A patent review of the antimicrobial applications of lectins: Perspectives on therapy of infectious diseases.

Patents of lectins with antiviral, antibacterial and antifungal applications were searched and reviewed. Lectins are proteins that reversibly bind to specific carbohydrates and have the potential for therapy of infectious diseases as biopharmaceuticals, biomedical tools or in drug design. Given the rising concerns over drug resistance and epidemics, our patent review aims to add information, open horizons and indicate our view of the future perspectives about the antimicrobial applications of lectins. Patents with publications until December 2020 were retrieved from Espacenet using defined search terms and Boolean operators. The documents were used to identify the geographical and temporal distribution of the patents, characterize their lectins, and classify and summarize their antiviral, antibiotic and antifungal applications. Lectins are promising antiviral agents against viruses with epidemics and drug resistance concerns. Mannose-binding lectins were the most suggested antiviral agents since glycans with mannose residues are commonly involved in viral entry mechanisms. They were also immobilized onto surfaces to trap viral particles and inhibit their spread and replication. Many patents described the extraction, isolation, amino acid and nucleotide sequences, and expression vectors of lectins with antibiotic and/or antifungal activities in terms of MIC and IC50 for in vitro assays. The inventions also included lectins as biological tools in nanosensors for antibiotics susceptibility tests, drug-delivery systems for the treatment of resistant bacteria, diagnostics of viral diseases and as a vaccine adjuvant. Although research and development of new medicines is highly expensive, antimicrobial lectins may be worth investments given the emergence of epidemics and drug resistance. For this purpose, less invasive routes should be developed as alternatives to the parenteral administration of biologics. While anti-glycan neutralizing antibodies are difficult to develop due to the low immunogenicity of carbohydrates, lectins can be produced more easily and have a broad-spectrum activity. Protein engineering technologies may make the antimicrobial applications of lectins more successful.

HPLC/HR-MS-Based Metabolite Profiling and Chemometrics: A Powerful Approach to Identify Bioactive Compounds from Abarema cochliacarpos.

Despite its importance as a medicinal plant, there is a lack of studies that assessed the chemical composition of A. cochliacarpos extracts. Herein, we used a metabolite profiling approach and chemometrics as a powerful strategy to correlate the chemical composition with the antioxidant activity of A. cochliacarpos extracts. Extracts obtained with ethyl acetate showed greater antioxidant activity and higher total phenolic content than extracts obtained with hexane. The chemical composition was assessed by HPLC/HR-MS and it encompassed fatty alcohols, terpenoids, phenolic derivatives, lipids, carotenoid-like compounds, alkaloids, flavonoids, polyketides, and glycerophospholipids. Chemometrics successfully differentiated not only the chemical composition of extracts in response to the nature of the extraction solvent and the botanical part used during extraction but also it allowed us to associate the chemical composition with the antioxidant activity of the extracts, which might be particularly helpful for drug discovery and development programs.

Castor (Ricinus communis L.) differential cell cycle and metabolism reactivation, germinability, and seedling performance under NaCl and PEG osmoticum: Stress tolerance related to genotype-preestablished superoxide dismutase activity.

Castor (Ricinus communis) is a relevant industrial oilseed feedstock for many industrial applications, being globally mainly cultivated by smallholder farmers in semiarid areas, where abiotic stresses predominate. Therefore, susceptible to generating reactive oxygen species (ROS) and subsequent oxidative stress, compromising cell metabolism upon seed imbibition and germination, seedling and crop establishment, and yield. The present study evaluated the consequences of water restriction by Polyethylene glycol (PEG) and Sodium chloride (NaCl) on cell cycle and metabolism reactivation on germinability, seedling growth, and vigor parameters in 2 commercial castor genotypes (Nordestina and Paraguaçu). PEG water restriction inhibited germination completely at -0.23 MPa or higher, presumably due to reduced oxygen availability. The restrictive effects of NaCl saline stress on germination were observed only from -0.46 MPa onwards, affecting dry mass accumulation and the production of normal seedlings. In general, superoxide dismutase (SOD) activity increased in NaCl -0.23 MPa, whereas its modulation during the onset of imbibition (24h) seemed to depend on its initial levels in dry seeds in a genotype-specific manner, therefore, resulting in the higher stress tolerance of Nordestina compared to Paraguaçu. Overall, results show that Castor germination and seedling development are more sensitive to the restrictive effects of PEG than NaCl at similar osmotic potentials, contributing to a better understanding of the responses to water restriction stresses by different Castor genotypes. Ultimately, SOD may constitute a potential marker for characterizing castor genotypes in stressful situations during germination, early seedling, and crop establishment, and a target for breeding for Castor-improved stress tolerance.

