Dynamic Double-Networked Hydrogels by Hybridizing PVA and Herbal Polysaccharides: Improved Mechanical Properties and Selective Antibacterial Activity

Chinese herbal medicine has offered an enormous source for developing novel bio-soft materials. In this research, the natural polysaccharide isolated from the Chinese herbal medicine Dendrobium was employed as the secondary building block to fabricate a "hybrid" hydrogel with synthetic poly (vinyl alcohol) (PVA) polymers. Thanks to the presence of mannose units that contain cis-diol motifs on the chain of the Dendrobium polysaccharides, efficient crosslinking with the borax is allowed and reversible covalent borate ester bonds are formed. Eventually, highly dynamic and double-networked hydrogels were successfully prepared by the integration of Dendrobium polysaccharides and PVA. Interestingly, the introduction of polysaccharides has given rise to more robust and dynamic hydrogel networks, leading to enhanced thermal stability, mechanical strength, and tensile capacity (>1000%) as well as the rapid self-healing ability (<5 s) of the "hybrid" hydrogels compared with the PVA/borax single networked hydrogel. Moreover, the polysaccharides/PVA double network hydrogel showed selective antibacterial activity towards S. aureus. The reported polysaccharides/PVA double networked hydrogel would provide a scaffold to hybridize bioactive natural polysaccharides and synthetic polymers for developing robust but dynamic multiple networked hydrogels that are tailorable for biomedical applications.

Untargeted metabonomics and TLR4/ NF-κB signaling pathway analysis reveals potential mechanism of action of Dendrobium huoshanense polysaccharide in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is marked by hepatic steatosis accompanied by an inflammatory response. At present, there are no approved therapeutic agents for NAFLD. Dendrobium Huoshanense polysaccharide (DHP), an active ingredient extracted from the stems of Dendrobium Huoshanense, and exerts a protective effect against liver injury. However, the therapeutic effects and mechanisms of action DHP against NAFLD remain unclear. DHP was extracted, characterized, and administered to mice in which NAFLD had been induced with a high-fat and high-fructose drinking (HFHF) diet. Our results showed that DHP used in this research exhibits the characteristic polysaccharide peak with a molecular weight of 179.935 kDa and is composed primarily of Man and Glc in a molar ratio of 68.97:31.03. DHP treatment greatly ameliorated NAFLD by significantly reducing lipid accumulation and the levels of liver function markers in HFHF-induced NAFLD mice, as evidenced by decreased serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC) and total triglyceride (TG). Furthermore, DHP administration reduced hepatic steatosis, as shown by H&E and Oil red O staining. DHP also inhibited the Toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling pathway expression, thereby reducing levels of hepatic proinflammatory cytokines. Besides, untargeted metabolomics further indicated that 49 metabolites were affected by DHP. These metabolites are strongly associated the metabolism of glycine, serine, threonine, nicotinate and nicotinamide, and arachidonic acid. In conclusion, DHP has a therapeutic effect against NAFLD, whose underlying mechanism may involve the modulation of TLR4/NF-κB, reduction of inflammation, and regulation of the metabolism of glycine, serine, threonine, nicotinate and nicotinamide metabolism, and arachidonic acid metabolism.

Protective Effects and Mechanism of Polysaccharides from Edible Medicinal Plants in Alcoholic Liver Injury: A Review

Alcohol use accounts for a large variety of diseases, among which alcoholic liver injury (ALI) poses a serious threat to human health. In order to overcome the limitations of chemotherapeutic agents, some natural constituents, especially polysaccharides from edible medicinal plants (PEMPs), have been applied for the prevention and treatment of ALI. In this review, the protective effects of PEMPs on acute, subacute, subchronic, and chronic ALI are summarized. The pathogenesis of alcoholic liver injury is analyzed. The structure-activity relationship (SAR) and safety of PEMPs are discussed. In addition, the mechanism underlying the hepatoprotective activity of polysaccharides from edible medicinal plants is explored. PEMPs with hepatoprotective activities mainly belong to the families Orchidaceae, Solanaceae, and Liliaceae. The possible mechanisms of PEMPs include activating enzymes related to alcohol metabolism, attenuating damage from oxidative stress, regulating cytokines, inhibiting the apoptosis of hepatocytes, improving mitochondrial function, and regulating the gut microbiota. Strategies for further research into the practical application of PEMPs for ALI are proposed. Future studies on the mechanism of action of PEMPs will need to focus more on the utilization of multi-omics approaches, such as proteomics, epigenomics, and lipidomics.

