Purification, Structural Characterization, and Anticandidal Activity of a Chitin-Binding Peptide with High Similarity to Hevein and Endochitinase Isolated from Pepper Seeds.

With the emergence of multidrug-resistant microorganisms, microbial agents have become a serious global threat, affecting human health and various plants. Therefore, new therapeutic alternatives, such as chitin-binding proteins, are necessary. Chitin is an essential component of the fungal cell wall, and chitin-binding proteins exhibit antifungal activity. In the present study, chitin-binding peptides isolated from Capsicum chinense seeds were characterized and evaluated for their in vitro antimicrobial effect against the growth of Candida and Fusarium fungi. Proteins were extracted from the seeds and subsequently the chitin-binding proteins were separated by chitin affinity chromatography. After chromatography, two fractions, Cc-F1 (not retained on the column) and Cc-F2 (retained on the column), were obtained. Electrophoresis revealed major protein bands between 6.5 and 26.6 kDa for Cc-F1 and only a ~ 6.5 kDa protein band for Cc-F2, which was subsequently subjected to mass spectrometry. The protein showed similarity with hevein-like and endochitinase and was then named Cc-Hev. Data are available via ProteomeXchange with identifier PXD054607. Next, we predicted the three-dimensional structure of the peptides and performed a peptide docking with (NAG)3. Subsequently, growth inhibition assays were performed to evaluate the ability of the peptides to inhibit microorganism growth. Cc-Hev inhibited the growth of C. albicans (up to 75% inhibition) and C. tropicalis (100% inhibition) and induced a 65% decrease in cell viability for C. albicans and 100% for C. tropicalis. Based on these results, new techniques to combat fungal diseases could be developed through biotechnological applications; therefore, further studies are needed.

Assessment of acute toxicity, genotoxicity, and anti-inflammatory activity of SteLL, a lectin from Schinus terebinthifolia Raddi. Leaves, in mice.

ETHNOPHARMACOLOGY RELEVANCE: Schinus terebinthifolia Raddi (Anacardiaceae), known as Brazilian pepper tree, stands out as a medicinal plant widely used in traditional medicine. The leaves are popularly used as anti-inflammatory agent and to relieve inflammatory conditions such as bronchitis, ulcers, and wounds, for example. AIM OF THE STUDY: The present study evaluated the acute toxicity, genotoxicity, and anti-inflammatory activity of S. terebinthifolia leaf lectin (SteLL) in mice (Mus musculus). MATERIALS AND METHODS: In the acute toxicity assay, the animals were treated intraperitoneally (i.p.) or orally (per os) with a single dose of 100 mg/kg. Genotoxicity was assessed by the comet and micronucleus assays. Carrageenan-induced peritonitis and paw edema models were used to evaluate the anti-inflammatory effects of SteLL (1, 5 and 10 mg/kg, i.p.). RESULTS: No animal died and no signs of intoxication or histopathological damage were observed in the acute toxicity assay. Genotoxic effect was not detected. In peritonitis assay, SteLL reduced in 56-69% leukocyte migration to the peritoneal cavity; neutrophil count decreased by 25-32%, while mononuclear cell count increased by 67-74%. SteLL promoted a notable reduction of paw edema after 4 h (61.1-63.4%). Morphometric analysis showed that SteLL also decreased the thickness of epidermal edema (30.2-40.7%). Furthermore, SteLL decreased MPO activity, plasma leakage, NO release, and modulated cytokines in both peritoneal fluid and paw homogenate. CONCLUSION: SteLL did not induce acute toxicity or genotoxicity in mice and stands out as a promising candidate in the development of new phytopharmaceuticals with anti-inflammatory action.

Carbohydrate-Binding Properties and Antimicrobial and Anticancer Potential of a New Lectin from the Phloem Sap of Cucurbita pepo.

