Plant lectins as prospective antiviral biomolecules in the search for COVID-19 eradication strategies.

Lectins or clusters of carbohydrate-binding proteins of non-immune origin are distributed chiefly in the Plantae. Lectins have potent anti-infectivity properties for several RNA viruses including SARS-CoV-2. The primary purpose of this review is to review the ability of lectins mediated potential biotherapeutic and bioprophylactic strategy against coronavirus causing COVID-19. Lectins have binding affinity to the glycans of SARS-COV-2 Spike glycoprotein that has N-glycosylation sites. Apart from this, the complement lectin pathway is a "first line host defense" against the viral infection that is activated by mannose-binding lectins. Mannose-binding lectins deficiency in serum influences innate immunity of the host and facilitates infectious diseases including COVID-19. Our accumulated evidence obtained from scientific databases particularly PubMed and Google Scholar databases indicate that mannose-specific/mannose-binding lectins (MBL) have potent efficacies like anti-infectivity, complement cascade induction, immunoadjuvants, DC-SIGN antagonists, or glycomimetic approach, which can prove useful in the strategy of COVID-19 combat along with the glycobiological aspects of SARS-CoV-2 infections and antiviral immunity. For example, plant-derived mannose-specific lectins BanLac, FRIL, Lentil, and GRFT from red algae can inhibit and neutralize SARS-CoV-2 infectivity, as confirmed with in-vitro, in-vivo, and in-silico assessments. Furthermore, Bangladesh has a noteworthy resource of antiviral medicinal plants as well as plant lectins. Intensifying research on the antiviral plant lectins, adopting a glyco-biotechnological approach, and with deeper insights into the "glycovirological" aspects may result in the designing of alternative and potent blueprints against the 21st century's biological pandemic of SARS-CoV-2 causing COVID-19.

Photoprotective Potential of the Natural Artocarpin against In Vitro UVB-Induced Apoptosis.

Apoptosis, a well-known pattern of programmed cell death, occurs in multicellular organisms not only for controlling tissue homeostasis but also for getting rid of severely damaged cells in order to protect the redundant growth of abnormal cells undergoing cancerous cells. The epidermis of the human skin, composed largely of keratinocytes (KCs), is renewed continuously. Therefore, KCs apoptosis plays a critical role in the maintenance of epidermis structure and function. However, regulated cell death can be disturbed by environmental factors especially ultraviolet radiation (UV) B, leading to the formation of sunburn cells (KCs undergoing UVB-induced apoptosis) and impairing the skin integrity. In the present study, we firstly reported the potential of the natural artocarpin (NAR) to regulate UVB-induced human KCs apoptosis. The NAR showed antilipid peroxidation with an IC50 value of 18.2 ± 1.6 µg/mL, according to TBARS assay while the IC50 value of trolox, a well-known antioxidant, was 7.3 ± 0.8 µg/mL. For cell-based studies, KCs were pretreated with 3.1 µg/mL of the NAR for 24 hr and then exposed to UVB at 55 mJ/cm2. Our data indicated that the NAR pretreatment reduces UVB-induced oxidative stress by scavenging free radicals and nitric oxide and therefore prevents reactive oxygen species (ROS) and reactive nitrogen species- (RNS-) mediated apoptosis. The NAR pretreatment has been shown also to reduce the UVB-induced cyclobutane pyrimidine dimer (CPD) lesions by absorbing UVB radiation and regulating the cell cycle phase. Additionally, the NAR pretreatment was found to modulate the expression of cleaved caspases-3 and 8 that trigger different signalling cascades leading to apoptosis. Thus, these results provide a basis for the investigation of the photoprotective effect of the NAR isolated from A. altilis heartwood and suggest that it can be potentially used as an agent against UVB-induced skin damages.