Transcriptomic responses to cold stress in Dendrobium huoshanense C.Z. Tang et S.J. Cheng

Dendrobium huoshanense C.Z. Tang et S.J. Cheng is a perennial epiphytic herb of the family Orchidaceae. The main metabolites of D. huoshanense include polysaccharides and flavonoids. Low temperature is the main environmental factor that limits the growth and development of plants. However, changes that occur at the molecular level in response to low temperatures in D. huoshanense are poorly understood. We performed a transcriptome analysis at two time points of 0 d (control group) and 7 d (cold stress group) under culture of D. huoshanense at 4 °C. A total of 37.63 Gb transcriptomic data were generated using the MGI 2000 platform. These reads were assembled into 170,754 transcripts and 23,724 differentially expressed genes (DEGs) were obtained. Pathway analysis indicated that "flavonoid biosynthesis," "anthocyanin biosynthesis," "flavone and flavonol biosynthesis," and "plant hormone signal transduction" might play a vital role in the response of D. huoshanense to cold stress. Several important pathway genes were identified to be altered under cold stress, such as genes encoding polysaccharides, flavonoids, and plant hormone-signaling transduction kinase. In addition, the content of mannose and total flavonoids increased under cold stress. Twelve DEGs related to polysaccharides, flavonoid, and hormone pathways were selected from the transcriptome data for validation with real-time quantitative PCR (RT-qPCR). Our results provide a transcriptome database and candidate genes for further study of the response of D. huoshanense to cold stress.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-023-01385-7.

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.

Curcumin/cyclodextrin polymer inclusion complex attenuates ethanol-induced liver injury by inhibition of DNA damage in mice

This study was to examine the protective effects of curcumin/cyclodextrin polymer inclusion complex (CUR/CDP) on ethanol-induced liver injury in mice and to explore its potential mechanisms. In the ethanol-induced acute injury mouse model, the effects of pretreatment with silymarin, cyclodextrin polymer (CDP), curcumin (CUR) and CUR/CDP at low, middle, and high doses were evaluated by biochemical and histopathological examination. The liver index, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) levels in serum of the mice were measured. The superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) activities, and malondialdehyde (MDA) level in liver tissue were assessed by assay kits. Moreover, hematoxylin-eosin (HE) staining was carried out to observe pathological changes of liver. Western blotting was performed for determining the changes in the expressions of DNA damage-associated proteins. The results showed that compared with the control group, the liver index and the levels of ALT, AST, LDH, and MDA in the ethanol treatment group were significantly increased and the activities of GSH-Px and SOD were obviously decreased. However, pretreatment with silymarin, CUR, and CUR/CDP reversed the change of above indicators except CDP. Moreover, CUR/CDP at high dose further weakened the liver index, inhibited the biochemical indexes, and enhanced the activities of antioxidant enzymes to a greater extent than silymarin and CUR. Western blot analysis indicated that CUR/CDP significantly down-regulated the expressions of DNA damage-related proteins including p-ATM, γ-H2AX, p-p53, and p-p38MAPK, which inhibited ethanol-induced the G2/M arrest and ultimately prevented liver function from oxidative stress injury. These results indicated that CUR/CDP possessed good protective effect on mice liver damage in vivo by increasing the activities of GSH-Px and SOD to suppress DNA damage.

Alleviation of Alcoholic Fatty Liver by Dendrobium officinale Flower Extracts due to Regulation of Gut Microbiota and Short-Chain Fatty Acids in Mice Exposed to Chronic Alcohol

Alcoholic fatty liver disease (AFLD) is caused by long-term heavy alcohol consumption; therefore, useful and practical methods for the prevention of AFLD are urgently needed. The edible flower of Dendrobium officinale contains diverse flavonoids, and has shown antioxidant activity as well as antihypertensive and anti-inflammatory effects. In this study, an AFLD model was established, the protective effect of D. officinale flower (DOF) ethanol extract on AFLD was evaluated, and its mechanisms were investigated by analyzing gut microbiota and short-chain fatty acids (SCFAs). DOF extract (DOFE) supplementation promoted alcohol metabolism, restored hepatic antioxidant capacity, alleviated oxidative stress, reduced inflammatory factor levels, and inhibited dyslipidemia induced by alcohol intake in chronic alcohol-exposed mice, especially in the high DOFE group. Moreover, DOFE supplementation increased the diversity, structure, and composition of the gut microbiota in mice, restored some of the abnormal SCFA levels caused by AFLD, and helped restore intestinal function. DOFE supplementation significantly increased the relative abundance of Akkermansia, suggesting that Akkermansia may be a potential target of the protective effect of DOFE. Therefore, DOFE supplementation to improve the composition of the gut microbiota may be an effective therapeutic strategy for the prevention of AFLD.

