Immunopotentiating effect of lentinan on chicks and its inhibitory effect on Marek's disease virus infection

Marek's disease virus (MDV) is a significant tumorigenic virus that causes severe immunosuppression in chickens. Lentinan (LNT) is an immunomodulator containing β-glucans and is widely used in areas such as antiviral, anticancer, and immune regulation. To investigate the immunomodulatory effects of LNT on specific pathogen-free (SPF) chicks and its potential to inhibit MDV infection, we conducted an MDV challenge experiment and observed the immune-enhancing effect of LNT on SPF chicks. The results showed that LNT promoted the growth and development of SPF chicks and induced the upregulation of cytokines such as Mx protein, interferon-γ (INF-γ), tumor necrosis factor-α (TNF-α), and interleukin-2 (IL-2). The specific gravity of CD4+ T-lymphocytes and CD8+ T-lymphocytes and their ratios were also significantly upregulated. Prophylactic use of LNT inhibited MDV replication in lymphocytes, liver, and spleen. It also alleviated MDV-induced weight loss and hepatosplenomegaly in SPF chicks. The present study confirms that LNT can enhance the levels of innate and cellular immunity in SPF chicks and contributes to the inhibition of MDV replication in vivo and mitigation of immune organ damage in chicks due to MDV infection. This provides an adjunctive measure for better control of MDV infection.

The Effects of Lentinan on the Hematological and Immune Indices of Dairy Cows

In this study, we investigated the effects of lentinan (LNT) on hematological parameters, immune indices, and metabolite levels in dairy cows. We randomly assigned forty Holstein cows to four treatment groups. The treatments consisted of 0, 5, 10, and 15 g/d of LNT. Compared with the control group, the addition of 10 g/d of LNT decreased the content of ALT and IL-8 but simultaneously increased the content of IL-4 in the cows' serum. Supplementation with 10 g/d of LNT decreased the levels of lymphocyte, RDW, ALT, AST, TC, IL-2, and IL-8, but, concurrently, in-creased the levels of granulocytes and IL-4 in their serum. In addition, supplementation with 15 g/d of LNT decreased the levels of RDW, TC, IL-2, and IL-8, but, at the same time, increased the levels of IL-4 and IgM in their serum. For the metabolomic analysis, cows fed with 0 and 10 g/d of LNT were selected. The results showed that 10 metabolites, including reduced nicotinamide riboside and trehalose, were upregulated in the 10 g/d group. These differential metabolites were enriched in tyrosine metabolism and trehalose degradation and altered two metabolic pathways of ubiquinone and other terpene quinone biosynthesis, as well as starch and sucrose metabolism. These findings provide evidence that LNT could be used to reduce the risk of inflammation in dairy cows.

Dextrans, Pullulan and Lentinan, New Scaffold Materials for Use as Hydrogels in Tissue Engineering

The development of hydrogels based on dextrans, pullulan and lentinan to be used in biomedical applications including tissue engineering is reported. Despite the fact that selected polysaccharides such as hyaluronic acid are well established, little is known, how these polysaccharides can be chemically modified to create hydrogels under controlled conditions. In this study we present a small library of chemically modified polysaccharides which are used for a divergent approach to achieve biomedical relevant hydrogels. In this case the crosslinking is based on thio ether formation between thiol modified donor and vinylsulfone or maleimide modified acceptor components. Successful synthesis of the linker systems and coupling at the polysaccharides, hydrogel formation takes place under physiological conditions. We extended the study by coupling small molecules like adhesion factors for increasing cell compatibility as well as a dye for further studies. The different hydrogels were studied to their rheological properties, water uptake, their permeability, biodegrability and their cytotoxicity.

Medicinal Mushrooms as Multicomponent Mixtures-Demonstrated with the Example of Lentinula edodes

Medicinal mushrooms are multicomponent mixtures (MOCSs). They consist of a large number of individual compounds, each with different chemical structures, functions, and possible pharmacological activities. In contrast to the activity of an isolated pure substance, the effects of the individual substances in a mushroom or its extracts can influence each other; they can strengthen, weaken, or complement each other. This results in both advantages and disadvantages for the use of either a pure substance or a multicomponent mixture. The review describes the differences and challenges in the preparation, characterization, and application of complex mixtures compared to pure substances, both obtained from the same species. As an example, we use the medicinal and culinary mushroom Lentinula edodes, shiitake, and some of its isolated compounds, mainly lentinan and eritadenine.

A novel method for detecting conformation-dependent β-glucans-single, double, and triple-helical from Shiitake mushroom

This pioneering study explores the structural intricacies of therapeutic β-glucan in Shiitake (Lentinula edodes), i.e. Lentinan (LNT). Lentinan, a neutral polysaccharide [β-(1,3; 1,6) glucan], exists in three forms; single, double, and triple-helical, but conformation-dependent bioactivity studies are lacking. In this context, we meticulously assessed indigenous Shiitake accessions from Northeast India, unveiling the conformational spectrum of LNT through an innovative pipeline. The experiment approached the simultaneous estimation of total glucan (TG), triple helical glucan (THG), and single-double helical glucan (SDG). Profiling revealed the exceptional LNT content in DMRO-623 (TG: 46.74%, SDG: 9.34%, THG: 37.39%) which emerged as the highest documented to date. Beyond the culinary delight, this research and the novel approach to LNT quantification will create a pivotal platform for advanced mushroom research, offering prospects for novel discoveries, innovative applications, and therapeutic potential.

Safety and efficacy of lentinan nasal drops in patients infected with the variant of COVID-19: a randomized, placebo-controlled trial

Objective: Lentinan has antiviral, anti-tumor, immunomodulatory, stimulating interferon production, and other pharmacological effects. Previous animal experiments have shown that lentinan nasal drops can assist [Corona Virus Disease 2019) COVID-19] vaccine to induce high levels of neutralizing antibodies and can effectively resist the invasion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to evaluate the safety and efficacy of lentinan nasal drops in patients infected with Omicron (SARS-CoV-2 variant) through a dose-escalation study and a placebo-controlled trial. Methods: A randomized, placebo-controlled trial. The study was divided into two phases: Phase I: a dose escalation trial in which 24 COVID-19 patients were enrolled, that is, 12 in the escalation dose group (50, 75, and 100 µg/day) and 12 in the standard treatment group. The aim was to evaluate the safety and tolerance of lentinan nasal drops. The second stage was a placebo-controlled study. The optimal dose group of the first stage was used as the therapeutic dose, and the sample size was expanded to verify the anti-COVID-19 efficacy of lentinan nasal drops. Results: In the dose-increasing study, lentinan nasal drops showed good safety, and no serious adverse reactions occurred. The virus shedding time of the 100 µg dose group was significantly shorter than that in the control group (7.75 ± 1.71 VS 13.41 ± 3.8 days) (p = 0.01), and the 100 µg/day lentinan nasal drops were tolerated well. The results of the placebo-controlled study showed that compared with that in the placebo group, the time for COVID-19 antigen to turn negative was significantly shorter in the 100 µg lentinan nasal drop group (p = 0.0298), but no significant difference was observed in symptom improvement between the two groups. In the placebo-controlled study, two patients experienced mild nasal discomfort with nasal drops, but the symptoms relieved themselves. Conclusion: Lentinan nasal drops are tolerated well and can shorten the time of virus clearance.

Lentinan alleviates sciatic nerve injury by promoting autophagy to remove myelin fragments

Lentinan, a natural drug with wide-ranging pharmacological activities, can regulate autophagy-the process through which Schwann cells (SCs) eliminate myelin fragments after peripheral nerve injury (PNI). However, the effect of lentinan after PNI and the role of accelerated myelin debris removal via autophagy in this process are unclear. This study examined the effect of lentinan on rat sciatic nerve repair following crush injury and the underlying mechanisms. After the successful establishment of the sciatic nerve compression injury model, group-specific treatments were performed. The treatment group received 20 mg/kg lentinan via intraperitoneal injection, while the model group was treated with normal saline. The recovery in each group was then evaluated. Further, a rat SC line (RSC96) was cultured in medium with/without lentinan after supplementation with homogenous myelin fractions to evaluate the removal of myelin particles. Our results showed that lentinan promotes autophagic flux in vivo via the AMPK/mTOR signaling pathway, accelerates the clearance of myelin debris by SCs, and inhibits neuronal apoptosis, thereby promoting neurological recovery. Similarly, in vitro experiments showed that lentinan promotes the phagocytosis of myelin debris by SCs. In conclusion, our results suggest that lentinan primarily promotes nerve regeneration by accelerating the autophagic clearance of myelin debris in SCs, and this process is likely regulated by the AMPK/mTOR signaling pathway. Therefore, this study provides compelling evidence that lentinan may be a cost-effective and natural treatment agent for PNI.

