Apaf1 nanoLuc biosensors identified lentinan as a potent synergizer of cisplatin in targeting hepatocellular carcinoma cells

Liver cancer is one of the most common malignancies that is difficult to treat due to late diagnosis and chemo-resistance. In the present study, we developed and validated a cell based split nanoLuc biosensor to monitor the Apaf1-Apaf1 interactions in response to apoptosis-inducing drugs such as cisplatin. We showed that the activity of split nanoLuc is reconstituted only in response to apoptotic inducer, cisplatin and in a dose-dependent manner. Apaf1 mutants which were unable to oligomerize failed to recover nanoLuc activity while constitutively active variant increased the nanoLuc activity. Generation of Apaf1 knockout HepG2 and treatment with cisplatin showed dramatic reduction in cell death suggesting that cisplatin mainly targets liver cancer cells through apoptosis. As the natural products are potent sources of compounds for adjuvant therapy, we screened a collection of natural products and identified lentinan as an inducer of apoptosome formation, a key step for induction of apoptosis. Lentinan is a polysaccharide with antitumor, pro-apoptotic properties that functions with poorly understood mechanisms. Lentinan was shown to have cytotoxic effects with the IC₅₀ of 650 μM. Sub-lethal lentinan concentration doubled the nanoLuc activity when co-treated with cisplatin. We also showed that lentinan hugely reduced the dose of cisplatin to induce certain amount of death and that lentinan co-treatment with cisplatin enhanced the Apaf1 transcription in HepG2 cells while lentinan or cisplatin alone failed to alter the transcription. In addition, lentinan and cisplatin co-treatment induced mitochondrial depolarization. This suggested that lentinan combinatorial therapy with cisplatin engaged a different signalling pathway to kill the liver cancer cells and that adjuvant therapy with lentinan can reduce the dose of cisplatin and thus reduce the possibility of chemo-resistance.

Lentinan inhibited colon cancer growth by inducing endoplasmic reticulum stress-mediated autophagic cell death and apoptosis

Lentinan (SLNT) has been shown to be directly cytotoxic to cancer cells. However, this direct antitumour effect has not been thoroughly investigated in vivo, and the mechanism remains unclear. We aimed to examine the direct antitumour effect of SLNT on human colon cancer and the mechanism in vivo and in vitro. SLNT significantly inhibited tumour growth and induced autophagy and endoplasmic reticulum stress (ERS) in HT-29 cells and tumour-bearing nonobese diabetic (NOD)/severe combined immunodeficiency (SCID) mice. Experiments with the autophagy inhibitors chloroquine (CQ) and 3-methyladenine (3-MA) showed that autophagy facilitated the antitumour effect of SLNT. Moreover, ERS was identified as the common upstream regulator of SLNT-induced increases in Ca2+concentrations, autophagy and apoptosis by using ERS inhibitors. In summary, our study demonstrated that SLNT exerted direct antitumour effects on human colon cancer via ERS-mediated autophagy and apoptosis, providing a novel understanding of SLNT as an anti-colon cancer therapy.

Lentinan protects against pancreatic β-cell failure in chronic ethanol consumption-induced diabetic mice via enhancing β-cell antioxidant capacity

Chronic ethanol consumption is a well-established independent risk factor for type 2 diabetes mellitus (T2DM). Recently, increasing studies have confirmed that excessive heavy ethanol exerts direct harmful effect on pancreatic β-cell mass and function, which may be a mechanism of pancreatic β-cell failure in T2DM. 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 ethanol and the possible mechanisms implicated. Functional studies reveal that LNT attenuates chronic ethanol consumption-induced impaired glucose metabolism in vivo. In addition, LNT ameliorates chronic ethanol consumption-induced β-cell dysfunction, which is characterized by reduced insulin synthesis, defected insulin secretion and increased cell apoptosis. Furthermore, mechanistic assays suggest that LNT enhances β-cell antioxidant capacity and ameliorates ethanol-induced oxidative stress by activating Nrf-2 antioxidant pathway. Our results demonstrated that LNT prevents ethanol-induced pancreatic β-cell dysfunction and apoptosis, and therefore may be a potential pharmacological agent for preventing pancreatic β-cell failure associated with T2DM and stress-induced diabetes.

