Schistosomiasis, a neglected tropical disease caused by Schistosoma species, harms over 250 million people in several countries. The treatment is achieved with only one drug, praziquantel. ...Cardamonin, a natural chalcone with in vitro schistosomicidal activity, has not been in vivo evaluated against Schistosoma. In this work, we evaluated the in vivo schistosomicidal activities of cardamonin against Schistosoma mansoni worms and conducted enzymatic apyrase inhibition assay, as well as molecular docking analysis of cardamonin against potato apyrase, S. mansoni NTPDase 1 and S. mansoni NTPDase 2. In a mouse model of schistosomiasis, the oral treatment with cardamonin (400 mg/kg) showed efficacy against S. mansoni, decreasing the total worm load in 46.8 % and reducing in 54.5 % the number of eggs in mice. Cardamonin achieved a significant inhibition of the apyrase activity and the three‐dimensional structure of the potato apyrase, obtained by homology modeling, showed that cardamonin may interact mainly through hydrogen bonds. Molecular docking studies corroborate with the action of cardamonin in binding and inhibiting both potato apyrase and S. mansoni NTPDases.
Synthetic Aurones: New Features for Schistosoma mansoni Therapy Silva Torres, Daniel; Alves de Oliveira, Bruna; Souza d Silveira, Lígia ...
Chemistry & biodiversity,
November 2021, 2021-Nov, 2021-11-00, 20211101, Letnik:
18, Številka:
11
Journal Article
Recenzirano
In this work, two synthetic aurones revealed moderate schistosomicidal potential in in vitro and in vivo assays. Aurones (1) and (2) promoted changes in tegument integrity and motor activity, leading ...to death of adult Schistosoma mansoni worms in in vitro assays. When administered orally (two doses of 50 mg/kg) in experimentally infected animals, synthetic aurones (1) and (2) promoted reductions of 56.20 % and 57.61 % of the parasite load and stimulated the displacement towards the liver of the remaining adult worms. The oogram analysis revealed that the treatment with both aurones interferes with the egg development kinetics in the intestinal tissue. Seeking an action target for compounds (1) and (2), the connection with NTPDases enzymes, recognized as important therapeutic targets for S. mansoni, was evaluated. Molecular docking studies have shown promising results. The dataset reveals the anthelmintic character of these compounds, which can be used in the development of new therapies for schistosomiasis.
Schistosomiasis, caused by parasites of the genus
, is a neglected disease with high global prevalence, affecting more than 240 million people in several countries. Praziquantel (PZQ) is the only ...drug currently available for the treatment.
NTPDases (known as SmNTPDases, ATP diphosphohydrolases or
-apyrases) are potential drug targets for the discovery of new antischistosomal drugs. In this study, we screen NTPDases inhibitors from
(Apiaceae) using an ultrafiltration combined UHPLC-QTOF-MS method and potato apyrase, identifying asiaticoside as one of the apyrase-binding compounds. After isolation of asiaticoside from
extract, we assessed its in vivo antischistosomal activities against
worms and its in vitro enzymatic apyrase inhibition. Also, molecular docking analysis of asiaticoside against potato apyrase,
NTPDases 1 and 2 were performed. Asiaticoside showed a significant in vitro apyrase inhibition and molecular docking studies corroborate with its possible actions in potato apyrase and
NTPDases. In mice harboring a patent
infection, a single oral dose of asiaticoside (400 mg/kg. p.o.) showed significantly in vivo antischistosomal efficacy, markedly decreasing the total worm load and egg burden, giving support for further exploration of apyrase inhibitors as antischistosomal agents.
•Selection and modeling of AMPs derived from Lippia transcriptome.•Peptides were active against both gram-positive and gram-negative bacterial strains.•Hemolysis was mitigated through rational design ...of the peptides.•Successful selection of AMPs was modeled from Lippia transcriptome.•Former peptides were active against Gram-positive and Gram-negative bacteria.•Rational design reduced hemolytic activity in blood cells.
Antimicrobial resistance is considered a health issue worldwide. This public health problem underscores the importance of searching for new antimicrobial molecules with different mechanisms of action. Leaf transcriptomes were used to search and develop synthetic antimicrobial peptides derived from mRNA sequences. The in silico search for new AMPs from the L. rotundifolia and L. alba transcriptomes allowed the identification of 120 putative peptide mRNA sequences. Eight of them fitted into optimal parameters and were translated and chemically synthesized antimicrobial peptides. Their biological activity was tested in both Gram-positive and Gram-negative bacteria against which they exhibited antibacterial activity. However, they showed an important hemolytic effect. Afterwards, two active peptides showing bactericidal activity isolated from each plant transcriptome tested were modified and modeled in 11 new variants to increase their antimicrobial activity and stability and to reduce or eliminate their hemolytic effect from their original peptides. The La-AMP1 (MSLLERKLLMHFLRV) the original peptide from L. alba showed a 52% hemolytic effect while the derived peptide La-AMP1a (GLMKLLRELLHMFSRVG) had its hemolytic effect reduced to 0.5% at 128 μg.mL-1. Similarly, we observed that the original peptide from L. rotundifolia, Lr-AMP1 (MRIGLRFVLM), displayed a 71.5% hemolytic effect, while its derived peptide Lr-AMP1f (GSVLRAIMRMFAKLMG) showed 0% hemolysis at 128 μg.mL-1, tested with fresh human erythrocytes. Our results indicate a promising method for the search for novel antimicrobial agents with reduced or zero hemolytic effect, as well as prediction and optimization of their activity from plant mRNA libraries.