Modulation of NF-YB genes in Ricinus communis L. in response to different temperatures and developmental stages and functional characterization of RcNF-YB8 as an important regulator of flowering time in Arabidopsis thaliana.

We have characterized the NF-YB gene family in R. communis using bioinformatics, ecotopic expression, and transcriptomics. A total of 14 RcNF-YB genes were identified in R. communis genome using the conserved NF-YB region. This number is similar to what is found in A. thaliana (13 genes) and O. sativa (11 genes), whereas it is considerably lower to what is found in P. trichocarpa (21 genes) and S. lycopersycum (29 genes). Several regulatory cis-elements were identified in the promoter region, including low temperature, defense and stress, MIC, MYB, and abscisic acid. RcNF-YB is strongly modulated by temperature and it is dependent on the stage of germination. In general, RcNF-YB genes showed higher expression levels in dry seeds and early imbibition (EI) samples as compared to later stages of seedling development. Ectopic expression of RcNF-YB8 reduced flowering time in Arabidopsis reducing the time required for the formation of the first visible bud, the time required to open the first flower, and the time required for the formation of the first visible silique. At the end of the life cycle, ectopic expression of RcNF-YB8 affected plant height (PH), silique length (SL), the total number of silique per plant, 1000-seed weight, and seed size. Our data demonstrated the role of RcNF-YB8 in flowering time, plant height and seed production, and it shows that it may constitute a key target gene for breeding superior R. communis genotypes.

Effect of temperature on biomass allocation in seedlings of two contrasting genotypes of the oilseed crop Ricinus communis.

Ricinus communis is becoming an important crop for oil production, and studying the physiological and biochemical aspects of seedling development may aid in the improvement of crop quality and yield. The objective of this study was to assess the effect of temperature on biomass allocation in two R. communis genotypes. Biomass allocation was assessed by measuring dry weight of roots, stems, and cotyledons of seedlings grown at three different temperatures. Root length of each seedling was measured. Biomass allocation was strongly affected by temperature. Seedlings grown at 25°C and 35°C showed greater biomass than seedlings grown at 20°C. Cotyledon and stem dry weight increased for both genotypes with increasing temperature, whereas root biomass allocation showed a genotype-dependent behavior. Genotype MPA11 showed a continuous increase in root dry weight with increasing temperature, while genotype IAC80 was not able to sustain further root growth at higher temperatures. Based on metabolite and gene expression profiles, genotype MPA11 increases its level of osmoprotectant molecules and transcripts of genes encoding for antioxidant enzymes and heat shock proteins to a higher extent than genotype IAC80. This might be causal for the ability to maintain homeostasis and support root growth at elevated temperatures in genotype MPA11.

Metabolite profiling of Ricinus communis germination at different temperatures provides new insights into thermo-mediated requirements for successful seedling establishment.

