1,3-Oxazolidine-2-thione derivatives are glucosinolate-related food constituents known to impart (thyreo)toxic properties to some cruciferous vegetables. In this work, ...5,5-dimethyl-1,3-oxazolidine-2-thione and (-)-(R)-5-phenyl-1,3-oxazolidine-2-thione, known goitrogens, were isolated from Draba lasiocarpa Rochel (Brassicaceae) and Reseda luteola L. (Resedaceae), respectively, and were fully spectrally characterized. Subsequently, the occurrence of the two 1,3-oxazolidine-2-thiones was verified in six additional taxa out of in total 78 screened Serbian Brassicales taxa. The stereochemistry of 5-phenyl-1,3-oxazolidine-2-thione was inferred from nuclear magnetic resonance experiments with a chiral lanthanide-shift reagent, employed in this work for the first time for this type of compounds. Unexpectedly, during gas chromatography, 5-phenyl-1,3-oxazolidine-2-thione underwent an unreported thermal core isomerization (1,3-oxazolidine-2-thione to 1,3-thiazolidine-2-one). These goitrogenic volatile glucosinolate products were tested for their effect on rat macrophage viability (three assays) and nitric oxide production. It was shown that the compounds displayed different levels of cytotoxicity. All tested compounds caused a significant lactate dehydrogenase leakage, but only (R)-5-phenyl-1,3-oxazolidine-2-thione statistically significantly reduced macrophage mitochondrial activity, whereas the racemic 5-phenyl-1,3-oxazolidine-2-thione and 5,5-dimethyl-1,3-oxazolidine-2-thione had little or no effect. Again only (R)-5-phenyl-1,3-oxazolidine-2-thione exerted nitric oxide production-inhibiting properties, suggesting the higher immunomodulatory potential of this enantiomer compared with its antipode and racemic mixture.
Display omitted
•5,5-Dimethyl-1,3-oxazolidine-2-thione (1) and 5-phenyl-1,3-oxazolidine-2-thione (2) were isolated from two Brassicales taxa.•Plant autolyzates (159 samples, including edible crucifers) were screened for these toxic (goitrogenic) food constituents.•Compounds 1 and 2 showed immunomodulatory activity by affecting the viability and NO-producing ability of macrophages.•Both 1,3-oxazolidine-2-thiones readily reacted with NO+ species generating products that themselves could yield NO.•Enantiomers of 2 were differentiated by a newly developed NMR-based methodology and its problematic GC behavior clarified.
Inflammatory bowel diseases (IBM), such as Crohn's disease, and their common complications represent a global health challenge. Many pyrazole derivatives, such as the spasmolytic drug metamizole, ...have already found their place among the frequently used therapeutic agents. Alteration of the structure of established therapeutic drugs by introducing a ferrocene moiety was shown to be a promising way for the discovery of new drugs. Herein, two libraries of analogous ferrocenyl (1a‐1j) and phenyl alkanols (2a‐2j) containing a pyrazole core, among which 17 completely new structures, have been synthesized, and structurally and electrochemically characterized. These compounds, along with the aldehydes used for their synthesis, were tested in parallel for their antispasmodic, acetylcholinesterase‐inhibitory, and antimicrobial activities to evaluate their potential as multitarget IBM drugs. The antispasmodic activity was investigated by assessing their effect on both the amplitude and number of spontaneous contractions of isolated rat ileum. Their antimicrobial effect was evaluated against a panel of Gram‐positive and Gram‐negative bacterial strains and fungi. It was found that several of the evaluated compounds displayed gastrointestinal smooth muscle relaxant activity, among them, 1‐(1H‐3‐ferrocenyl‐1‐phenylpyrazol‐4‐yl)‐3‐methylbutan‐1‐ol (1d) showed a remarkable effect by superseding the activity of papaverine. Together with the fact that it represents one of the most antimicrobially active investigated compounds, 1d is a good candidate for further pharmacological evaluation as a multitarget drug for IBM.
Two libraries of analogous ferrocenyl and phenyl alkanols containing a pyrazole core, among which 17 completely new structures, have been synthesized, and structurally and electrochemically characterized. Several of the evaluated compounds displayed gastrointestinal smooth muscle relaxant activity, among them, 1‐(1H‐3‐ferrocenyl‐1‐phenylpyrazol‐4‐yl)‐3‐methylbutan‐1‐ol showed a remarkable effect by superseding the activity of papaverine and represents a good candidate for further pharmacological evaluation as a multitarget drug for inflammatory bowel diseases.
