal stem cells (MSCs). However, the limited induction efficiency of cells in vitro has restricted their use. Therefore, identifying a simple and efficient treatment method is necessary. Dendrobium officinale is an important traditional Chinese medicine, and its main component, polysaccharides, has many pharmacological activities. However, the effects of D. officinale polysaccharide (DOP) on the neuronal differentiation of bone marrow mesenchymal stem cells (BMSCs) and treatment of ischaemic stroke remain unknown. We found that DOP promoted the neuronal differentiation of BMSCs by increasing the expression levels of neural markers, and the optimal concentration of DOP was 25 μg/mL. Additionally, the Notch signalling pathway was inhibited during the neuronal differentiation of BMSCs induced by DOP, and this effect was strengthened using an inhibitor of this pathway. The Wnt signalling pathway was activated during the differentiation of BMSCs, and inhibition of the Wnt signalling pathway downregulated the expression of neuronal genes. Furthermore, the transplantation of neuron-like cells induced by DOP improved neuronal recovery, as the brain infarct volume, neurologic severity scores and levels of inflammatory factors were all significantly reduced in vivo. In conclusion, DOP is an effective inducer of the neuronal differentiation of BMSCs and treatment option for ischaemic stroke.

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.

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.

Isolation, structural properties, bioactivities of polysaccharides from Dendrobium officinale Kimura et. Migo: A review

Dendrobium officinale Kimura et Migo (D. officinale) is used as herbal medicine and new food resource in China, which is nontoxic and harmless, and can be used as common food. Polysaccharide as one of the main bioactive components in D. officinale, mainly composed of glucose and mannose (Manp: Glcp = 2.01:1.00-8.82:1.00), along with galactose, xylose, arabinose, and rhamnose in different molar ratios and types of glycosidic bonds. Polysaccharides of D. officinale exhibit a variety of biological effects, including immunomodulatory, anti-tumor, gastro-protective, hypoglycemic, anti-inflammatory, hepatoprotective, and vasodilating effects. This paper presents the extraction, purification, structural characteristics, bioactivities, structure-activity relationships and analyzes gaps in the current research on D. officinale polysaccharides. In addition, based on in vitro and in vivo experiments, the possible mechanisms of bioactivities of D. officinale polysaccharides were summarized. We hope that this work may provide helpful references and promising directions for further study and development of D. officinale polysaccharides.

Effects of Various Processing Methods on the Metabolic Profile and Antioxidant Activity of Dendrobium catenatum Lindley Leaves

The metabolite profiles and antioxidant activity of Dendrobium catenatum Lindley leaf, a new functional ingredient for food product development, were evaluated in samples that had been prepared using various methods, including freeze-drying, hot-air drying, rolling before drying, steaming before drying, steaming and rolling before drying, and drying at 100, 80, and 60 °C. The concentrations of polysaccharides and flavonoids, as well as the antioxidant capacity of each sample, were determined. Furthermore, two nucleosides, four amino acids, one monoaromatic compound, and eight flavonoids were identified in dried leaves using high-performance liquid chromatography-diode array detector-electrospray ionization-multistage mass spectrometry (HPLC-DAD-ESI-MSn) and ultraviolet (UV) spectral analyses. The content of polar compounds such as cytidylic acid, arginine, tyrosine, and hydroxybenzoic acid hexose increased dramatically during hot-air-drying and rolling-before-drying treatments, while flavonol C-glycosides remained stable throughout the various treatments and drying temperatures. Rolling before drying at 100 °C was identified as the most suitable process when manufacturing tea products from D. catenatum leaves. This process resulted in a high-antioxidant-activity and visually appealing tea. This report details a potential strategy that should be applied in the manufacturing processes of high-quality products from D. catenatum leaves.

Effects of D-pinitol on myocardial apoptosis and fibrosis in streptozocin-induced aging-accelerated mice

Diabetic cardiomyopathy (DCM) causes heart failure and increases the mortality in diabetic patients. Myocardial apoptosis and fibrosis are the main features of DCM and aging. The aim is to study the underlying mechanism of D-pinitol (DP) on myocardial apoptosis and fibrosis in an elderly diabetic mouse model. The diabetic model was established by SAMP-8 mice that were injected with streptozotocin daily for five consecutive days. The mice were administrated of DP (150 mg kg^-1  day^-1 ) by gavage for 10 weeks. The common metabolic disorder indices, cardiac dysfunction, oxidative stress, myocardial apoptosis and fibrosis, and PI3K/Akt/mTOR pathway were investigated. Our findings suggested that DP has a protective effect on DCM, which may be related to regulating oxidative stress, and PI3K/Akt/mTOR pathway involving cardiac fibrosis and apoptosis. DP may be a novel clinical application in fighting against DCM. PRACTICAL APPLICATIONS: D-pinitol (DP) was found in large quantities in soybean and legume foods. DP has a variety of functions, including hypoglycemic, anti-oxidation, anti-inflammatory, cardioprotective, and anti-tumor activity. We used the streptozotocin-induced SAMP8 mice as the diabetic model and treated with DP. We found that DP can improve cardiac dysfunction and inhibits the oxidative stress, myocardial apoptosis and fibrosis. DP has a significant effect on diabetic cardiomyopathy (DCM). The molecular mechanisms are related to regulating oxidative stress, and PI3K/Akt/mTOR pathway involving cardiac fibrosis and apoptosis. DP can prevent and/or delay the onset of DCM.

