pH control strategy in a shaken minibioreactor for polysaccharide production by medicinal mushroom Phellinus linteus and its anti-hyperlipemia activity

Isolation Techniques, Structural Characteristics, and Pharmacological Effects of Phellinus Polysaccharides: A Review

Phellinus is a precious perennial medicinal fungus. Its polysaccharides are important bioactive components, and their chemical composition is complex. The polysaccharides are mainly extracted from the fruiting body and mycelium. The yield of the polysaccharides is dependent on the extraction method. They have many pharmacological activities, such as antitumor, immunomodulatory, antioxidant, hypoglycemic, anti-inflammatory, etc. They are also reported to show minor toxic and side effects. Many studies have reported the anticancer activity of Phellinus polysaccharides. This review paper provides a comprehensive examination of the current methodologies for the extraction and purification of Phellinus polysaccharides. Additionally, it delves into the structural characteristics, pharmacological activities, and mechanisms of action of these polysaccharides. The primary aim of this review is to offer a valuable resource for researchers, facilitating further studies on Phellinus polysaccharides and their potential applications.

Structural diversity and bioactivity of polysaccharides from medicinal mushroom Phellinus spp.: A review

Phellinus spp., an important medicinal fungus mushroom extensively cultivated and consumed in East Asia for over 2000 years, is traditionally considered a precious food supplement and medicinal ingredient. Published studies showed that the polysaccharides are major bioactive macromolecules from Phellinus spp. (PPs) with multiple health-promoting effects, including immunomodulatory, anti-cancer, anti-inflammatory, hepatoprotective, hypoglycemic, hypolipidemic, antioxidant, and other bioactivities. Although the polysaccharides extracted from the fruiting body, mycelium, and fermentation broth of Phellinus spp. have been extensively studied for the extraction and purification methods, structural characteristics, and pharmacological activities, the knowledge for their structures and bioactivity relationship, toxicologic effects, and pharmacokinetic profile is limited. This review systematically summarizes the recent progress in the isolation and purification, chemical structures, bioactivities, and the underlying mechanisms of PPs. Information from this review provides insights into the further development of polysaccharides from PPs as therapeutic agents and functional foods.

Dietary Fiber: An Opportunity for a Global Control of Hyperlipidemia

Dietary fiber has a long history in the intervention study of hyperlipidemia. In this review, current understandings of structures, sources, and natures of various kinds of dietary fibers (DFs) were analyzed first. Available evidences for the use of different varieties of DFs in the lipid-lowering action both in vitro and in vivo were subsequently classified, including both soluble ones, such as glucans, pectins, and gums, and insoluble ones, including arabinooxylans and chitosans, in order to draw a primary conclusion of their dose and molecular weight relationship with lipid-lowering effect. Their potential mechanisms, especially the related molecular mechanism of protective action in the treatment and prevention of hyperlipidemia, were summarized at last. Five major mechanisms are believed to be responsible for the antihyperlipidemic benefits of DFs, including low levels of energy, bulking effect, viscosity, binding capacity, and fermentation thus ameliorating the symptoms of hyperlipidemia. From the molecular level, DFs could possibly affect the activities of HMG-CoA reductase, LDL receptors, CYP7A1, and MAPK signaling pathway as well as other lipid metabolism-related target genes. In summary, dietary fibers could be used as alternative supplements to exert certain lipid-lowering effects on humans. However, more clinical evidence is needed to strengthen this proposal and its fully underlying mechanism still requires more investigation.