A Cucurbita phloem exudate lectin (CPL) from summer squash (Cucurbita pepo) fruits was isolated and its sugar-binding properties and biological activities were studied. The lectin was purified by affinity chromatography and the hemagglutination assay method was used to determine its pH, heat stability, metal-dependency and sugar specificity. Antimicrobial and anticancer activities were also studied by disc diffusion assays and in vivo and in vitro methods. The molecular weight of CPL was 30 ± 1 KDa and it was stable at different pH (5.0 to 9.0) and temperatures (30 to 60 °C). CPL recovered its hemagglutination activity in the presence of Ca2+. 4-nitrophenyl-α-D-glucopyranoside, lactose, rhamnose and N-acetyl-D-glucosamine strongly inhibited the activity. With an LC50 value of 265 µg/mL, CPL was moderately toxic and exhibited bacteriostatic, bactericidal and antibiofilm activities against different pathogenic bacteria. It also exhibited marked antifungal activity against Aspergillus niger and agglutinated A. flavus spores. In vivo antiproliferative activity against Ehrlich ascites carcinoma (EAC) cells in Swiss albino mice was observed when CPL exerted 36.44% and 66.66% growth inhibition at doses of 3.0 mg/kg/day and 6.0 mg/kg/day, respectively. A 12-day treatment by CPL could reverse their RBC and WBC counts as well as restore the hemoglobin percentage to normal levels. The MTT assay of CPL performed against human breast (MCF-7) and lung (A-549) cancer cell lines showed 29.53% and 18.30% of inhibitory activity at concentrations of 128 and 256 µg/mL, respectively.

Glucose-Binding Dioclea bicolor Lectin (DBL): Purification, Characterization, Structural Analysis, and Antibacterial Properties.

In this study, we purified a lectin isolated from the seeds of Dioclea bicolor (DBL) via affinity purification. Electrophoresis analysis revealed that DBL had three bands, α, ß, and γ chains, with molecular masses of approximately 29, 14, and 12 kDa, respectively. Gel filtration chromatography revealed that the native form of DBL had a molecular mass of approximately 100 kDa, indicating that it is a tetramer. Interestingly, DBL-induced hemagglutination was inhibited by several glucosides, mannosides, ampicillin, and tetracycline with minimum inhibitory concentration (MIC) values of 1.56-50 mM. Analysis of the complete amino acid sequence of DBL revealed the presence of 237 amino acids with high similarity to other Diocleinae lectins. Circular dichroism showed the prominent ß-sheet secondary structure of DBL. Furthermore, DBL structure prediction revealed a Discrete Optimized Protein Energy (DOPE) score of -26,642.69141/Normalized DOPE score of -1.84041. The DBL monomer was found to consist a ß-sandwich based on its 3D structure. Molecular docking showed the interactions between DBL and α-D-glucose, N-acetyl-D-glucosamine, α-D-mannose, α-methyl-D-mannoside, ampicillin, and tetracycline. In addition, DBL showed antimicrobial activity with an MIC of 125 µg/mL and exerted synergistic effects in combination with ampicillin and tetracycline (fractional inhibitory concentration index ≤ 0.5). Additionally, DBL significantly inhibited biofilm formation and showed no toxicity in murine fibroblasts (p < 0.05). These results suggest that DBL exhibits antimicrobial activity and works synergistically with antibiotics.

Alocasia macrorrhiza rhizome lectin inhibits growth of pathogenic bacteria and human lung cancer cell in vitro and Ehrlich ascites carcinoma cell in vivo in mice.

Cancer and antibiotic resistance represent significant global challenges, affecting public health and healthcare systems worldwide. Lectin, a carbohydrate-binding protein, displays various biological properties, including antimicrobial and anticancer activities. This study focused on anticancer and antibacterial properties of Alocasia macrorrhiza lectin (AML). AML, with a molecular weight of 11.0 ± 1.0 kDa was purified using Ion-exchange chromatography, and the homotetrameric form was detected by gel-filtration chromatography. It agglutinates mouse erythrocytes, that was inhibited by 4-Nitrophenyl-α-d-mannopyranoside. Maximum hemagglutination activity was observed below 60 °C and within a pH range from 8 to 11. Additionally, it exhibited moderate toxicity against brine shrimp nauplii with LD50 values of 321 µg/ml and showed antibacterial activity against Escherichia coli and Shigella dysenteriae. In vitro experiments demonstrated that AML suppressed the proliferation of mice Ehrlich ascites carcinoma (EAC) cells by 35 % and human lung cancer (A549) cells by 40 % at 512 µg/ml concentration. In vivo experiments involved intraperitoneal injection of AML in EAC-bearing mice for five consecutive days at doses of 2.5 and 5.0 mg/kg/day, and the results indicated that AML inhibited EAC cell growth by 37 % and 54 %, respectively. Finally, it can be concluded that AML can be used for further anticancer and antibacterial studies.

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.

Prokaryotic expression, purification, physicochemical properties and antifungal activity analysis of phloem protein PP2-A1 from cucumber.

