Immunoadjuvant and Humoral Immune Responses of Garlic (Allium sativum L.) Lectins upon Systemic and Mucosal Administration in BALB/c Mice.

Dietary food components have the ability to affect immune function; following absorption, specifically orally ingested dietary food containing lectins can systemically modulate the immune cells and affect the response to self- and co-administered food antigens. The mannose-binding lectins from garlic (Allium sativum agglutinins; ASAs) were identified as immunodulatory proteins in vitro. The objective of the present study was to assess the immunogenicity and adjuvanticity of garlic agglutinins and to evaluate whether they have adjuvant properties in vivo for a weak antigen ovalbumin (OVA). Garlic lectins (ASA I and ASA II) were administered by intranasal (50 days duration) and intradermal (14 days duration) routes, and the anti-lectin and anti-OVA immune (IgG) responses in the control and test groups of the BALB/c mice were assessed for humoral immunogenicity. Lectins, co-administered with OVA, were examined for lectin-induced anti-OVA IgG response to assess their adjuvant properties. The splenic and thymic indices were evaluated as a measure of immunomodulatory functions. Intradermal administration of ASA I and ASA II had showed a four-fold and two-fold increase in anti-lectin IgG response, respectively, vs. the control on day 14. In the intranasal route, the increases were 3-fold and 2.4-fold for ASA I and ASA II, respectively, on day 50. No decrease in the body weights of animals was noticed; the increases in the spleen and thymus weights, as well as their indices, were significant in the lectin groups. In the adjuvanticity study by intranasal administration, ASA I co-administered with ovalbumin (OVA) induced a remarkable increase in anti-OVA IgG response (~six-fold; p < 0.001) compared to the control, and ASA II induced a four-fold increase vs. the control on day 50. The results indicated that ASA was a potent immunogen which induced mucosal immunogenicity to the antigens that were administered intranasally in BALB/c mice. The observations made of the in vivo study indicate that ASA I has the potential use as an oral and mucosal adjuvant to deliver candidate weak antigens. Further clinical studies in humans are required to confirm its applicability.

Evaluation of the Potential of a Lectin Extracted from Polygonumpersicaria L. as a Biorational Agent against Sitophilusoryzae L.

Rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae), is one of the most destructive stored-product pests that is resistant to a wide range of chemical insecticides. In the present study, we investigated whether a lectin extracted from Polygonum persicaria L. (PPA) can be used as a biorational agent to control such insect pests. Along with the lethal digestive assay, the sub-lethal insecticidal activities of PPA, including the effects on digestive, detoxifying, and antioxidant enzyme activities, were evaluated against S. oryzae adults. The effect of feeding a diet containing PPA and carob extract as a food attractant on the mortality of S. oryzae adults was also investigated. Feeding on the diet containing PPA resulted in a significant mortality of S. oryzae adults with a LC50 (Lethal Concentration to kill 50% of insects) of 3.68% (w/w). The activity of digestive enzymes, including α-amylase, α-glucosidase, TAG-lipase, trypsin, chymotrypsin, elastase, and carboxy- and aminopeptidase, were decreased by the sub-lethal concentration of PPA. Detoxifying and antioxidant enzymes, including esterase, superoxide dismutase, catalase, glutathione-S-transferase, ascorbate peroxidase, glucose 6-phosphate dehydrogenase, and malondialdehyde, were activated in adults affected by PPA. These findings indicated that PPA, in addition to causing digestive disorders, leads to oxidative stress in S. oryzae. The presence of carob extract had no effect on the PPA-induced mortality of the insect. According to the results of the present study, PPA has promising insecticidal efficiency against S. oryzae. In addition, the usage of PPA with a food attractant carob extract in bait traps can be recommended as a new biorational formulation in S. oryzae management.

In silico analysis of carbohydrate-binding pockets in the lectin genes from various species of Canavalia.

