Mouse models are valuable in preclinical studies of inflammatory arthritis. However, current methods for measuring disease severity or responses to treatment are not optimal. In this study a smart ...cage system using multiple sensors to measure locomotor activity was evaluated in the K/BxN serum transfer model of inflammatory arthritis.
Arthritis was induced in C57BL/6 mice with injections of K/BxN serum. Clinical index and ankle thickness were measured for 14 days. Locomotor activity was measured in smart cages for 23 h periods on Days 0, 7, and 13. The same measurements were taken in mice consuming diets supplemented or not with fish oil to evaluate a preventative treatment.
Initiation, peak and resolution phases of disease could be measured with the smart cages. Locomotor activity including speed, travel distance, number of active movements and rear movements were all significantly lower on Days 7-8 of illness (peak) compared to Days 0 and 13-14 (resolution) (one-way repeated measures analyses, p<0.05). The clinical index and ankle thickness measurements did not capture differences between dietary groups. Significantly increased activity was measured in most of the locomotor parameters in the fish oil group compared to the control mice at both Days 8 and 14 (2-way repeated measures ANOVA, p<0.05).
The measurement of locomotor activity provided a more detailed evaluation of the impact of inflammatory arthritis on animal well-being and mobility than that provided by measuring clinical index and ankle thickness, and could be a valuable tool in preclinical studies of inflammatory arthritis.
Sinapic acid is found in many edible plants and fruits, such as rapeseed, where it is the predominant phenolic compound. New sinapic acid phenethyl ester (SAPE) analogues were synthesized and ...screened as inhibitors of the biosynthesis of 5-lipoxygenase (5-LO) in stimulated HEK293 cells and polymorphonuclear leukocytes (PMNL). Inhibition of leukotriene biosynthesis catalyzed by 5-LO is a validated therapeutic strategy against certain inflammatory diseases and allergies. Unfortunately, the only inhibitor approved to date has limited clinical use because of its poor pharmacokinetic profile and liver toxicity. With the new analogues synthesized in this study, the role of the phenolic moiety, ester function, and bioisosterism was investigated. Several of the 34 compounds inhibited the biosynthesis of 5-LO products, and 20 compounds were 2–11 times more potent than zileuton in PMNL, which are important producers of 5-LO products. Compounds 5i (IC50: 0.20 μM), 5l (IC50: 0.20 μM), and 5o (IC50: 0.21 μM) bearing 4-trifluoromethyl, methyl, or methoxy substituent at meta-position of the phenethyl moiety were 1.5 and 11.5 times more potent than SAPE (IC50: 0.30 μM) and zileuton (IC50: 2.31 μM), respectively. Additionally, compound 9 (IC50: 0.27 μM), which was obtained after acetylation of the 4-hydroxyl of SAPE, was equivalent to SAPE and 8 times more active than zileuton. Furthermore, compound 20b (IC50: 0.27 μM) obtained after the bioisosteric replacement of the ester function of SAPE by the 1,2,4-oxadiazole heterocycle was equivalent to SAPE and 8 times more active than zileuton. Thus, this study provides a basis for the rational design of new molecules that could be developed further as anti 5-LO therapeutics.
Alkyne and azide analogs of natural compounds that can be coupled to sensitive tags by click chemistry are powerful tools to study biological processes. Arachidonic acid (AA) is a FA precursor to ...biologically active compounds. 19-Alkyne-AA (AA-alk) is a sensitive clickable AA analog; however, its use as a surrogate to study AA metabolism requires further evaluation. In this study, AA-alk metabolism was compared with that of AA in human cells. Jurkat cell uptake of AA was 2-fold greater than that of AA-alk, but significantly more AA-Alk was elongated to 22:4. AA and AA-alk incorporation into and remodeling between phospholipid (PL) classes was identical indicating equivalent CoA-independent AA-PL remodeling. Platelets stimulated in the presence of AA-alk synthesized significantly less 12-lipoxygenase (12-LOX) and cyclooxygenase products than in the presence of AA. Ionophore-stimulated neutrophils produced significantly more 5-LOX products in the presence of AA-alk than AA. Neutrophils stimulated with only exogenous AA-alk produced significantly less 5-LOX products compared with AA, and leukotriene B4 (LTB4)-alk was 12-fold less potent at stimulating neutrophil migration than LTB4, collectively indicative of weaker leukotriene B4 receptor 1 agonist activity of LTB4-alk. Overall, these results suggest that the use of AA-alk as a surrogate for the study of AA metabolism should be carried out with caution.
Glioblastoma multiforme (GBM) is an aggressive brain tumor that correlates with short patient survival and for which therapeutic options are limited. Polyphenolic compounds, including caffeic acid ...phenethyl ester (CAPE,
), have been investigated for their anticancer properties in several types of cancer. To further explore these properties in brain cancer cells, a series of caffeic and ferulic acid esters bearing additional oxygens moieties (OH or OCH₃) were designed and synthesized. (CAPE,
), but not ferulic acid phenethyl ester (FAPE,
), displayed substantial cytotoxicity against two glioma cell lines. Some but not all selected compounds derived from both (CAPE,
) and (FAPE,
) also displayed cytotoxicity. All CAPE-derived compounds were able to significantly inhibit 5-lipoxygenase (5-LO), however FAPE-derived compounds were largely ineffective 5-LO inhibitors. Molecular docking revealed new hydrogen bonds and π-π interactions between the enzyme and some of the investigated compounds. Overall, this work highlights the relevance of exploring polyphenolic compounds in cancer models and provides additional leads in the development of novel therapeutic strategies in gliomas.