Besides psyche-related symptoms, patients with anxiety disorders can have a large number of somatic symptoms as well. Although the treatment of these disorders is mainly focused on resolving their ...mental component, one cannot neglect the need for the treatment of accompanying somatic symptoms. Melissa officinalis L. (lemon balm), in various formulations, has been extensively used as an ethnomedicinal remedy for the treatment of different psyche-related symptoms, and its use is considered relatively safe.
Aim of the study: In the present study, the activity of M. officinalis (MO) essential oil was evaluated in several in vitro and in vivo models mimicking or involving anxiety-related somatic symptoms.
To address the effect of MO essential oil on the gastrointestinal and heart-related symptoms accompanying anxiety disorders, in vitro models were utilized that follow the function of the isolated mouse ileum and atria tissues, respectively, after exposure to MO essential oil. Effects of MO essential oil on BALB/c mice motor activity was estimated using the open field, rota-rod, and horizontal wire tests. Additionally, the essential oil was assayed for its potential in inhibiting acetylcholinesterase activity.
The performance of mice treated with 25 mg/kg of the oil showed a statistically significant decrease in the motor impairment arising from acute anxiety (open field test), while there was a prolonged latency and a reduction of the frequency of falling from a rotating rod and/or a horizontal wire (signs of muscle weakness/spasms). Concentrations of the essential oil higher than 1 μg/mL were found to inhibit both spontaneous and induced ileum contractions. Moreover, the essential oil and citronellal were found to decrease isolated mouse atria contraction frequency, as well as contraction force. However, the oil was found to be a very weak acetylcholinesterase inhibitor.
The modulation of anxiety-related symptoms by the oil was found not to be mediated through the inhibition of the acetylcholinesterase, nonetheless, the mechanistic studies involving the ileum and cardiac tissues, revealed that the activity of MO and citronellal might be related to the modification of either voltage-gated Ca2+ channels or muscarinic receptors. Mice locomotion, balance, and muscle strength were not impacted by the essential oil; however, its main constituent, citronellal, was found to exert a certain degree of muscle function inhibition. All these results suggest that the activity of MO essential oil arises from synergistic and/or antagonistic interactions of its constituents, and is not completely dependent on the oil's main constituent.
Display omitted
•Melissa officinalis (MO) is utilized for different psyche-related disorders including anxiety.•MO essential oil and citronellal were tested in models involving anxiety-linked somatic symptoms.•MO essential oil and citronellal were found to inhibit spontaneous and induced ileum contractions.•They decreased heart rate and force of contraction but differently affected mice motor function.•They were both weak acetylcholine inhibitors but act via voltage-gated Ca2+ channels.
Due to an increased need for new immunomodulatory agents, many previously known molecules have been structurally modified in order to obtain new drugs, preserving at the same time some of the ...benevolent characteristics of the parent molecule. This study aimed to evaluate the immunomodulatory potential of a selected library of bile acid derivatives (BAD) using a broad spectrum of assays, evaluating rat peritoneal macrophages viability, cell membrane damage, lysosomal and adhesion function, and nitric oxide and cytokine production as a response to lipopolysaccharide stimulation. Also, in silico studies on two bile acid-activated receptors were conducted and the results were related to the observed in vitro effects. All tested BAD exerted significant toxicity in concentrations higher than 10 μM, which was determined based on mitochondria and cell membrane damage in a panel of assays. On the other hand, at lower concentrations, the tested BAD proved to be immunomodulatory since they affected lysosomal function, cell adhesion capacities and the ability to produce inflammatory cytokines in response to a stimulus. One of the compounds proved to exhibit significant toxicity toward macrophages, but also caused a concentration-dependent decrease in nitric oxide levels and was identified as a potential farnesoid X receptor agonist.
•For compounds 1–4, immunomodulatory effects were observed at lower concentrations.•As a potential FXR agonist, 5 was toxic toward macrophages but decreased NO levels.•Exploring receptor affinity in silico could help understand physiological effects of bile acids.