The Mushroom Glucans: Molecules of High Biological and Medicinal Importance

Carbohydrates, including polysaccharide macromolecules, are the main constituents of the fungal cell wall. Among these, the homo- or heteropolymeric glucan molecules are decisive, as they not only protect fungal cells but also have broad, positive biological effects on the animal and human bodies. In addition to the beneficial nutritional properties of mushrooms (mineral elements, favorable proteins, low fat and energy content, pleasant aroma, and flavor), they have a high glucan content. Folk medicine (especially in the Far East) used medicinal mushrooms based on previous experience. At the end of the 19th century, but mainly since the middle of the 20th century, progressively more scientific information has been published. Glucans from mushrooms are polysaccharides that contain sugar chains, sometimes of only one kind (glucose), sometimes having several monosaccharide units, and they have two (α and β) anomeric forms (isomers). Their molecular weights range from 10⁴ to 10⁵ Da, and rarely 10⁶ Da. X-ray diffraction studies were the first to determine the triple helix configuration of some glucans. It seems that the existence and integrity of the triple helix structure are criteria for their biological effects. Different glucans can be isolated from different mushroom species, and several glucan fractions can be obtained. The biosynthesis of glucans takes place in the cytoplasm, the processes of initiation and then chain extension take place with the help of the glucan synthase enzyme complex (EC 2.4.1.34), and the sugar units are provided by sugar donor UDPG molecules. The two methods used today for glucan determination are the enzymatic and Congo red methods. True comparisons can only be made using the same method. Congo red dye reacts with the tertiary triple helix structure, and the resulting glucan content better reflects the biological value of glucan molecules. The biological effect of β-glucan molecules is proportional to the integrity of the tertiary structure. The glucan contents of the stipe exceed the values of the caps. The glucan levels of individual fungal taxa (including varieties) differ quantitatively and qualitatively. This review presents in more detail the glucans of lentinan (from Lentinula edodes), pleuran (from Pleurotus ostreatus), grifolan (from Grifola frondose), schizophyllan (from Schizophyllum commune), and krestin (from Trametes versicolor), along with their main biological effects.

Effect of lentinan on proliferation and apoptosis of human astrocytoma U251 cells

AIM OF THE STUDY

Aim of the study is To investigate the effect of lentinan on proliferation and apoptosis of human astrocytoma U251 cells. Lentinan was dissolved in DMEM complete medium to form different concentrations (0, 25, 50, 100, 200, 400, 500, 600 µg/ml). CCK8 was used to detect the effect of lentinan with different concentrations on proliferation of human astrocytoma U251 cells, and the expression of Ki-67 was detected by immunofluorescence. In addition, the effect of different concentrations of lentinan on apoptosis of human astrocytoma U251 cells was detected by flow cytometry. Compared with the blank control group, 50 and 100 µg/ml lentinan significantly promoted proliferation of human astrocytoma U251 cells. When the concentration is more than 100 µg/ml, the cell activity gradually decreases, and the cell activity is the lowest when the concentration is 600 µg/ml. In addition, the low concentration lentinan (25, 50, and 100 µg/ml) had no significant effect on apoptosis of human astrocytoma U251 cells. However, lentinan above 200 µg/ml significantly promoted apoptosis of human astrocytoma U251 cells and had a concentration gradient effect, and the highest apoptosis rate was at 600 µg/ml.

CONCLUSIONS

Lentinan can effectively inhibit proliferation and promote apoptosis of human astrocytoma U251 cells.

Theranostic Cancer Treatment Using Lentinan-Coated Selenium Nanoparticles and Label-Free CEST MRI

Selenium nanoparticle (SeNP)-based nanotherapeutics have become an emerging cancer therapy, while effective drug delivery remains a technical hurdle. A theranostic approach, through which imaging companions are integrated with SeNPs, will allow image-guided drug delivery and, therefore, is highly desirable. Traditional methods require the chemical conjugation of imaging agents to the surface of nanoparticles, which may impede the later clinical translation. In this study, we developed a label-free strategy in which lentinan-functionalized SeNPs (LNT-SeNPs) are detected using MRI by the hydroxyl protons carried on LNT molecules. The in vitro phantom study showed that LNT and LNT-SeNPs have a strong CEST signal at 1.0 ppm apart from the water resonance, suggesting an in vivo detectability in the µM concentration range. Demonstrated on CT26 colon tumor cells, LNT-SeNPs exert a strong anticancer effect (IC50 = 4.8 μM), prominently attributed to the ability to generate intracellular reactive oxygen species. However, when testing in a mouse model of CT26 tumors, administration of LNT-SeNPs alone was found unable to deliver sufficient drugs to the tumor, leading to poor treatment responses. To improve the drug delivery, we co-injected LNT-SeNPs and TNF-α, a previously reported drug that could effectively damage the endothelial cells in the tumor vasculature, thereby increasing drug delivery to the tumor. Our results revealed a 75% increase in the intratumoral CEST MRI signal, indicating a markedly increased delivery efficiency of LNT-SeNPs when combined with TNF-α. The combination therapy also resulted in a significantly enhanced treatment outcome, as revealed by the tumor growth study. Taken together, our study demonstrates the first label-free, SeNP-based theranostic system, in which LNT was used for both functional surface coating and CEST MRI signal generating. Such a theranostic LNT-SeNP system is advantageous because it requires chemical labeling and, therefore, has high biocompatibility and low translatable barriers.

Shiitake dermatitis: experience of the Poison Control Centre Network in France from 2014 to 2019

OBJECTIVE

Shiitake mushrooms (Lentinus edodes) are an edible fungus, initially grown in Japan and China that are increasingly marketed in Europe. We previously presented 15 shiitake dermatitis cases reported to Poison Control Centres (PCCs) in France from January 2000 to December 2013. The aim of this study was to describe changes in the number of shiitake dermatitis cases since 2014, and to better describe the clinical characteristics and risk factors of this reaction.

CASE SERIES

This observational study is a retrospective review of cases in the French PCCs database between 1 January 2014 and 31 December 2019. Out of 125 shiitake exposures, we identified 59 cases of dermatitis: sex ratio of 1.80 M/F; ages ranging from 19 to 69 years (median: 39 years). Dermatitis occurred after raw or undercooked shiitake consumption (e.g., from the wok, in soup, or on pizza). The rash appeared 1-168 h (median: 48 h) after shiitake ingestion. Linear, erythematous, urticarial papules and plaques developed across the trunk, arms, and legs within a few hours and persisted for 1-40 d (median 10 d). The amount of shiitake eaten (low vs. medium vs. high) significantly increased the duration of dermatitis (median days 4 vs. 7 vs. 15, respectively; p = .007). In all, 38 patients received corticosteroids, antihistamine drugs, or both without demonstrated benefit. All patients made a complete recovery.

CONCLUSIONS

The mechanism of shiitake dermatitis is thought to involve lentinan, a heat-labile polysaccharide component. Inadequate cooking clearly seems to be a driver of the occurrence of shiitake dermatitis. This study highlighted a dose-dependent response, suggesting a partial toxic mechanism or a th1-type hypersensitivity mechanism. Treatment is focused on symptom management. Health professionals and the general population should be aware of both the risk associated with inadequately cooked shiitake consumption and the favourable prognosis of this still poorly known toxic dermatitis.

Lentinan Protects against Nonalcoholic Fatty Liver Disease by Reducing Oxidative Stress and Apoptosis via the PPARα Pathway

Lentinan (LNT), a type of polysaccharide derived from Lentinus edodes, has manifested protective effects during liver injury and hepatocellular carcinoma, but little is known about its effects on nonalcoholic fatty liver disease (NAFLD). This study aimed to investigate whether LNT can affect the progression of NAFLD and the associated mechanisms. C57BL/6J mice were fed a normal chow diet or a high-fat diet (HFD) with or without LNT (6 mg/kg/d). AML12 cells were exposed to 200 μM palmitate acid (PA) with or without LNT (5 μg/mL). After 21 wk of the high-fat diet, LNT significantly decreased plasma triglyceride levels and liver lipid accumulation, reduced excessive reactive oxygen species production, and subsequently attenuated hepatic apoptosis in NAFLD mice. These effects were associated with increased PPARα levels, a decreased Bax/Bcl-2 ratio, and enhancement of the antioxidant defense system in vivo. Similar effects were also observed in cultured cells. More importantly, these protective effects of LNT on palmitate acid-treated AML12 cells were almost abolished by PPARα knockdown. In conclusion, this study demonstrates that LNT may ameliorate hepatic steatosis and decrease oxidative stress and apoptosis by activating the PPARα pathway and is a potential drug target for NAFLD.

Upregulation of miR-216a-5p by Lentinan Targeted Inhibition of JAK2/STAT3 Signaling Pathway to Reduce Lung Adenocarcinoma Cell Stemness, Promote Apoptosis, and Slow Down the Lung Adenocarcinoma Mechanisms

To investigate the effect of Lentinan (LNT) on lung adenocarcinoma (LUAD) cell stemness and its mechanism. In this study, we founded that LNT significantly reduce the cell proliferation, activity, migration, invasion, and stemness of LUAD cells, and promote their apoptosis compared with the control group in vitro. Moreover, LNT significantly inhibited the volume and weight of tumors of nude mice in vivo. At the same time, LNT can significantly up-regulate miR-216a-5p levels and reduce the protein expression of phospho-JAK2 (Y1007/1008) and phospho-STAT3 (Tyr705), thereby inhibiting the JAK2/STAT3 signaling pathway. Interfering with miR-216a-5p expression and activating the JAK2/STAT3 signaling pathway can significantly reverse LNT inhibitory effects on LUAD. Collectively, LNT can inhibit the JAK2/STAT3 signaling pathway by up-regulating miR-216a-5p, reducing stemness, and promoting LUAD cells apoptosis, then slow down LUAD occurrence and development, providing concepts and experimental foundation treating patients with LUAD.