Overexpression of DoUGP Enhanced Biomass and Stress Tolerance by Promoting Polysaccharide Accumulation in Dendrobium officinale

Uridine diphosphate glucose pyrophosphorylase (UDP-glucose pyrophosphorylase, UGPase), as one of the key enzymes in polysaccharide synthesis, plays important roles in the growth and development of plants. In this study, the DoUGP gene of Dendrobium officinale was overexpressed. The expression of DoUGP and genes playing roles in the same and other saccharide synthesis pathways was determined, and the total soluble polysaccharide was also tested in wild-type and transgenic seedlings. We also performed freezing and osmotic stress treatments to determine whether overexpression of DoUGP could influence stress resistance in transgenic seedlings. Results showed that mRNA expression levels of DoUGP and its metabolic upstream and downstream genes in the transgenic seedlings were increased compared to the expression of these genes in wild-type seedlings. Additionally, most CSLA genes involved in the biosynthesis of mannan polysaccharides were significantly upregulated. The total polysaccharide and mannose content of transgenic seedlings were increased compared to the content of wild type, and enhanced stress tolerance was found in the overexpressed seedlings compared to the wild type.

A review of isolation methods, structure features and bioactivities of polysaccharides from Dendrobium species

Dendrobium, orchid, is a traditional Chinese herb medicine applied extensively as tonic and precious food for thou-sands of years recorded in ancient Chinese medical book "Shen Nong's Materia Medica". It's well known that bioactivities are usually related to the ingredients' basis. Based on the previous research, Dendrobium species contain amino acid, sesquiterpenoids, alkaloids and polysaccharides. As the bioactive substances, carbohydrate shows extensive activities in antitumor, antiglycation, immune-enhancing, antivirus, antioxidant, antitumor and etc. Therefore, as the main biologically active substance, the exact structures and latent activities of polysaccharides from Dendrobium species are widely focused on. In this review, we focus on the advancements of extraction methods and diversity of structures and bioactivities of polysaccharides obtained from Dendrobium species.

Comparative metabolomic analyses of Dendrobium officinale Kimura et Migo responding to UV-B radiation reveal variations in the metabolisms associated with its bioactive ingredients

Background

Dendrobium officinale Kimura et Migo, a member of the genus Dendrobium, is a traditional Chinese medicine with high commercial value. The positive roles of UV-B radiation on active ingredient metabolism in various medicinal plants have been studied. However, the metabolic responses of D. officinale stems to UV-B treatment is largely unknown.

Methods

An untargeted metabolomics method was used to investigate the metabolic variations in D. officinale stems between the control and UV-B treatments.

Results

In total, 3,655 annotated metabolites, including 640 up- and 783 down-regulated metabolites, were identified and grouped into various primary metabolic categories. Then, a number of metabolites involved in the polysaccharide, alkaloid and flavonoid biosynthesis pathways were identified. For polysaccharide biosynthesis, several intermediate products, such as pyruvate, secologanate, tryptophan and secologanin, were significantly up-regulated by the UV-B treatment. For polysaccharide biosynthesis, many key fundamental building blocks, from the glycolysis, starch and sucrose metabolism, and fructose and mannose metabolism pathways, were induced by the UV-B treatment. For flavonoid metabolism, accumulations of several intermediate products of chalcone synthase, chalcone isomerase and flavanone 3-hydroxylase were affected by the UV-B treatment, indicating an involvement of UV-B in flavonoid biosynthesis. The UV-B induced accumulation of polysaccharides, alkaloids and flavonoids was confirmed by HPLC analysis. Our study will help to understand the effects of UV-B on the accumulation of active ingredients in D. officinale.