Legumes are endowed with an opulent class of proteins called lectins that can detect tenuous variations in carbohydrate structures and bind them reversibly with high affinity and specificity. The genus Canavalia, in the family of Leguminosae, is considered to be an affluent source of lectin. An effort has been made to analyse the sequences encoded by the lectin gene and its carbohydrate binding pockets from three species of Canavalia, including C. virosa, C. rosea, and C. pubescens. Crude seed extract showed highest haemagglutination titer against buffalo RBCs and has high affinity to mannose and trehalose. Amplification of the lectin gene by gene-specific primers showed the presence of an 870 bp amplicon. Physicochemical characterization using various bioinformatic tools showed that the isoelectric point was below 7, suggesting that lectin molecules were acidic. A high aliphatic index and high instability index were observed, which indicated that lectin molecules were stable towards a wide range of temperatures. The occurrence of N-glycosylation sites at two sites was also identified in all three species. Prediction of secondary structure showed that approximately 59.05 %, 56.76 % and 54.88 % of the elements were random coils in the case of C. virosa, C. pubescens and C. rosea, respectively. Comparative modelling of the proteins and docking of hypothetical models with sugar moieties that inhibited the agglutination activity suggested that asparagine, serine, alanine, valine, tyrosine and threonine were the major residues involved in hydrogen bonding and other stacking interactions. This can further provide insights on its prospective antibiosis property.

Immunostimulatory and anti-allergic potential of novel heterotrimeric lectin from seeds of Zizyphus mauritiana Lam.

Zizyphus mauritiana Lam. seeds (ZMS) have been used medicinally as sedative or hypnotic drugs in most of Asian countries. ZMS has significant benefits to the human health. Therefore, we have evaluated immunomodulatory effect of lectin extracted from these ZMSL in both in vitro and in vivo study. Anaphylaxis is a severe life-threatening allergic reaction and Arthus reaction is deposition of immune complex and complement system activation, so we hypothesized that if ZMSL can protect these severe allergic diseases. We have studied the effect of ZMSL on macrophages and Wistar albino rats and confirmed its protective effect against anaphylaxis and Arthus reaction. Results of this study suggest ZMSL have immunostimulatory and antiallergic activity.

Green tea polyphenols mitigate the plant lectins-induced liver inflammation and immunological reaction in C57BL/6 mice via NLRP3 and Nrf2 signaling pathways.

Plant-derived dietary lectins have been reported to be involved in the pathogenesis of several inflammatory diseases, including hepatitis, inflammatory bowel disease, diabetes, and celiac disease. In this present study, we aimed to assess whether green tea polyphenols (GTPs) exerts protective effects against plant lectins-induced liver inflammation and immunological reaction in mice. The C57BL/6 mice received intragastric GTPs (200 mg/kg b.w.) once per day for 7 consecutive days prior to plant lectins stimulation (50 mg/kg b.w., intraperitoneally). GTPs supplementation alleviated the histopathological changes of liver and the disorder of serum biochemical parameters in plant lectins-challenged mice. GTPs supplementation also alleviated plant lectins-induced oxidative stress and liver inflammation, decreasing protein contents and gene expression levels of pro-inflammatory cytokines in the plasma and hepatic tissue and increasing antioxidant capacity in the liver. GTPs decreased the protein expression levels of myeloperoxidase, F4/80 and neutrophil, as determined by immunohistochemical analysis, and T lymphocytes (CD4 and CD8) contents as determined by immunofluorescence analysis, in the liver. Moreover, we found that GTPs inhibited Nod-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome expression and increased nuclear factor erythroid 2-related factor 2 (Nrf2) pathways in the liver tissues of plant lectins-challenged mice. Taken together, these results show that GTPs alleviates hepatic inflammatory damage and immunological reaction after plant lectins challenge, and GTPs (or green tea intake) supplements can be beneficial for people exposed to plant lectins.

The Lectin Isolated from the Alga Hypnea cervicornis Promotes Antinociception in Rats Subjected to Zymosan-Induced Arthritis: Involvement of cGMP Signalization and Cytokine Expression.