Novel external-loop-airlift milliliter scale bioreactors for cell growth studies: Low cost design, CFD analysis and experimental characterization

Many researchers have limited access to fully equipped laboratory-scale batch bioreactors and chemostats due to their relatively high cost. This becomes particularly prohibitive when multiple replicas of the same experiment are required, but not enough bioreactors are available to operate simultaneously. Additionally, experiments using shaken flasks are common but show significant limitations in terms of maintaining homogeneous conditions in liquid cultures or installing instrumentation for monitoring. Here, we proposed to tackle this significant hurdle by providing a route to make available the manufacture of low-cost, milliliter-scale bioreactors. This approach seems plausible for enabling proof-of-concept experiments before moving to a larger scale without significant investments. The conceptually designed systems were based on external-loop bioreactors due to their flexibility, simplicity, and ease of assembling and testing. Designs were initially evaluated in silico with the aid of COMSOL Multiphysics. The successfully evaluated systems were then constructed via additive manufacturing and assembled for hydrodynamics testing via tracer methods. This was enabled by a newly home-made optical absorbance sensor (OAS) for in-line and real-time measurements. Both the in silico and experimental results indicated close to ideal mixing conditions and low shear stress. Cell growth curves were prepared by culturing Escherichia coli and following its cell density in real-time. Our cell growth rate and maximum cell density were similar to those previously obtained in closely related systems. Therefore, the proposed bioreactors are an affordable alternative for batch and continuous cell growth studies rapidly and inexpensively.

Anti-hyperlipidemic effect of rice bran polysaccharide and its potential mechanism in high-fat diet mice

Hyperlipidemia occurs very often in modern society along with a high calorie intake and is regarded as one of the greatest risk factors for the prevalence of cardiac vascular disease (CVD). In this study, we investigated the anti-hyperlipidemic effect of the rice bran polysaccharides (RBP) and its mechanism in a high fat diet animal model. 60 ICR mice were randomly divided into 3 groups, which included Control, HFD (high fat diet) and HFD + RBP, and each group included 20 mice. The control group was fed with a standard diet while the other two groups were fed with HFD. In addition, the HFD + RBP group was fed with 500 mg kg-1 of rice bran polysaccharides by intragastric administration while the other two groups were intragastrically administered with water. The results showed that RBP treatment for 10 weeks obviously decreased the body weight, liver weight and adipose tissues of mice; and it decreased the levels of total cholesterol (TC), triglycerides (TG) and low density lipoprotein-cholesterol (LDL-c) in the plasma. H&E staining of the liver tissues showed that RBP treatment decreased the size of fat droplets compared with the HFD group. Microarray analysis revealed that RBP treatment results in 80 genes being up-regulated while 72 genes were down-regulated in the tissues of liver. IPA software analysis suggested that NF-κB may play a vital role in the lipid-lowering effect of RBP. Real-time quantitative PCR confirmed that the mRNA levels of PPAR-α, PPAR-γ, PPAR-δ, SREBP-1C, FASN, ACC, SIRT and CD36, which are related to lipid metabolism, were significantly regulated by RBP supplementation compared to HFD. The western blot analysis further confirmed these altered expressions after RBP treatment. Taken together, these results suggest that the oral administration of RBP exerts lipid-lowering in high fat diet mice via regulating the lipid metabolism-related gene expression.

Traditional uses, fermentation, phytochemistry and pharmacology of Phellinus linteus: A review

Medicinal mushroom Phellinus linteus ("Sanghuang" in Chinese, ) is a famous fungus which is widely used in China, Korea, and other Asian countries. As a traditional Chinese medicine with a 2000-year long history, medicinal applications of Phellinus linteus mainly include treating hemorrhage, hemostasis and diseases related to female menstruation according to Chinese clinical empirical practice. A number of studies reported Phellinus linteus possessed good therapeutic effects on various ailments including tumor, diabetes, inflammation, obesity, etc. The present paper comprehensively reviewed the traditional uses, fermentation, constituent and pharmacology of Phellinus linteus based on scientific literature as well as critical analysis of the research. This review aimed to provide latest information and new foundations and directions for further investigations on Phellinus linteus. All available information about Phellinus linteus was supplied by library database and electronic search (CNKI, Google Scholar, ScienceDirect, Web of Science, PubMed, etc.). Some local and ancient books as well as brilliant scholars were also important information resources. Improvement of fermentation techniques promoted the production of Phellinus linteus. Studies of constituents showed the main chemical composition of Phellinus linteus included polysaccharides, flavones, triterpenes, aromatic acids, amino acids, etc. and polysaccharides were found to account for the largest proportion. Pharmacological researches revealed Phellinus linteus possessed a variety of biological activities including anti-cancer, immuno-regulation, anti-diabetes, anti-oxidation and anti-inflammation. Based on these summarized information, this review was presented to provide helpful references and beneficial directions for future studies of Phellinus linteus.