L-Glutamic acid decarboxylase (GAD) is an enzyme that ensures the balance between the levels of two neurotransmitters, γ-aminobutyric acid (GABA) and L-glutamic acid (L-Glu), necessary for proper ...brain functioning. A reduction in the concentrations of GABA and/or GAD activity has been implicated in the symptoms associated with epilepsy, which could be plausibly alleviated by the application of GAD activators. As any unnecessary interference in GAD catalytic activity could be detrimental, it is important to study whether CNS (or other) drug candidates act on GAD or not. The ability to identify and reduce this risk early could significantly improve the process of drug development. Although many methods for measuring GAD activity in various biological samples have been described, only few (such as manometric and radiometric) were adopted as in vitro assays for the screening of potential GAD inhibitors/activators. However, these methods require specialized equipment and/or an expensive radiolabeled substrate, and may have sensitivity and/or reliability issues. Therefore, this study aimed to develop an HPLC-DAD-based assay that would allow a simple and more accurate measurement of GAD inhibition or activation using unpurified mice or rat brain homogenates. This assay is based on the quantification of GABA, formed during the enzymatic reaction, after its derivatization with dansyl chloride. Various parameters were evaluated to optimize the assay procedure (e.g. homogenate volume, incubation time, DMSO content, GAD, GABA, and dansyl-GABA stabilities). This assay was validated for pharmacological screenings using 3-mercaptopropionic acid and gallic acid and GAD obtained from different experimental animals.
Display omitted
•Glutamate decarboxylase (GAD) regulates the interconversion of L-Glu to GABA.•Only 2 methods with serious issues are in use for in vitro measurements of GAD.•An improved simple HPLC-based assay for GAD activity was developed.•No need for specialized equipment, expensive reagents, and pure enzyme use.•Possibility of sample storage and different enzyme sources utilization.
•The essential oils of two Mediterranean pines were analyzed.•The total number of identified volatile constituents was 64.•Diterpene alcohol thunbergol might be an important antibacterial ...agent.•Total content of pinenes is positively correlated to the larvicidal activity.
Pines (Pinus spp.) are a potentially viable source of bioactive molecules. The present paper investigates the chemical composition as well as biological activity of the needle essential oils (EOs) of the two Mediterranean pines (Pinus halepensis and P. heldreichii). The EOs were tested against respiratory pathogenic bacterial strains isolated from human swabs. Furthermore, a subchronic test on Drosophila melanogaster was conducted to assess insecticidal potential of the investigated EOs against dipteran insects. Regarding the composition of the studied EOs, significant differences in relation to the major components as well as the content of the different terpene classes was observed. Sesquiterpenes and diterpenes were most present classes in the oil of P. halepensis, where (E)-caryophyllene and thunbergol were dominant compounds (32.2% and 29.2%, resp.). Oil of P. heldreichii was rich in monoterpenes, among which limonene (34.4%) followed by α-pinene (23.8%) make up more than 50%. Tested EOs showed inhibitory action against respiratory pathogenic bacterial strains in the range of 0.19–12.00 mg/mL (MICs) and bactericidal effect (MBCs) at concentrations from 0.50 to 12.00 mg/mL. Among two presently and four previously tested pine EOs, P. halepensis demonstrated the highest potential, which might be contributed to relatively unusual composition. Namely, the results suggested that diterpene alcohol thunbergol might be an important antimicrobial agent either alone or in combination with other compounds, which should be the subject of the future studies. On the other hand, toxicity of P. heldreichii oil towards developing Drosophila melanogaster larvae was low, while oil of P. halepensis did not show any signs of toxicity at concentrations up to 3%. The data indicated that total content of pinenes in the EO of the Pinus species is positively correlated to the inhibition of development and larvicidal activity in a fruit fly model.
Objectives
As there are no previous studies of the European wild‐garlic (Allium ursinum) effects on the gastrointestinal system, despite its traditional applications in gastrointestinal disorders' ...treatment and regular use in the human diet, we have quantified and compared spasmolytic, antimicrobial and antioxidant activities of its different leaf extracts.
Methods
Wild‐garlic extracts were tested for spasmolytic activity on isolated rat ileum, antimicrobial activity on selected Gram‐positive and Gram‐negative bacteria and fungi by microdilution method and antioxidant capacity by DPPH radical‐scavenging assay.