Lentinan as a natural stabilizer with bioactivities for preparation of drug-drug nanosuspensions

Lentinan is a natural β-glucan with various bioactivities and is combined with chemotherapy drugs for cancer treatment. Regorafenib is an oral multi-kinase inhibitor approved by FDA for treatment of metastatic colorectal cancer, advanced hepatocellular carcinoma, and metastatic gastrointestinal stromal tumors. Regorafenib has poor water solubility and multiple toxicities. We report drug-drug nanosuspensions of regorafenib and lentinan. Results of dynamic light scattering and scanning electron microscopy showed that the mean particle size of the regorafenib-lentinan nanosuspensions was approximately 200 nm and was uniformly distributed. Transmission electron microscopy findings indicated that lentinan stabilized the nanosuspensions by steric manner. Hydrogen bonds and hydrophobic interactions were found between regorafenib and lentinan by molecular dynamics simulation. The results of cytotoxicity assay and pharmacokinetics study in rats showed that the regorafenib-lentinan nanosuspensions reduced the toxicity and enhanced the in vitro anticancer activity and oral bioavailability of regorafenib. Lentinan as a natural stabilizer has the potential using for drug nanosuspensions. Drug-drug nanosuspensions are a new form of combination therapies that can reduce the number of drugs taken by patients and improve their compliance.

Lentinan administration alleviates diarrhea of rotavirus-infected weaned pigs via regulating intestinal immunity

BACKGROUND

Lentinan (LNT) may regulate many important physiological functions of human and animals. This study aimed to verify whether LNT administration could relieve diarrhea via improving gut immunity in rotavirus (RV)-challenged weaned pigs.

METHODS

Twenty-eight weaned pigs were randomly fed 2 diets containing 0 or 84 mg/kg LNT product for 19 d (n = 14). RV infection was executed on d 15. After extracting polysaccharides from LNT product, its major monosaccharides were analyzed. Then, LNT polysaccharide was used to administrate RV-infected IPEC-J2 cells.

RESULTS

Dietary LNT supplementation supported normal function of piglets even when infected with RV, as reflected by reduced growth performance loss and diarrhea prevalence, and maintained gut immunity (P < 0.05). The polysaccharide was isolated from LNT product, which molecular weight was 5303 Da, and major monosaccharides included glucose, arabinose and galactose. In RV-infected IPEC-J2 cells, this polysaccharide significantly increased cell viability (P < 0.05), and significantly increased anti-virus immunity via regulating pattern recognition receptors and host defense peptides (P < 0.05).

CONCLUSION

Those results suggest that LNT administration increases the piglets' resistance to RV-induced stress, likely by supporting intestinal immunity.

A carboxymethyl lentinan layer by layer self-assembly system as a promising drug chemotherapeutic platform

Surface functionalization of mesoporous silica nanoparticles (MSNs) has been proposed as an efficient strategy for enhancing the biocompatibility and efficiency of an MSN-based carrier platform. Herein, natural polyelectrolyte multilayers composed of poly-l-ornithine (PLO) and carboxymethyl lentinan (LC) were coated on the surface of MSNs through a layer-by-layer (LbL) self-assembly technique, and were characterized by ζ-potential, FTIR, ¹³C NMR, SEM, TEM, XRD, and TG. The prepared carrier presented alternating positive and negative potentials when coated with the polyelectrolytes, and the surface of MSN-PLO/LC was rougher compared to the naked MSNs. The biocompatibility tests, including cytocompatibility, hemocompatibility, and histocompatibility, showed that MSNs biocompatibility could be improved by modifying LC. A high loading and sustained release drug delivery system was constructed after loading doxorubicin (DOX) into the prepared MSN-PLO/LC, which exhibited significant anti-proliferative efficiency in human cervical cancer cell lines (Hela). Therefore, the PLO/LC LbL NPs (layer-by-layer self-assembled nanoparticles coated with PLO/LC layers) based on MSNs, which is easily prepared by electrostatic interactions, can be considered a promising drug chemotherapeutic platform and delivery technique for future human cervical cancer therapy.

Green synthesis of platinum nanoclusters using lentinan for sensitively colorimetric detection of glucose

The sensitive colorimetric detection of glucose using nanomaterials has been attracting considerable attention. To improve the detection sensitivity, highly stable lentinan stabilized platinum nanoclusters (Pt-LNT NCs) were prepared, in which lentinan was employed as a mild reductant and stabilizer. The size of platinum nanoclusters (Pt NCs) was only 1.20 ± 0.29 nm. Pt-LNT NCs catalyzed the oxidation of substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H₂O₂) to produce a blue oxidation product with absorption peak at 652 nm, indicating their peroxidase-like properties. Their enzymatic kinetics followed typical Michaelis-Menten theory. In addition, fluorescence experiments confirmed their ability to efficiently catalyze the decomposition of H₂O₂ to generate •OH, which resulted in the peroxidase-like mechanism of Pt-LNT NCs. Moreover, a colorimetric method for highly selective and sensitive detection of glucose was established by using Pt-LNT NCs and glucose oxidase. The linear range of glucose detection was 5-1000 μM and the detection limit was 1.79 μM. Finally, this method was further used for detection of glucose in human serum and human urine. The established colorimetric method may promote the development of biological detection and environmental chemistry in the future.

