Inhibitory effect of CDP, a polysaccharide extracted from the mushroom Collybia dryophila, on nitric oxide synthase expression and nitric oxide production in macrophages

Potential Medicinal Fungi from Freshwater Environments as Resources of Bioactive Compounds

Owing to their nutritional, culinary, and nutraceutical, mushrooms are worldwide consumed and appreciated. Moreover, many of these mushrooms are also known as medicinal mushrooms since they possess several pharmacological properties attributable to a huge number of bioactive compounds derived from their sporophores. Several studies are available in the literature about in vitro and in vivo mechanisms of actions of such bioactive compounds. Most of these surveys are focused on macrofungi belonging to the genera Pleurotus, Ganoderma, or specific taxa such as Agaricus bisporus, Agaricus blazei, Boletus eduliInonotus obliquus, Hericium erinaceus, Lentinula edodes, and Grifola frondose. On the other hand, there is a lack of information on the under investigated ecological group of freshwater fungi. These fungi play a very important role in freshwater environments and some of them, belonging to Basidiomycota, are also edible and largely consumed. In this review we collected information about the medicinal properties of freshwater macro- and micromycetes. Among them, macrofungi, such as Amanita vaginata, Armillaria mellea, Armillaria tabescens, Astraeus hygrometricus, Auricularia auricula-judae, Bjerkandera adusta, Bovista nigrescens, Calocybe gambosa, Candolleomyces candolleanus, Collybia dryophila, Coprinus comatus, Cyclocybe cylindracea, Hypsizygus ulmarius, Inonotus hispidus, Lactarius controversus, Lentinus tigrinus, and Schizophyllum commune, observed in riparian habitat, and microfungi, such as Penicillium aculeatum, P. chrysogenum, and Fusarium incarnatum, isolated from aquatic plants, have been reported to have antimicrobial, anticancer, anti-inflammatory, antioxidant, antidiabetic, immunomoludatory, hypoglycaemic, and other pharmaceutical activities. Such fungal species are noteworthy since they represent an important quote of biodiversity to preserve their fundamental ecological role and a possible solution for different health problems for humans and animal farms.

Antioxidation and immune-stimulatory actions of cold alkali extracted polysaccharide fraction from Macrocybe lobayensis, a wild edible mushroom

Mushroom β-glucans are presently gaining widespread attention, being one of the promising healthy compounds with excellent antioxidative and immunomodulatory activities. Conventionally, hot water extraction procedure is followed to isolate the polymers where the residue is discarded after filtration. However, the remnants still contain plenty of bioactive components that could provide a unique opportunity for the discovery of novel therapeutic agents. In this backdrop, the present study was aimed to expand utilization of a popularly edible mushroom, Macrocybe lobayensis, by re-cycling left-over material that has passed through traditional aqueous process. For that, the residue was immersed in alkaline solution followed by ethanol precipitation and repeated washing resulting preparation of a water soluble and partially purified polysaccharidic fraction (ML-CAP). Chemical and molecular characterization by FT-IR, HPTLC, GC-MS, GPC and spectroscopy unveiled that ML-CAP was consisted of a homo-polymer with Mw of ~ 122 kDa. The backbone was mainly composed of β-glucan where galactose was identified as the second most abundant unit. Subsequently, the fraction exhibited potent antioxidant activity in terms of radical scavenging, chelating ability and reducing power. Furthermore, strong immune enhancing property was also recorded as the polymer, particularly at the concentration of 100 µg/ml, triggered murine macrophage functionality in terms of cell proliferation, phagocytosis, pseudopods formation and nitric oxide production. The study thus advocates for potential application and further extraction of hot water extracted mushroom residue in drug development and nutraceutical industries, as the example of ML-CAP showed promising biological effects.

Medicinal Properties and Bioactive Compounds from Wild Mushrooms Native to North America

Mushrooms, the fruiting bodies of fungi, are known for a long time in different cultures around the world to possess medicinal properties and are used to treat various human diseases. Mushrooms that are parts of traditional medicine in Asia had been extensively studied and this has led to identification of their bioactive ingredients. North America, while home to one of the world's largest and diverse ecological systems, has not subjected its natural resources especially its diverse array of mushroom species for bioprospecting purposes: Are mushrooms native to North America a good source for drug discovery? In this review, we compile all the published studies up to September 2020 on the bioprospecting of North American mushrooms. Out of the 79 species that have been investigated for medicinal properties, 48 species (60%) have bioactivities that have not been previously reported. For a mere 16 selected species, 17 new bioactive compounds (10 small molecules, six polysaccharides and one protein) have already been isolated. The results from our literature search suggest that mushrooms native to North America are indeed a good source for drug discovery.