Phloem protein 2 (PP2) is a protein having lectin properties that can be isolated from the phloem sap. Based on our previous proteomic study of phloem sap of Cucumis sativus, it was found that the expression of PP2 A1-like was significantly up-regulated under salt stress, which may be a molecular mechanism of plant adaptation to stress. This paper carried out the expression and purification of the CsPP2-A1 gene in E. coli for further characteristic analysis. The results demonstrated that the CsPP2-A1 in shake flask cultures was mainly expressed in the soluble form at 15 °C or in inclusion bodies at 37 °C. Secondly, Ni-IDA affinity chromatography and SDS-PAGE were employed to yield highly purified CsPP2-A1 protein. The purified CsPP2-A1 was then subjected to Western blot and MALDI-TOF-MS analysis for protein identification. The biological activity analysis results showed that CsPP2-A1 had hemagglutinating activities to rabbit erythrocytes, and Chitotetraose may be the specific inhibitory sugar of CsPP2-A1. The optimal hemagglutination activity of CsPP2-A1 protein was achieved between pH 5-9, and between 20 and 60 °C. Moreover, CsPP2-A1 had significant inhibitory effects on Botrytis cinerea and Phytophthora infestans, and the inhibitory effect on B. cinerea was better than that on P. infestans.

Immunomodulatory and anti-infective effects of Cratylia mollis lectin (Cramoll) in a model of wound infection induced by Staphylococcus aureus.

This work evaluated the immunomodulatory and anti-infective effects of Cratylia mollis lectin (Cramoll) in a model of wound infection induced by S. aureus. Swiss mice were divided into 3 groups (n = 12/group): non-inoculated (Control group); inoculated with S. aureus (Sa group); inoculated with S. aureus and treated with Cramoll (Sa + Cramoll group). In each animal, one lesion (64 mm2) was induced on the back and contaminated with S. aureus (~4.0 × 106 CFU/wound). The treatment with Cramoll (5 µg/animal/day) started 1-day post-infection (dpi) and extended for 10 days. Clinical parameters (wound size, inflammatory aspects, etc.) were daily recorded; while cytokines levels, bacterial load and histological aspects were determined in the cutaneous tissue at 4th dpi or 11th dpi. The mice infected with S. aureus exhibited a delay in wound contraction and the highest inflammatory scores. These effects were impaired by the treatment with Cramoll which reduced the release of key inflammatory mediators (TNF-α, NO, VEGF) and the bacterial load at wound tissue. Histological evaluations showed a restauration of skin structures in the animals treated with Cramoll. Taken together, these results provide more insights about the healing and immunomodulatory properties of Cramoll and suggest this lectin as a lead compound for treatment of wound infection.

A New Lectin from Auricularia auricula Inhibited the Proliferation of Lung Cancer Cells and Improved Pulmonary Flora.

Lectins are widely distributed in the natural world and are usually involved in antitumor activities. Auricularia auricula (A. auricula) is a medicinal and edible homologous fungus. A. auricula contains many active ingredients, such as polysaccharides, melanin, flavonoids, adenosine, sterols, alkaloids, and terpenes. In this study, we expected to isolate and purify lectin from A. auricula, determine the glycoside bond type and sugar-specific protein of A. auricula lectin (AAL), and finally, determine its antitumor activities. We used ammonium sulfate fractionation, ion exchange chromatography, and affinity chromatography to separate and purify lectin from A. auricula. The result was a 25 kDa AAL with a relative molecular mass of 18913.22. Protein identification results suggested that this lectin contained four peptide chains by comparing with the UniProt database. The FT-IR and ß-elimination reaction demonstrated that the connection between the oligosaccharide and polypeptide of AAL was an N-glucoside bond. Analyses of its physical and chemical properties showed that AAL was a temperature-sensitive and acidic/alkaline-dependent glycoprotein. Additionally, the anticancer experiment manifested that AAL inhibited the proliferation of A549, and the IC50 value was 28.19 ± 1.92 µg/mL. RNA sequencing dataset analyses detected that AAL may regulate the expression of JUN, TLR4, and MYD88 to suppress tumor proliferation. Through the pulmonary flora analysis, the bacterial structure of each phylum in the lectin treatment group was more reasonable, and the colonization ability of the normal microflora was improved, indicating that lectin treatment could significantly improve the bacterial diversity characteristics.

Structure and properties of the giant reed (Arundo donax) lectin (ADL).