Molecular dynamics simulation of lentinan and its interaction with the innate receptor dectin-1

Lentinan, a β-1,3-D-glucan, is clinically used as an immune enhancement drug for tumor therapy. Dectin-1 is a cell-surface immune receptor, which plays an important role in immunological defense against fungal pathogens and β-glucan-mediated immune modulation. Herein we attempted to study the advanced structure of lentinan and how lentinan interacts with dectin-1 for its immune enhancement effect. We firstly used MD simulation and rigid macromolecule docking, combining some spectral techniques, to uncover the complex 3D conformation of a typical polysaccharide - lentinan, and the detailed interaction mode of lentinan with dectin-1. We proved by computational simulation that lentinan can maintain its triple-helix through hydrogen network and disclosed some structural properties of lentinan. We also characterized the affinity of lentinan to dectin-1 by LSPR and binding free energy calculation, and we found out that hydrogen bonds and CH-π interaction are the major contributors for lentinan's binding to dectin-1. Besides, after bound with lentinan, dectin-1 might surprisingly go through a conformational change. In summary, our work provided insights into lentinan's advanced structure and β-glucan recognition by dectin-1.

Lentinan Inhibited the Activation of Th2 Cells in Allergic Mice by Reducing the Amplitude of Changes in Biological Rhythm

INTRODUCTION

Biological rhythm is inextricably linked to the physiological mechanisms of allergic diseases, but the exact mechanisms are still poorly understood. Clinical studies have reported rhythmic fluctuations in allergic diseases. The search for natural and harmless active ingredients based on biological rhythm with which to regulate allergic diseases is essential for the control of food allergy.

METHODS

In this study, mice were treated at different time points to determine the link between the severity of allergic reactions and the circadian clock genes. The mice were treated with lentinan, either continuously or discontinuously, to assess their clinical symptoms, vascular permeability, immune cells, cytokines, and clock genes. Specifically, rat basophilic leukemia (RBL-2H3) cells were treated with lentinan and the rhythmic changes of cell degranulation were measured.

RESULTS

The results in different models showed that the allergic reactions in mice treated at different time points were significantly different and thus related to fluctuations in biological rhythm. Treatment with lentinan was found to reduce the amplitude of changes in the clock genes, such as the activation of Per and Cry proteins in allergic mice, as well as to regulate biological rhythm in cells, inhibit the activation of Th2 cells, and alleviate allergic reactions. Furthermore, lentinan changed the rhythm of degranulation in RBL-2H3 cells.

CONCLUSION

Lentinan was, therefore, determined to successfully alleviate allergic reactions by reducing the amplitude of changes in the body's biological rhythm, inhibiting the activation of Th2 cells, and affecting the immune microenvironment.

Preparation of lentinan-calcium carbonate microspheres and their application as vaccine adjuvants

Adjuvants improve vaccine potency by enhancing immunogenicity and sustaining long-term immune responses. Lentinan (LNT), a β-1,3-glucohexaose with β-1,6-branches, is extracted from the mushroom Lentinus edodes and functions as an effective immunostimulatory drug. Previous studies have demonstrated the adjuvant activity of calcium carbonate (CaCO₃) microspheres as well as their use as antigen delivery systems. In this study, we successfully loaded CaCO₃ microspheres with LNT and evaluated their physicochemical characteristics prior to the adsorption of ovalbumin. Our experimental results demonstrated that LNT-CaCO₃ significantly enhanced lymphocyte proliferation, and boosted the frequency of CD69 + B cells and the ratio of CD4+ to CD8 + T cells in spleen lymphocytes. Moreover, LNT-CaCO₃ unexpectedly induced the secretion of IgG and Th-associated cytokines (IL-2, IL-4, IFN-γ, and TNF-α) in immunized mice. Therefore, LNT-CaCO₃ microspheres induce robust cellular and humoral immune responses and have potential utility as vaccine delivery systems.