Avaliação dos Efeitos Cardíacos de Lectina Solúvel em Água (WSMoL) de Sementes de Moringa Oleifera / Evaluation of the Cardiac Effects of a Water-Soluble Lectin (Wsmol) from Moringa Oleifera Seeds

Resumo Fundsamento As sementes de Moringa oleifera , que são utilizadas para clarificação de água, contêm uma lectina chamada WSMoL que tem mostrado atividade antibacteriana e imunomoduladora in vitro . Devido ao seu valor nutritivo e potencial terapêutico, as folhas e as sementes dessa árvore são consumidas em algumas comunidades. Algumas lectinas de plantas não são tóxicas para mamíferos, mas tem sido relatado que outras são prejudiciais quando ingeridas ou administradas por outros meios. Objetivo Como um dos passos necessários para determinar a segurança de WSMoL, nós avaliamos os possíveis efeitos cardiotóxicos desta proteína purificada. Métodos Durante 21 dias consecutivos, a WSMoL foi administrada a camundongos por gavagem. Foram investigadas as funções eletrofisiológicas, mecânicas e metabólicas in vivo e ex vivo por meio de registros eletrocardiográficos, ressonância magnética nuclear e respirometria de alta resolução. Resultados O tratamento com WSMoL não induziu alterações nos níveis de glicose no sangue ou peso corporal em comparação com o grupo controle. Adicionalmente, as relações peso cardíaco/peso corporal e peso cardíaco/comprimento tibial estavam semelhantes em ambos os grupos. A ingestão de lectina também não modificou a tolerância à glicose ou resistência à insulina. Não foram observadas alterações nos parâmetros eletrocardiográficos ou na duração do potencial de ação cardíaco. Os corações dos camundongos dos grupos controle e WSMoL mostraram função ventricular esquerda preservada. Além disso, a WSMoL não induziu alterações na função mitocondrial (em todos os casos, p > 0,05). Conclusões A administração de WSMoL demonstrou ter um perfil de segurança cardíaca. Estes resultados contribuem à avaliação de segurança do uso de sementes de M. oleifera para tratar água, visto que essa lectina está presente na preparação empregada por algumas populações com esse fim. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)

Abstract Background Moringa oleifera seeds, which are used for water clarification, contain a lectin named WSMoL which has shown in vitro antibacterial and immunomodulatory activity. Due to their nutritional value and therapeutic potential, the leaves and seeds of this tree are eaten in some communities. Some plant lectins are non-toxic to mammals, but others have been reported to be harmful when ingested or administered by other means. Objective As one of the steps needed to define the safety of WSMoL, we evaluated possible cardiotoxic effects of this purified protein. Methods: WSMoL was administered for 21 consecutive days to mice by gavage. Electrophysiological, mechanical, and metabolic cardiac functions were investigated by in vivo and ex vivo electrocardiographic recordings, nuclear magnetic resonance, and high-resolution respirometry. Results The treatment with WSMoL did not induce changes in blood glucose levels or body weight in comparison with control group. Moreover, the heart weight/body weight and heart weight/tibia length ratios were similar in both groups. Lectin ingestion also did not modify glucose tolerance or insulin resistance. No alterations were observed in electrocardiographic parameters or cardiac action potential duration. The heart of mice from the control and WSMoL groups showed preserved left ventricular function. Furthermore, WSMoL did not induce changes in mitochondrial function (in all cases, p > 0.05). Conclusions The administration of WSMoL demonstrated a cardiac safety profile. These results contribute to the safety evaluation of using M. oleifera seeds to treat water, since this lectin is present in the preparation employed by some populations to this end. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)

Antinociceptive activity of Schinus terebinthifolia leaf lectin (SteLL) in sarcoma 180-bearing mice.

ETHNOPHARMACOLOGY RELEVANCE: Schinus terebinthifolia Raddi leaves have been used in folk medicine due to several properties, including antitumor and analgesic effects. The variable efficacy and adverse effects of analgesic drugs have motivated the search for novel antinociceptive agents. It has been reported that the S. terebinthifolia leaf lectin (SteLL) has antitumor activity against sarcoma 180 in mice. AIM OF THE STUDY: This work aimed to evaluate whether SteLL would reduce cancer pain using an orthotopic tumor model. MATERIALS AND METHODS: A sarcoma 180 cell suspension was inoculated into the right hind paws of mice, and the treatments (150 mM NaCl, negative control; 10 mg/kg morphine, positive control; or SteLL at 1 and 2 mg/kg) were administered intraperitoneally 24 h after cell inoculation up to 14 days. Spontaneous nociception, mechanical hyperalgesia, and hot-plate tests were performed. Further, the volume and weight of the tumor-bearing paws were measured. RESULTS: SteLL (2 mg/kg) improved limb use during ambulation. The lectin (1 and 2 mg/kg) also inhibited mechanical hyperalgesia and increased the latency time during the hot-plate test. Naloxone was found to reverse this effect, indicating the involvement of opioid receptors. The tumor-bearing paws of mice treated with SteLL exhibited lower volume and weight. CONCLUSION: SteLL reduced hyperalgesia due to sarcoma 180 in the paws of mice, and this effect can be related to its antitumor action.