Protective Effects of Lentinan Against Lipopolysaccharide-Induced Mastitis in Mice

Mastitis is a worldwide production disease in dairy cows, which mainly affects milk yield, causing huge economic losses to dairy farmers. Lentinan is a kind of polysaccharide extracted from Lentinus edodes, which has no toxicity and possesses various pharmacological activities including antibacterial and immunomodulatory effects. Therefore, the anti-inflammatory function of lentinan on LPS-stimulated mastitis was carried out, and the mechanism involved was explored. In vivo, lentinan greatly reduced LPS-stimulated pathological injury, myeloperoxidase (MPO) activity, and the proinflammatory factor production (TNF-α and IL-1β) in mice. Further study was performed to determine the activation of the Wnt/β-catenin pathway during LPS stimulation. These results suggested that LPS-induced activation of the Wnt/β-catenin pathway was suppressed by lentinan administration. In vitro, we observed that the mouse mammary epithelial cell (mMEC) viability was not affected by lentinan treatment. As expected, LPS increased the TNF-α and IL-1β protein secretion and the activation of the Wnt/β-catenin pathway that was inhibited by lentinan administration in a dose-dependent manner in mMECs. Conclusively, lentinan exerts the anti-inflammatory function in LPS-stimulated mastitis via inhibiting the activation of the Wnt/β-catenin pathway. Thus, the results of our study also gave an insight that lentinan may serve as a potential treatment for mastitis.

Lentinan-Based Oral Nanoparticle Loaded Budesonide With Macrophage-Targeting Ability for Treatment of Ulcerative Colitis

Ulcerative colitis (UC) is a global, chronic, and refractory disease. Corticosteroids are first-line drugs for the treatment of UC but also cause adverse side effects. Budesonide (BUD), a corticosteroid with relatively low side effects, has been approved by the Food and Drug Administration for use as enteric capsules (Entocort EC) for the treatment of inflammatory bowel disease (IBD). However, this formulation lacks specific targeting ability to UC lesions. Herein, we describe the development of an advanced macrophage-targeted oral lentinan (LNT)–based nanoparticles (NPs) loaded BUD for treatment of UC. Briefly, LNT was used as a food source and natural carrier to load BUD by a simple solvent evaporation method to form LNT/BUD-NPs. LNT showed good loading capacity with high encapsulation and loading efficiencies to BUD of approximately 92.19 and 9.58%, respectively. Evaluation of the gastric stability of LNT/BUD-NPs indicated that LNT could effectively protect BUD from gastric acid and digestive enzymes. The release behavior and transmission electron microscopy image of LNT/BUD-NPs in the intestinal content of mice confirmed that intestinal flora can promote BUD release from LNT. Moreover, evaluation of cellular uptake showed that LNT/BUD-NPs could specifically target macrophages and enhance their uptake rate via the Dectin-1 receptor. In biodistribution studies, LNT/BUD-NPs were able to efficiently accumulate in the inflamed colon of mice. As expected, LNT/BUD-NPs could significantly alleviate inflammation by inhibiting the TLR4/MyD88/NF-κB signaling pathway. Therefore, LNT/BUD-NPs have the advantages of good gastric stability, release mediated by mouse intestinal content, macrophage-targeting, and anti-UC effects. These advantages indicate LNT-based NPs are a promising oral drug delivery system for UC therapy.

Lentinan Inhibits Tumor Progression by Immunomodulation in a Mouse Model of Bladder Cancer

Background: Lentinan (LNT), an isolated traditional Chinese herbal component, has antitumor potential. In the current study, the intrinsic mechanism of LNT-induced immunity against bladder cancer was explored in a mouse model. Methods: In the mouse model of bladder cancer, we used flow cytometry to detect the LNT caused population changes of T cells, macrophages, MDSC cells, and Treg cells. ELISA was used to evaluate cytokines expression in the supernatant of splenocytes. Results: We found that the administration of LNT increased the proportions of CD3⁺CD4⁺ and CD3⁺CD8⁺ T cell subsets as well as CD11b⁺F480⁺ macrophages, whereas it diminished the subpopulations of CD4⁺CD25⁺Foxp3⁺ regulatory T cells (Tregs) and Gr-1⁺CD11b⁺ myeloid-derived suppressor cells (MDSCs). LNT also upregulated the expression of interferon (IFN)-γ and interleukin (IL)-12, accompanied by a significant reduction in IL-10 and tumor growth factor (TGF)-β (P < .05). Our research further confirmed the synergy between LNT and gemcitabine (GEM) to activate immunity and inhibit the growth of bladder tumors in mouse model. Conclusions: LNT induced macrophage activation, followed by the enhanced proliferation of CD4⁺ and CD8⁺ T cells, and the upregulated expression of IFN-γ and IL-2. Meanwhile, the proportions of MDSCs and Tregs were downregulated, leading to a reduced expression of the anti-inflammatory cytokines IL-10 and TGF-β. The synergy between LNT and GEM provides additional evidence supporting the application of this traditional Chinese herbal component for bladder cancer therapy.

Nutraceuticals as Potential Radionuclide Decorporation Agents

Exposure of individuals to radioactive material as a result of ingestion of contaminated food and water is an increasing public health concern. Unfortunately, there are limited treatment modalities for dealing with these types of potentially toxic exposures. Recent research suggests that many plant-based nutraceuticals may possess metal-binding properties. This preliminary study investigated the ability of genistein, curcumin, quercetin, and lentinan to bind metals considered internal contamination risks, namely cesium, uranium, cobalt, and strontium, in a variety of matrices. The efficacy of these nutraceuticals in protecting cultured cells from metal-induced toxicity was also explored. Results showed that none of the compounds bound cesium or strontium. However, genistein, curcumin, and quercetin could bind uranium. Curcumin and quercetin also bound cobalt and could also protect cultured cells from metal-induced cytotoxicity. Lentinan did not bind any of the metals tested. Metal binding was also pH dependent, with no binding observed at lower pH values. This project showed that nutraceuticals could function as chelators for metals considered internal radionuclide contamination hazards. Further investigations are required in order to determine whether these compounds will become a new nontoxic arsenal of pharmaceutical compounds with which to treat radionuclide contamination.

Mechanism of Lentinan Intestinal Absorption: Clathrin-Mediated Endocytosis and Macropinocytosis

Lentinan (LNT), a typical triple helix β-glucan extracted from Lentinus edodes, has been widely used as a functional food and an orally administered drug. However, its oral pharmacokinetics has been rarely reported. The aim of this work is to systematically study the pharmacokinetics and intestinal absorption mechanism of LNT after oral administration. Radioactive 99m-technetium (^99mTc) was introduced to label LNT to determine the plasma concentration, tissue distribution, and excretion of the β-glucan in rats after oral administration. The results confirmed the absorption of LNT, with the maximal plasma concentration reached at 1 h. 5-([4,6-Dichlorotriazin-2-yl]amino)fluorescein (DTAF) was used to label LNT to explore the absorption mechanism of LNT, utilizing both a Ussing chamber and a monolayer of Caco-2 cells. These transport assays showed that LNT could penetrate through the intestine and epithelial monolayer, which was mediated by macropinocytosis and clathrin-mediated endocytosis. These findings provide a pharmacokinetic reference for LNT and help provide a greater understanding of the absorption of β-glucans in general.

Oridonin improves the therapeutic effect of lentinan on lung cancer

Oridonin, a compound from Rabdosia rubescens, has been shown to exhibit a potent ability to improve the antitumor effects of lentinan (LNT). In the present study, the effects of oridonin, LNT, and the combination of these treatments were assessed on the normal human fetal lung fibroblast cell line MRC-5, as well as the non-small cell lung cancer cell line A549. Next, their effects on metastasis and survival in vivo were assessed in a mouse model of lung cancer. The effects of the treatments on the mRNA and protein expression levels of several regulatory factors in A549 cells and lung tissues were determined using reverse transcription-quantitative PCR and western blotting. The results showed that the viability of MRC-5 and A549 cells were not affected by 0-20 µg/ml oridonin; 0-300 µg/ml LNT did not affect the viability of MRC-5 cells, but 50-400 µg/ml LNT reduced the viability of A549 cells. Thus, 20 µg/ml oridonin and 100 or 300 µg/ml LNT were used in the subsequent experiments. Treatment with oridonin and LNT, alone or combined, had no effect on MRC-5 cell viability. Oridonin treatment had no effect on A549 cell viability; however, LNT suppressed A549 cell viability, and oridonin promoted the suppressive effects of LNT on A549 cells. In vivo analysis showed that oridonin alone had no effect on metastasis and survival, but LNT decreased metastasis and survival in mice. Oridonin augmented the effects of LNT against metastasis and further improved the survival rates of mice. In both A549 cells and lung tissues, LNT increased the mRNA and protein expression levels of caspase-3, caspase-8, caspase-9, Bax, p53, p21 and inhibitor of nuclear factor-κB (NF-κB)-α, and reduced the mRNA and protein expression levels of Bcl-2 and NF-κB. Oridonin augmented all the effects of LNT on expression of these proteins in the cells. Together, the results showed that oridonin enhanced the antitumor effects of LNT, and may thus serve as an adjuvant alongside LNT as a novel anticancer regimen for treatment of lung cancer.