Intrathoracic infusion therapy with Lentinan and chemical irritants for malignant pleural effusion: a systematic review and meta-analysis of 65 randomized controlled trials

BACKGROUND

Aderivative of Shiitake mushrooms, Lentinan is used to control malignant pleural effusion (MPE) through intrathoracic infusion.

PURPOSE

To determine the clinical response, survival and safety of Lentinan plus chemical irritants, and the optimal combinations with chemical irritants, indication, threshold and optimal regimen for achieving the desired responses.

STUDY DESIGN

We performed a new systematic review and meta-analysis following the PRISMA guidelines.

METHODS

We collected all randomized controlled trials (RCTs) regarding Lentinan plus chemical irritants from Chinese and English electronic databases (from inception until March 2019). We evaluated their bias risk, synthesized data using meta-analysis, and summarized evidence quality following the Grades of Recommendation Assessment, Development and Evaluation approach.

RESULTS

We included 65 RCTs involving 4,080 patients and nine chemical irritants. Most trials had unclear bias risk. Lentinan with cisplatin significantly improved complete response [Risk ratio (RR) = 1.68, 95% confidence intervals (CI) (1.51 to 1.87), p < 0.00001, Fig.3a] and quality of life [RR = 1.51 95% CI (1.41 to 1.62), p < 0.00001, Fig.4], and decreased the risk of treatment failure, myelosuppression, gastrointestinal reaction, and chest pain. For patients with moderate to large volume of the pleural effusion, primary treatment, KPS score ≥ 50-60, or anticipated survival time ≥ 3months, Lentinan (3-4 mg/time, once a week for three to four times) withcisplatin (30-40 mg/m2 or 50-60 mg/m2) significantly improved complete response and decreased failure. Most results were robust and moderate quality.

CONCLUSION

The results suggest that Lentinan with chemical irritants, especially cisplatin is beneficial to the patient with MPE, and provide evidence for the indication, threshold, and optimal regimen that may achieve success and decrease failure.

Evaluation of Efficacy and Safety for Lentinan in the Control of the Malignant Pleural Effusions via Intrapleural Injection

BACKGROUND

Many studies have investigated the efficacy and safety of lentinan combined with cisplatin versus cisplatin alone for controlling malignant pleural effusion (MPE). This study is a meta-analysis of available evidence.

MATERIALS AND METHODS

Seventeen studies reporting lentinan combined with cisplatin versus cisplatin alone for controlling MPE were reviewed. Pooled odds ratios and hazard ratio with 95% confidence intervals were calculated using the fixed effects model of meta-analysis.

RESULTS

The overall response rate (ORR) of lentinan combined with cisplatin for controlling MPE was significantly higher than that of cisplatin alone (P < 0.001). In addition, lentinan combined with cisplatin showed a better benefit of quality of life (QOL) compared with cisplatin alone (P < 0.001). The main adverse effects (AEs) found in the control plan were hematological reactions, nausea/vomiting, chest pain and fever. However, the presence of lentinan did not have an extra influence on the incidence of AEs (P > 0.05).

CONCLUSIONS

Intrapleural injection of lentinan combined with cisplatin had a better benefit of ORR and QOL for controlling MPE, compared with cisplatin alone. Moreover, lentinan combined with cisplatin had a similar incidence of AEs with cisplatin alone.

Effect of Lentinan on Peyer's patch structure and function in an immunosuppressed mouse model

Lentinan (LNT), a polysaccharide isolated from Lentinus edodes, has been shown to stimulate immune response. Despite its widespread use owing to its health benefits, epidemiologic and experimental studies that address the biological activities of LNT after oral administration to animals or humans are rare. In this study, the effects of LNT on the intestinal mucosal immune system of immunosuppressed mice were investigated. The number and size of the Peyer's patches (PPs), proliferation ability of PP lymphocytes, T and B lymphocyte percentage, and T-cell activation proportion, as well as the number of M-like cells in PPs, were determined. The antigen transfer ability of M-like cells and intestinal secretory immunoglobulin A (IgA) levels were also detected. After oral administration of LNT for 7 days, the number of PPs, lymphocytes in PPs, and the level of intestinal soluble IgA in immunosuppressed mice were increased. LNT maintained the percentage of T and B lymphocytes and upregulated the proportion of activated T cells in PPs. Furthermore, the number of M-like cells, which were differentiated from intestinal epithelial cells, and their antigen transfer ability were enhanced. These results indicate that orally administered LNT can improve the immune status of the intestinal mucosa in immunosuppressed mice.