Purification of GNA-Related Lectins from Natural Sources.

The Galanthus nivalis lectin, abbreviated as GNA, is the model protein for a large group of mannose-binding lectins. Here, we describe the purification of GNA starting from dry bulbs. Using a combination of ion exchange chromatography and affinity chromatography on mannose-Sepharose, a highly pure preparation of GNA can be obtained.

Evaluation of the Cardiac Effects of a Water-Soluble Lectin (Wsmol) from Moringa Oleifera Seeds. / Avaliação dos Efeitos Cardíacos de Lectina Solúvel em Água (WSMoL) de Sementes de Moringa Oleifera.

Background Moringa oleifera seeds, which are used for water clarification, contain a lectin named WSMoL which has shown in vitro antibacterial and immunomodulatory activity. Due to their nutritional value and therapeutic potential, the leaves and seeds of this tree are eaten in some communities. Some plant lectins are non-toxic to mammals, but others have been reported to be harmful when ingested or administered by other means. Objective As one of the steps needed to define the safety of WSMoL, we evaluated possible cardiotoxic effects of this purified protein. Methods: WSMoL was administered for 21 consecutive days to mice by gavage. Electrophysiological, mechanical, and metabolic cardiac functions were investigated by in vivo and ex vivo electrocardiographic recordings, nuclear magnetic resonance, and high-resolution respirometry. Results The treatment with WSMoL did not induce changes in blood glucose levels or body weight in comparison with control group. Moreover, the heart weight/body weight and heart weight/tibia length ratios were similar in both groups. Lectin ingestion also did not modify glucose tolerance or insulin resistance. No alterations were observed in electrocardiographic parameters or cardiac action potential duration. The heart of mice from the control and WSMoL groups showed preserved left ventricular function. Furthermore, WSMoL did not induce changes in mitochondrial function (in all cases, p > 0.05). Conclusions The administration of WSMoL demonstrated a cardiac safety profile. These results contribute to the safety evaluation of using M. oleifera seeds to treat water, since this lectin is present in the preparation employed by some populations to this end. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0).

Characterization of bromelain indicates a molar excess of inhibitor vs. enzyme molecules, a Jacalin-like lectin and Maillard reaction products.

The phytotherapeutic bromelain is a heterogeneous protein mixture, extracted from pineapple stem, with high proteolytic activity based on cysteine proteases. Its global protein chemical composition was analyzed qualitatively and quantitatively by SDS-PAGE and RP-HPLC. A SDS-PAGE method with elaborate sample pretreatment was developed, to cope with the bromelain's self-digestion properties and the hypothetical disulfide scrambling during electrophoresis. Both can produce misleading results, if not considered. RP-HPLC was applied for its high separation power for bromelain proteinaceous compounds. A peak identification and assignment to different protein classes in bromelain was done by enzyme kinetics and MS. The method was successfully applied for the quantitative determination of the molar ratio between inhibitor and enzyme and resulted to be approximately 3:2. Bromelain contains, from a molar point of view, inhibitor molecules as major component, which thus might be considered as a natural pharmaceutical excipient in Bromelain, because it protects the enzymes against autolysis. We described two methods to separate the inhibitor fraction from the enzyme fraction, RP-HPLC and size exclusion chromatography. A pineapple derived Jacalin-like-lectin, herein called 'Anlec', was identified and quantified by RP-HPLC-MS in bromelain and its content was determined to be 5%, related to all proteins in bromelain. Anlec binds specifically to mannose-containing glycans and is discussed in literature to possess anti-HIV medical potential. Bromelain could therefore be a possible and economic source for the production of Anlec. An isolation strategy of Anlec from bromelain, in high purity, is shown in this work. The presented RP-HPLC results are comprehensive in chemical information, and the method is expedient to provide appropriate bromelain protein isolations but also to accomplish quality control, covering all relevant protein components. It is furthermore shown, that proteins in bromelain may react with reducing sugars in a Maillard reaction to form glycated proteins. Maillard reaction products in bromelain are detected and characterized and could be responsible for the limited stability and storage times at room temperature of bromelain. Even the active center thiol group could be potentially glycated.