Lentinan Attenuated the PM2.5 Exposure-Induced Inflammatory Response, Epithelial-Mesenchymal Transition and Migration by Inhibiting the PVT1/miR-199a-5p/caveolin1 Pathway in Lung Cancer

PM2.5 plays an important role in the physiological and pathological progression of lung cancer. Lentinan exerts antitumor activity in many kinds of human cancers. Plasmacytoma variant translocation 1 (PVT1) exerts antitumor activity in many kinds of human cancers. However, the role and underlying molecular mechanism of PVT1 in the role of lentinan in PM2.5-exposed lung cancer are still largely unknown. Our study confirmed that PM2.5 exposure induced the production of inflammatory factors, epithelial-mesenchymal transition (EMT) and migration of lung cancer cells. Lentinan exerted antitumor effects by inhibiting the production of inflammatory factors, EMT, and migration of lung cancer cells. Lentinan suppressed PM2.5 exposure-induced cellular progression by inhibiting the PM2.5 exposure-induced elevation of PVT1 expression. PVT1 absorbed miR-199a, and miR-199a inhibited caveolin1 expression and thus formed the PVT1/miR-199a/caveolin1 signaling pathway in lung cancer cells. Our study revealed that silencing of the PVT1/miR-199a/caveolin1 signaling pathway affected the role of lentinan in PM2.5-exposed lung cancer cells. Thus, this study first investigated the role of lentinan in PM2.5-exposed lung cancer cells and further displayed the underlying molecular mechanism, providing a potential treatment for PM2.5-exposed lung cancer.

Lentinan combined with cisplatin for the treatment of non-small cell lung cancer

BACKGROUND

A growing number of studies suggest that lentinan combined with cisplatin thoracic injection for the treatment of lung cancer is an effective combination of traditional Chinese and Western medicine, which has a continuous and beneficial effect on eliminating clinical symptoms and improving cachexia in lung cancer patients. However, whether this treatment is effective and safe for lung cancer patients or not, evidence supporting the effectiveness and safety of this treatment is still incomplete. Besides, there is lack of systematic review to assess the detailed situation (including risk of bias and methodology) of current related clinical studies.

OBJECTIVE

This study aimed to evaluate the effectiveness and safety of lentinan combined with cisplatin thoracic injection in the treatment of lung cancer.

METHODS

The major databases (Embase, PubMed, the Cochrane Library, China National Knowledge Infrastructure, Chinese Scientific Journals Database [VIP] Database, Chinese Biomedical Literature Service System [SinoMed], and Wanfang Database) were searched from inception to March 1, 2020. Randomized controlled trials (RCTs) of lentinan combined with cisplatin chest injection on patients with non-small cell lung cancer (NSCLC) were identified. Two assessors reviewed each trial independently. The methodological quality of the eligible studies was evaluated according to the Cochrane Collaboration's tool for assessing risk of bias. Both the data extraction and the literature quality screening evaluation were conducted independently by 2 researchers.

RESULTS

Totally 17 clinical RCTs were included in this study, involving 1390 patients. Meta-analysis results showed that the clinical efficacy (risk ratio [RR] = 1.34, 95% confidence interval [CI] 1.21-1.48), effective subgroup analysis (RR = 1.51, 95% CI 1.3-1.77), and quality of life (RR = 1.48, 95% CI 1.27-1.72), the differences are statistically significant. In terms of adverse reactions, mainly related to gastrointestinal reactions and bone marrow suppression, the incidence and degree of adverse reactions of lentinan combined with cisplatin thoracic injection group were lower than those of cisplatin thoracic injection group alone.

CONCLUSIONS

The current evidence prompted that Lentinan combined with cisplatin in thoracic injection might benefit patients with NSCLC on a certain extent; this systematic review revealed some definite conclusions about the application of Lentinan combined with cisplatin in thoracic injection for NSCLC. Due to the low methodological quality, high risk of bias, and inadequate reporting on clinical data, these results still require verification by a large number of well designed, heterogeneous RCT studies. More rigorous, multicenter, sufficient-sample, and double-blind RCTs are warranted.

Lentinan-Functionalized Graphene Oxide Is an Effective Antigen Delivery System That Modulates Innate Immunity and Improves Adaptive Immunity

Graphene oxide (GO) and lentinan have received great attention because of their utility in biomedical applications. Graphene oxide is utilized in drug- and vaccine-delivery systems due to its biocompatibility, large surface area, and outstanding adsorption capability, while lentinan has immunity-enhancing effects. In this study, we synthesized and characterized GO grafted with lentinan (LNT) as an adjuvant and investigated how to impact the immune responses. Lentinan-modified GO (GO-LNT) facilitated antigen uptake in macrophages and improved the efficiency of antigen application in vitro. Furthermore, in vivo, compared with GO/OVA, GO-LNT/OVA decreased the release rate of ovalbumin (OVA) to sustain long-term immune responses and boost the levels of IgG and IgG subtypes. Hence, we can infer that the effects of GO-LNT were a result of the increased amounts of antigen uptake by cells. Overall, our studies demonstrated that GO-LNT could suffice for a safe and effective vaccine-delivery system as well as an excellent adjuvant that both elicits a long-term immune memory response and potentiates cellular and humoral immunity.

Lentinan Inhibits AGE-Induced Inflammation and the Expression of Matrix-Degrading Enzymes in Human Chondrocytes

Background

Chondrocyte-mediated inflammation is an important pathological component of osteoarthritis (OA) development. There are currently no therapies that completely reverse the development of OA. Lentinan, a type of polysaccharide derived from Lentinus edodes, has been demonstrated to possess significant anti-viral, anti-cancer, and anti-inflammatory effects, and has been recently used in the treatment of several inflammatory diseases. However, little research has focused on the pharmacological effect of lentinan in human OA.

Materials and Methods

We evaluated the anti-inflammatory and anti-ROS effects of lentinan in SW1353 chondrocytes treated with AGEs using real-time polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and the nitro oxide-specific stain DAF-FM DA. The regulatory effects of lentinan on NF-κB and MAPK p38 signaling were investigated via promoter assay and Western blot analysis.

Results

We found that lentinan inhibits the production of pro-inflammatory cytokines, including IL-1β, TNF-α, IL-8 and the secretion of PGE₂ and NO, by reducing the expression of COX-2 and iNOS in AGE-challenged chondrocytes. Lentinan also reduces AGE-induced increased expression of matrix metalloproteinases-1, −3, and −13 (MMP-1, MMP-3, MMP-13). Furthermore, lentinan has a similar effect on a disintegrin and metalloproteinase with thrombospondin motifs-4 and −5 (ADAMTS-4, ADAMTS-5). Mechanistically, lentinan reduces the activation of NF-κB.

Conclusion

Our findings indicate that lentinan shows a protective effect against AGE-induced inflammatory response in chondrocytes. These findings suggest that lentinan is a promising agent for the treatment of OA that could be used as a dietary supplement for patients with OA.

Lentinan-functionalized Selenium Nanoparticles target Tumor Cell Mitochondria via TLR4/TRAF3/MFN1 pathway

Rationale: Malignant ascites caused by cancer cells results in poor prognosis and short average survival time. No effective treatment is currently available for malignant ascites. In this study, the effects of lentinan (LNT)-functionalized selenium nanoparticles (Selene) on malignant ascites were evaluated. Furthermore, the mechanism of Selene targeting mitochondria of tumor cells were also investigated.

Methods: Selene were synthesized and characterized by TEM, AFM and particle size analysis. The OVCAR-3 and EAC cells induced ascites models were used to evaluate the effects of Selene on malignant ascites. Proteomic analysis, immunofluorescence, TEM and ICP-MS were used to determine the location of Selene in tumor cells. Mitochondrial membrane potential, ROS, ATP content, and caspase-1/3 activity were detected to evaluate the effect of Selene on mitochondrial function and cell apoptosis. Immunofluorescence, Co-IP, pull-down, duolink, Western blot, and FPLC were used to investigate the pathway of Selene targeting mitochondria.

Results: Selene could effectively inhibit ascites induced by OVCAR-3 and EAC cells. Selene was mainly located in the mitochondria of tumor cells and induced apoptosis of tumor cells. The LNT in Selene was involved in caveolae-mediated endocytosis through the interaction between toll-like receptor-4 (TLR4) and caveolin 1 (CAV1). Furthermore, the Selene in the endocytic vesicles could enter the mitochondria via the mitochondrial membrane fusion pathway, which was mediated by TLR4/TNF receptor associated factor 3 (TRAF3)/mitofusin-1 (MFN1) protein complex.

Conclusion: Selene is a candidate anticancer drug for the treatment of malignant ascites. And TLR4/TRAF3/MFN1 may be a specific nano-drug delivery pathway that could target the mitochondria.

Effects of lentinan on NF-κB activity in the liver of burn rats with sepsis

Effects of lentinan on nuclear factor-κB (NF-κB) activity in liver of burn rats with sepsis were investigated. To mimic the clinical sepsis after burn, rats were subjected to 30% full-thickness scald injury, followed by intraperitoneal (i.p.) injection of lipopolysaccharide (LPS). Seventy-two adult rats were randomly divided into six groups: the normal control group (n=12); the burn sepsis group (n=12); the burn sepsis with positive drugs; the burn sepsis with low-dose lentinan treatment group (50.0 mg/kg, n=12); the burn sepsis with middle-dose lentinan treatment group (100.0 mg/kg, n=12) and the burn sepsis with high-dose lentinan treatment group (200.0 mg/kg, n=12). Expression of NF-κB in the liver was measured with western blot analysis. The morphology of liver was evaluated with hematoxylin and eosin staining. The expression of NF-κB significantly increased in the liver of burn rats with sepsis. Compared with the burn sepsis group, lentinan treatment obviously reduced the damage of hepatic cell morphology, and decreased the activity of NF-κB significantly in the medium and high concentrations of lentinan treatment groups (P<0.05). Most importantly, treatment with lentinan was able to reverse the increased concentration of IL-4, IL-6, IL-10 and TNF-α in plasma which was induced by LPS. Lentinan treatment can significantly decrease the expression of NF-κB in the liver of burn rats with sepsis.