Lentinan in-situ coated tungsten oxide nanorods as a nanotherapeutic agent for low power density photothermal cancer therapy

Development of high photothermal performance and biocompatible nanotherapeutic agents is of great importance for photothermal cancer treatment. In this paper, we have developed lentinan decorated tungsten oxide nanorods (W₁₈O₄₉@LTN NRs) via a mild one-step solvothermal route. Owing to the numerous surface hydroxyl groups of polymer chains, the presence of lentinan layer in the surface of W₁₈O₄₉ NRs lead to good biocompatibility. The lentinan layer also affects the crystal structure of W₁₈O₄₉ and improves near-infrared absorption (~1.7 × 10⁹ M^-1 cm^-1 at 980 nm), which is two orders of higher than previously reported PEGylated W₁₈O₄₉ nanowires. Even under near-infrared (NIR) laser irradiation at a very low power density of 0.4 W/cm², the temperature of W₁₈O₄₉@LTN NRs aqueous dispersion (125 μg/mL) could increase by 15.1 °C. The photothermal conversion efficiency of W₁₈O₄₉@LTN NRs reaches 33.86%, which is higher than previously reported WO_3-x hierarchical nanostructures (28.1%). Importantly, when cancer cells were treated with W₁₈O₄₉@LTN NRs (200 μg/mL) and 980 nm laser (0.4 W/cm²), a significant photo-induced cell killing behavior was observed. This work demonstrates that W₁₈O₄₉@LTN NRs have the potential for precise cancer treatment.

[Reflectance confocal microscopy in Shiitake dermatitis]

Shiitake dermatitis usually occurs 1-2 days after consumption of incompletely cooked or raw shiitake mushrooms and is characterized by linear, pruritic, erythematous papulovesicular rashes. It is caused by lentinan, a polysaccharide component of the cell walls of shiitake mushrooms. The histological examination showed an eczema-like morphology with spongiosis and lymphohistiocytic infiltrates. The results of reflectance confocal microscopy (RCM) correlated with the histopathological investigations. Therefore, RCM can be used for non-invasive diagnostic confirmation of Shiitake dermatitis in the future.

Immunomodulatory Effect of Lentinan on Aberrant T Subsets and Cytokines Profile in Non-small Cell Lung Cancer Patients

As a purified active component from traditional Chinese medicine, lentinan administration can be applied as beneficial chemo-immunotherapy for anti-tumor. In this study, the immunomodulatory effects of lentinan on aberrant T subsets and cytokines profile were evaluated for non-small cell lung cancer (NSCLC). Of all NSCLC patients treated with NP chemotherapeutic protocol (combination of vinorelbin and cisplatin), 73 cases were recruited in this retrospective cohort trial study, of which 38 cases received additional lentinan. The changes of aberrant T subsets and cytokines profile were compared between two groups (chemotherapy in combination with lentinan vs. conserved single chemotherapy) by flow cytometry and molecular biology. Higher subset ratio of CD3⁺CD8⁺ cytotoxic T cells was confirmed in the peripheral blood of NSCLC patients. Chemo-immunotherapy of lentinan resulted in a significant increase of CD3 + CD56+ NKT cells (15.7 ± 3.1%), compared with 8.6 ± 1.4% of NKT cells in single chemotherapy group, and up-regulated CD3⁺CD8⁺ and CD3⁺CD4⁺ subsets as well, but caused the decrease of CD4⁺CD25⁺ Tregs induction, accompanied by significant alleviation of IL-10 and TGF-β1, and elevation of IFN-γ, TNF-α, and IL-12 (P < 0.05). It could be confirmed that lentinan could not only enhance the cellular immunity and promote the beneficial of anti-tumor by associated immunotherapy, but also had the ability to inhibit the expansion of immune suppressive Tregs in the NSCLC patients, in whom there was a raised Tregs induction compared to health control. Lentinan-based chemo-immunotherapy is a promising strategy for anti-tumor via enhancing the proliferation of cytotoxic T cells, followed by the elevation of inflammatory chemokines/cytokines. Meanwhile, the percentage of CD4+ CD25+ Tregs is down-regulated, leading to a shift in the inflammatory status from Th2 to Th1 in NSCLC patients treated with lentinan.

Lentinan inhibits tumor angiogenesis via interferon γ and in a T cell independent manner

Background

Antiangiogenic agents are commonly used in lung and colon cancer treatments, however, rapid development of drug resistance limits their efficacy.