Arundo donax lectin (ADL) is a 170 amino acid protein that can be purified from the rhizomes of the giant reed or giant cane by exploiting its selective binding to chitin followed by elution with N-acetylglucosamine. The lectin is listed in the UniProt server, the largest protein sequence database, as an uncharacterized protein with chitin-binding domains (A0A0A9P802). This paper reports the purification, structure and ligand-binding properties of ADL. The lectin is a homodimer in which the two protomers are linked by two disulfide bridges. Each polypeptide chain presents four carbohydrate-binding modules that belong to carbohydrate-binding module family 18. A high degree of sequence similarity is observed among the modules present in each protomer. We have determined the X-ray structure of the apo-protein to a resolution of 1.70 Å. The carbohydrate-binding modules, that span a sequence of approximately 40 amino acids, present four internal disulfide bridges, a very short antiparallel central beta sheet and three short alpha helices, two on one side of the beta sheet and one on the other. The structures of the complexes of the lectin with N-acetylglucosamine, N-acetyllactosamine, N-acetylneuraminic acid and N-N'diacetylchitobiose reveal that ADL has two primary and two secondary carbohydrate-binding sites per dimer. They are located at the interface between the two protomers, and each binding site involves residues of both chains. The lectin presents structural similarity to the wheat germ agglutinin family, in particular, to isoform 3.

Anti-staphylococcal effects of Myracrodruon urundeuva lectins on nonresistant and multidrug resistant isolates.

AIMS: To evaluate the anti-staphylococcal effects of lectins isolated from bark (MuBL), heartwood (MuHL) and leaves (MuLL) of Myracrodruon urundeuva. METHODS AND RESULTS: The lectins were evaluated for: effects on growth, aggregation, haemolytic activity and biofilm-forming ability of Staphylococcus aureus clinical isolates nonresistant (8325-4) and multidrug resistant (LAC USA300); interference with the expression of virulence genes (hla, rnaIII and spa) of the Agr system of S. aureus; and synergistic effect with the antibiotics cefoxitin and cefotaxime. MuBL, MuHL and MuLL reduced growth (minimal inhibitory concentration (MIC): 12·5-50 µg ml-1 ) and viability (minimal bactericidal concentration (MBC): 100 µg ml-1 ) of 8325-4 and LAC USA300 cells. MuLL (at ½MIC and MIC) reduced LAC USA300 agglutination. The lectins did not interfere with haemolytic activity and expression of hla, rnaIII and spa genes. Only MuHL was able to reduce the biofilm production by 8325-4 (50-400 µg ml-1 ) and LAC USA300 (400 µg ml-1 ). CONCLUSION: The M. urundeuva lectins showed antibacterial activity against nonresistant and resistant clinical isolates of S. aureus and synergistic effects with antibiotics in reducing growth and biofilm formation. SIGNIFICANCE AND IMPACT OF THE STUDY: This work reports bioactive molecules capable of acting as anti-staphylococcal agents, since there are increasing reports of multiresistant isolates of this bacterium.

Soybean lectin induces autophagy through P2RX7 dependent activation of NF-κB-ROS pathway to kill intracellular mycobacteria.

BACKGROUND: Host-directed therapy is considered a novel anti-tuberculosis strategy in tackling the tuberculosis burden through autophagy induction by various inducers to curtail the growth of intracellular Mycobacterium tuberculosis. METHODS: In this study, we investigated the anti-tubercular role of soybean lectin, a lectin isolated from Glycine max (Soybean). Effect of SBL on intracellular mycobacterial viability through autophagy and the mechanism involved in differentiated THP-1 cells was studied using different experimental approaches. RESULTS: We initially performed a time kinetic experiment with the non-cytotoxic dose of SBL (20 µg/ml) and observed autophagy induction after 24 h of treatment. Abrogation of autophagy in the presence of 3-MA and an increase in LC3 puncta formation upon Baf-A1 addition elucidated the specific effect on autophagy and autophagic flux. SBL treatment also led to autophagy induction in mycobacteria infected macrophages that restricted the intracellular mycobacterial growth, thus emphasizing the host defensive role of SBL induced autophagy. Mechanistic studies revealed an increase in P2RX7 expression, NF-κB activation and reactive oxygen species generation upon SBL treatment. Inhibition of P2RX7 expression suppressed NF-κB dependent ROS level in SBL treated cells. Moreover, SBL induced autophagy was abrogated in the presence of either different inhibitors or P2RX7 siRNA, leading to the reduced killing of intracellular mycobacteria. CONCLUSION: Taken together, these results conclude that SBL induced autophagy exerts an anti-mycobacterial effect in P2RX7-NF-κB dependent manner through the generation of ROS. GENERAL SIGNIFICANCE: This study has provided a novel anti-mycobacterial role of SBL, which may play an important role in devising new therapeutic interventions.

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.

In vitro effects of Moringa oleifera seed lectins on Haemonchus contortus in larval and adult stages.

