We investigated the putative fungistatic and fungicidal activities of pomegranate sarcotesta lectin (PgTeL) against Cryptococcus neoformans B3501 (serotype D), specifically the ability of PgTeL to ...inhibit yeast capsule and biofilm formation in this strain.
PgTeL showed a minimum inhibitory concentration of 172.0 μg ml-1, at which it did not exhibit a fungicidal effect. PgTeL concentrations of 4.0-256.0 μg ml-1 reduced biofilm biomass by 31.0%-64.0%. Furthermore, 32.0-256.0 μg ml-1 PgTeL decreased the metabolic activity of the biofilm by 32.0%-93.0%. Scanning electron microscopy images clearly revealed disruption of the biofilm matrix. Moreover, PgTeL disrupted preformed biofilms. At concentrations of 8.0-256.0 μg ml-1, PgTeL reduced metabolic activity in C. neoformans by 36.0%-92.0%. However, PgTeL did not inhibit the ability of B3501 cells to form capsules under stress conditions.
PgTeL inhibited biofilm formation and disrupted preformed biofilms, demonstrating its potential for use as an anticryptococcal agent.
This article presents a study on the degradation of a residual textile mixture composed of cationic surfactant cetyltrimethylammonium bromide (CTAB) and the remazol yellow gold RNL-150% and reactive ...blue BF-5G textile dyes. This was carried out by employing the photo-peroxidation and photo-Fenton processes in LED and UV-C photoreactors. The photo-Fenton process was the most efficient as regards the degradation of the CTAB and dye mixture, for both types of radiation. In the kinetic study, degradations of 99% were obtained in 180 min for the chromophore groups using both types of radiation. The degradation of the CTAB and aromatic groups was, meanwhile, an average of 25% when employing LED radiation. The behavior of the degradation reaction was pseudo-first-order. Toxicity tests indicated that the solutions were better able to grow seeds and bacteria after treatment with the photo-Fenton process, using both types of radiation. The photo-Fenton processes carried out by employing LED and UV-C photoreactors were able to degrade the CTAB and dye mixture, thus highlighting the efficiency of LED radiation when its power (three times smaller) is compared to that of UV-C radiation. This process, therefore, represents an alternative for use in textile wastewater treatment systems.
Population growth has led to an increase in the production and use of synthetic compounds such as drugs, whose different classes are being investigated. However, the antiretrovirals are still poorly ...studied. Since the conventional treatments used in the effluent treatment plants have not been able to degrade these substances, other treatment techniques have been evaluated. Therefore, the objective of this work was to study and optimize the use of advanced oxidative processes (AOPs) in the degradation of lamivudine. It was found, initially, that the photo-peroxidation degraded 69% of the compound after 60 min of exposure to UV-C radiation, and that after evaluating the effect of the H2O2, a degradation of 95% was achieved by using 250 mg L−1 of this reagent. The reaction kinetics showed a good fit to the pseudo-first-order model, and the artificial neural network MLP (3-12-1) demonstrated a good accuracy, managing to predict percentages of degradation for the studied AOP. Toxicity tests indicated an increase in the toxic effect on seeds, but the same was not observed in relation to enterobacteria. In general, the appropriateness of the application of AOP in the degradation of the aqueous solution has been demonstrated, with the largest studies regarding the effects of toxicity.
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.
•A trehalose-binding lectin (PeRoL) was isolated from P. elatior root extract.•PeRoL is an acidic (pI 3.8) and thermostable protein comprised of subunits of 15 kDa linked by disulfide bonds.•Trehalose is an endogenous inhibitor of PeRoL present in the roots.•PeRoL showed bacteriostatic and fungicidal activities.•PeRoL is the first bioactive protein isolated from P. elatior.
•CasuL is an acidic (pI 5.82) and oligomeric protein of approximately 48kDa.•CasuL did not undergo unfolding when heated up to100°C.•CasuL was cytotoxic to K562 and T47D cancer cells.•CasuL showed ...bacteriostatic effect and antibiofilm activity.•CasuL was active against Candida krusei causing damage to cell wall.