Methods

Lentinan (LNT) is a biologically active compound extracted from Lentinus edodes. The effects of LNT on tumor angiogenesis were evaluated by immunohistochemistry in murine LAP0297 lung and CT26 colorectal tumor models. The impacts of LNT on immune cells and gene expression in tumor tissues were determined by flow cytometry, qPCR, and ELISA. Nude mice and IFNγ blockade were used to investigate the mechanism of LNT affecting on tumor angiogenesis. The data sets were compared using two-tailed student’s t tests or ANOVA.

Results

We found that LNT inhibited tumor angiogenesis and the growth of lung and colon cancers. LNT treatments elevated the expression of angiostatic factors such as IFNγ and also increased tumor infiltration of IFNγ-expressing T cells and myeloid cells. Interestingly, IFNγ blockade, but not T cell deficiency, reversed the effects of LNT treatments on tumor blood vessels. Moreover, long-lasting LNT administration persistently suppressed tumor angiogenesis and inhibited tumor growth.

Conclusions

LNT inhibits tumor angiogenesis by increasing IFNγ production and in a T cell-independent manner. Our findings suggest that LNT could be developed as a new antiangiogenic agent for long-term treatment of lung and colon cancers.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0932-y) contains supplementary material, which is available to authorized users.

Protective effects of lentinan on lipopolysaccharide induced inflammatory response in intestine of juvenile taimen (Hucho taimen, Pallas)

Antioxidant effects of lentinan on LPS induced inflammatory response in intestine of juvenile taimen were evaluated, and its prebiotic-like efficacy on intestinal microbiota was also investigated. The results showed that LPS decreased the activities of antioxidant enzymes and increased the expression levels of inflammatory cytokines in intestine of juvenile taimen. Dietary lentinan significantly enhanced intestinal antioxidant ability by increasing the activities of SOD, GSH-Px and CAT, and inhibiting the lipid peroxidation in juvenile taimen. Appropriate lentinan prevented the increases in the expression levels of TGF-β, TNF-α, IL1β, IL6 and IL8 and ensured the relatively high expression levels of claudin d, SOD, CAT and IκBα after LPS challenge. Furthermore, dietary lentinan effectively modified intestinal microbiota, represented by increasing the relative abundance of beneficial bacteria such as Lactobacillaceae, Lachnospiraceae and Ruminococcaceae, and decreasing those of detrimental bacteria such as Enterobacteriaceae, Fusobacteriaceae and Flavobacteriaceae. Taken together, dietary lentinan availably decreased LPS induced inflammatory response, indicating that lentinan has the potential anti-inflammatory effects for preventing inflammation diseases in cold-water fish.

Lentinan as an immunotherapeutic for treating lung cancer: a review of 12 years clinical studies in China

PURPOSE

Lentinan is a polysaccharide extracted from Shiitake mushrooms that have been used to improve general health for thousands of years in Asia. Lentinan injection is a clinically approved drug in several countries in Asia. The purpose of this study is to review the structure, preclinical and clinical studies, and molecular mechanisms of lentinan. Most importantly, the clinical effectiveness of lentinan as an adjuvant therapeutic drug in treating patients with lung cancer in China during the past 12 years is analyzed statistically.

METHODS

We carried out literature search of randomized controlled trials (RCTs) published from 2004 to 2016 based on CNKI (China National Knowledge Infrastructure), VIP (Chongqing VIP Chinese Scientific Journals Database) and Wanfang database, and 38 eligible RCTs of lentinan-associated lung cancer treatment were identified, containing 3,117 patients.

RESULTS

The structure and function relationship and underlying molecular mechanism of lentinan as an immunostimulant has been summarized. The mean value of overall response rate in treating lung cancer was increased from 43.3% of chemotherapy alone to 56.9% of lentinan plus chemotherapy [p < 0.001, 95% confidence interval (CI) 0.102-0.170]. Compared with chemotherapy alone, lentinan plus chemotherapy showed more efficacy in treating lung cancer (pooled RR 0.79, 95% CI 0.74-0.85) and no statistical heterogeneity was found among studies (I² = 11%).

CONCLUSION

Clinical data presented in the past 12 years shows that lentinan is effective not only in improving quality of life, but also in promoting the efficacy of chemotherapy during lung cancer treatment.

