Biological assays and noncovalent interactions of pyridine-2-carbaldehyde thiosemicarbazonecopper(II) drugs with [poly(dA–dT)]2, [poly(dG–dC)]2, and calf thymus DNA

The interaction of the Cu(II) drugs CuL(NO₃) and CuL′(NO₃) (HL is pyridine-2-carbaldehyde thiosemicarbazone and HL′ is pyridine-2-carbaldehyde 4N-methylthiosemicarbazone, in water named [CuL]⁺ and [CuL′]⁺) with [poly(dA–dT)]₂, [poly(dG–dC)]₂, and calf thymus (CT) DNA has been probed in aqueous solution at pH 6.0, I = 0.1 M, and T = 25 °C by absorbance, fluorescence, circular dichroism, and viscosity measurements. The results reveal that these drugs act as groove binders with [poly(dA–dT)]₂, with a site size n = 6–7, whereas they act as external binders with [poly(dG–dC)]₂ and/or CT-DNA, thus establishing overall electrostatic interaction with n = 1. The binding constants with [CuL′]⁺ were slightly larger than with [CuL]⁺. The title compounds display some cleavage activity in the presence of thiols, bringing about the rupture of the DNA strands by the reactive oxygen species formed by reoxidation of Cu(I) to Cu(II); this feature was not observed in the absence of thiols. Mutagenic assays performed both in the presence and in the absence of S9 mix, probed by the Ames test on TA 98, TA 100, and TA 102, were negative. Weak genotoxic activity was detected for [CuL]⁺ and [CuL′]⁺, with a significative dose–response effect for [CuL′]⁺, which was shown to be more cytotoxic in the Ames test and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell proliferation assays. Methylation of the terminal NH₂ group enhances the antiproliferative activity of the pyridine-2-carbaldehyde thiosemicarbazones.     

Effects of dietary inulin,Bacillus subtilis and microalgae on intestinal gene expression in gilthead seabream (Sparus aurata L.)

The present work describes effects of dietary inulin, two microalgae (Tetraselmis chuii and Phaeodactylum tricornutum) and Bacillus subtilis (solely or combined with inulin or microalgae) on the expression of different genes in the intestine of the gilthead seabream (Sparus aurata L.) following four weeks of a feeding trial. Selected genes were grouped into five categories: genes involved in inflammation (genes encoding proinflammatory proteins), genes related to the cytoskeleton, genes encoding proteins of junction complexes, genes implicated in digestion processes and genes related to transport proteins. Regarding proinflammatory genes, interleukin-8 (IL-8) expression showed a significant increase in the fish fed all the assayed diets, except the B. subtilis + inulin diet, whereas the expression of caspase-1 (CASP-1) was also increased by the B. subtilis and B. subtilis + T. chuii diets. Cyclooxygenase-2 (COX-2) gene expression only increased in fish fed the B. subtilis diet. Among cytoskeletal and junctional genes, only β-actin and occludin were significantly affected by the assayed diets. β-actin expression was up-regulated by the inulin-containing diets (inulin and B. subtilis + inulin diets), whereas occludin expression increased in the fish fed all the assayed diets, except the P. tricornutum diet. Finally, the expression of transport protein genes demonstrated that the inulin diet and all the experimental diets containing B. subtilis significantly increased transferrin expression, whereas digestive enzymes were not affected by the experimental diets. In conclusion, our results demonstrated that inulin, B. subtilis and microalgae can modulate intestinal gene expression in the gilthead seabream. To our knowledge, this is the first study of the effects of some food additives on the intestinal expression of different genes in this species. More studies are needed to understand the role of these genes in maintaining the integrity and functionality of the intestine.     

Changes in intestinal morphology and microbiota caused by dietary administration of inulin and Bacillus subtilis in gilthead sea bream (Sparus aurata L.) specimens

Changes produced in gilthead sea bream (Sparus aurata L.) intestinal morphology and microbiota caused by dietary administration of inulin and Bacillus subtilis have been studied. Gilthead sea bream specimens were fed diets containing 0 (control), inulin (10 g kg^?1), B. subtilis (10⁷ cfu g^?1), or B. subtilis + inulin (10⁷ cfu g^?1 + 10 g kg^?1) for four weeks. Curiously, fish fed the experimental diets (inulin, B. subtilis, or B. subtilis + inulin) showed the same morphological alterations when studied by light and electron microscopy, while significant differences in the signs of intestinal damage were detected by the morphometric study. All of the observed alterations were present only in the gut mucosa, and intestinal morphometric study revealed no effect of inulin or B. subtilis on the intestinal absorptive area. Furthermore, experimental diets cause important alterations in the intestinal microbiota by significantly decreasing bacterial diversity, as demonstrated by the specific richness, Shannon, and range-weighted richness indices. The observed alterations demonstrate that fish fed experimental diets had different signs of gut oedema and inflammation that could compromise their body homeostasis, which is mainly maintained by the epithelial lining of the gastrointestinal tract. To our knowledge, this is the first in vivo study regarding the implications of the use of synbiotics (conjunction of probiotics and prebiotics) on fish gut morphology and microbiota.     