This study investigated the effects of the alga lectin Hypnea cervicornis agglutinin (HCA) on rat zymosan-induced arthritis (ZyA). Zymosan (50-500 µg/25 µL) or sterile saline (Sham) was injected into the tibio-tarsal joint of female Wistar rats (180-200 g). Arthritic animals received morphine (4 mg/kg, intraperitoneal), indomethacin (5 mg/kg, intraperitoneal), or 2% lidocaine (100 µL, subcutaneous). HCA (0.3-3 mg/kg) was administered by intravenous route 30 min before or 2 h after zymosan. 1H-[1,2,4]oxadiazolo[4,3-a]-quinoxalin-1-one (ODQ, 4 µg, intra-articular) was given 30 min prior HCA. Hypernociception was measured every hour until 6 h, time in which animals were sacrificed for evaluation of leukocytes of the intra articular fluid and gene expression of TNF-α, IL-1, IL-10, and iNOS in the joint tissues using PCR techniques. Hypernociception was responsive to morphine and indomethacin, and its threshold was not altered by lidocaine. The post-treatment of HCA reduced both hypernociception and leukocyte influx. This antinociceptive effect was abolished either by ODQ and glibenclamide. HCA also reduced gene expression of iNOS and TNF-α. In conclusion, the antinociceptive effect of HCA in ZyA involves cyclic GMP signalization and selective modulation of cytokine expression.

Purification of a lectin from Cratylia mollis crude extract seed by a single step PEG/phosphate aqueous two-phase system.

The partitioning and purification of lectins from the crude extract of Cratylia mollis seeds (Cramoll 1,4) was investigated in aqueous two-phase systems (ATPS). A factorial design model (24) was used to evaluate the influence of polyethylene glycol (PEG) molar mass (1500-8000 g/mol), PEG concentration (12.5-17.5% w/w), phosphate (10-15% w/w) concentration, and pH (6-8) on the differential partitioning, purification factor, and yield of the lectin. Polymer and salt concentration were the most important variables affecting partition of lectin and used to find optimum purification factor by experimental Box-Behnken design together with the response surface methodology (RSM). ATPS showed best conditions composed by 13.9% PEG1500, 15.3% phosphate buffer at pH 6, which ensured purification factor of 4.70. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed a single band of protein with 26.1 kDa. Furthermore, results demonstrated a thermostable lectin presenting activity until 60 °C and lost hemagglutinating activity at 80 °C. According to the obtained data it can be inferred that the ATPS optimization using RSM approach can be applied for recovery and purification of lectins.

In Vivo Immunomodulatory Potential of Partial Purified Lectin from the Saffron Milk Cap Mushroom, Lactarius deliciosus (Agaricomycetes), against Colloidal Carbon Particles.

Mushroom compounds and biomolecules are known for their biological beneficial effects and dietary properties. Their molecules can be used in immunology for their ability to stimulate immune cells and in biotherapy of diseases. In this study, the immunomodulatory effect using carbon clearance test in vivo of partial purified lectin of Lactarius deliciosus using DEAE-Sephacyl column, with sugar affinity against galactose, methyl-ß-D-galactopyranoside and lactose, showed a significant effect on phagocytic activity and half-life of carbon particles in mice with different concentrations (5, 10, 15, and 30 mg/kg). The results showed that the immunomodulatory effect increased in low doses and decreased in high doses compared with the control group p < 0.0001. L. deliciosus lectin exerted a dose-dependent immunostimulant activity toward the reticulo-endothelial system, and phagocytic activity toward macrophages and neutrophils in spleen and liver against the colloidal carbon.

Antitumor effects of chitin specific lectin from Praecitrullus fistulosus by targeting angiogenesis and apoptosis.