This work describes the isolation of a lectin (CasuL) from the leaf pinnulae of Calliandra surinamensis and the evaluation of its cytotoxic, antimicrobial and antibiofilm properties. Proteins from pinnulae extract were precipitated with ammonium sulphate (60% saturation) and submitted to Sephadex G-75 chromatography, which yielded isolated CasuL (purification factor: 113). Native CasuL is an acidic protein (pI 5.82) with a relative molecular mass of 48kDa. This lectin is also an oligomeric protein composed of three subunits and mass spectrometry revealed similarities with a Sorghum bicolor protein. CasuL did not undergo unfolding when heated but changes in conformation and hemagglutinating activity were detected at basic pH. CasuL did not reduce the viability of human peripheral blood mononuclear cells but was toxic to leukemic K562 cells (IC50 67.04±5.78μg/mL) and breast cancer T47D cells (IC50: 58.75±2.5μg/mL). CasuL (6.25–800μg/mL) only showed bacteriostatic effect but was able to reduce biofilm formation by Staphylococcus saprophyticcus and Staphylococcus aureus (non-resistant and oxacillin-resistant isolates). CasuL showed antifungal activity against Candida krusei causing alterations in cell morphology and damage to cell wall. In conclusion, the pinnulae of C. surinamensis leaves contain a thermo-stable lectin with biotechnological potential as cytotoxic, antibiofilm, and antifungal agent.
•PgTeL is an antifungal agent against C. albicans and C. krusei.•The lectin caused energy collapse and oxidative stress in yeast cells.•Treatment with PgTeL led to damage of cell wall and rupture of ...yeast cells.•PgTeL showed antibiofilm effect on C. albicans at sub-inhibitory concentrations.•PgTeL effects can be linked to the bioactivities attributed to P. granatum fruit.
The pomegranate (Punica granatum) sarcotesta contains a chitin-binding lectin (PgTeL) with antibacterial activity against human pathogenic species. In this work, the structural stability of PgTeL was evaluated by fluorimetric analysis and the lectin was evaluated for cytotoxicity to human peripheral blood mononuclear cells (PBMCs) and antifungal activity against Candida albicans and Candida krusei. PgTeL folding was impaired when lectin was incubated at pH≥6.0. On the other hand, the lectin did not undergo unfolding even when heated at 100°C. PgTeL (1, 10, and 100μg/mL) was not cytotoxic to PBMCs. Antifungal activity was detected for C. albicans (MIC: 25μg/mL; MFC: 50μg/mL) and C. krusei (MIC and MFC of 12.5μg/mL). Treatment of yeast cells with PgTeL resulted in decrease of intracellular ATP content even at sub-inhibitory concentrations (½MIC and ¼MIC) and induced lipid peroxidation. In addition, PgTeL damaged the integrity of fungal cell wall of both species, with more pronounced effects in C. krusei. The lectin showed significant antibiofilm activity on C. albicans at sub-inhibitory concentrations (0.195 and 0.39μg/mL). In conclusion, PgTeL is an anti-Candida agent whose action mechanism involves oxidative stress, energetic collapse, damage to the cell wall and rupture of yeast cells.
This study describes the purification of Bixa orellana L. leaf lectin (BoLL) and the evaluation of its antimicrobial activity and in vivo toxicity. BoLL was isolated from saline extract of leaves ...through protein precipitation with ammonium sulfate (60% saturation) followed by ion exchange (CM-Sephadex) and size exclusion (Sephadex G-75) chromatographies. The lectin was characterized by polyacrylamide gel electrophoresis under denaturing conditions (SDS-PAGE), stability towards heating and pH variation, as well as influence of ions on its hemagglutinating activity (HA). HA inhibition assay by different carbohydrates and glycoproteins was also performed. The antimicrobial activity of BoLL was investigated against pathogens for humans and plants. In vivo acute toxicity in mice was assessed using a dose of 100 mg/kg per os or i.p. BoLL was isolated with high specific HA (purification fold: 53.89) and showed a single 19-kDa polypeptide band in SDS-PAGE. BoLL SHA increased in the presence of 20 mM Mg2+ ions, was resistant to heating at 100 °C, and stable at acidic pH range. HA inhibition was detected especially by glycoproteins, but also by monosaccharides. BoLL showed bacteriostatic and bactericidal effects against Escherichia coli minimum inhibitory (MIC) and bactericidal (MBC) concentrations of 400 and 800 μg/mL, respectively and Staphylococcus aureus (MIC and MBC: 400 μg/mL), as well as bacteriostatic effect against Bacillus megaterium and Micrococcus luteus (MIC: 18.2 and 800 μg/mL, respectively). No changes were observed in hematological, biochemical, and behavioral parameters in the acute toxicity test. However, animals treated with BoLL at 100 mg/kg per os or i.p. showed histopathological alterations in the liver, spleen, and kidneys. In conclusion, our data add new biotechnological value for B. orellana leaves, since they contain a thermostable lectin with antibacterial activity, which stimulate future studies aiming at its biomedical application. However, caution should be considered in future studies due to some signs of toxicity in mice.