Bioactivities and Health Benefits of Mushrooms Mainly from China

Many mushrooms have been used as foods and medicines for a long time. Mushrooms contain polyphenols, polysaccharides, vitamins and minerals. Studies show that mushrooms possess various bioactivities, such as antioxidant, anti-inflammatory, anticancer, immunomodulatory, antimicrobial, hepatoprotective, and antidiabetic properties, therefore, mushrooms have attracted increasing attention in recent years, and could be developed into functional food or medicines for prevention and treatment of several chronic diseases, such as cancer, cardiovascular diseases, diabetes mellitus and neurodegenerative diseases. The present review summarizes the bioactivities and health benefits of mushrooms, and could be useful for full utilization of mushrooms.

Quantifying the sensitivity of G. oxydans ATCC 621H and DSM 3504 to osmotic stress triggered by soluble buffers

In Gluconobacter oxydans cultivations on glucose, CaCO3 is typically used as pH-buffer. This buffer, however, has disadvantages: suspended CaCO3 particles make the medium turbid, thereby, obstructing analysis of microbial growth via optical density and scattered light. Upon searching for alternative soluble pH-buffers, bacterial growth and productivity was inhibited most probably due to osmotic stress. Thus, this study investigates in detail the osmotic sensitivity of G. oxydans ATCC 621H and DSM 3504 using the Respiratory Activity MOnitoring System. The tested soluble pH-buffers and other salts attained osmolalities of 0.32-1.19 osmol kg(-1). This study shows that G. oxydans ATCC 621H and DSM 3504 respond quite sensitively to increased osmolality in comparison to other microbial strains of industrial interest. Osmolality values of >0.5 osmol kg(-1) should not be exceeded to avoid inhibition of growth and product formation. This osmolality threshold needs to be considered when working with soluble pH-buffers.

Discovery of a new sesquiterpenoid from Phellinus ignarius with antiviral activity against influenza virus

Seven natural products, including one new sesquiterpenoid (eudesm-1β, 6α, 11-triol, compound 1), one ergosta -4, 6, 8(14), 22-tetraen-3-one (compound 2), four polyphenols (compounds 3, 4, 5, 6), and one pyrone (3-hydroxy-2-methyl-4-pyrone, compound 7) were isolated from cultures of Phellinus ignarius by column chromatography. The detailed structure of compound 1 was determined using a combination of one- and two-dimensional nuclear magnetic resonance, mass spectrometry and infrared spectroscopy. The antiviral activity of these compounds against H5N1 influenza A virus was investigated using an MTT colorimetric assay system in Madin-Darby canine kidney cells. The results indicate that compound 1 possesses significant ability to inhibit influenza virus. The 50 % effective concentration was 0.14 ± 0.04 μM. Molecular modeling further suggested that the anti-influenza virus activity of this compound was partially attributed to the interactions of hydroxyl groups with an amino acid residue (Asn 170) of neuraminidase (NA) at the binding site. Moreover, the results of enzyme inhibition assays indicated that 50 % inhibition of NA was achieved by compound 1 at a concentration of 0.657 ± 0.325 mg/mL, which suggested that compound 1 is likely to interact with the NA enzyme.