Protective Effect of a Novel Polysaccharide from Lonicera japonica on Cardiomyocytes of Mice Injured by Hydrogen Peroxide

Lonicera japonica is a traditional Chinese herbal medicine with antioxidation, anti-inflammatory, antibacterial, and immunoregulation functions. A method to isolate polysaccharides from Lonicera japonica (LJP) has been reported previously by our group. We also reported previously that LJP was consisted of 6 types of monosaccharides and had the characteristic absorption of typical polysaccharides. In this study, we investigated the protective effect of LJP on cardiomyocytes of mice injured by hydrogen peroxide (H2O2). The results showed that LJP can increase the cardiomyocyte viability and the activities of the enzyme (SOD, CAT, GSH-Px, AST, CPK, and LDH) in cardiomyocytes of mice injured by hydrogen peroxide. The results of intracellular ROS contents showed that a high dose (40 μg mL-1) of LJP had the best effects on protecting the cardiomyocytes of mice injured by H2O2. In addition, the measurement results of the cardiomyocyte apoptosis and the activity of caspase-3, caspase-8, and caspase-9 in cardiomyocytes confirmed this conclusion from another perspective.

Selenium supplementation protects against oxidative stress-induced cardiomyocyte cell cycle arrest through activation of PI3K/AKT

Oxidative stress significantly contributes to heart disease, and thus might be a promising target for ameliorating heart failure. Mounting evidence suggests that selenium has chemotherapeutic potential for treating heart disease due to its regulation of selenoproteins, which play antioxidant regulatory roles. Oxidative stress-induced cardiomyocyte cell cycle arrest contributes to the loss of cardiomyocytes during heart failure. The protective effects and mechanism of selenium against oxidative stress-induced cell cycle arrest in cardiomyocytes warrant further study. H9c2 rat cardiomyoblast cells were treated with hydrogen peroxide in the presence or absence of selenium supplementation. Na2SeO3 pretreatment alleviated H2O2-induced oxidative stress, increased thioredoxin reductase (TXNRD) activity and glutathione peroxidase (GPx) activity and counteracted the H2O2-induced cell cycle arrest at the S phase. These effects were accompanied by attenuation of the H2O2-induced strengthening of the G2/M-phase inhibitory system, including increased mRNA and protein levels of cyclin-dependent kinase 1 (CDK1) and decreased p21 mRNA levels. Notably, Na2SeO3 pretreatment activated the PI3K/AKT signaling pathway, and inhibition of PI3K counteracted the protective effects of selenium on H2O2-induced cell cycle arrest. We corroborated our findings in vivo by inducing oxidative stress in pig heart by feeding a selenium deficient diet, which decreased the TXNRD activity, inactivated PI3K/AKT signaling and strengthened the G2/M-phase inhibitory system. We concluded that the cardioprotective effects of selenium supplementation against oxidative stress-induced cell cycle arrest in cardiomyocytes might be mediated by the selenoprotein-associated (GPx and TXNRD) antioxidant capacity, thereby activating redox status-associated PI3K/AKT pathways, which promote cell cycle progression by targeting the G2/M phase inhibitory system. This study provides new insight into the underlying mechanisms of cardioprotection effects of selenium at the cellular level.

Protective effects of Platycodon grandiflorus polysaccharides against apoptosis induced by carbonyl cyanide 3-chlorophenylhydrazone in 3D4/21 cells

This study aimed to investigate the potential protective effects of Platycodon grandiflorus polysaccharide (PGPS) on carbonyl cyanide 3-chlorophenylhydrazone (CCCP)-induced mitochondrial apoptosis in 3D4/21 cells. Apoptosis-related indicators such as cell viability, apoptosis rate, mitochondrial membrane potential (MMP), and apoptosis-related protein were examined. Results indicated that PGPS_t can inhibit CCCP-induced cell damage, with cell-survival rate reaching 81% and apoptotic rate decreasing to 23%. Nuclear deformation was also significantly reduced in the PGPS_t group, and changes in MMP were inhibited by PGPS_t. Further analyses showed that the protein expression of Caspase-9 and Bcl-2 increased and the expression of cleaved Caspase-3 decreased, indicating that PGPS_t significantly inhibited the CCCP-induced change in apoptotic protein expression. All these results suggested that PGPS_t can antagonize 3D4/21 cell apoptosis by restoring MMP, protecting the integrity of nuclear morphology, and increasing Bcl-2 expression.