•A protocol for purification of a lectin from Bixa orellana leaf (BoLL) was defined.•BoLL showed a single 19-kDa polypeptide band in SDS-PAGE.•Hemagglutinating activity of BoLL increased in the presence of Mg2+ ions, was resistant to heating at 100 °C, and stable at acidic pH range.•BoLL showed bacteriostatic and bactericidal effects•BoLL (100 mg/kg per os or i.p.) did not cause the death of Swiss mice.
This study reports the development of conjugates based on quantum dots (QD)s and lectins from Schinus terebinthifolia leaves (SteLL) and Punica granatum sarcotesta (PgTeL). Cryptococcus neoformans ...cells were chosen to evaluate the efficiency of the conjugates. Lectins were conjugated to QDs via adsorption, and the optical parameters (emission and absorption) were monitored. Lectin stability in the conjugates towards denaturing agents was investigated via fluorometry. The conjugation was evaluated using fluorescence microplate (FMA) and hemagglutination (HA) assays. The labeling of the C. neoformans cell surface was quantified using flow cytometry and observed via fluorescence microscopy. The QDs-SteLL and QDs-PgTeL conjugates, obtained at pH 7.0 and 8.0, respectively, showed the maintenance of colloidal and optical properties. FMA confirmed the conjugation, and the HA assay indicated that the lectin carbohydrate-binding ability was preserved after conjugation. SteLL and PgTeL showed stability towards high urea concentrations and heating. Conjugates labeled over 90% of C. neoformans cells as observed via flow cytometry and confirmed through fluorescence microscopy. C. neoformans labeling by conjugates was inhibited by glycoproteins, suggesting specific interactions through the lectin carbohydrate-binding site. Thus, an effective protocol for the conjugation of SteLL or PgTeL with QDs was proposed, yielding new nanoprobes useful for glycobiological studies.
Lectins are carbohydrate-binding proteins with several bioactivities, including antimicrobial properties.
Portulaca elatior
is a species found at Brazilian Caatinga and data on the biochemical ...composition of this plant are scarce. The present work describes the purification of
P. elatior
leaf lectin (PeLL) as well as the assessment of its antimicrobial activity and toxicity. PeLL, isolated by chromatography on a chitin column, had native liquid charge and subunit composition evaluated by electrophoresis. Hemagglutinating activity (HA) of PeLL was determined in the presence of carbohydrates or divalent cations, as well as after heating and incubation at different pH values. Changes in the lectin conformation were monitored by evaluating intrinsic tryptophan fluorescence and using the extrinsic probe bis-ANS. Antimicrobial activity was evaluated against
Pectobacterium
strains and
Candida
species
.
The minimal inhibitory (MIC), bactericidal (MBC), and fungicidal (MFC) concentrations were determined. Finally, PeLL was evaluated for in vitro hemolytic activity in human erythrocytes and in vivo acute toxicity in mice (5 and 10 mg/kg b.w
.
per os). PeLL (pI 5.4; 20 kDa) had its HA was inhibited by mannose, galactose, Ca
2+
, Mg
2+
, and Mn
2+
. PeLL HA was resistant to heating at 100 °C, although conformational changes were detected. PeLL was more active in the acidic pH range, in which no conformational changes were observed. The lectin presented MIC and MBC of 0.185 and 0.74 μg/mL for all
Pectobacterium
strains, respectively; MIC of 1.48 μg/mL for
C. albicans
,
C
.
tropicalis
, and
C. krusei
; MIC and MFC of 0.74 and 2.96 μg/mL for
C. parapsilosis
. No hemolytic activity or signs of acute toxicity were observed in the mice. In conclusion, a new, low-toxic, and thermostable lectin was isolated from
P. elatior
leaves, being the first plant compound to show antibacterial activity against
Pectobacterium
.
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