A lectin with anti-microbial and anti proliferative activities from Lantana camara, a medicinal plant.

BACKGROUND: Lectins are known to possess interesting biological properties such as anti microbial, nematicidal, anti tumor and anti viral activities. Lantana camara from verbenaceae family is a medicinal plant known for possessing anti oxidant and anticancer activities. Since anticancer activity is reported in plant lectins, leaves of Lantana camara was used to check the presence of lectin. METHODS AND RESULTS: Here we report the purification, characterization and biological properties of a lectin from Lantana camara (LCL) leaves. LCL was purified by ion exchange chromatography on CM-cellulose column followed by affinity chromatography on mucin coupled Sepharose 4B column and gel filtration chromatography on Superdex G75 column. LCL is a glycoprotein with 10% of the carbohydrate and is blood group non specific. SDS-PAGE analysis of affinity purified LCL showed two proteins with apparent molecular weight of 14.49 kDa and 17.4 kDa which were subsequently separated by Gel filtration chromatography on Superdex G75 column. Hapten inhibition studies of LCL revealed its highest affinity for Chitin, Milibiose, α-D-Methyl galactopyranoside and glycoproteins like mucin, asialomucin. LCL showed strong binding to human colon adenocarcinoma HT29 cells with MFI of 242 which was effectively blocked by 68.1 and 62.5% by both mucin and milibiose. LCL showed dose and time dependent growth inhibitory effects on HT29 cells with IC50 of 3.75  µg/ml at 48 h. LCL has potent antibacterial and anti fungal activity. CONCLUSION: LCL can be explored for its clinical potential.

Antifungal Proteins from Plant Latex.

Latex, a milky fluid found in several plants, is widely used for many purposes, and its proteins have been investigated by researchers. Many studies have shown that latex produced by some plant species is a natural source of biologically active compounds, and many of the hydrolytic enzymes are related to health benefits. Research on the characterization and industrial and pharmaceutical utility of latex has progressed in recent years. Latex proteins are associated with plants' defense mechanisms, against attacks by fungi. In this respect, there are several biotechnological applications of antifungal proteins. Some findings reveal that antifungal proteins inhibit fungi by interrupting the synthesis of fungal cell walls or rupturing the membrane. Moreover, both phytopathogenic and clinical fungal strains are susceptible to latex proteins. The present review describes some important features of proteins isolated from plant latex which presented in vitro antifungal activities: protein classification, function, molecular weight, isoelectric point, as well as the fungal species that are inhibited by them. We also discuss their mechanisms of action.

Phaseolus vulgaris L. Extract: Alpha-Amylase Inhibition against Metabolic Syndrome in Mice.

To examine the effects of the alpha-amylase inhibitor isoform 1 called phaseolamin, a standardized extract from white kidney beans (Phaseolus vulgaris L) was tested against the hallmarks of metabolic syndrome. The efficacy of a per os repeated treatment with P. vulgaris extract (500 mg/kg) was compared with metformin (100 mg/kg) and atorvastatin (10 mg/kg) in a model of metabolic syndrome evoked by prolonged high fat diet (HFD; week 1 to week 19) in C57BL/6 mice. Bean extract and compounds administration started after metabolic syndrome establishment (week 11). P. vulgaris extract reduced the body weight overtime, as well as effectively lowered glycaemia, triglycerides, and cholesterol. On week 19, bean extract normalized the HFD-evoked tolerance to glucose and insulin. According to the phytochemical characterization, it inhibited the alpha-amylase activity. Animals treated with the extract were rescued from motor impairments and nociceptive threshold alterations induced by HFD. Specific organs analysis revealed that P. vulgaris extract decreased hepatic steatosis and lipid peroxidation in liver. It protected the heart from HFD oxidative alterations increasing the expression of the detoxifying enzymes catalase and glutathione reductase, and normalizing NADH dehydrogenase level. The histological analysis of aorta showed a protection about the development of fatty streaks in the muscular layers. In conclusion, a prolonged treatment with the standardized extract of P. vulgaris significantly reduced several pathological features related to a metabolic syndrome-like condition; a multifactorial approach that candidates this vegetal product as a possible therapeutic option against metabolic syndrome.