Rapid identification of Dendrobium officinale using Loop-Mediated Isothermal Amplification (LAMP) method

Dendrobium officinale is not only an ornamental plant, but also a valuable medicinal herb that is widely used in traditional Chinese medicine. However, distinguishing D. officinale from other Dendrobium species is usually a difficult task. In this study, we developed a rapid identification protocol for D. officinale using the loop-mediated isothermal amplification (LAMP) method. A set of primers were specifically designed to detect a modified internal transcribed spacer region of D. officinale at 65 °C within 40 min after adding SYBR^® Green I, which was used for the detection of D. officinale. Unlike commonly used adulterants, reaction mixtures containing D. officinale DNA changed from orange to green, and this color change was easily observed with the naked eye. Thus, this methodology can be used to accurately differentiate D. officinale from other Dendrobium species, is quick as all D. officinale samples were amplified within 40 min, and specific as samples of the adulterants were not amplified. The specificity of this LAMP-based method was confirmed by testing 17 samples of D. officinale and 32 adulterant samples from other Dendrobium species. This LAMP-based rapid identification method does not require expensive equipment or specialized techniques and can be used in field surveys for accurate and fast on-site identification.

Autophagy plays a pro-survival role against methamphetamine-induced apoptosis in H9C2 cells

Methamphetamine (METH) is a commonly abused psychostimulant that can induce severe neurotoxicity. Cardiovascular injury caused by METH has recently gained increasing attention; however, the underlying mechanisms remain unclear. As autophagy has been shown to be associated with cell injury, the association between autophagy and METH-mediated cell apoptosis was investigated in the present study. METH treatment significantly increased the expression of two key autophagy proteins, i.e., Beclin-1 and LC3-II, in the cardiomyocyte cell line H9C2. Furthermore, according to western blot and flow cytometry analyses, METH contributed to cell injury and markedly enhanced cleaved-caspase 3 and PARP expression. In addition, the corresponding AKT-mTOR survival pathway axis was appeared deactivated. The autophagic activity was closely associated with METH-mediated cell injury because rapamycin, which is an autophagy inducer, markedly attenuated METH-induced cell injury, while 3-Methyladenine (3-MA), which is an autophagy inhibitor, and bafilomycinA1 (Baf-A1), which is a blocker of autophagosome-lysosome fusion, markedly exacerbated METH-induced cell injury. Notably, defective autophagosome-lysosome fusion might be partially involved in the METH-induced enhancement of LC3-II expression and cell injury. However, the underlying mechanisms require further investigation.

Protective effects of radish (Raphanus sativus L.) leaves extract against hydrogen peroxide-induced oxidative damage in human fetal lung fibroblast (MRC-5) cells

Natural antioxidants play a critical role in the promotion of good health for its prevention of oxidative stress. The main purpose of this study is to investigate the protective effects of radish leaves extract on the oxidative damage in human fetal lung fibroblast (MRC-5) cells. F2, a fraction of radish leaves extracts, which was fractionated by different polarity solvents and AB-8 macroporous resins column shows the best free radical scavenging ability, the highest total polyphenol contents (TPC), and the most potent protective effects on H₂O₂-induced oxidative damage in MRC-5 cells. The results indicated that pretreatment with F2 before the exposure of cells to H₂O₂ led to a significant increase in cell viability and internal antioxidant enzyme activities, and a decrease in the content of malondialdehyde (MDA). Furthermore, F2 attenuated the increase in intracellular reactive oxygen species (ROS) level and restored the loss of mitochondria membrane potential (MMP) caused by H₂O₂. In addition, pretreatment of F2 down-regulated the pro-apoptosis protein (Bax) and up-regulated the anti-apoptosis protein (Bcl-2) suggested its preliminary mechanism of protective effect. In summary, F2 from radish leaves might be used as a source of antioxidant for protecting the oxidative damage of lung.

Purification, characterization and anti-tumor activities of polysaccharides extracted from wild Russula griseocarnosa

The anti-tumor activity of a novel polysaccharide, PRG1-1, obtained from Russula griseocarnosa sporocarp was investigated in this paper. PRG1-1 has a molecular weight of 630kDa and was extracted and purified using DEAE-cellulose and gel filtration chromatography from crude polysaccharide extract of R. griseocarnosa sporocarp. PRG1-1 was composed of glucose, galactose, mannose, xylose and fructose, in a molar ratio of 66.5:29.2:3.17: 0.663:0.447, respectively. Purified PRG1-1 significantly reduced cell viability, increased the production of lactate dehydrogenase (LDH) and reactive oxygen species (ROS), and enhanced the apoptotic rate in HeLa and SiHa cells. Furthermore, after 24h of PRG1-1 exposure the expression levels of cleaved PARP and caspase-3 were increased and mitochondrial cytochrome c was induced to release to the cytosol. Collectively, our results suggested that the cytotoxicity effects of PRG1-1 on human cervical carcinoma are associated with the apoptotic pathway. These data indicate the promising potential of bioactive PRG1-1 as natural agent to inhibit tumor cell proliferation in the treatment of cervical carcinoma.