Dendrobium and its active ingredients: Emerging role in liver protection

Dendrobium is a traditional medicinal plant, which has a variety of clinical applications in China. It has been reported that Dendrobium contains various bioactive components, mainly including polysaccharides and alkaloids. Previous studies have shown that Dendrobium has pharmacological activities including antiviral, anti-inflammatory, and antioxidant effects, as well as immune regulation. Particularly, the anti-aging functions and neuroprotective effects of Dendrobium have been well characterized in a wide array of cell and animal models. In recent years, the effect of Dendrobium on the liver has emerged as a new direction to explore its therapeutic benefits and has received more and more attention. This review is focused on the beneficial effects of Dendrobium on liver toxicity and various liver disorders, which presumably are attributed to a consequence of an array of modes of action due to its multiple bioactive components, and largely lack mechanistic and pharmacokinetic characterization. A particular emphasis is placed on the potential action mechanisms related to Dendrobium's liver protection. Research perspectives in regard to the potential therapeutic application for Dendrobium are also discussed in this review.

Dendrobium huoshanense C.Z.Tang et S.J.Cheng: A Review of Its Traditional Uses, Phytochemistry, and Pharmacology

Dendrobium huoshanense, a traditional medicinal and food homologous plant, belongs to the family Orchidaceae and has a long history of medicinal use. It is reported that the stem of D. huoshanense has a variety of bioactive ingredients such as polysaccharides, flavonoids, sesquiterpenes, phenols, etc. These bioactive ingredients make D. huoshanense remarkable for its pharmacological effects on anti-tumor, immunomodulation, hepatoprotective, antioxidant, and anticataract activities. In recent years, its rich pharmacological activities have attracted extensive attention. However, there is no systematic review focusing on the chemical compositions and pharmacological effects of D. huoshanense. Therefore, the present review aims to summarize current research on the chemical compositions and pharmacological activities of D. huoshanense. This study provides valuable references and promising ideas for further investigations of D. huoshanense.

Comparative Proteome and Phosphoproteome Analyses Reveal Different Molecular Mechanism Between Stone Planting Under the Forest and Greenhouse Planting of Dendrobium huoshanense

The highly esteemed Chinese herb, Dendrobium huoshanense, whose major metabolites are polysaccharides and alkaloids, is on the verge of extinction. The stone planting under the forest (SPUF) and greenhouse planting (GP) of D. huoshanense are two different cultivation methods of pharmaceutical Dendrobium with significantly differences in morphology, metabolites content and composition, and medication efficacy. Here, we conducted proteomics and phosphoproteomics analyses to reveal differences in molecular mechanisms between SPUF and GP. We identified 237 differentially expressed proteins (DEPs) between the two proteomes, and 291 modification sites belonging to 215 phosphoproteins with a phosphorylation level significantly changed (PLSC) were observed. GO, KEGG pathway, protein domain, and cluster analyses revealed that these DEPs were mainly localized in the chloroplast; involved in processes such as posttranslational modification, carbohydrate transport and metabolism, and secondary metabolite biosynthesis; and enriched in pathways mainly including linoleic acid metabolism, plant-pathogen interactions, and phenylpropanoid, cutin, suberin, and wax biosynthesis. PLSC phosphoproteins were mainly located in the chloroplast, and highly enriched in responses to different stresses and signal transduction mechanisms through protein kinase and phosphotransferase activities. Significant differences between SPUF and GP were observed by mapping the DEPs and phosphorylated proteins to photosynthesis and polysaccharide and alkaloid biosynthesis pathways. Phosphorylation characteristics and kinase categories in D. huoshanense were also clarified in this study. We analyzed different molecular mechanisms between SPUF and GP at proteomic and phosphoproteomic levels, providing valuable information for the development and utilization of D. huoshanense.