Dual-Action Pesticide Carrier That Continuously Induces Plant Resistance, Enhances Plant Anti-Tobacco Mosaic Virus Activity, and Promotes Plant Growth

Improving plant resistance against systemic diseases remains a challenging research topic. In this study, we developed a dual-action pesticide-loaded hydrogel with the capacity to significantly induce plant resistance against tobacco mosaic virus (TMV) infection and promote plant growth. We produced an alginate-lentinan-amino-oligosaccharide hydrogel (ALA-hydrogel) by coating the surface of an alginate-lentinan drug-loaded hydrogel (AL-hydrogel) with amino-oligosaccharide using electrostatic action. We determined the formation of the amino-oligosaccharide film using various approaches, including Fourier transform infrared spectrometry, the ζ potential test, scanning electron microscopy, and elemental analysis. It was found that the ALA-hydrogel exhibited stable sustained-release activity, and the release time was significantly longer than that of the AL-hydrogel. In addition, we demonstrated that the ALA-hydrogel was able to continuously and strongly induce plant resistance against TMV and increase the release of calcium ions to promote Nicotiana benthamiana growth. Meanwhile, the ALA-hydrogel maintained an extremely high safety to organisms. Our findings provide an alternative to the traditional approach of applying pesticide for controlling plant viral diseases. In the future, this hydrogel with the simple synthesis method, green synthetic materials, and its efficiency in the induction of plant resistance will attract increasing attention and have good potential to be employed in plant protection and agricultural production.

Lentinan inhibits oxidative stress and inflammatory cytokine production induced by benzo(a)pyrene in human keratinocytes

BACKGROUND

Benzo(a)pyrene, a major environmental pollutant, is known to accelerate skin aging through oxidative stress, increase the production of inflammatory mediators, and cause skin cancer. Lentinan, prepared from Lentinus edodes (Shiitake mushroom), has been reported to exhibit anti-coagulant, anti-viral, anti-cancer, anti-tumor, and anti-coagulant effects. However, the effect of lentinan on human keratinocytes treated with benzo(a)pyrene is unknown.

AIMS

The aim of this study was to explore whether lentinan inhibits benzo(a)pyrene-induced oxidative stress and inflammatory cytokine production in human keratinocytes.

METHODS

We investigated the effect of lentinan on benzo(a)pyrene-induced oxidative stress indicators (malondialdehyde, superoxide dismutase, and glutathione peroxidase) in human immortalized keratinocytes (HaCaT cells). We also assessed the production of inflammatory factors interleukin-8 and chemokine ligand-2 induced by benzo(a)pyrene exposure at both mRNA and protein levels.

RESULTS

Lentinan inhibited oxidative stress induced by benzo(a)pyrene, as shown by the concentration-dependent reduction in reactive oxygen species in HaCaT cells. In addition, malondialdehyde levels were reduced to 53% of those of cells treated with benzo(a)pyrene without lentinan. The activities of superoxide dismutase and glutathione peroxidase were approximately 18- and 2.7-fold higher in benzo(a)pyrene-treated cells with lentinan than in those without lentinan. Moreover, lentinan significantly reduced interleukin-8 and chemokine ligand-2 mRNA and protein levels.

CONCLUSIONS

These findings suggest that lentinan has two biological activities that are potentially useful for managing inflammatory skin diseases or disorders related to oxidative stress induced by benzo(a)pyrene. Therefore, cosmetics containing L edodes have promising dermatological applications, with potential utility in protecting the skin against environmental pollutants.

Clinical effects of lentinan combined with budesonide inhalation in treating acute exacerbation of chronic obstructive pulmonary disease under mechanical ventilation

In the present study, the clinical efficacy of the immune modulator lentinan combined with inhalation of the corticosteroid budesonide in treating acute exacerbation of chronic obstructive pulmonary disease (AECOPD) under mechanical ventilation was assessed. A total of 72 cases of AECOPD treated at Shanghai Jiao Tong University Affiliated Sixth People's Hospital (Shanghai, China) between June 2016 and September 2017 were enrolled. The AECOPD patients were randomly divided into an experimental group (n=36) and a control group (n=36). All of the patients received ventilator support and endotracheal intubation was performed. The experimental group was orally administered lentinan and budesonide was administered via atomization inhalation through a Y-tube and the control group received only budesonide via Y-tube. After the treatment, airway pressure, the time of mechanical ventilation and the time of stay at the intensive care unit for the experimental group were significantly lower than those for the control group (P<0.001). The plasma levels of adiponectin, D-dimer, interleukin-17 and high-sensitivity C-reactive protein, as well as the pressure of CO₂ in the experimental group were significantly lower than those in control group (P<0.001). Furthermore, the partial O₂ pressure in the experimental group was significantly higher than that in the control group (P<0.001). After the combined treatment, the proportions of CD3⁺ and CD4⁺T-cells in the blood were elevated, while the proportion of CD8⁺T-cells was decreased, compared with those in the experimental group at baseline or the control group post-treatment. In conclusion, the strategy of lentinan treatment combined with budesonide inhalation for AECOPD patients under mechanical ventilation demonstrated improved clinical efficacy compared with budesonide alone. (Chinese Clinical Trial Registry no. ChiCTR1800019088).

Therapeutic effects of lentinan on inflammatory bowel disease and colitis-associated cancer

In this study, we investigated the therapeutic potential of lentinan in mouse models of inflammatory bowel disease (IBD) and colitis-associated cancer (CAC). Lentinan decreased the disease activity index and macroscopic and microscopic colon tissue damage in dextran sulphate sodium (DSS)-induced or TNBS-induced models of colitis. High-dose lentinan was more effective than salicylazosulfapyridine in the mouse models of colitis. Lentinan decreased the number of tumours, inflammatory cell infiltration, atypical hyperplasia and nuclear atypia in azoxymethane/DSS-induced CAC model. It also decreased the expression of pro-inflammatory cytokines, such as IL-13 and CD30L, in IBD and CAC model mice possibly by inhibiting Toll-like receptor 4 (TLR4)/NF-κB signalling and the expression of colon cancer markers, such as carcinoembryonic antigen, cytokeratin 8, CK18 and p53, in CAC model mice. In addition, lentinan restored the intestinal bacterial microbiotal community structure in IBD model mice. Thus, it shows therapeutic potential in IBD and CAC model mice possibly by inhibiting TLR4/NF-κB signalling-mediated inflammatory responses and disruption of the intestinal microbiotal structure.

Conformation-Dependent Manipulation of Human Islet Amyloid Polypeptide Fibrillation by Shiitake-Derived Lentinan

Misfolding and aggregation of human islet amyloid polypeptide (hIAPP) into fibrils are important contributions to the pathology of type 2 diabetes. Developing effective inhibitors of protein aggregation and fibrillation has been considered a promising therapeutic approach to preventing and treating type 2 diabetes. Herein, we report that Shiitake-derived polysaccharide lentinan manipulates in vitro hIAPP fibrillation and modulates IAPP-induced cytotoxicity in a conformation-dependent manner. In its triple-helical conformation, lentinan effectively inhibits hIAPP fibrillation, either in bulk solution or in the presence of lipid membrane, suppresses reactive oxygen species (ROS) generation, and attenuates hIAPP-induced cell toxicity. In contrast, lentinan accelerates hIAPP aggregation when it exists in a random-coil conformation and shows no suppression on hIAPP-mediated ROS production. Further investigation shows that the interaction between triple-helical lentinan and monomeric hIAPP is more favorable than the intermolecular binding of hIAPP, which redirects hIAPP aggregates to discrete nontoxic nanocomposites. To the best of our knowledge, this is the first time to report a conformation-dependent inhibition of hIAPP aggregation, which will provide new insights for our understanding of the manipulation mechanisms on hIAPP by natural polysaccharides and open a new avenue for designing and screening potential amyloid inhibitors against type 2 diabetes.

Lentinan up-regulates microRNA-340 to promote apoptosis and autophagy of human osteosarcoma cells

BACKGROUND

Osteosarcoma (OS) is a common tumor of bone, and the high incidence and poor prognosis of OS call for novel therapeutic strategies. We aimed to explore the functional role of lentinan (LNT) in human OS MG63 cells as well as the underlying mechanisms.

METHODS

Cell viability of MG63 cells under LNT stimulation was measured by CCK-8 assay to explore the adequate concentration of LNT. Cell proliferation, apoptosis and expression of microRNA (miR)-340 in MG63 cells after LNT treatments were assayed by BrdU incorporation assay, flow cytometry assay and quantitative reverse transcription PCR, respectively. Expression of proteins associated with cell cycle, apoptosis, and autophagy were determined by western blot analysis. Subsequently, whether LNT affected MG63 cells through miR-340 as well as the related signaling pathway was explored.

RESULTS

Cell viability was reduced by 5-100 mg/mL of LNT. Percentage of BrdU-positive cells was reduced while that of apoptotic cells was enhanced by LNT treatment. LNT decreased cyclin D1 level but increased levels of active caspase-3 and caspase-9. After treatment, LNT enhanced LC3B-II/LC3B-I and Beclin-1 levels but reduced the p62 level. The miR-340 level was up-regulated by LNT, and further experiments showed LNT promoted apoptosis and autophagy through up-regulating miR-340. Moreover, LNT reduced the phosphorylated levels of MAPK and ERK through up-regulating miR-340.