Haemonchus contortus is a hematophagous parasite causing damage to the production of ruminant animals throughout the world. This study evaluated the in vitro effect of proteins from Moringa oleifera (WSMoL - Water Soluble M. oleifera Lectin and cMoL - coagulant M. oleifera Lectin) on the motility of infective larvae and adult male and female worms of H. contortus. The specific activity of total proteases and the morphology of the worms exposed to the lectins were observed. Both lectins inhibited motility of all parasite stages tested. WSMoL and cMoL at 500 µg mL-1 interfered in the motility of larvae. Values of 11.1% and 8.1% were the lowest motility indices of larvae with sheath, and 30.6% and 16.4% were the lowest motility indices of exsheathed larvae treated with WSMoL and cMoL, respectively. In 1 mg mL-1 solutions of WSMoL and of cMoL, the motility index of adult male worms was 23.3% (p < 0.001) and 20% (p < 0.001), while the motility index of adult female worms was 63.3% (p > 0.05) and 26.6% (p < 0.001), respectively. Greater proteolytic activity was detected in extracts obtained from adult worms, male and female, after incubation with the lectins. Morphological changes caused by the lectins were revealed by changes in the crests of the cuticle, in the longitudinal striations and at the vulva.

A novel mannose-binding lectin from Liparis nervosa with anti-fungal and anti-tumor activities.

Plant lectins are carbohydrate-binding proteins with nonimmune origin, which can reversibly bind with carbohydrates, agglutinate cells, and precipitate polysaccharides and glycoconjugates. Plant lectins have attracted much attention for their anti-virus, anti-proliferation, and pro-apoptosis properties. Thus the exploration of new lectins has received special attention. Here we purified a mannose-binding lectin from the rhizomes of Liparis nervosa by ion exchange chromatography on DEAE-Sepharose, affinity chromatography on Mannose-Sepharose 4B, and gel filtration chromatography on Sephacryl S-100. The purified L. nervosa lectin (LNL) was identified to be a monomeric protein with a molecular mass of 13 kDa. LNL exhibited hemagglutinating activity towards rabbit erythrocytes, and its activity could be strongly inhibited by D-mannose, N-acetyl glucosamine and thyroglobulin. In vitro experiments showed that LNL exhibited a comparable anti-fungal activity against Piricularia oryzae (Cavara), Bipolaris maydis, Fusarium graminearum, and Sclerotium rolfsii, and anti-proliferation activity against tumor cells by inducing apoptosis. The full-length cDNA sequence of LNL is 715 bp in length and contains a 525 bp open reading frame (ORF) encoding a 110-residue mature protein. It was predicted to have three mannose-binding conserved motifs 'QXDXNXVXY'. The binding pattern of LNL was further revealed by homology modeling and molecular docking. We demonstrated that LNL is not only a potential therapeutic candidate against tumor but also a new anti-fungal agent.

Comprehensive review on Caelsalpinioideae lectins: From purification to biological activities.

Lectins are a class of proteins with specific and reversible carbohydrate binding properties. Plant lectins constitute the group of these proteins most studied, placing emphasis on the legume family. The Caesalpinioideae subfamily is part of Leguminosae and second only to Papilionoideae with more published works on lectins. Classically, Caesalpinioideae is formed by 171 genera and 2250 species. It presents 13 genera with reports of lectins, featuring the Bauhinia genus with the greatest number of species having purified and characterized lectins. Comparing genera, the lectins in this subfamily do not have similar physicochemical or structural properties. Collectively, however, antibacterial, antiviral, and anticancer activities have been reported, as well as applications as biosensors and biomarkers. This review aims to summarize the available data on purified lectins from species of the Caesalpinioideae subfamily, demonstrating the characteristics of these molecules and the potential for their application in future studies of new lectins, as well as of application in several areas.

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.

ArtinM: Purification and Evaluation of Biological Activities.

The immunomodulatory activity of plant lectins has been evaluated because of their high selectivity for glycans linked to receptors on innate and adaptative immune cells. ArtinM is a mannosyl-binding lectin, obtained from the seeds of Artocarpus heterophyllus, that induces the differentiation of CD4+ T cells and macrophages by interacting with CD3 and TLR2/CD14, respectively. This ArtinM property ultimately favors the combat of intracellular pathogens, opening new perspectives on the lectins application as immunomodulatory agents. The current section describes protocols for purification and evaluation of ArtinM biological activity. The purification is based on the ArtinM-D-mannose affinity. The effect of inducing IL-12 production by murine macrophages cell line is adopted to evaluate the ArtinM biological activity.

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.