In the present study, chitin specific lectin was purified from fruit exudates of Praecitrullus fistulosus. The lectin was purified and analyzed using affinity chromatography, RP-HPLC and electrophoretic studies. Furthermore, protein was identified by MALDI-MS/MS and peptide mass fingerprinting. Purified lectin (PfL) effectively agglutinates RBC, lymphocytes and displayed strong cytotoxicity against colon cancer (line HT29) cells among screened cells. PfL induced apoptosis by altering the expression of apoptotic proteins via caspadse-3 dependent pathway. In vivo studies using EAC mice model proves the efficacy of PfL by activating apoptosis and inhibiting the tumor neovasculature by targeting the MVD, VEGF and MMP's secretion. More importantly, the PfL treatment leads to effective inhibition of tumor growth and a ∼2.71 fold increase in the lifespan of EAC mice. Collectively, our study provides comprehensive evidence that the role of dietary lectins with significant cytotoxic potential by targeting tumor angiogenesis and activating apoptosis in cancer study models.

Looking for alternative treatments for bovine and caprine mastitis: Evaluation of the potential of Calliandra surinamensis leaf pinnulae lectin (CasuL), both alone and in combination with antibiotics.

This work aimed to evaluate the effects of CasuL on growth and viability of 15 mastitis isolates from cows and goats, to determine the synergistic potential between CasuL and antibiotics, and to investigate the effects on bacterial ultrastructure and antibiofilm activity. The lectin inhibited the growth of Staphylococcus isolates from either bovine (Ssp6PD and Sa) or caprine (Ssp5D and Ssp01) mastitis. The minimal inhibitory concentrations were ranged from 3.75 to 15 µg/ml. Synergistic effect was observed for CasuL-tetracycline against Sa and Ssp6PD and CasuL-ampicillin against Ssp01. No structural damage was observed under the scanning electron microscope in CasuL treatments. Flow cytometry analysis using thiazol orange and propidium iodide demonstrated that CasuL was unable to reduce the cell viability of the isolates tested. At sub-inhibitory concentrations, CasuL reduced biofilm formation by the isolates Sa and Ssp5D. However, CasuL-tetracycline and CasuL-ampicillin combinations inhibited biofilm formation by Ssp6PD and Ssp01, respectively. In conclusion, CasuL is a bacteriostatic and antibiofilm agent against some mastitis isolates and displayed a synergistic potential when used in combination with either ampicillin (against one isolate) or tetracycline (against two isolates). The results stimulate the evaluation of CasuL for the treatment of mastitis, particularly when used in conjunction with antibiotics.

Biomedical Applications of Lectins from Traditional Chinese Medicine.

Lectins are proteins or glycoproteins of non-immune origin which have at least one noncatalytic domain that bind reversibly to specific mono or oligosaccharides. Traditional Chinese Medicine (TCM) involves a broad range of medicinal practices sharing common concepts which have been developed in China and are based on a tradition of more than thousands of years. Plant materials which are commonly used in TCM as a complementary or alternative for Western medical treatments contain a considerable number of important lectins. These lectins have been reported to have various applications and uses such as cancer treatment, glycoconjugate research, biomarker development, and others. Here, we summarize the available literature related to lectins from TCM and recent trends in their potential biomedical applications.

Portulaca elatior root contains a trehalose-binding lectin with antibacterial and antifungal activities.

Lectins are carbohydrate-binding proteins broadly distributed in plants and have several biological functions, including antimicrobial action. Portulaca elatior is a Caatinga plant whose chemical composition and biotechnological potential have not been extensively studied. In this work, a lectin was isolated from P. elatior root extract and evaluated for antimicrobial activity. The P. elatior root lectin (PeRoL) showed native molecular mass of 33 kDa, pI 3.8 and is comprised of two subunits of 15 kDa linked by disulfide bonds. No sequence similarities with Viridiplantae proteins were observed. The PeRoL hemagglutinating activity (HA) was not affected by heating and was detected in a pH ranging from 4.0 to 8.0. Trehalose was identified as an endogenous inhibitor of PeRoL present in the roots. Bacteriostatic activity was detected against Enterococcus faecalis, Pseudomonas aeruginosa and Staphylococcus aureus (minimal inhibitory concentration of 8.1, 32.5 and 4.06 µg/mL, respectively). PeRoL induced the death of Candida albicans, Candida parapsilosis, Candida krusei, and Candida tropicalis cells, with a minimal fungicidal concentration of 16 µg/mL. The lectin (100 µg/mL) was not cytotoxic to human peripheral blood mononuclear cells (PBMCs) and did not show hemolytic activity. In conclusion, the roots of P. elatior contain a trehalose-binding, thermostable, and antimicrobial lectin.