GIRK channel activity of Hungarian mushrooms: From screening to biologically active metabolites

In the current study effects of fungal extracts on the G-protein-activated inwardly rectifying potassium channel (GIRK1/4) were screened using the automated patch-clamp method. 40 organic (n-hexane, chloroform, and 50% methanol) and aqueous extracts were prepared from 10 mushroom species native to Hungary. Among the examined fungal fractions of different polarities some n-hexane and chloroform extracts exerted considerable ion channel activity. One of the most active fungal species, Hypholoma lateritium was selected for further detailed examination to determine the compounds responsible for the observed pharmacological property. Evaluation of the ion channel activity of mushroom metabolites 1-10 revealed that lanosta-7,9(11)-diene-12β,21α-epoxy-2α,3β,24β,25-tetraol (5) demonstrates remarkable blocking activity on GIRK current (IC₅₀ 395.1 ± 31.8 nM). Investigation of the selectivity of the GIRK inhibitory effect proved that lanosta-7,9(11)-diene-12β,21α-epoxy-2α,3β,24β,25-tetraol (5) has only weak inhibitory activity on hERG channel (7.9 ± 2.8% at 100 μM), exerting more than three orders of magnitude lower blocking activity on hERG channel than on GIRK channel.

Inhibition of lipopolysaccharide (LPS)-induced neuroinflammatory response by polysaccharide fractions of Khaya grandifoliola (C.D.C.) stem bark, Cryptolepis sanguinolenta (Lindl.) Schltr and Cymbopogon citratus Stapf leaves in raw 264.7 macrophages and U87 glioblastoma cells

Background

Khaya grandifoliola (C.D.C.) stem bark, Cymbopogon citratus (Stapf) and Cryptolepis sanguinolenta (Lindl.) Schltr leaves are used in Cameroonian traditional medicine for the treatment of inflammatory diseases. Several studies have been performed on the biological activities of secondary metabolites extracted from these plants. However, to the best of our knowledge, the anti-neuro inflammatory and protective roles of the polysaccharides of these three plants have not yet been elucidated. This study aimed at investigating potential use of K. grandifoliola, C. sanguinolenta and C. citratus polysaccharides in the prevention of chronic inflammation.

Methods

Firstly, the composition of polysaccharide fractions isolated from K. grandifoliola stem bark (KGF), C. sanguinolenta (CSF) and C. citratus (CCF) leaves was assessed. Secondly, the cytotoxicity was evaluated on Raw 264.7 macrophages and U87-MG glioblastoma cell lines by the MTT assay. This was followed by the in vitro evaluation of the ability of KGF, CSF and CCF to inhibit lipopolysaccharides (LPS) induced overproduction of various pro-inflammatory mediators (NO, ROS and IL1β, TNFα, IL6, NF-kB cytokines). This was done in Raw 264.7 and U87-MG cells. Finally, the in vitro protective effect of KGF, CSF and CCF against LPS-induced toxicity in the U87-MG cells was evaluated.

Results

CCF was shown to mostly contain sugar and no polyphenol while KGP and CSP contained very few amounts of these metabolites (≤ 2%). The three polysaccharide fractions were non-toxic up to 100 μg.mL^− 1. All the polysaccharides at 10 μg/mL inhibited NO production, but only KGF and CCF at 12.5 μg/mL down-regulated LPS-induced ROS overproduction. Finally, 100 μg/mL LPS reduced 50% of U87 cell viability, and pre-treatment with the three polysaccharides significantly increased the proliferation.

Conclusion

These results suggest that the polysaccharides of K. grandifoliola, C. citratus and C. sanguinolenta could be beneficial in preventing/treating neurodegenerative diseases in which neuroinflammation is part of the pathophysiology.

High doses of TGF-β potently suppress type I collagen via the transcription factor CUX1

Uncontrolled expression of collagen often leads to tissue scarring and loss of organ function. In this study, we identify a molecular mechanism that may enable us to switch off collagen production when unnecessary (i.e., fibrosis). We conclude that CUX1, which is a CCAAT binding factor displacement protein, may serve as a therapeutic target in treating fibrosis.