Influence of rutin, FeSO4, Tween 80, aspartate and complex vitamins on synthesis of fungal exopolysaccharide

The influence of several components on exopolysaccharide (EPS) production and antioxidative activity (TEAC, Trolox-Equivalent Antioxidant Capacity) as well as their effects on the morphological development and cell viability of Phellinus sp. P0988 was determined. Rutin, FeSO(4), Tween 80 and complex vitamins were found to impose a stronger influence on EPS production and TEAC compared to their effects on the mycelia growth of Phellinus sp. P0988. The relative effects of these components on EPS activity were found to be different from that on EPS yield. Rutin and aspartate significantly affected EPS TEAC (P<0.05), while FeSO(4) and Tween 80 significantly influenced EPS production (P<0.05). These results yielded the optimum culture medium composition, with an EPS yield and TEAC of 6.2±0.2 g/L and 5.5±0.1 mM, respectively.

pH-control modes in a 5-L stirred-tank bioreactor for cell biomass and exopolysaccharide production by Tremella fuciformis spore

The effect of pH-control modes on cell growth and exopolysaccharide production by Tremella fuciformis was evaluated in a 5-L bioreactor. The results show that the maximal dry cell weight (DCW) and exopolysaccharide production were 23.57 and 4.48 g L⁻¹ in pH-stat fermentation, where the maximal specific growth rate (μ(max)) and specific production rate of exopolysaccharide (P(P/X)) were 1.03 and 0.24 d⁻¹, respectively; under pH-shift cultivation, the maximal DCW and exopolysaccharide production were 30.57 and 3.90 g L⁻¹, where the μ(max) and P(P/X) were 1.21 and 0.06 d⁻¹. Unlike batch fermentation, maximal DCW and exopolysaccharide production merely reached 15.04 and 2.0 g L⁻¹, where the μ(max) and P(P/X) were 0.86 and 0.05 d⁻¹, respectively. These results suggest that a pH-stat strategy is a more efficient way of performing the fermentation process to increase exopolysaccharide production. Furthermore, this research has also proved that the three-stage pH-control mode is effective for cell growth.

Optimization of culture medium for enhanced production of exopolysaccharide from Aureobasidium pullulans

Polysaccharides produced by microorganisms are utilized for a variety of purposes, including the use in cosmetics and as food additives. More recently, polysaccharides have been exploited by the medical and pharmaceutical industries, and those originated from many species of mushrooms have been especially useful in industrial applications; however, the production and synthesis of these compounds is costly and time consuming. In this study, we developed a method for low-cost production of exopolysaccharide (EPS) that effectively screens components and optimizes medium composition using statistical methods (Plackett-Burman and Box-Behnken design). As a result, we obtained the following optimized medium: sucrose 165.73 g/L, sodium nitrate 3.08 g/L, dipotassium phosphate 1.00 g/L, potassium chloride 0.50 g/L, magnesium sulfate 0.50 g/L, ferrous sulfate 0.01 g/L, and 0.71 g/L of Ashbya gossypii extract. The maximum production of about 29 g/L EPS was achieved in the optimized medium during 84 h batch fermentation.

Current advances in Phellinus sensu lato: medicinal species, functions, metabolites and mechanisms

Twenty-six species of Phellinus sensu lato, reported as medicinal mushrooms, are enumerated in this review. The species' names were checked and revised according to contemporary taxonomy and the latest version of the International Code of Botanical Nomenclature (Vienna Code); two misapplied names of Phellinus baumii Pilát and Phellinus himalayensis Y.C. Dai in previous reports are also discussed. Of the 20 types of medicinal functions, the most shared functions are antitumor and improving immunity, both of which may be viewed as the basal functions of Phellinus s. l. In addition, alleviating septic shock, anti-inflammatory, and antioxidation are also a routine functions mentioned often. The main medicinal metabolites, including several kinds of polysaccharides and polyphenols, are introduced. Different methods and conditions could purify various polysaccharides with difference in activity level even from the same species, while all polyphenols are hispidin and its derivatives in general. Three aspects of mechanism contribute to antitumor activities of polysaccharides: (1) promoting an immune response, (2) inducing cell apoptosis, and (3) inhibiting metastasis. Other general mechanisms of the metabolites in antioxidant activity, and in treating diabetes, as well as complications are summarized. We also elaborate on potential scientific strategies for obtaining the medicinal metabolites from Phellinus s. l., such as artificial cultivation, the discoveries of more species with medicinal functions, the utilization of species growing quickly, and the optimization of culture conditions and media supplements in fermentation.