The Regulatory Roles of Polysaccharides and Ferroptosis-Related Phytochemicals in Liver Diseases

Liver disease is a global health burden with high morbidity and mortality worldwide. Liver injuries can develop into severe end-stage diseases, such as cirrhosis or hepatocellular carcinoma, without valid treatment. Therefore, identifying novel drugs may promote liver disease treatment. Phytochemicals, including polysaccharides, flavonoids, alkaloids, and terpenes, are abundant in foods and medicinal plants and have various bioactivities, such as antioxidation, immunoregulation, and tumor killing. Recent studies have shown that many natural polysaccharides play protective roles in liver disease models in vitro and in vivo, such as fatty liver disease, alcoholic liver disease, drug-induced liver injury, and liver cancer. The mechanisms of liver disease are complex. Notably, ferroptosis, a new type of cell death driven by iron and lipid peroxidation, is considered to be the key mechanism in many hepatic pathologies. Therefore, polysaccharides and other types of phytochemicals with activities in ferroptosis regulation provide novel therapeutic strategies for ferroptosis-related liver diseases. This review summarizes our current understanding of the mechanisms of ferroptosis and liver injury and compelling preclinical evidence of natural bioactive polysaccharides and phytochemicals in treating liver disease.

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.

Chlorogenic Acid Protects against Advanced Alcoholic Steatohepatitis in Rats via Modulation of Redox Homeostasis, Inflammation, and Lipogenesis

The aim of this study was to evaluate the therapeutic effects of chlorogenic acid (CGA) in rats with advanced alcoholic steatohepatitis. The rats were fed on a high-fat diet and gavaged with ethanol (4 g/kg) for 8 weeks. The livers of ethanol-treated rats showed steatosis; necrosis and mononuclear infiltration; and significant upregulation of the mRNA expression of the prooxidant (Cyp2e1, iNos), lipogenic (Srebp1, Acc), proinflammatory (Tlr4, Nf-κb, TnfA, Il-1B, and Il-6), and profibrogenic (TgfB, Col1, VegfA) genes. Simultaneously, a downregulation of level of Sod and Nrf2 was observed, which was accompanied by increased serum transaminase, TnfA, and serum and liver triglycerides levels. CGA administration (40 and 80 mg/kg, 8 weeks) to ethanol-fed group reduced the liver expression levels of Cyp2e1 and iNos, whereas it markedly enhanced the expression of Sod, Nrf2, and Ho-1. CGA at both doses downregulated the expressions of lipogenic, proinflammatory, and profibrogenic genes, while the expression of Tlr4 was lowered only after the higher dose of CGA. The higher dose of CGA efficiently prevented the progression of alcohol-induced steatosis and reduced inflammation through regulation of the expression of genes encoding the proteins involved in the Tlr4/Nf-κB signaling pathway and fibrosis. The study revealed hepatoprotective and anti-inflammatory effects of CGA through the regulation of expression of genes encoding Cyp2e1/Nrf2 involved in oxidative stress modulation. These results demonstrate CGA as a therapeutic candidate for the prevention and treatment of alcoholic steatohepatitis.

Carbonized biosorbent assisted matrix solid-phase dispersion microextraction for active compounds from functional food

In this study, mangosteen peel based activated carbon was prepared and first applied as adsorbent in matrix solid-phase dispersion (MSPD) for simultaneously extraction of flavonoids from Dendrobium huoshanense prior to their separation and determination by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF/MS). The MSPD-UHPLC-Q-TOF/MS method was validated exhaustively. Good linearities (r² ≥ 0.9929) were obtained for all target analytes. The limits of detection was in the range of 0.00387-0.159 μg/g. Satisfactory recoveries of six target compounds were between 80.02 and 99.49% and 85.32-99.86% for the low and high spiked level, respectively. Furthermore, relative to other common sorbent, the prepared mangosteen peel based activated carbon was less expensive and more environmentally-friendly. Consequently, the proposed method was a simple, efficient, low-cost, eco-friendly, time-saving and sensitive approach that could be successfully applied to the extraction and determination of flavonoids compounds in complex matrix.