Mistletoe extract Fraxini inhibits the proliferation of liver cancer by down-regulating c-Myc expression.

Mistletoe (Viscum album) is a type of parasitic plant reported to have anticancer activity including in hepatocellular carcinoma (HCC). However, the mechanism of mistletoe's anticancer activity, and its effectiveness in treating HCC are not fully understood. We report here that mistletoe extracts, including Fraxini (grown on ash trees) and Iscador Q and M (grown on oak and maple trees), exert strong antiproliferative activity in Hep3B cells, with median inhibitory concentrations (IC50) of 0.5 µg/mL, 7.49 µg/mL, and 7.51 µg/mL, respectively. Results of Reversed Phase Proteomic Array analysis (RPPA) suggests that Fraxini substantially down-regulates c-Myc expression in Hep3B cells. Fraxini-induced growth inhibition (at a concentration of 1.25 µg/ml) was less pronounced in c-Myc knockdown Hep3B cells than in control cells. Furthermore, in the Hep3B xenograft model, Fraxini-treated (8 mg/kg body weight) mice had significantly smaller tumors (34.6 ± 11.9 mm3) than control mice (161.6 ± 79.4 mm3, p < 0.036). Similarly, c-Myc protein expression was reduced in Fraxini treated Hep3B cell xenografts compared to that of control mice. The reduction of c-Myc protein levels in vitro Hep3B cells appears to be mediated by the ubiquitin-proteasome system. Our results suggest the importance of c-Myc in Fraxini's antiproliferative activity, which warrants further investigation.

ConBr, the Lectin from Canavalia brasiliensis Mart. Seeds: Forty Years of Research.

Lectins are defined as proteins or glycoproteins capable of specific and reversible binding to carbohydrates. Inside this group of proteins, the most well-studied lectins belong to the Leguminosae family, and inside this family, the Diocleinae subtribe includes the most characterized lectin Concanavalin A (ConA), as well as ConBr, the lectin from Canavalia brasiliensis, the subject of this review. Since 1979, several studies have been published in the literature regarding this lectin, from its isolation and characterization to its several biological activities. This year, 2019, will mark 40 years since researchers have begun to study ConBr and 100 years since the discovery of ConA, making 2019 a momentous year for lectinology. Owing to the abundance of studies involving ConBr, this review will focus on ConBr's purification, physicochemical properties, functional and structural analyses, biological activities and biotechnological applications. This will give researchers a broad glimpse into the potential of this lectin, as well as it characteristics, as we look ahead to its expanding applications in glycomics and biotechnology.

Griffithsin carrageenan fast dissolving inserts prevent SHIV HSV-2 and HPV infections in vivo.

Human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) strategies with proven in vivo efficacy rely on antiretroviral drugs, creating the potential for drug resistance and complicated treatment options in individuals who become infected. Moreover, on-demand products are currently missing from the PrEP development portfolio. Griffithsin (GRFT) is a non-antiretroviral HIV entry inhibitor derived from red algae with an excellent safety profile and potent activity in vitro. When combined with carrageenan (CG), GRFT has strong activity against herpes simplex virus-2 (HSV-2) and human papillomavirus (HPV) in vitro and in vivo. Here, we report that GRFT/CG in a freeze-dried fast dissolving insert (FDI) formulation for on-demand use protects rhesus macaques from a high dose vaginal SHIV SF162P3 challenge 4 h after FDI insertion. Furthermore, the GRFT/CG FDI also protects mice vaginally against HSV-2 and HPV pseudovirus. As a safe, potent, broad-spectrum, on-demand non-antiretroviral product, the GRFT/CG FDI warrants clinical development.