Ricinus communis seeds germinate to a high percentage and faster at 35 °C than at lower temperatures, but with compromised seedling establishment. However, seedlings are able to cope with high temperatures at later stages of seedling establishment if germination occurred at lower temperatures. Our objective was to assess the biochemical and molecular requirements of R. communis germination for successful seedling establishment at varying temperatures. For that, we performed metabolite profiling (GC-TOF-MS) and measured transcript levels of key genes involved in several energy-generating pathways, such as storage oil mobilization, ß-oxidation and gluconeogenesis of seeds germinated at three different temperatures. We identified a thermo-sensitive window during seed germination in which high temperatures compromise seedling development, most likely by down-regulating some energy-generating pathways. Overexpression of malate synthase (MLS) and glycerol kinase (GK) genes resulted in higher starch levels in Nicotiana benthamiana leaves, which highlights the importance of these genes in energy-generating pathways for seedling establishment. Additionally, we showed that GABA, which is a stress-responsive metabolite, accumulated in response to the water content of the seeds during the initial phase of imbibition. Herewith, we provide new insights into the molecular requirements for vigorous seedling growth of R. communis under different environmental conditions.

Metabolite profiling, antioxidant and antibacterial activities of Brazilian propolis: Use of correlation and multivariate analyses to identify potential bioactive compounds.

The production of propolis by honeybees results from a selective collection of exudates from various plant species and present many potentialities in the pharmaceutical industry. The objective of this study was to investigate the chemical profile of Brazilian propolis, as well as their in vitro antioxidant and antibacterial activities. Gas chromatography-mass spectrometry was applied for chemical profiling of propolis extracts. Total phenolic compounds were quantified by Folin-Ciocalteu and antioxidant properties were assessed by 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Antibacterial activity was assessed against Staphylococcus aureus, Bacillus subtilis, and Micrococcus luteus. Correlation and multivariate statistical analysis were used to identify potential bioactive compounds in the extracts. Twenty-nine metabolites were identified along with 34 other metabolites that were classified into the following classes: triterpenoids (12), acetyltriterpenoids (3), sesquiterpenes (6), steroids (4), and hydrocarbons (9). The antioxidant capacity (IC50) ranged from 21.50 to 78.77µg/mL, whereas the content of total phenolic compounds ranged from 31.88 to 204.30mg GAE/g of dry weight. Total phenolic compounds and methyl retinoate showed a positive correlation with the antioxidant capacity, whereas tetradecanal, γ-palmitolactone and ethyl hydrocinnamate showed a negative correlation. Different sets of metabolites are shown to correlate with the antibacterial activity of the extracts, which is largely dependent on the type of microorganism. This innovative approach allowed us to identify likely bioactive compounds in the extracts, although the mechanism(s) underlying antibacterial activity encompass a complex trait, which might involve synergistic effects.

Amburana cearensis seed extracts protect PC-12 cells against toxicity induced by glutamate

ABSTRACT Amburana cearensis (Allemão) A.C. Sm., Fabaceae, has been widely studied for its medicinal activities. Many neurodegenerative disorders are caused by oxidative stress, mitochondrial dysfunction, excitotoxicity induced by glutamate and ultimately cell death. This study describes the chemical profile of the ethanolic, hexane, dichloromethane, and ethyl acetate extracts obtained from seeds of A. cearensis. The objective of this study was to investigate the chemical profile of extracts obtained from seeds of A. cearensis, as well as their cytotoxicity and neuroprotective effects in cultures of neural PC12 cells. Metabolite profile was performed by GC–MS. PC12 cells were treated with increasing concentrations of the extracts (0.01–2000 µg/ml) and the cell viability was analyzed after 24 and 72 h using an MTT test. For the excitotoxicity assay, PC12 cells were pre-treated with glutamate (1 mM) for 6 h and treated with increasing concentrations (0.1–1000 µg/ml) of the extracts. The chromatographic analysis of the extracts detected various compounds with antioxidant properties, with the majority of peaks corresponding to the isoflavone coumarin. Only the hexane extract showed toxicity after 72 h exposure at the highest concentration (1000 µg/ml). By contrast, all extracts increased the cellular viability of PC12 cells against the toxicity caused by glutamate. Therefore, the extracts from the seeds of A. cearensis showed no toxicity and have neuroprotective potential against neuronal damage induced by glutamate, which may be related to their antioxidant properties.