Dendrobium huoshanense Polysaccharides Prevent Inflammatory Response of Ulcerative Colitis Rat through Inhibiting the NF-κB Signaling Pathway

The polysaccharides of the Chinese herbal medicine Dendrobium huoshanense exhibit anti-inflammatory effects in multiple organs through regulating the immune responses. In the present study, we constructed ulcerative colitis (UC) model rats using dextran sulfate sodium to investigate the anti-inflammatory effects of D. huoshanense polysaccharides (DHP). After oral administration of DHP for two weeks, the indices of UC symptoms, including the ratio of colon weight to length, Disease Activity Index (DAI), and Colon Mucosal Damage Index (CMDI), all decreased significantly compared with the UC model group. The histological sections also revealed better cell orders in DHP treatments than in the UC model rats. Moreover, in treatment with high dose of DHP (200 mg/kg), the treatment efficacy arrived the similar levels to those in the treatment with 300 mg/kg sulfasalazine, which is a typical medicine to treat UC. These results indicated that DHP has a high efficacy to treat UC in model rats. Furthermore, serum levels of interleukin-1β, tumor necrosis factor-α, interleukin-17, and transforming growth factor-β were assessed using the enzyme linked immunosorbent assay (ELISA) method, and the levels of nuclear factor-κB in colon tissue sections were determined using the immunohistochemical method. The results showed that all these indices decreased significantly after administration of DHP in UC model rats, which might be the mechanisms underlying the DHP-suppressed UC inflammation. Overall, this study indicated that DHP might be directly used to treat UC and is a promising source to develop novel drugs against UC.

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.

Anti-aging properties of Dendrobium nobile Lindl.: From molecular mechanisms to potential treatments

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium Nobile Lindl. (DNL) is one of the central herbs in traditional Chinese medicine which mainly distributes in Guizhou, Yunnan, Guangxi and other sub-tropical areas south of the Yangtze River. In the past decades, it has been used to treat tumors, hyperglycemia, hyperlipidemia, and diseases of the nervous system that may be caused by aging.

AIM OF THE REVIEW

The purpose of this review is to summarize the anti-aging information of DNL from the molecular mechanism level, including classic theories related to aging, main chemical components, pharmacological research and anti-aging theory based on traditional Chinese medicine theory, for exploring the future development and clinical treatment.

MATERIALS AND METHODS

The information in this paper has been collected from the scientific literature databases including PubMed, Google Scholar, Web of Science, Science Direct, Springer, China National Knowledge Infrastructure, published books, Ph.D. and M.S. dissertations systematically.

RESULTS

In this paper, we have reviewed the several mechanisms underlying the potential effects of DNL on the prevention of aging, including the scavenging of free radicals for oxidation, delaying of DNA impairment, inhibition of apoptosis, and alteration of DNA methylation. Together with the theory of telomeres, this review also has summarized recent research progress in the use of DNL and its traditional efficacy.

CONCLUSIONS

We conclude that "strengthening Yin and benefiting the spirit", "thickening the intestine and stomach", "lightning the body and prolonging the life-span", and delaying aging, are key effects of DNL that can be used to combat age-related diseases (ARDs) such as Alzheimer's disease, hyperlipidemia, and diabetes. This review provides a reference for future study of ARDs and the clinical application of DNL.

Resource, chemical structure and activity of natural polysaccharides against alcoholic liver damages

Many natural polysaccharides from bio-resources hold advantages of multi-functions, high efficiency, non-toxicity or low side effect, and have strong potentials in protection against alcoholic liver damages. This review summarized the bio-resources, chemical and structural characteristics of natural polysaccharides with potentials in inhibition against alcoholic liver damages, and also emphasized knowledge on correlations between their chemical structure and function. Approximately 95 species were confirmed in generation of hepatoprotective polysaccharides. Products as crude polysaccharides originated from 17 species were sum up despite the indetermination of their accurate structure. Additional four polysaccharides were described for their known chemical structures. Possible roles of hepatoprotective polysaccharides were provided with evidence on antioxidant promotion, lipids regulation, apoptosis inhibition and anti-inflammation, as well as confirmations in immune enhancement, iron removal and anti-fibrosis when currently treated against the alcoholic liver damages. To sum up, this overview could serve to guide development and utilization of natural hepatoprotective polysaccharides.