A rapid and effective method for purification of a heat-resistant lectin from potato (Solanum tuberosum) tubers.

The potato lectin has been identified to consist of two chitin-binding modules, each containing twin hevein domains. Based on the thermotolerance of the hevein polypeptide, a simple, rapid, and effective protocol for the small-scale purification of the potato lectin has been developed in this study. The method involves only one anion exchange chromatographic step beyond the ammonium sulfate precipitation and the heating treatment. With this method, the potato lectin, a glycoprotein with molecular mass of approximately 60 kDa was found and purified to homogeneity with 9513.3 u/mg of specific hemagglutination (HA) activity in 76.8% yield. The homogeneity was confirmed by SDS-PAGE electrophoresis and reverse-phase HPLC analysis. The purified lectin was identified using MS-based peptide sequencing (MALDI-TOF/TOF) and showed a 100% Confidence Interval as being homologous to hevein domains in potato lectin. The periodic acid-Schiff staining and ferric-orcinol assay for pentose, as well as its HA activity inhibition by chitosan oligomers further confirmed the purified lectin as a potato chitin-binding lectin. It is noteworthy that the purified potato lectin exhibited heat resistance, by which, together with a short time precipitation by ammonium sulfate, more than 96% of the total proteins in the crude extract were removed. The lectin therefore was easily resolved from the other remining proteins on a DEAE-methyl polyacrylate column.

Bauhinia lectins: Biochemical properties and biotechnological applications.

Lectins are proteins of non-immune origin present throughout all kingdoms of life. They are capable of binding to specific carbohydrates reversibly, thus performing several biological roles. Plant lectins are the most studied ones, with hundreds of isolated and characterized hemagglutinins. Most of the known lectins have been isolated from plants belonging to family Leguminosae, which includes genus Bauhinia. This genus comprises over 300 species located in the tropical zones of the planet, where these are utilized in folk medicine because of their numerous medicinal effects, such as anti-inflammatory and antidiabetic actions. Despite being studied for over fifty years, the literature regarding Bauhinia hemagglutinins is scarce, describing just ten proteins isolated from seven different species. Structurally as well as biophysically, there is great similarity among all the known Bauhinia lectins, which may classify them as chemotaxonomic markers; however, the carbohydrate-binding sites and further specificities are unique for each of these proteins. The activities identified for these lectins include growth inhibition in cancer cell lines, cell marking, anti-inflammatory and insecticidal effects, which are just a few among their various other activities of high economic importance. Besides their versatility, four recombinant Bauhinia lectins have already been successfully expressed in heterologous microbial systems, further suggesting that these proteins could serve as promising biotechnological products in future.

Purification of lectin and Kunitz trypsin inhibitor from soya seeds.

The search for potent and selective therapeutic agents is progressing by the study of natural compounds in plants. Plant-derived macromolecules are considered emerging therapeutic agents and an alternative to synthetic and small molecule drugs. Where it has long been known that plants possess medicinal properties, the compounds responsible for their action are in many cases still unknown: often only whole crude plant extracts or fractionated extracts are tested for the ability to inhibit common pathogens. Here, we present a fast protein liquid chromatography method for the separation of crude plant proteins. Kunitz trypsin inhibitor (KTI; 24.2 kDa) and lectin (31 kDa) were purified from Glycine max by liquid extraction followed by ion exchange column chromatography. The need for serial chromatographic separation steps has been eliminated by introducing more complex elution profiles hence reducing cost, time and improving recovery. The identity of KTI-A and lectin was confirmed by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-ToF MS). Cell proliferation assays using B16F1 melanoma cells revealed that both KTI and the monomeric lectin retained some antiproliferative activity. This method could be useful for rapid and cost-effective purification of bioactive compounds from plant material.

Immunomodulatory Effects of the Water-soluble Lectin from Moringa oleifera Seeds (WSMoL) on Human Peripheral Blood Mononuclear Cells (PBMC).