Purification, characterization and fine sugar specificity of a N-Acetylgalactosamine specific lectin from Adenia hondala.

Plant lectins are gaining interest because of their interesting biological properties. Several Adenia species, that are being used in traditional medicine to treat many health ailments have shown presence of lectins or carbohydrate binding proteins. Here, we report the purification, characterization and biological significance of N-Acetyl galactosamine specific lectin from Adenia hondala (AHL) from Passifloraceae family. AHL was purified in a single step by affinity chromatography on asialofetuin Sepharose 4B column, characterized and its fine sugar specificity determined by glycan array analysis. AHL is human blood group non specific and also agglutinates rabbit erythrocytes. AHL is a glycoprotein with 12.5% of the carbohydrate, SDS-PAGE, MALDI-TOF-MS and ESI-MS analysis showed that AHL is a monomer of 31.6 kDa. AHL is devoid of DNase activity unlike other Ribosome inactivating proteins (RIPs). Glycan array analysis of AHL revealed its highest affinity for terminal lactosamine or polylactosamine of N- glycans, known to be over expressed in hepatocellular carcinoma and colon cancer. AHL showed strong binding to human hepatocellular carcinoma HepG2 cells with MFI of 59.1 expressing these glycans which was effectively blocked by 93.1% by asialofetuin. AHL showed dose and time dependent growth inhibitory effects on HepG2 cells with IC50 of 4.8 µg/ml. AHL can be explored for its clinical potential.

Antimicrobial potential of Alpinia purpurata lectin (ApuL): Growth inhibitory action, synergistic effects in combination with antibiotics, and antibiofilm activity.

The Alpinia purpurata inflorescence contains a lectin (ApuL), which has immunomodulatory activities on human cells. In the present work, it was evaluated the antibacterial and antifungal effects of ApuL against human pathogens. ApuL showed bacteriostatic activity against non-resistant (UFPEDA-02) and an oxacillin-resistant isolate (UFPEDA-672) of Staphylococcus aureus with minimal inhibitory concentrations (MIC50) of 50 and 400 µg/mL, respectively. In addition, it showed bactericidal effect on the non-resistant isolate (minimal bactericidal concentration: 200 µg/mL). For Candida albicans and Candida parapsilosis, ApuL showed fungistatic effect (MIC50: 200 and 400 µg/mL, respectively). The lectin was able to impair the viability of the microorganism cells, as indicated by propidium iodide (PI) staining. Analysis of growth curves, protein leakage, and ultrastructural changes supported that ApuL acts through distinct mechanisms on S. aureus isolates. Ultrastructural analysis of ApuL-treated Candida cells revealed malformations with elongations and bulges. ApuL-oxacillin combination showed synergistic effect on the oxacillin-resistant isolates UFPEDA-670 and 671, which were not sensitive to lectin alone. Synergism was also detected for ApuL-ceftazidime against a multidrug-resistant isolate of Pseudomonas aeruginosa. Synergistic action of ApuL-fluconazole was detected for C. parapsilosis, which was insensitive to the drug alone. Biofilm formation by S. aureus non-resistant isolate and C. albicans was remarkably inhibited by ApuL at sub-inhibitory concentrations. In conclusion, ApuL showed differential effects on non-resistant and resistant bacterial isolates, was active against Candida species, and showed synergistic action in combination with antibiotics.

Phenoloxidase activation, antimicrobial, and antibiofilm properties of ß-glucan binding protein from Scylla serrata crab hemolymph.