CONCLUSION

LNT reduced proliferation and induced apoptosis and autophagy by up-regulating miR-340 in MG63 cells, along with inhibition of the MAPK/ERK pathway.

A polysaccharide from Lentinus edodes inhibits human colon cancer cell proliferation and suppresses tumor growth in athymic nude mice

The antitumor effect of Lentinan is thought rely on the activation of immune responses; however, little is known about whether Lentinan also directly attacks cancer cells. We therefore investigated the direct antitumor activity of SLNT (a water-extracted polysaccharide from Lentinus edodes) and its probable mechanism. We showed that SLNT significantly inhibited proliferation of HT-29 colon cancer cells and suppressed tumor growth in nude mice. Annxein V-FITC/PI, DAPI, AO/EB and H&E staining assays all showed that SLNT induced cell apoptosis both in vitro and in vivo. SLNT induced apoptosis by activating Caspase-3 via both intrinsic and extrinsic pathways, which presented as the activation of Caspases-9 and -8, upregulation of cytochrome c and the Bax/Bcl-2 ratio, downregulation of NF-κB, and overproduction of ROS and TNF-α in vitro and in vivo. Pretreatment with the caspase-3 inhibitor Ac-DEVD-CHO or antioxidant NAC blocked SLNT-induced apoptosis. These findings suggest that SLNT exerts direct antitumor effects by inducing cell apoptosis via ROS-mediated intrinsic and TNF-α-mediated extrinsic pathways. SLNT may thus represent a useful candidate for colon cancer prevention and treatment.

Antioxidant action and protective and reparative effects of lentinan on oxidative damage in HaCaT cells

BACKGROUND

Lentinus edodes is one of the largest edible fungi. Lentinan, extracted from its fruiting body has clinically significant anticancer, antibacterial, antiviral, and anticoagulant effects; however, its preventive effects on skin oxidative damage are unclear.

AIMS

We aimed to evaluate the in vitro antioxidation capability of lentinan and its protective and reparative effects on a model of cell oxidative damage.

METHODS

We evaluated the in vitro antioxidant potential of lentinan by assessing its free-radical quenching ability using DPPH and ABTS and superoxide anions. Using the HaCaT cell line as the experimental system, we tested the protective and reparative effects of lentinan on a model of H₂ O₂ -induced cellular oxidative damage through assessment of cell survival rate, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity.

RESULTS

Lentinan displayed high antioxidant potential: DDPH and ABTS quenching rates were above 60%; superoxide anions, approximately 18%. Furthermore, lentinan could dose-dependently prevent the reduction of activity in HaCaT cells by H₂ O₂ , reduce MDA formation, and increase SOD activity. Moreover, lentinan showed not only a protective effect against oxidative damage but also reparative effects to a certain extent, in HaCaT cells.

CONCLUSIONS

Our findings demonstrated the ability of lentinan to enhance cellular tolerance to oxidative damage, stress resistance, and to have protective and reparative effects on damaged cells. Therefore, with L. edodes as a source for antiaging substances, cosmetics with homology to foods have great potential clinical applications.

Use of Lentinan To Control Sharp Eyespot of Wheat, and the Mechanism Involved

Lentinan (LNT), a complex polysaccharide with a β-(1→3)-linked backbone of d-glucose residues, has been reported to inhibit plant diseases. Our objective was to explore the efficacy and action mechanism of LNT used as a seed dressing to control sharp eyespot of wheat. Seed dressing promoted wheat growth. At control germination rates of 50%, 8 g of LNT/100 kg of seeds of the Jimai 22, Shannong 23, and Luyuan 502 cultivars significantly increased seed germination to 54%, 52%, and 51%, respectively. Seven days after emergence, the heights and root activity of wheat treated with LNT were significantly greater than those of controls. These effects were dose-dependent. At this time, the plant heights of Jimai 22, Shannong 23, and Luyuan 502 cultivars were 9.52, 8.52, and 10.52 cm, respectively, significantly higher than that of the controls. LNT prevented the development of wheat sharp eyespot. In the highly susceptible Jimai 22 cultivar, sharp eyespot development was reduced by 33.7%, 31.9%, and 30.4% at 7, 14, and 21 days after germination. LNT somewhat increased phenylalanine ammonia-lyase, peroxidase, and superoxide dismutase activity; reduced the malondialdehyde content; increased chlorophyll a and b levels; and enhanced the root vigor of wheat. These effects peaked 7 days after germination. LNT increased transcription of the genes encoding alternative oxidase (AOX) and β-1,3-glucanase (GLU), the salicylic acid signaling pathway-related gene NbPR1a, and the sharp eyespot resistance-related gene RS33. A significant dose-effect relationship was evident in terms of AOX transcription; we thus speculate that AOX may be the target gene.

Oridonin increases anticancer effects of lentinan in HepG2 human hepatoblastoma cells

The aim of the present study was to investigate whether oridonin is able to increase the effects of lentinan (LNT) in HepG2 human hepatoblastoma cells by MTT, flow cytometry, reverse transcription-quantitative polymerase chain reaction and western blot analysis. The in vitro results demonstrated that 20 µg/ml of oridonin was a nontoxic concentration for L02 normal liver cells and HepG2 liver cancer cells. Furthermore, treatment with 0-200 µg/ml LNT was only able to decrease the viability of HepG2 liver cancer cells. The growth inhibitory rate of the LNT-L (100 µg/ml) treatment group was 20.7% and the rate of the LNT-H (200 µg/ml) treatment group was 54.8%. Notably, the growth inhibitory rate of the oridonin + LNT-H group was 84.3%. The highest percentage of apoptotic cells was observed in the oridonin + LNT-H group (20 µg/ml oridonin and 200 µg/ml LNT). The percentage of apoptotic cells in the oridonin + LNT-H group was significantly different from the percentage of apoptotic cells in the LNT-H (26.1%) and the LNT-L (16.8%) groups. Treatment with LNT produced an increase in caspase-3, caspase-9, Bcl-2-like protein 4, p53, p21, nuclear factor κB inhibitor-α mRNA and protein expression and a decrease in B-cell lymphoma 2 and nuclear factor-κB expression in HepG2 cells compared with untreated control cells. Treatment with a combination of oridonin and LNT-H induced a further increase in expression with the biggest differences in expression observed between the oridonin + LNT-H group and control. It was observed that treatment with oridonin was able to increase the anticancer effects of LNT in HepG2 cells. Therefore, oridonin may be used to sensitize cells to LNT.

Efficacy of biological response modifier lentinan with chemotherapy for advanced cancer: a meta-analysis

Lentinan is a common biological response modifier. This study was sought to evaluate the efficacy of adjuvant lentinan combined with chemotherapy for advanced cancer. A meta-analysis of published prospective controlled trials investigating the effects of lentinan for kinds of advanced cancer was performed. Sensitivity analysis, inverted funnel plots, and trial sequence analysis were conducted to explore the reliability and stability of results. Seventeen clinical studies were identified containing 1423 patients. Twelve trials included gastrointestinal cancer (GIC), three trials included lung cancer (LC), and two trials included the two cancers. There was a increase in survival rate in 1 year (risk ratios [RR], 1.46, P = 0.001) and overall response rate including both complete and partial response (RR, 1.28, P = 0.005). There was also a reduction in progressive disease (RR, 0.57, P = 0.0005), nonsevere adverse events (RR, 0.88, P = 0.004), and severe adverse events (RR, 0.73, P = 0.007). Similar results were shown in the two subgroups of GIC and LC. Limited trials reported the data of median overall survival and time to treatment failure, and the data were insufficient for quantitative analysis, and no significant difference were found in 2-year survival rate. Adjuvant lentinan used with chemotherapy achieved improvements in 1-year survival rate, response rate, and adverse events in advanced cancer. The effect seemed to be similar irrespective of cancer type. However, its sustained efficacy on survival was still unclear.

Oridonin enhances in vitro anticancer effects of lentinan in SMMC-7721 human hepatoma cells through apoptotic genes

The aim of the present study was to determine the ability of oridonin to enhance the anticancer activity of lentinan (LNT) in SMMC-7721 human hepatoma cells in vitro by using various techniques, including MTT, flow cytometry, quantitative PCR and western blot assays. The results demonstrated that 20 µg/ml was a non-toxic concentration of oridonin for L02 normal liver cells and SMMC-7721 cells, while 0-200 µg/ml of LNT only had anti-proliferative effects on SMMC-7721 cells. LNT at 100 and 200 µg/ml inhibited the growth of SMMC-7721 cells by 22.8 and 60.0%, respectively, and after addition of 20 µg/ml oridonin, the inhibitory rate of 100 and 200 µg/ml LNT was increased to 47.2 and 80.7%, respectively. Oridonin (20 µg/ml) + LNT (200 µg/ml)-treated SMMC-7721 cells showed the highest apoptotic rate, which was 40.5±2.5%, which was higher than that of cells treated with LNT only. LNT raised the mRNA and protein expression of caspase-3, -8 and -9 as well as B-cell lymphoma 2 (Bcl-2)-associated X protein, p53 and p21, while reducing the expression of Bcl-2, Bcl extra large protein, epidermal growth factor (EGF) and EGF receptor expression in SMMC-7721 cells as compared to that in control cells. Treatment with 20 µg/ml oridonin and 200 µg/ml LNT increased these changes of gene expression. From the obtained results, it may be concluded that oridonin raised the in vitro anti-cancer effects of LNT in SMMC-7721 cells. Oridonin may also be used as a sensitizing agent to increase the anticancer activity of LNT in vivo.