Dendrobium officinale polysaccharides protected against ethanol-induced acute liver injury in vivo and in vitro via the TLR4/NF-κB signaling pathway

Alcohol-induced liver injury is characterized by strong inflammation. Polysaccharides separated from herbs can prevent ethanol-induced liver injury. Dendrobium officinale Kimura et Migo leaves (D. officinale) are a new food resource that contains a certain amount of polysaccharide. However, the hepatoprotective effects and the potential mechanisms of D. officinale polysaccharide (DOP) remain unknown. Thus, this study aimed to assess the hepatoprotective effects and potential mechanism in vivo and in vitro of DOP. Male Sprague-Dawley rats were used to establish alcohol-induced liver injury models through the oral gavage of absolute alcohol (5 mL/kg) after the oral administration of DOP (400 and 100 mg/kg) for 30 days. Hematoxylin-eosin staining was used for the histological assessments of hepatocyte degeneration, and the AST and ALT levels in the serum and liver tissue were measured. The inflammatory markers were evaluated using ELISA and immunohistochemistry. The potential mechanism of DOP in alcohol-induced liver cell (LO2) injury in vitro was further identified. Results showed that DOP clearly decreased the AST in the serum and hepatic tissue, obviously reduced the production of inflammatory cytokines (such as IL-1β, IL-6, and TNF-α), and can successfully inhibit NF-κB phosphorylation in vivo. In vitro experiments indicated that DOP increased the LO2 cell viability; prevented LDH release prominently; reduced the secretion of IL-1β, IL-6, and TNF-α; and reversed the expression of IL-1β, IL-6, TNF-α, caspase 1, NLRP3, p-NF-κB, and TLR4. Overall, DOP can alleviate ethanol-induced acute liver injury via the TLR4/NF-κB signaling pathway.

Chemical modifications of polysaccharides and their anti-tumor activities

With the rising trend of incidence of cancers, effective therapies are urgently needed to control human malignancies. However, the chemotherapy drugs currently on the market cause serious side effects. Polysaccharides belong to a class of biomacromolecules, which have drawn considerable research interest over the years as it possess anti-cancer activities or can increase the efficacy of conventional chemotherapy drugs with fewer side effects. The antitumor activity of many polysaccharides was significantly increased after modification. Based on these encouraging observations, a great deal of effort has been focused on discovering anti-cancer polysaccharides and modified derivatives for the development of effective therapeutics for various human cancers. This review highlights recent advances on the major chemical modification methods of polysaccharides, and discusses the effect of molecular modification on the physicochemical properties and anti-tumor activities of polysaccharides. Meanwhile, the underlying anti-tumor mechanisms of polysaccharide and its modified derivatives were also discussed.

Discrimination of Different Species of Dendrobium with an Electronic Nose Using Aggregated Conformal Predictor

A method using electronic nose to discriminate 10 different species of dendrobium, which is a kind of precious herb with medicinal application, was developed with high efficiency and low cost. A framework named aggregated conformal prediction was applied to make predictions with accuracy and reliability for E-nose detection. This method achieved a classification accuracy close to 80% with an average improvement of 6.2% when compared with the results obtained by using traditional inductive conformal prediction. It also provided reliability assessment to show more comprehensive information for each prediction. Meanwhile, two main indicators of conformal predictor, validity and efficiency, were also compared and discussed in this work. The result shows that the approach integrating electronic nose with aggregated conformal prediction to classify the species of dendrobium with reliability and validity is promising.

Sulfated Laminaria japonica polysaccharides inhibit macrophage foam cell formation

In this work, a purified Laminaria japonica polysaccharide (LJP61A) was chemically modified to obtain three sulfated polysaccharides (SLJP1, SLJP2 and SLJP3) with different degrees of sulfation using the method of chlorosulfonic acid/pyridine. The effects and underlying mechanism of SLJP1, SLJP2 and SLJP3 on the suppression of macrophage foam cell formation were further investigated using the model of oxidized low-density lipoprotein (ox-LDL)-induced foam cell formation. Results exhibited that the macrophage foam cell formation induced by ox-LDL could be significantly alleviated by these sulfated polysaccharides in a dose-dependent manner. Meanwhile, the enhancement of PPAR-γ mRNA expression in ox-LDL induced macrophages was remarkably inhibited by these sulfated polysaccharides. Moreover, the cellular inflammation induced by ox-LDL could also be remarkably mitigated by these sulfated polysaccharides. These results indicated that the sulfated L. japonica polysaccharides could inhibit the conversion of macrophage into foam cell via obstructing PPAR-γ activation and alleviating cellular inflammation.

The medicinal and pharmaceutical importance of Dendrobium species

Plants of the Dendrobium genus, one of the largest in the Orchidaceae, manifest a diversity of medicinal effects encompassing antiangiogenic, immunomodulating, antidiabetic, cataractogenesis-inhibiting, neuroprotective, hepatoprotective, anti-inflammatory, antiplatelet aggregation, antifungal, antibacterial, antiherpetic, antimalarial, aquaporin-5 stimulating, and hemagglutininating activities and also exert beneficial actions on colonic health and alleviate symptoms of hyperthyroidism. The active principles include a wide range of proteinaceous and non-proteinaceous molecules. This mini-review discusses the latest advances in what is known about the medicinal and pharmaceutical properties of members of the Dendrobium genus and explores how biotechnology can serve as a conduit to mass propagate valuable germplasm for sustainable exploration for the pharmaceutical industry.