In this study, we purified ß-GBP from hemolymph of Scylla serrata crabs using affinity chromatography. The purified S. serrata ß-GBP (Ss-ß-GBP) had 100kDa molecular mass in the SDS-PAGE. MALDI-TOF/TOF analysis was conducted, revealing that the purified 100kDa protein had 96% similarity with ß-GBP of Astacus leptodactylus. Ss-ß-GBP was characterized using high-performance liquid chromatography (HPLC), X-ray diffraction (XRD) analysis, circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy, which confirmed the structure of the Ss-ß-GBP. The purified Ss-ß-GBP was functionally analyzed by yeast agglutination and phagocytic reaction assays. Moreover, the PO enhancing ability of Ss-ß-GBP was evidenced through PO activity. Specifically, the antibacterial activity of the Ss-ß-GBP against Gram-positive (Enterococcus faecalis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria was evaluated by determining its minimum inhibitory concentration (MIC)<60µg/ml for all tested species. Furthermore, the antibiofilm efficacy of Ss-ß-GBP at 50 and 100µg/ml was outlined using light microscopy and confocal laser scanning microscopy (CLSM). Bacterial viability assays also outlined the dose-dependent activity of Ss-ß-GBP based on the ratio of live/dead bacterial cells. The results of this study revealed that crab-borne Ss-ß-GBP might be widely used to suppress the growth of pathogenic bacteria.

Moringa oleifera seed lectin inhibits Ehrlich ascites carcinoma cell growth by inducing apoptosis through the regulation of Bak and NF-κB gene expression.

A Moringa oleifera seed lectin (MOSL) was purified by using chitin column with the molecular mass of 17±1kDa. The lectin agglutinated mouse, cow and human erythrocytes and the hemagglutination activity was inhibited by methyl-α-d-mannopyranoside, methyl-ß-d-galactopyranoside, lactose and glucose. The lectin exhibited 100% hemagglutination activity at the pH range from 8.0 to 9.0 and temperature range from 30 to 60°C. Additionally, the lectin gradually lost its activity in the presence of urea but the activity abolish completely when treated with EDTA. MOSL showed mild toxicity against brine shrimp nauplii with a LC50 value of 131.0µg/ml. Antiproliferative activity was studied against Ehrlich ascites carcinoma (EAC) cells and 71.08% cell growth inhibition was observed in vitro at 200µg/ml. The lectin was injected (i.p.) into EAC mice at the doses of 2.0 and 4.0mg/kg/day for five consecutive days and 25.38% and 55% of cell growth inhibition was observed, respectively. MOSL caused the cell cycle arrest at G2/M phase as determined by FACS flow cytometry. The cell growth inhibition was due to the induction of apoptosis in the EAC cells which was confirmed by cell morphological study, caspase-3 inhibitor and activation of Bak and suppression of Bcl-2 and NF-κB genes expression.

Isolation and Characterization of Lectin from the Artist's Conk Medicinal Mushroom, Ganoderma applanatum (Agaricomycetes), and Evaluation of Its Antiproliferative Activity in HT-29 Colon Cancer Cells.

The growth and lectin production of Ganoderma applanatum, a white rot fungus, was optimized in broth cultures. The fungus was found to have a higher growth rate and higher lectin activity when grown in a medium adjusted to pH 6.5 at 26°C under stationary conditions. Expression of lectin activity started in 5-day-old mycelial culture; maximum activity was expressed after the 15th day of incubation. Among the various carbon and nitrogen sources tested, the carbon source sucrose and the nitrogen source yeast extract support maximum growth and lectin production. Lectin from G. applanatum was purified by ammonium sulfate precipitation and ion exchange chromatography. The purified fraction revealed a single band with a molecular weight of 35.0 kDa. Moreover, carbohydrates such as mannitol, glucose, sucrose, maltose, mannose, galactose, sorbose, and fructose were found to inhibit the hemagglutinating activity of the lectin. The purified lectins from G. applanatum contain cytotoxic and proapoptotic activities against HT-29 colon adenocarcinoma cells.

Multi-effect of the water-soluble Moringa oleifera lectin against Serratia marcescens and Bacillus sp.: antibacterial, antibiofilm and anti-adhesive properties.