Lentinan dose dependence between immunoprophylaxis and promotion of the murine liver cancer

Lentinan could exhibit significant biological activity favorable for human health and disease control such as the recovery of patients with liver cancer. In order to investigate the effect of lentinan dose dependence between immunoprophylaxis and promotion of cancer cell proliferation of the murine liver cancer, different concentrations of lentinan were prepared for the test in vitro (MTT assay) and in vivo (cumulative survival assay, spleen lymphocyte proliferation tests and peritoneal macrophage phagocytosis assays). New emerging proteins of the H22 cell incubated with lentinan was demonstrated by MS analysis and protein database searching. Lentinan was non-toxic for HL7702 cells but inhibited H22 cells proliferation obviously in a dose-dependent manner. In vivo, the proliferation of H22 hepatocarcinoma cells was inhibited by lentinan 0.4mg/kg body weight (L2, survival rate, 20%, PPP<0.01). Six proteins 60Sacidic ribosomal protein P2, Peroxiredoxin-2, Annexin A5, PDZ and LIM domain protein 1, Src substrate cortactin and Moesin were found as emerging proteins of the H22 cell incubated with high dose lentinan which related to cancer promotion closely. In conclusion, Thelentinan was relatively safe and could inhibit the proliferation of H22 cancer cells through immunity improvement when it's intake was in proper quantity.

Lentinula edodes Genome Survey and Postharvest Transcriptome Analysis

Lentinula edodes is a popular, cultivated edible and medicinal mushroom. Lentinula edodes is susceptible to postharvest problems, such as gill browning, fruiting body softening, and lentinan degradation. We constructed a de novo assembly draft genome sequence and performed gene prediction for Lentinula edodesDe novo assembly was carried out using short reads from paired-end and mate-paired libraries and by using long reads by PacBio, resulting in a contig number of 1,951 and an N₅₀ of 1 Mb. Furthermore, we predicted genes by Augustus using transcriptome sequencing (RNA-seq) data from the whole life cycle of Lentinula edodes, resulting in 12,959 predicted genes. This analysis revealed that Lentinula edodes lacks lignin peroxidase. To reveal genes involved in the loss of quality of Lentinula edodes postharvest fruiting bodies, transcriptome analysis was carried out using serial analysis of gene expression (SuperSAGE). This analysis revealed that many cell wall-related enzymes are upregulated after harvest, such as β-1,3-1,6-glucan-degrading enzymes in glycoside hydrolase (GH) families GH5, GH16, GH30, GH55, and GH128, and thaumatin-like proteins. In addition, we found that several chitin-related genes are upregulated, such as putative chitinases in GH family 18, exochitinases in GH20, and a putative chitosanase in GH family 75. The results suggest that cell wall-degrading enzymes synergistically cooperate for rapid fruiting body autolysis. Many putative transcription factor genes were upregulated postharvest, such as genes containing high-mobility-group (HMG) domains and zinc finger domains. Several cell death-related proteins were also upregulated postharvest.IMPORTANCE Our data collectively suggest that there is a rapid fruiting body autolysis system in Lentinula edodes The genes for the loss of postharvest quality newly found in this research will be targets for the future breeding of strains that keep fresh longer than present strains. De novoLentinula edodes genome assembly data will be used for the construction of a complete Lentinula edodes chromosome map for future breeding.

Removal of cadmium from contaminated Lentinula edodes by optimized complexation and coagulation

Heavy metal pollution is a serious problem for Lentinula edodes; however, the treatment of contaminated L. edodes has seldom been studied. This study investigated the removal of cadmium (Cd) from contaminated L. edodes and its lentinan by complexation and coagulation. Some influencing factors, such as pH, medical dosage, and preoxidation were examined. Cd complexation from contaminated L. edodes was shown to be more efficient under acidic conditions (pH 5.0), with a clearance rate of 80.47% in 25 mmol/L EDTA and 78.45% in 25 mmol/L sodium citrate. The Cd content in the lentinan of the contaminated L. edodes was markedly lower than that in the powdered mushroom (2.77 mg/kg vs. 19.49 mg/kg) and was easier to remove. The maximum Cd clearance rate (96.3%) for lentinan was obtained using an optimized process that involved preoxidation with 0.5 mg/L KMnO4, complexing with 25 mmol/L EDTA and 25 mmol/L sodium citrate, and coagulation with 50 mg/L activated carbon (AC) at pH 10.0.

Lentinan-Modified Carbon Nanotubes as an Antigen Delivery System Modulate Immune Response in Vitro and in Vivo

Adjuvants enhance immunogenicity and sustain long-term immune responses. As vital components of vaccines, efficient adjuvants are highly desirable. Recent evidence regarding the potential of carbon nanotubes (CNTs) to act as a support material has suggested that certain properties, such as their unique hollow structure, high specific surface area, and chemical stability, make CNTs desirable for a variety of antigen-delivery applications. Lentinan, a β-1,3-glucohexaose with β-1,6-branches that is extracted from the mushroom Lentinus edodes, is an effective immunostimulatory drug that has been clinically used in Japan and China, and recent studies have proved that specific beta-glucans can bind to various immune receptors. In this research, we covalently attached lentinan to multiwalled carbon nanotubes (MWCNTs) and tested their ability to enhance immune responses as a vaccine delivery system. In vitro study results showed that the nanotube constructs could rapidly enter dendritic cells and carry large amounts of antigen. Moreover, maturation markers were significantly upregulated versus the control. Thus, lentinan-modified multiwalled carbon nanotubes (L-MWCNTs) were regarded as an effective intracellular antigen depot and a catalyzer that could induce phenotypic and functional maturation of dendritic cells. Furthermore, compared with L-MWCNTs (35 μg/mL), a corresponding concentration of carboxylic carbon nanotubes (C-MWCNTs, 31.8 μg/mL) and an equivalent concentration of lentinan (3.2 μg/mL) did not remarkably influence the immune reaction in vitro or in vivo. Hence, we can hypothesize that the capability of L-MWCNTs was a consequence of the increased intracellular quantity of lentinan grafted onto the nanotubes. Overall, our studies demonstrated that L-MWCNTs significantly increased antigen accumulation in the cells and potentiated cellular and humoral immunity. In conclusion, L-MWCNTs constitute a potential vaccine delivery system to enhance immunogenicity for therapeutic purposes.

Lentinan protects pancreatic β cells from STZ-induced damage

Pancreatic β‐cell death or dysfunction mediated by oxidative stress underlies the development and progression of diabetes mellitus (DM). In this study, we evaluated the effect of lentinan (LNT), an active ingredient purified from the bodies of Lentinus edodes, on pancreatic β‐cell apoptosis and dysfunction caused by streptozotocin (STZ) and the possible mechanisms implicated. The rat insulinoma cell line INS‐1 were pre‐treated with the indicated concentration of LNT for 30 min. and then incubated for 24 hrs with or without 0.5 mM STZ. We found that STZ treatment causes apoptosis of INS‐1 cells by enhancement of intracellular reactive oxygen species (ROS) accumulation, inducible nitric oxide synthase (iNOS) expression and nitric oxide release and activation of the c‐jun N‐terminal kinase (JNK) and p38 mitogen‐activated protein kinase (MAPK) signalling pathways. However, LNT significantly increased cell viability and effectively attenuated STZ‐induced ROS production, iNOS expression and nitric oxide release and the activation of JNK and p38 MAPK in a dose‐dependent manner in vitro. Moreover, LNT dose‐dependently prevented STZ‐induced inhibition of insulin synthesis by blocking the activation of nuclear factor kappa beta and increasing the level of Pdx‐1 in INS‐1 cells. Together these findings suggest that LNT could protect against pancreatic β‐cell apoptosis and dysfunction caused by STZ and therefore may be a potential pharmacological agent for preventing pancreatic β‐cell damage caused by oxidative stress associated with diabetes.

Chemo-Immunotherapy Using Lentinan for the Treatment of Gastric Cancer with Liver Metastases

Gastric cancer is the third leading cause of cancer-related mortality worldwide. Systemic chemotherapy is the main treatment option for advanced gastric cancer when the tumor is inoperable. Despite recent advances in chemotherapeutic agents, the prognosis of unresectable or recurrent gastric cancer remains extremely poor. In Japan, combination therapy including S-1 and cisplatin is the standard first-line treatment for advanced gastric cancer; however, the five-year survival rate remains very low. Lentinan, the backbone of beta-(1,3)-glucan with beta-(1,6) branches, an active ingredient purified from Shiitake mushrooms, has been approved as a biological response modifier for the treatment of gastric cancer. This agent has been used in combination with oral fluoropyrimidines to improve the overall survival of gastric cancer patients. A retrospective chart review on 138 metastatic gastric cancer patients receiving chemotherapy was performed in Nagoya Memorial Hospital from 1 September 2010 to 31 August 2015. 12 patients with liver metastases were treated by lentinan in combination with S-1-based chemotherapy. The rate of objective response was 42% (5/12) and the disease control rate was 83% (10/12) in response to chemo-immunotherapy using lentinan, with a median overall survival of 407 days (95% CI: 207-700 days).