Effects of early exercise on cardiac function and lipid metabolism pathway in heart failure

We employed an early training exercise program, immediately after recovery from surgery, and before severe cardiac hypertrophy, to study the underlying mechanism involved with the amelioration of cardiac dysfunction in aortic stenosis (AS) rats. As ET induces angiogenesis and oxygen support, we aimed to verify the effect of exercise on myocardial lipid metabolism disturbance. Wistar rats were divided into Sham, trained Sham (ShamT), AS and trained AS (AST). The exercise consisted of 5-week sessions of treadmill running for 16 weeks. Statistical analysis was conducted by anova or Kruskal–Wallis test and Goodman test. A global correlation between variables was also performed using a two-tailed Pearson's correlation test. AST rats displayed a higher functional capacity and a lower cardiac remodelling and dysfunction when compared to AS, as well as the myocardial capillary rarefaction was prevented. Regarding metabolic properties, immunoblotting and enzymatic assay raised beneficial effects of exercise on fatty acid transport and oxidation pathways. The correlation assessment indicated a positive correlation between variables of angiogenesis and FA utilisation, as well as between metabolism and echocardiographic parameters. In conclusion, early exercise improves exercise tolerance and attenuates cardiac structural and functional remodelling. In parallel, exercise attenuated myocardial capillary and lipid metabolism derangement in rats with aortic stenosis-induced heart failure.     

Biobutanol production from apple pomace: the importance of pretreatment methods on the fermentability of lignocellulosic agro-food wastes

Applied Microbiology and Biotechnology - Apple pomace was studied as a possible raw material for biobutanol production. Five different soft physicochemical pretreatments (autohydrolysis, acids,...     

Immune-priming in ant larvae: social immunity does not undermine individual immunity

Social insects deploy numerous strategies against pathogens including behavioural, biochemical and immunological responses. While past research has revealed that adult social insects can generate immunity, few studies have focused on the immune function during an insect''s early life stages. We hypothesized that larvae of the black carpenter ant Camponotus pennsylvanicus vaccinated with heat-killed Serratia marcescens should be less susceptible to a challenge with an active and otherwise lethal dose of the bacterium. We compared the in vivo benefits of prior vaccination of young larvae relative to naive and ringer injected controls. Regardless of colony of origin, survival parameters of vaccinated individuals following a challenge were significantly higher than those of the other two treatments. Results support the hypothesis that ant larvae exhibit immune-priming. Based on these results, we can infer that brood care by workers does not eliminate the need for individual-level immunological responses. Focusing on these early stages of development within social insect colonies can start addressing the complex dynamics between physiological (individual level) and social (collective) immunity.     

Effects of phosphonium-based ionic liquids on the lipase activity evaluated by experimental results and molecular docking

In this work, the effect of several phosphonium-based ionic liquids (ILs) on the activity of lipase from Burkholderia cepacia (BCL) was evaluated by experimental assays and molecular docking. ILs comprising different cations ([P₄₄₄₄]⁺, [P_444(14)]⁺, [P_666(14)]⁺) and anions (Cl⁻, Br⁻, [Deca]⁻, [Phosp]⁻, [NTf₂]⁻) were investigated to appraise the individual roles of IL ions on the BCL activity. From the activity assays, it was found that an increase in the cation alkyl chain length leads to a decrease on the BCL enzymatic activity. ILs with the anions [Phosp]⁻ and [NTf₂]⁻ increase the BCL activity, while the remaining [P_666(14)]-based ILs with the Cl⁻, Br⁻, and [Deca]⁻ anions display a negative effect on the BCL activity. The highest activity of BCL was identified with the IL [P_666(14)][NTf₂] (increase in the enzymatic activity of BCL by 61% at 0.055 mol·L⁻¹). According to the interactions determined by molecular docking, IL cations preferentially interact with the Leu17 residue (amino acid present in the BCL oxyanion hole). The anion [Deca]⁻ has a higher binding affinity compared to Cl⁻ and Br⁻, and mainly interacts by hydrogen-bonding with Ser87, an amino acid residue which constitutes the catalytic triad of BCL. The anions [Phosp]⁻ and [NTf₂]⁻ have high binding energies (−6.2 and −5.6 kcal·mol⁻¹, respectively) with BCL, and preferentially interact with the side chain amino acids of the enzyme and not with residues of the active site. Furthermore, FTIR analysis of the protein secondary structure show that ILs that lead to a decrease on the α-helix content result in a higher BCL activity, which may be derived from an easier access of the substrate to the BCL active site.     

Associations between gelatinous zooplankton and hyperiid amphipods (Crustacea: Peracarida) in the Gulf of California

Hydrobiologia - Hyperiid amphipods are pelagic crustaceans that live associated with gelatinous zooplankton including medusae, ctenophores, siphonophores, and salps. Standard plankton sampling...