Evaluation of the hepatotoxicity of Abarema cochliacarpos extracts in mice Mus musculus

Abarema cochliacarpos (Gomes) Barneby & J.W. Grimes, Fabaceae, is a native species of Brazil popularly known as "barbatimão", frequently found along the north coast of the state of Bahia. Local communities make an infusion from its stem bark, which is used to treat several diseases. This study aimed to evaluate the hepatotoxicity of A. cochliacarpos extracts in mice Mus musculus. The bark infusion and hydroalcoholic extract were administered nasogastrically into two groups of eight animals (four male and four female each). After 45 days all mice were killed and the livers were collected for further histological analysis. Hepatic steatosis, congestion of the hepatic vessels and medicinal plantspresence of macrophages and lymphocytes infiltrates in the liver, were observed in both steatosis group of animals, additionally animals that received the stem bark infusion presented an accumulation of pigments. None of the animals belonging to the negative control group showed any of the symptoms described above. In conclusion, the hydroalcoholic extract and infusion of A. cochliacarpos stem bark were proven to cause intoxication in mice. The hepatotoxicity of the infusion was more aggressive in females. Further studies are necessary to isolate compounds responsible for the toxic characteristics of A. cochliacarpos.

Atividade antimicrobiana in vitro do extrato de Abarema cochliocarpos (Gomes) Barneby & Grimes / In vitro antimicrobial activity of the extract of Abarema cochliocarpos (Gomes) Barneby & Grimes

O presente trabalho objetivou avaliar o potencial antimicrobiano in vitro do extrato hidro-alcoólico da casca de Abarema cochliocarpos (Gomes) Barneby & Grimes, conhecido como barbatimão, nas cepas de Staphylococcus aureus (ATCC 6538), Micrococcus luteus (ATCC 9341), Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 15442) e Staphylococcus aureus isolado de amostra clínica (SAIACLIN). Coletaram-se cascas de um espécime de barbatimão no Parque Ecológico INDES, localizado em Vila de Sauípe, Bahia, para preparação do extrato hidro-alcoólico. Os testes de susceptibilidade bacteriana foram realizados através do método de difusão em disco e da concentração inibitória mínima (CIM). O extrato hidro-alcoólico de A. cochliocarpos inibiu o crescimento somente das bactérias Gram-positivas. S. aureus (ATCC 6538), SAIACLIN e M. luteus apresentaram halos crescentes de inibição bacteriana de acordo com o aumento da concentração do extrato (1, 2 e 3 mg/disco), que variaram entre 8 a 15 mm, de 8 a 16 mm e de 13 a 22 mm para os respectivos microrganismos. Os resultados confirmaram a capacidade de inibição do crescimento bacteriano in vitro pelo extrato da casca de A. cochliocarpos, corroborando os relatos populares.

The present study aimed at evaluating the in vitro antimicrobial potential of the hydroalcoholic extract from the bark of Abarema cochliocarpos (Gomes) Barneby & Grimes, known as 'barbatimão', over the strains of Staphylococcus aureus (ATCC 6538), Micrococcus luteus (ATCC 9341), Escherichia coli (ATCC 6538), Pseudomonas aeruginosa (ATCC 15442) and over a Clinical Sample isolated from Staphylococcus aureus (SAIACLIN). Samples of 'barbatimão' bark were collected from a specimen at the INDES Ecological Park, located at Vila de Sauípe, Bahia to prepare the hydroalcoholic extract. The bacterial susceptibility tests were carried through the disk diffusion method and through the minimum inhibitory concentration (MIC). The hydroalcoholic extract of A. cochliocarpos only inhibited the growth of the Gram-positive bacteria. S. aureus (ATCC 6538), SAIACLIN and M. luteus had presented increasing zones of bacterial inhibition in accordance with the increase of the extract concentration (1, 2 and 3 mg/disco), that had varied between 8 to 15 mm, from 8 to 16 mm and from 13 to 22 mm for the respective microorganisms. The results had confirmed the capacity of inhibition of the in vitro bacterial growth for the extract of the bark of A. cochliocarpos, corroborating the popular stories.