Transforming growth factor-β (TGF-β) is an inducer of type I collagen, and uncontrolled collagen production leads to tissue scarring and organ failure. Here we hypothesize that uncovering a molecular mechanism that enables us to switch off type I collagen may prove beneficial in treating fibrosis. For the first time, to our knowledge, we provide evidence that CUX1 acts as a negative regulator of TGF-β and potent inhibitor of type I collagen transcription. We show that CUX1, a CCAAT displacement protein, is associated with reduced expression of type I collagen both in vivo and in vitro. We show that enhancing the expression of CUX1 results in effective suppression of type I collagen. We demonstrate that the mechanism by which CUX1 suppresses type I collagen is through interfering with gene transcription. In addition, using an in vivo murine model of aristolochic acid (AA)-induced interstitial fibrosis and human AA nephropathy, we observe that CUX1 expression was significantly reduced in fibrotic tissue when compared to control samples. Moreover, silencing of CUX1 in fibroblasts from kidneys of patients with renal fibrosis resulted in increased type I collagen expression. Furthermore, the abnormal CUX1 expression was restored by addition of TGF-β via the p38 mitogen-activated protein kinase pathway. Collectively, our study demonstrates that modifications of CUX1 expression lead to aberrant expression of type I collagen, which may provide a molecular basis for fibrogenesis.

The biocontrol fungus Trichoderma stromaticum downregulates respiratory burst and nitric oxide in phagocytes and IFN-gamma and IL-10

Trichoderma stromaticum, a biocontrol agent of the cacao witches' broom pathogen Moniliophthora perniciosa, has been used in Brazil as part of the integrated pest management of cacao. At the present time, little is known about the effects of T. stromaticum on the modulation of in vitro or in vivo immune responses. The present study examined the interaction of T. stromaticum spores with cellular and molecular components of the immune system following intranasal sensitization of mice. Our results showed that T. stromaticum spores prevented the expression and production of inflammatory mediators in macrophages stimulated with interferon (IFN)-γ plus lipopolysaccharide (LPS) and neutrophils stimulated with phorbol myristate 13-acetate (PMA). Quantitative polymerase chain reaction (qPCR) assays revealed that T. stromaticum spores inhibited the expression of dectin-1 and Toll-like-receptor (TLR)2/TLR4. Intranasal injection of BALB/c mice and subsequent challenge with spores of T. stromaticum induced a discrete inflammatory response in the lungs. Interestingly, the spores inhibited local and systemic production of the regulatory IL-10 and proinflammatory IFN-γ cytokines. In addition the spores presented an antiproliferative effect on spleen cells. These findings showed that the biopesticide T. stromaticum may exert immunosuppressive effects in vitro and in vivo.

Biological activities and safety of Thanaka (Hesperethusa crenulata) stem bark

ETHNOPHARMACOLOGICAL RELEVANCE

The stem bark powder of Hesperethusa crenulata or Thanaka has been used on the face by Myanmar women for more than a thousand years as a skin care regiment.

AIM OF THE STUDY

The aim of the current study was to both verify the safety and evaluate some biological activities of the Thanaka bark.

MATERIALS AND METHODS

Maceration of the Thanaka bark powder resulted in hexane, dichloromethane, ethyl acetate, methanol, 85% ethanol and water extracts. For the safety evaluation, cytotoxicity and genotoxicity of each extract were tested. Antibacterial, tyrosinase inhibition, antioxidant and anti-inflammatory activities were evaluated for each extract.

RESULTS AND CONCLUSIONS

Extracts from Thanaka bark showed strong anti-inflammatory, significant antioxidation, mild tyrosinase inhibition and slight antibacterial activities. All extracts and the original bark powder showed no detectable genotoxicity while very low cytotoxicity with IC(50) value of more than 12 mg/ml was detected in the water extract. Thus, the use of the Thanaka bark in the form of a watery paste as a skin care regiment is not only safe but also beneficial to skin.

A novel beta-glucan produced by Paenibacillus polymyxa JB115 induces nitric oxide production in RAW264.7 macrophages

The effect of extracellular β-(1→3), (1→6)-glucan, produced by Paenibacillus polymyxa JB115, on nitric oxide (NO) production in RAW264.7 macrophages was investigated. β-glucan induced the production of NO by RAW264.7 macrophages in a concentration- and time-dependent manner. Moreover, β-glucan stimulation increased the mRNA expression of iNOS, COX-2 and IL-6 in RAW264.7 macrophages in a concentration-dependent manner.