AIMS: To evaluate the antibiofilm potential of water-soluble Moringa oleifera seed lectin (WSMoL) on Serratia marcescens and Bacillus sp. METHODS AND RESULTS: WSMoL inhibited biofilm formation by S. marcescens at concentrations lower than 2·6 µg ml-1 and impaired bacterial growth at higher concentrations, avoiding biofilm formation. For Bacillus sp., the lectin inhibited bacterial growth at all concentrations. The antibiofilm action of WSMoL is associated with damage to bacterial cells. WSMoL did not disrupt preformed S. marcescens biofilms but was able to damage cells inside them. On the other hand, the lectin reduced the number of cells in Bacillus sp. biofilm treated with it. WSMoL was able to control biofilm formation when immobilized on glass surface (116 µg cm-2 ), damaging S. marcescens cells and avoiding adherence of Bacillus sp. cells on glass. The Bacillus sp. isolate is member of Bacillus subtilis species complex and closely related to species of the conspecific 'amyloliquefaciens' group. CONCLUSION: WSMoL prevented biofilm development by S. marcescens and Bacillus sp. and the antibiofilm effect is also observed when the lectin is immobilized on glass. SIGNIFICANCE AND IMPACT OF THE STUDY: Taking together, our results provide support to the potential use of WSMoL for controlling biofilm formation by bacteria.

Lectin from the Late Oyster Mushroom, Hohenbuehelia serotina (Agaricomycetes), and Its Novel Effect as an Adjuvant of the HBV DNA Vaccine.

The biological macromolecule Hohenbuehelia serotina lectin (HSL) was first isolated from dried fruiting bodies of the mushroom H. serotina and identified as a heterodimer with 2 subunits of the same molecular weight (15.6 kDa) but different isoelectric points. Lactose and d-galactose inhibited the hemagglutinating activity of HSL, whereas mental ions Mn2+ and Ca2+ could stimulate its hemagglutination. The HSL hemagglutinating activity was stable for 1 hour in NaOH and HCl solutions up to a concentration of 12.5 or 6 mmol/L. In addition, HSL was stable up to 50°C for 30 minutes; its hemagglutinating activity was halved at 60°C and totally inactivated above 90°C. HSL (10 µg) as an immune adjuvant co-inoculated with the proVAX/S2 vaccine enhanced the level of hepatitis B surface antigen in C57BL/6 mice, induced a high level of T-cell proliferation, and induced the expression of IFN- of CD4+ cells. We further illustrate that HSL, as an adjuvant upregulating the expression of major histocompatibility complex II, contributed to the maturation of dendritic cells. As the first lectin isolated from H. serotina, HSL is a potential adjuvant to chronic hepatitis B virus DNA vaccines and lays a foundation for the prevention of HBV infection.

Medicinal Properties of the Genus Clitocybe and of Lectins from the Clouded Funnel Cap Mushroom, C. nebularis (Agaricomycetes): A Review.

Current knowledge of the medicinal properties of Basidiomycetes mushroom species of the genus Clitocybe and of the biological activity of C. nebularis fruiting bodies is reviewed. The main focus is the therapeutic potential of lectins from C. nebularis. Species of the genus Clitocybe, including C. nebularis, have not been traditionally considered as medicinal mushrooms; however, recent studies have demonstrated their antitumor, immunomodulatory, and antioxidative properties, their antimicrobial (antiviral, antibacterial, and antifungal) activities against various bacteria and fungi, as well as their potential use in therapy for alcoholism and as psychotropic agents. These activities have been shown to be due to various compounds, either isolated or in extracts, mainly polysaccharides but also phenols, ribonucleosides, and proteins. These include laccase, protease inhibitors, and lectins. C. nebularis has been shown to be rich in a variety of lectins and isolectins with distinct carbohydrate-binding specificities, showing versatile biological activities. They exhibit immunostimulatory and adhesion-/phagocytosis-promoting properties, as well as toxicity in various invertebrates. Mushroom species of the genus Clitocybe, including C. nebularis, thus constitute a valuable source of compounds showing diverse biological activities with a broad potential for applications in biomedicine or biotechnology. On the basis of such evidence reviewed here, we propose that C. nebularis and other Clitocybe species can be considered to be medicinal mushrooms.