Metabolomics insights into the modulatory effects of long-term compound polysaccharide intake in high-fat diet-induced obese rats

Background

Polysaccharides can alleviate obesity in mammals; however, studies on mechanism of this alleviation are limited. A few studies have indicated that polysaccharides improve obesity by regulating the metabolism of the body. Therefore, a metabolomics approach, consisting of high resolution nuclear magnetic resonance (NMR) spectroscopy and a multivariate statistical technique, was applied to explore the mechanism of the protective effects of lentinan and Flos Lonicera polysaccharides (LF) on high-fat diet (HFD) induced obesity.

Methods

In this study, rats were randomly divided into three groups: control diet (CD), HFD, and HFD supplemented with a mixture of lentinan and Flos Lonicera polysaccharide. Histopathological and clinical biochemical assessments were also conducted. A combination of a NMR metabolomics study and a multivariable statistical analysis method to distinguish urinary and fecal metabolites was applied.

Results

Significant obesity symptoms appeared in HFD rats (for example, significant weight gain, epididymal adipose accumulation and lipid deposition in hepatocytes), which was attenuated in the LF group. Additionally, the HFD induced a reduction of choline, citrate, pyruvate and glycerol and increased the levels of trimethylamine oxide (TMAO) and taurine. Of note, these metabolic disorders were reversed by LF intervention mainly through pathways of energy metabolism, choline metabolism and gut microbiota metabolism.

Conclusions

LF supplementation had a re-balancing effect on the disturbed metabolic pathways in the obese body. The results of this study validate the therapeutic effect of the compound polysaccharide--LF in obesity and described the biochemical and metabolic mechanisms involved.

Electronic supplementary material

The online version of this article (10.1186/s12986-018-0246-2) contains supplementary material, which is available to authorized users.

[A retrospective analysis of chemotherapy for gastric cancer in later-stage elderly patients]

AIM

Despite the significant advances in chemotherapy, the prognosis of unresectable or recurrent gastric cancer is still very poor. Given that older adults are likely to have a number of concomitant diseases and an impaired major organ function, cancer chemotherapy in elderly patients requires particular caution. We examined what factors are associated with the overall survival of gastric cancer patients undergoing chemotherapy.

METHODS

A retrospective chart review of gastric cancer patients receiving oral fluoropyrimidines (N=130) was performed at Nagoya Memorial Hospital over 9 years. The overall survival was calculated from the beginning of chemotherapy until death or the most recent date of follow-up. The Kaplan-Meier method was used to plot survival curves, which were compared using the log-rank test. A multivariate analysis was performed using stepwise Cox proportional hazards models. A comprehensive geriatric assessment was conducted for the elderly patients. The chart review was approved by the ethics committee of Nagoya Memorial Hospital.

RESULTS

The objective response rate and overall survival did not differ markedly between the patients < 75 years (N=64) and those ≥ 75 years of age (N=28). The addition of lentinan significantly prolonged the survival of the stage 4 gastric cancer patients. In a multivariate analysis of those ≥ 75 years of age, the only independent prognostic factor for the survival was the functional capacity, as measured by the TMIG Index of Competence.

CONCLUSIONS

This comprehensive geriatric assessment was useful for predicting the longevity of patients with stage 4 gastric cancer ≥ 75 years of age.

Lentinan diminishes apoptotic bodies in the ileal crypts associated with S-1 administration

S-1 is an oral agent containing tegafur (a prodrug of 5-fluorouracil) that is used to treat various cancers, but adverse effects are frequent. Two pilot clinical studies have suggested that lentinan (LNT; β-1,3-glucan) may reduce the incidence of adverse effects caused by S-1 therapy. In this study, we established a murine model for assessment of gastrointestinal toxicity associated with S-1 and studied the effect of LNT. S-1 was administered orally to BALB/c mice at the effective dose (8.3mg/kg, as tegafur equivalent) once daily (5days per week) for 3weeks. Stool consistency and intestinal specimens were examined. We investigated the effect of combined intravenous administration of LNT at 0.1mg, which is an effective dose in murine tumor models. We also investigated the effect of a single administration of S-1. During long-term administration of S-1, some mice had loose stools and an increase in apoptotic bodies was observed in the ileal crypts. An increase in apoptotic bodies was also noted after a single administration of S-1 (15mg/kg). Prior or concomitant administration of LNT inhibited the increase in apoptotic bodies in both settings. Administration of LNT also increased the accumulation of CD11b⁺TIM-4⁺ cells in the ileum, while depletion of these cells by liposomal clodronate diminished the inhibitory effect of LNT on S-1 toxicity. Combined administration of LNT with S-1 led to a decrease in apoptotic bodies in the ileal crypts, possibly because LNT promoted phagocytosis of damaged cells by CD11b⁺TIM-4⁺ cells.