BACKGROUND: Moringa oleifera is used in traditional medicine as well as in food, cosmetic, and pharmaceutical industries. Water-soluble M. oleifera lectin (WSMoL) is an anionic protein isolated from the seeds of this tree. Until now, immune responses promoted by this lectin in human PBMC have not been investigated. OBJECTIVE: The main objective of this study was to investigate the immunomodulatory effects of WSMoL on human PBMC through measurement of lymphocytes subsets, cytokine and nitric oxide levels. METHODS: Human peripheral blood mononuclear cells (PBMC) were isolated through Ficoll technique, were incubated with WSMoL (10 µg/mL) for 24, 48 and 72 hours, and was performed immunophenotyping assay of lymphocytes and monocytes. Culture supernatants were used to determined cytokine and nitric oxide levels. Assays with cells subsets and cytokine production were performed through cytometry. Nitric oxide release assay was determinate by spectrophotometry. RESULTS: WSMoL induced the release of the cytokines TNF-α, IL-2, IL-6, IL-10 as well as nitric oxide. Incubation of PBMC with this lectin also led to activation of CD8+ T lymphocytes. CONCLUSION: WSMoL promotes immunomodulation in human PBMC inducing a potential wound healing profile and, in future in vivo assays, can be evaluated as adjuvant in immunosuppressive diseases and wound repair.

Carbohydrate Analogue Microarrays for Identification of Lectin-Selective Ligands.

Fifty-five mono- and disaccharide analogues were prepared and used for the construction of microarrays to uncover lectin-selective ligands. The microarray study showed that two disaccharide analogues, 28' and 44', selectively bind to Solanum tuberosum lectin (STL) and wheat germ agglutinin (WGA), respectively. Cell studies indicated that 28' and 44' selectively block the binding of STL and WGA to mammalian cells, unlike the natural ligand LacNAc, which suppresses binding of both STL and WGA to cells.

Lectin Digestibility and Stability of Elderberry Antioxidants to Heat Treatment In Vitro.

Elderberry contains healthy low molecular weight nutraceuticals and lectins which are sequence-related to the elderberry allergen Sam n1. Some of these lectins are type II ribosome-inactivating proteins. The sensitivity of native lectins present in elderberry fruits and bark to the proteolysis triggered by in vitro simulated gastric and duodenal fluids has been investigated. It was found that these lectins are refractory to proteolysis. Nonetheless, incubation for 5-10 min in a boiling water bath completely sensitized them to the hydrolytic enzymes in vitro. Under these conditions neither total Folin-Ciocalteau's reagent reactive compounds, total anthocyanins and the mixture of cyanidin-3-glucoside plus cyanidin-3-sambubioside, nor antioxidant and free-radical scavenging activities were affected by more than 10% for incubations of up to 20 min. Therefore, short-time heat treatment reduces potential allergy-related risks deriving from elderberry consumption without seriously affecting its properties as an antioxidant and free-radical scavenging food.

A new TRAF-like protein from B. oleracea ssp. botrytis with lectin activity and its effect on macrophages.

Lectins are involved in a wide range of biological mechanisms, like immunomodulatory agent able to activate the innate immunity. In this study, we purified and characterized a new lectin from cauliflower (Brassica oleracea ssp. botrytis - BOL) by three sequential chromatographic steps and confirmed the purity by SDS-PAGE. Additionally, we evaluated the role of the lectin in innate immunity by a phagocytosis assay, production of H2O2 and NO. BOL was characterized like a non-glycosylated protein that showed a molecular mass of ∼34kDa in SDS-PAGE. Its N-terminal sequence (ETRAFREERPSSKIVTIAG) did not reveal any similarity to the other lectins; nevertheless, it showed 100% homology to a putative TRAF-like protein from Brassica rapa and Brassica napus. This is a first report of the TRAF-protein with lectinic activity. The BOL retained its complete hemagglutination activity from 4°C up to 60°C, with stability being more apparent between pH 7.0 and 8.0. Moreover, the lectin was able to stimulate phagocytosis and induce the production of H2O2 and NO. Therefore, BOL can be explored as an immunomodulatory agent by being able to activate the innate immunity and favor antigen removal.