The increasing number of antibiotic resistant bacteria motivates prospective research toward discovery of new antimicrobial active substances. There are, however, controversies concerning the ...cost-effectiveness of such research with regards to the description of new substances with novel cellular interactions, or description of new uses of existing substances to overcome resistance. Although examination of bacteria isolated from remote locations with limited exposure to humans has revealed an absence of antibiotic resistance genes, it is accepted that these genes were both abundant and diverse in ancient living organisms, as detected in DNA recovered from Pleistocene deposits (30,000 years ago). Indeed, even before the first clinical use of antibiotics more than 60 years ago, resistant organisms had been isolated. Bacteria can exhibit different strategies for resistance against antibiotics. New genetic information may lead to the modification of protein structure affecting the antibiotic carriage into the cell, enzymatic inactivation of drugs, or even modification of cellular structure interfering in the drug-bacteria interaction. There are still plenty of new genes out there in the environment that can be appropriated by putative pathogenic bacteria to resist antimicrobial agents. On the other hand, there are several natural compounds with antibiotic activity that may be used to oppose them. Antimicrobial peptides (AMPs) are molecules which are wide-spread in all forms of life, from multi-cellular organisms to bacterial cells used to interfere with microbial growth. Several AMPs have been shown to be effective against multi-drug resistant bacteria and have low propensity to resistance development, probably due to their unique mode of action, different from well-known antimicrobial drugs. These substances may interact in different ways with bacterial cell membrane, protein synthesis, protein modulation, and protein folding. The analysis of bacterial transcriptome may contribute to the understanding of microbial strategies under different environmental stresses and allows the understanding of their interaction with novel AMPs.
Snakes of the Philodryadini tribe are included in the Dipsadidae family, which is a diverse group of rear-fanged snakes widespread in different ecological conditions, including habitats and diet. ...However, little is known about the composition and effects of their venoms despite their relevance for understanding the evolution of these snakes or even their impact on the occasional cases of human envenoming. In this study, we integrated venom gland transcriptomics, venom proteomics and functional assays to characterize the venoms from eight species of the Philodryadini tribe, which includes the genus
,
and
. The most abundant components identified in the venoms were snake venom metalloproteinases (SVMPs), cysteine-rich secretory proteins (CRISPs), C-type lectins (CTLs), snake endogenous matrix metalloproteinases type 9 (seMMP-9) and snake venom serinoproteinases (SVSPs). These protein families showed a variable expression profile in each genus. SVMPs were the most abundant components in
, while seMMP-9 and CRISPs were the most expressed in
and
, respectively. Lineage-specific differences in venom composition were also observed among
species, whereas
presented the highest amount of SVSPs and
was the only species to express significant amounts of 3FTx. The variability observed in venom composition was confirmed by the venom functional assays.
species presented the highest SVMP activity, whereas
species showed higher levels of gelatin activity, which may correlate to the seMMP-9 enzymes. The variability observed in the composition of these venoms may be related to the tribe phylogeny and influenced by their diets. In the presented study, we expanded the set of venomics studies of the Philodryadini tribe, which paves new roads for further studies on the evolution and ecology of Dipsadidae snakes.
Carbon dioxide (CO
2
) concentrations have grown in recent decades and will continue to increase during this century, affecting plant physiology and development. Aiming to evaluate the effect of CO
2
...elevation on growth, anatomy, essential oil qualitative production and expression of genes related to biosynthesis of these compounds, three chemotypes of
Lippia alba
(BGEN-01, BGEN-02 and BGEN-42) were cultivated in vitro. Firstly, we focused on the effects of gas exchange in the essential oil profile by comparing three CO
2
exchange rates: 14, 21 and 25 µL L
−1
s
−1
CO
2
. Continuing, in addition to the previous 14 and 25 µL L
−1
s
−1
CO
2
treatments, plants were placed into acrylic chambers with continuous forced air at 360 and 1000 μL L
−1
of CO
2;
an additional control without allowing gas exchange was added inside the chambers, totaling five treatments with 6 replicates. After 45 days, essential oil profile, histochemical, stomatal density, growth evaluation analyses and transcript analysis were performed. The enrichment with CO
2
enhanced plant dry and fresh weight, total chlorophylls and carotenoids in BGEN-01 and BGEN-02, and also increased stomatal density and lignin content for all chemotypes. The multivariate analysis showed that the essential oil profile varied, not only among the different chemotypes, but also within BGEN-01 and BGEN-02 treatments. The qualitative production was different in the treatments with forced air renovation and CO
2
enrichment. Regarding the gene expression analyses,
Farnesyl pyrophosphate synthase
(
LaFPPS
) and
Geranyl pyrophosphate synthase
(
LaGPPS
) did not vary, except for the treatments with forced air ventilation (360 and 1000 µL L
−1
) in the BGEN-01, which had
LaFPPS
upregulated.