Beta-glucan contamination of pharmaceutical products: How much should we accept?

Beta-glucans are large polysaccharides produced by a range of prokaryotic and eukaryotic organisms. They have potential immunostimulatory properties and have been used with therapeutic intent as anti-microbial and anti-tumour agents. A range of other potentially beneficial effects have been described, and oral forms of beta-glucans are widely available over-the-counter and online. Parenteral formulations are popular in parts of Asia and are the subject of ongoing trials, worldwide. Beta-glucans are also potential contaminants of pharmaceutical products, and high levels have been described in some blood products. However, little is known about the clinical effects of such contamination, considerable uncertainty exists over the level at which immunostimulation may occur, and there are no guidelines available on acceptable levels. We encountered beta-glucan contamination of one of our products, and we suspect that others may encounter similar issues since the origin of beta-glucan contamination includes commonly used filters and solutions applied in the manufacture of biotherapeutic agents. It is likely that regulators will increasingly enquire about beta-glucan levels in pharmaceutical products, especially those with an immunomodulatory mechanism of action. Here, we review the literature on beta-glucans in pharmaceutical products and propose an acceptable level for therapeutic agents for parenteral use.

Lentinan produces a robust antidepressant-like effect via enhancing the prefrontal Dectin-1/AMPA receptor signaling pathway

Lentinan (LNT) is an immune regulator and its potential and mechanism for the treatment of mood disorder is of our interest. Dectin-1 is a β-glucan (including LNT) receptor that regulates immune functions in many immune cell types. Cumulative evidence has suggested that the glutamatergic system seems to play an important role in the treatment of depression. Here, we studied the antidepressant-like effects of LNT and its therapeutical target in regulating the functions of AMPA receptors. We found that 60min treatment with LNT leads to a significant antidepressant-like effect in the tail suspension test (TST) and the forced swim test (FST) in mice. The antidepressant-like effects of LNT in TST and FST remained after 1day or 5days of injections. Additionally, LNT did not show a hyperactive effect in the open field test. Dectin-1 receptor levels were increased after LNT treatment for 5days and the specific Dectin-1 inhibitor laminarin was able to block the antidepressant-like effects of LNT. After 5days of treatment, LNT enhanced p-GluR1 (S845) in the prefrontal cortex (PFC); however, the total GluR1, GluR2, and GluR3 expression levels remained unchanged. We also found that the AMPA-specific blocker GYKI 52466 was able to block the antidepressant-like effects of LNT. This study identified LNT as a novel antidepressant with clinical potential and a new antidepressant mechanism for regulating prefrontal Dectin-1/AMPA receptor signaling.

Randomised phase III study of S-1 alone versus S-1 plus lentinan for unresectable or recurrent gastric cancer (JFMC36-0701)

BACKGROUND

Lentinan (LNT) is a purified β-1, 3-glucan that augments immune responses. The present study was conducted to assess the efficacy of LNT in combination with S-1 as a first-line treatment for unresectable or recurrent gastric cancer.

PATIENTS AND METHODS

Eligible patients were randomly assigned to receive S-1 alone or S-1 plus LNT. The primary end-point was overall survival (OS). Secondary end-points were time-to-treatment failure (TTF), overall response rate (ORR), safety, quality of life (QOL), and biomarker. The percentages of LNT-binding monocytes in peripheral blood prior to treatment were analysed for the biomarker assessment.

RESULTS

One hundred and fifty-four and 155 patients were randomly assigned to receive S-1 alone or S-1 plus LNT, respectively. The median OS was 13.8 and 9.9 months (P = 0.208), the median TTF was 4.3 and 2.6 months (P < 0.001), the ORR was 22.3% and 18.7% for the S-1 and S-1 plus LNT groups, respectively. The incidences of haematologic and non-haematologic adverse events were similar, and no significant changes in QOL scores were observed during the treatment in both groups. In a subpopulation of patients with LNT-binding monocytes ≥2%, patients who received more than two cycles of chemotherapy showed a longer survival time in the S-1 plus LNT group.

CONCLUSIONS

OS did not improve and TTF was significantly worse in the S-1 plus LNT group as compared with the S-1-only group. This study showed no efficacy of LNT when combined with S-1 treatment in patients with unresectable or recurrent gastric cancer.

CLINICAL TRIAL REGISTRATION ID NUMBER

UMIN 000000574.