Key findings
Wild‐garlic extracts were found to decrease ileal basal tone. As the relaxation of K+‐induced contractions was similar to one caused by papaverin, the observed spasmolytic effect was most likely mediated through Ca2+‐channel inhibition. Ethanolic extract (with the highest phenolic and high alk(en)yl cysteine sulphoxides’ levels) produced the strongest spasmolytic activity. In case of acetylcholine‐induced contractions, only hydromethanolic extract showed no statistical difference in comparison with positive control. All samples exhibited certain antioxidant potential and strong antimicrobial activity against tested enteropathogenic strains (Salmonella enteritidis was the most sensitive, followed by Escherichia coli, Proteus mirabilis and Enterococcus faecalis).
Conclusion
Besides other already established health‐promoting effects, wild garlic could be useful in treatment of mild gastrointestinal disturbances.
The currently used immunohistochemical approach in determining the estrogen receptor (ER) positivity of breast cancers (BCs) is inherently subjective and additionally limited by its semi-quantitative ...nature. The application of software in the analysis of digitized slide images may overcome some of these limitations. However, the utilization of such an approach requires that the entire staining procedure is standardized.
We aimed to establish a procedure for the photometric and morphometric analysis of BC immunohistochemical parameters that can possibly be used for a diagnostic purpose that is in line with the current semi-quantitative scoring system.
Semi-quantitative analysis of ER-stained tissue sections was performed following the Allred scoring system guidelines. The quantitative analysis was performed in ImageJ software after color deconvolution. The quantitative analysis of 66 cases of invasive lobular BC included: Percent of ER-positive cells, average nuclear coloration intensity, and the quantitative ER score. The percent of ER-positive tumor cells was counted using a standard grid overlay, while optical density (0.0-1.0) was measured within each nucleus at the grid points.
A statistical analysis revealed a significant positive correlation (
= 0.886,
< 0.001) between the subjective semi-quantitative and quantitative ER scores, with a large effect size (
= 3.8215). We observed strong statistically significant correlations between individual parameters of the total ER score, percentage of ER-positive nuclei, and color intensity, obtained by the two independent methods.
Additionally, besides excluding subjectivity, the up to now unreported cases of 3 + 0, 4 + 0, and 5 + 0 Allred scores were detected only by the application of the proposed quantitative approach.
The present study aimed to evaluate the protective action of thymol towards l-arginine-induced acute pancreatitis (AP) by studying the function of rat peritoneal immune cells.
Rat peritoneal exudate ...cells (PECs), obtained 24 h after the injection of l-arginine (350 mg/100 g of b.w.), were evaluated for mitochondrial activity (MTT assay), adherence capacity (methylene-blue assay), and phagocyte enzyme activity (myeloperoxidase, MPO, assay). The activity of α-amylase and free MPO, as well as the concentration of reactive oxygen species (ROS, i.e. O2−), were determined in the peritoneal exudate fluid. Also, serum α-amylase activity determination and pancreatic tissue pathohistological analysis were performed.
The administered thymol (50 and 100 mg/kg, per os) caused a significant decrease in the PEC mitochondrial activity and adherence capacity when compared with these functions of PECs isolated from rats with AP. A decrease in cellular MPO activity, as well as in the levels of ROS, α-amylase, and free MPO in peritoneal exudates was found in animals treated with thymol compared to the control animals with AP. Additionally, thymol administration prevented an increase in serum α-amylase activity, accompanied by the decrease in pancreatic tissue damage that follows l-arginine application.
The present results showed that thymol exerts significant immunomodulatory properties and a potential to silence PEC functions in inflammatory conditions such as the AP induced by l-arginine.
Motivated by the ethnopharmacological use of
, in the present study, the antimicrobial potential of the extracted essential oil was investigated against a panel of eighteen microorganism strains. ...Additionally, anti-acetylcholinesterase and antispasmodic (isolated rat distal colon) activities, general acute toxicity (
model), and immunomodulatory properties (cytotoxicity on isolated mouse macrophages) were studied. Detailed analyses of the essential oil led to the identification of 3-methoxycuminyl 2-methylbutanoate (a new natural product) and 3-methoxycuminyl 3-methylbutanoate (a rare natural product). The obtained esters and intermediates in the synthesis of the starting alcohol (3-methoxycuminol) were subjected to a battery of 1D- and 2D-NMR experiments. The synthesized esters were additionally characterized by GC-MS, IR, and UV-Vis. The synthesized compounds (ten in total) were biologically tested in the same way as the extracted
essential oil. The obtained low acute toxicity and promising antimicrobial potential suggest that the
essential oil might partially explain the ethnopharmacological application of
plant material for the treatment of gastrointestinal infections.
PDF