Geraniol synthase
(
LaGES
) was upregulated in all BGEN-02 treatments and for BGEN-01 treatments with 360 and 1000 µL L
−1
CO
2
.
Nerolidol
/
Linalool synthase
(
LaNES
/
LIS
) was upregulated only in the BGEN-01, in the 360 and 1000 µL L
−1
CO
2
treatments. These findings provide a better understanding of how CO
2
regulates secondary metabolites production, providing a basis to clarify the pathway regulation, further enabling the targeted production of essential oils with greater economic and industrial interest.
Mutation in the ethionamide (ETH) activating enzyme, EthA, is the main factor determining resistance to this drug, used to treat TB patients infected with MDR and XDR Mycobacterium tuberculosis ...isolates. Many mutations in EthA of ETH resistant (ETH-R) isolates have been described but their roles in resistance remain uncharacterized, partly because structural studies on the enzyme are lacking. Thus, we took a two-tier approach to evaluate two mutations (Y50C and T453I) found in ETH-R clinical isolates. First, we used a combination of comparative modeling, molecular docking, and molecular dynamics to build an EthA model in complex with ETH that has hallmark features of structurally characterized homologs. Second, we used free energy computational calculations for the reliable prediction of relative free energies between the wild type and mutant enzymes. The ΔΔG values for Y50C and T453I mutant enzymes in complex with FADH2-NADP-ETH were 3.34 (+/−0.55) and 8.11 (+/−0.51) kcal/mol, respectively, compared to the wild type complex. The positive ΔΔG values indicate that the wild type complex is more stable than the mutants, with the T453I complex being the least stable. These are the first results shedding light on the molecular basis of ETH resistance, namely reduced complex stability of mutant EthA.
Lippia alba
(Mill.) N.E. Brown (Verbenaceae) is a medicinal plant of commercial interest because it is a source of essential oils, such as citral and linalool. Abiotic stress can modulate ...biosynthetic pathways and regulate the production of secondary metabolites found in essential oils. RT-qPCR is a useful tool for investigating the expression of biosynthetic genes and select cultivars with improved essential oil composition. However, RT-qPCR requires normalization to a stable reference genes, appropriate for each experimental condition. Here, we describe the evaluation of reference genes for RT-qPCR analysis in
L. alba
. Six constitutive genes (
NADH
,
CIT
,
G6i
,
TUB
,
RNApol
, and
ELONG
) were analyzed using BestKeeper, GeNorm, NormFinder, and RefFinder software.
TUB
emerged as the most stable gene under osmotic stress; whereas
NADH
was most stable under saline, wounding, cold, and exogenous abscisic acid and salicylic acid stress. Therefore,
TUB
and
NADH
are recommended for use as reference genes in expression studies involving
L. alba
.
Key message
Experimental conditions affect the expression of reference genes.
NADH
is the most stable gene under saline, exogenous hormones, wounding, and cold stress; whereas
TUB
is most stable under osmotic stress.
Bixin is a commercially valuable apocarotenoid pigment found in the seed aril of
Bixa orellana
. The dynamics and regulation of its biosynthesis and accumulation during seed development remain ...largely unknown. Here, we combined chemical, anatomical, and transcriptomic data to provide stage-specific resolution of the cellular and molecular events occurring during
B. orellana
seed development. Seeds at five developmental stages (S1–S5) were used for analysis of bixin content and seed anatomy, and three of them (S1, S3, and S4) were selected for Illumina HiSeq sequencing. Bixin accumulated in large quantities in seeds compared with other tissues analyzed, particularly during the S2 stage, peaking at the S4 stage, and then decreasing slightly in the S5 stage. Anatomical analysis revealed that bixin accumulated in the large central vacuole of specialized cells, which were scattered throughout the developing mesotesta at the S2 stage, but enlarged progressively at later stages, until they occupied most of the parenchyma in the aril. A total of 13 million reads were generated and assembled into 73,381 protein-encoding contigs, from which 312 were identified as containing 1-deoxy-D-xylulose-5-phosphate/2-C-methyl-D-erythritol-4-phosphate (DOXP/MEP), carotenoid, and bixin pathways genes. Differential transcriptome expression analysis of these genes revealed that 50 of them were sequentially and differentially expressed through the seed developmental stages analyzed, including seven carotenoid cleavage dioxygenases, eight aldehyde dehydrogenases, and 22 methyltransferases. Taken together, these results show that bixin synthesis and accumulation in seeds of
B. orellana
are a developmentally regulated process involving the coordinated expression of DOXP/MEP, carotenoid, and bixin biosynthesis genes.
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