Lentinan exerts synergistic apoptotic effects with paclitaxel in A549 cells via activating ROS-TXNIP-NLRP3 inflammasome

Paclitaxel is generally used to treat cancers in clinic as an inhibitor of cell division. However, the acquired resistance in tumours limits its clinical efficacy. Therefore, the aim of this study was to detect whether co-treatment with lentinan enhanced the anti-cancer effects of paclitaxel in A549 cells. We found that the combination of paclitaxel and lentinan resulted in a significantly stronger inhibition on A549 cell proliferation than paclitaxel treatment alone. Co-treatment with paclitaxel and lentinan enhanced cell apoptosis rate by inducing caspase-3 activation. Furthermore, co-treatment with paclitaxel and lentinan significantly triggered reactive oxygen species (ROS) production, and increased thioredoxin-interacting protein (TXNIP) expression. Moreover, co-treatment with paclitaxel and lentinan enhanced TXNIP-NLRP3 interaction, and activated NLRP3 inflammasome whereat interleukin-1β levels were increased and cell apoptosis was induced. In addition, combination of paclitaxel and lentinan could activate apoptosis signal regulating kinase-1 (ASK1)/p38 mitogen-activated protein kinase (MAPK) signal which also contributed to cell apoptosis. Taken together, co-treatment with paclitaxel and lentinan exerts synergistic apoptotic effects in A549 cells through inducing ROS production, and activating NLRP3 inflammasome and ASK1/p38 MAPK signal pathway.

Inhibition of aflatoxin synthesis in Aspergillus flavus by three structurally modified lentinans

The chemical properties of β-glucans leading to their inhibition on aflatoxin (AF) production by Aspergillus flavus remain unclear. In this study, structurally modified lentinan derivatives were prepared by carboxymethylation, sulfation, and phosphorylation to explore their inhibition activity to AF synthesis. The results demonstrated that inhibitory activity of lentinan decreased at higher or lower concentrations than 200 μg/mL. Compared with lentinan, the sulphated derivatives only performed a reduced optimal inhibition rate at a higher concentration. The phosphorylated derivatives achieved complete inhibition of AF production at 50 μg/mL, but the inhibitory activity was attenuated with an increase of concentration. The minimum concentration of carboxymethylated derivatives to completely inhibit AF synthesis was the same as that of the original lentinan, whereas their inhibition activity was not reduced at the increasing concentration. RT-PCR analyses were conducted to understand the effects of lentinan and its carboxymethylated derivatives on the transcription of certain genes associated with AF biosynthesis. The results showed that lentinan delayed the transcription of aflQ, whereas its carboxymethylated derivatives promoted the transcriptions of all the tested genes. Our results revealed that some chemical group features apart from the β-bond could play the vital role in the prevention of AF formation by polysaccharide, and highlighted the structural modifications which could promote its practicability in the control of aflatoxin contamination.

Anticancer properties of polysaccharides isolated from fungi of the Basidiomycetes class

Basidiomycete mushrooms represent a valuable source of biologically active compounds with anticancer properties. This feature is primarily attributed to polysaccharides and their derivatives. The anticancer potential of polysaccharides is linked to their origin, composition and chemical structure, solubility and method of isolation. Moreover, their activity can be significantly increased by chemical modifications. Anticancer effects of polysaccharides can be expressed indirectly (immunostimulation) or directly (cell proliferation inhibition and/or apoptosis induction). Among the wide range of polysaccharides with documented anticancer properties, lentinan, polysaccharide-K (PSK) and schizophyllan deserve special attention. These polysaccharides for many years have been successfully applied in cancer treatment and their mechanism of action is the best known.

Dendritic cells might be one of key factors for eliciting antitumor effect by chemoimmunotherapy in vivo

In this study, we demonstrated that chemoimmunotherapy using S-1, a novel oral fluoropyrimidine anticancer drug, combined with lentinan (LNT), a beta (1 --> 3) glucan, was effective in vivo, and we clarified the augmentation of the function of dendritic cells (DCs) in vivo and in vitro. The survival period of Colon-26-bearing mice treated with S-1 + LNT was significantly more prolonged than that of mice treated with S-1 alone (P < 0.05). On the other hand, LNT did not prolong the survival period when combined with S-1 in Colon-26-bearing athymic mice. The frequency of CD86+ DCs infiltrated into Colon-26 was increased in mice treated with S-1 + LNT, and splenic DCs harvested from mice treated with S-1 + LNT showed more potent T-cell proliferation activity than that of DCs from mice treated with S-1 alone (P < 0.05). Furthermore, the activity of cytotoxic T lymphocytes (CTLs) in splenocytes of S-1 + LNT-treated mice was specific and more potent than that of CTLs from mice treated with S-1 alone (P < 0.05). These results suggest that modulation of specific immunity with LNT has a significant role in enhanced antitumor effects through the modification of DC function. We demonstrated that DCs might play an important role in chemotherapy, and the combination therapy of S-1 and LNT presents a promising chemoimmunotherapy, which might lead to better survival for cancer patients.

Synergistic antimetastatic effects of lentinan and interleukin 2 with pre- and post-operative treatments

The antimetastatic activity of a combination of lentinan and interleukin 2 (IL-2) was evaluated against spontaneously metastatic 3-methylcholanthrene-induced DBA/2.MC.CS.T fibrosarcoma. Although pre-operative treatment with either IL-2 or lentinan alone exerted little effect on the reduction of lung metastasis colony numbers (7.1% or 28.4% reduction, respectively), the combination exhibited a synergistic effect (85% reduction). Furthermore, 3 of 13 mice given the pre-operative combination treatment achieved complete cure, while no mice given saline did. Although the post-operative combination treatment also reduced the colony number (71% reduction), it caused little prolongation of survival and no mouse achieved complete cure. Synergistic effects were observed between pre- and post-operative treatments with lentinan and IL-2: 8 of 12 mice were completely cured. The anti-metastatic activity was abolished in mice treated simultaneously with antibodies to CD4 and CD8 antigens, whereas either CD4, CD8, or NK1.1 antibody alone was ineffective. Analysis of the cellular mechanism involved in the antimetastatic activity revealed the involvement of a tumor-associated antigen-specific delayed-type hypersensitivity response. These data suggest that the life-prolonging effect of the combination of lentinan and IL-2 is mediated by antigen-specific T cells and that the combination of pre- and post-operative therapy with lentinan and IL-2 may be effective to prevent cancer recurrence and metastasis after surgical resection.

Reconstitution of anti-tumor effects of lentinan in nude mice: roles of delayed-type hypersensitivity reaction triggered by CD4-positive T cell clone in the infiltration of effector cells into tumor

Lentinan, an antitumor polysaccharide used clinically in Japan, requires the intact T cell compartment to manifest its antitumor effects. The aim of the current study was to clarify the mechanisms playing crucial roles in the T cell requirement in the expression of antitumor effects of lentinan. Lentinan treatment of BDF1 mice transplanted intradermally with FBL-3 induced complete tumor regression and a marked increase in survival time. The antitumor action of lentinan was abolished in mice treated simultaneously with antibodies to CD4 and CD8 antigens, whereas antibody to CD4, CD8 or NK1.1 alone was ineffective. The natural killer, cytotoxic T lymphocyte, and helper T cell activities were already augmented in this FBL-3/BDF1 system and thus further augmentation of these activities by lentinan was not observed. These activities did not correlate with the antitumor activity of lentinan, as was confirmed in lymphocyte subset depletion experiments. On the contrary, the delayed-type hypersensitivity (DTH) response against tumor-associated antigens was triggered by lentinan and was abrogated only in mice treated simultaneously with antibodies to CD4 and CD8 antigens. Furthermore, a non-cytolytic tumor-associated antigen-specific CD4+ T cell clone able to induce the DTH response in concert with lentinan reconstituted the antitumor effects in B6 nude mice when administered with lentinan. These results suggest that, in addition to the augmentation of immune effector cell activity against tumors, infiltration of these cells into the tumor burden initiated by the DTH responses at tumor sites may be involved in eradication of tumors by lentinan.

Curative effects of combination therapy with lentinan and interleukin-2 against established murine tumors, and the role of CD8-positive T cells

The antitumor activity of a combination of an antitumor polysaccharide, lentinan (a beta 1-3 glucan with beta 1-6 branches), and interleukin-2 (IL-2) was evaluated against established MBL-2 lymphoma and S908.D2 sarcoma at i.d. sites. Treatment of the MBL-2-tumor-bearing BDF1 mice with lentinan and IL-2 induced complete regression of tumor in 87.5% of mice treated. In contrast, treatments using either lentinan or IL-2 alone failed to induce complete regression of tumor, although temporal growth inhibition of tumor was observed about in half of the mice treated. Improvements of antitumor effects by the combination of lentinan and IL-2 were also observed in the MBL-2/B6 and S908.D2/B10.D2 systems. Expression of the antitumor effects of lentinan/IL-2 treatments required the intact T cell compartment, because the effects were not observed when nude mice were used. In the MBL-2/B6 system, the antitumor action of lentinan/IL-2 treatment was abolished in mice treated with antibody to CD8 antigen, whereas antibodies to CD4 or NK1.1 were ineffective. Furthermore, augmented tumor-specific cytotoxic T lymphocyte (CTL) activity was observed in regional lymph node cells of the mice after lentinan and IL-2 administration. These data indicate that the antitumor effects of lentinan/IL-2 are mediated by CD8+ CTL but not by CD4+ T cells or NK1.1+ NK/LAK cells, and suggest that this combined therapy may be effective against even established tumors that are resistant to IL-2 therapy.