Protective effect of Curcuma longa L. extract on CCl4-induced acute hepatic stress

BACKGROUND

The Curcuma longa L. (CLL) rhizome has long been used to treat patients with hepatic dysfunction. CLL is a member of the ginger family of spices that are widely used in China, India, and Japan, and is a common spice, coloring, flavoring, and traditional medicine. This study was performed to evaluate the hepatoprotective activity of CLL extract and its active component curcumin in an acute carbon tetrachloride (CCl4)-induced liver stress model.

METHODS

Acute hepatic stress was induced by a single intraperitoneal injection of CCl4 (0.1 ml/kg body weight) in rats. CLL extract was administered once a day for 3 days at three dose levels (100, 200, and 300 mg/kg/day) and curcumin was administered once a day at the 200 mg/kg/day. We performed alanine transaminase (ALT) and aspartate transaminase (AST). activity analysis and also measured total lipid, triglyceride, and cholesterol levels, and lipid peroxidation.

RESULTS

At 100 g CLL, the curcuminoid components curcumin (901.63 ± 5.37 mg/100 g), bis-demethoxycurcumin (108.28 ± 2.89 mg/100 g), and demethoxycurcumin (234.85 ± 1.85 mg/100 g) were quantified through high liquid chromatography analysis. In CCl4-treated rats, serum AST and ALT levels increased 2.1- and 1.2-fold compared with the control. AST but not ALT elevation induced by CCl4 was significantly alleviated in CLL- and curcumin-treated rats. Peroxidation of membrane lipids in the liver was significantly prevented by CLL (100, 200, and 300 mg/kg/day) on tissue lipid peroxidation assay and immunostaining with anti-4HNE antibody. We found that CLL extract and curcumin exhibited significant protection against liver injury by improving hepatic superoxide dismutase (p < 0.05) and glutathione peroxidase activity, and glutathione content in the CCl4-treated group (p < 0.05), leading to a reduced lipid peroxidase level.

CONCLUSION

Our data suggested that CLL extract and curcumin protect the liver from acute CCl4-induced injury in a rodent model by suppressing hepatic oxidative stress. Therefore, CLL extract and curcumin are potential therapeutic antioxidant agents against acute hepatotoxicity.

Identification of Multiple Cryptococcal Fungicidal Drug Targets by Combined Gene Dosing and Drug Affinity Responsive Target Stability Screening

Cryptococcus neoformans is a pathogenic fungus that is responsible for up to half a million cases of meningitis globally, especially in immunocompromised individuals. Common fungistatic drugs, such as fluconazole, are less toxic for patients but have low efficacy for initial therapy of the disease. Effective therapy against the disease is provided by the fungicidal drug amphotericin B; however, due to its high toxicity and the difficulty in administering its intravenous formulation, it is imperative to find new therapies targeting the fungus. The antiparasitic drug bithionol has been recently identified as having potent fungicidal activity. In this study, we used a combined gene dosing and drug affinity responsive target stability (GD-DARTS) screen as well as protein modeling to identify a common drug binding site of bithionol within multiple NAD-dependent dehydrogenase drug targets. This combination genetic and proteomic method thus provides a powerful method for identifying novel fungicidal drug targets for further development.

Cryptococcosis is a neglected fungal meningitis that causes approximately half a million deaths annually. The most effective antifungal agent, amphotericin B, was developed in the 1950s, and no effective medicine has been developed for this disease since that time. A key aspect of amphotericin B’s effectiveness is thought to be because of its ability to kill the fungus (fungicidal activity), rather than just stop or slow its growth. The present study utilized a recently identified fungicidal agent, bithionol, to identify potential fungicidal drug targets that can be used in developing modern fungicidal agents. A combined protein and genetic analysis approach was used to identify a class of enzymes, dehydrogenases, that the fungus uses to maintain homeostasis with regard to sugar nutrients. Similarities in the drug target site were found that resulted in simultaneous inhibition and killing of the fungus by bithionol. These studies thus identify a common, multitarget site for antifungal development.