Soxhlet (SE), microwave-assisted (MAE) and ultrasound-assisted (UAE) extraction were compared using ten extraction solvents for their efficiency to extract phenolic and flavonoid antioxidants from ...Eastern Canada propolis. Extracts were compared for total phenolic (TPC) and total flavonoid (TFC) content, and radical scavenging activities. Anti-inflammatory activity through inhibition of 5-lipoxygenase (5-LO) products biosynthesis in HEK293 cells was also evaluated. The results showed that SE extracts using polar solvents had the highest TPC and TFC. Extracts obtained with ethanol, methanol and acetone were effective free radical scavengers, and showed 5-LO inhibition similar to zileuton. UAE was an effective extraction method since the extracts obtained were comparable to those using SE and the MAE while being done at room temperature. With UAE, extracts of less polar solvents showed similar free radical scavenging and 5-LO inhibition to extracts of much more polar solvents such as methanol or ethanol. Reversed-phase liquid chromatography tandem mass spectrometry confirmed the presence of 21 natural compounds in the propolis extracts based on the comparison of intact mass, chromatographic retention time and fragmentation patterns derived from commercial analytical standards. The current study is the first of its kind to concurrently investigate solvent polarity as well as extraction techniques of propolis.
Like a sore thumb: Niobium stands out among neighboring transition metals for its catalytic performance in the synthesis of cyclic carbonates. Readily available NbCl5 is a very efficient catalyst for ...the preparation of industrially relevant carbonates at ambient temperature, low CO2 pressure, and low concentrations. DMAP=N,N‐dimethylaminopyridine.
The inhibition of 5-lipoxygenase (5-LO), the key enzyme for the biosynthesis of leukotrienes (LTs), has generated increasing enthusiasm as anti-inflammatory and antitumor strategies in recent years. ...Based on our previous studies, we synthesized a series of dihydroxycinnamic acid-based analogs that might be 5-LO inhibitors. LTs biosynthesis inhibition in HEK293 cells and polymorphonuclear leukocytes (PMNL) was measured and antitumor activities were investigated in Renal Cell Carcinoma (RCC). Results showed that the 2,5-dihydroxycinnamic acid phenethyl ester (10b) was the best 5-LO inhibitor and was 7-fold more potent than Zileuton (1), the only clinically approved 5-LO inhibitor. 2,5-Dihydroxy substitution was more favorable to 5-LO inhibition since compound 10b is twice as active as CAPE (2) which is a 3,4-dihydroxylcinnamic acid ester. Meanwhile, 10b reduced the cell viability of renal cancer cells and was more selective toward RCC4 and 786.0 cells which are deficient for the Von Hippel-Lindau (VHL) tumor suppressor gene. As to the underlying cell-death mechanisms, 10b induced apoptosis in VHL-deficient RCC4 cells. Also, increases in LC3B and p62 expression suggest a blockage of the autophagic flux in RCC in response to 10b.
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•New dihydroxycinnamic acid-based analogs were screened for their 5-LO inhibition.•2,5-Dihydroxycinnamic acid phenethyl ester was the best 5-LO inhibitor.•2,5-Dihydroxycinnamic acid phenethyl was 7-fold more potent than Zileuton.•2,5-Dihydroxycinnamic acid phenethyl ester decreased cell viability of RCC4.•2,5-Dihydroxycinnamic acid phenethyl ester induced apoptosis in of RCC4 cells.
The involvement of lipoxygenases in various pathologies, combined with the unavailability of safe and effective inhibitors of the biosynthesis of their products, is a source of inspiration for the ...development of new inhibitors. Based on a structural analysis of known inhibitors of lipoxygenase products biosynthesis, a comprehensive structure–activity study was carried out, which led to the discovery of several novel compounds (16a‐c, 17a) demonstrating promising potency to inhibit the biosynthesis of products of 5‐, 12‐ and 15‐LO. Compounds 16b and 16c outperformed zileuton (1), the only FDA‐approved 5‐LO inhibitor, as well as known inhibitors such as caffeic acid phenethyl ester (CAPE (2)) and cinnamyl‐3,4‐dihydroxy‐α‐cyanocinnamate (CDC (4)). However, the introduction of a cyano group at the α‐position of the carbonyl abolished the activity. Compounds 16a and 17a also inhibited the biosynthesis of 12‐ and 15‐LO products. Compounds 16a, 17a far surpassed baicalein, a known 12‐LO inhibitor, as inhibitors of 12‐LO products biosynthesis. Compound 17a and CDC (4) showed equivalent inhibition of LO products, proposing that the double bond in the ester moiety is not necessary for the inhibitory activity. The introduction of the cyano group, as in compound 17a, at the α‐position of the carbonyl in compound 16a significantly reduced the inhibitory activity against the biosynthesis of 15‐LO products. In addition to the interactions with residues His372 and Phe421 also found with zileuton and CAPE, compounds 16a and 16c each interact with residue His367 as shown by molecular docking. This new interaction may explain their high affinity with the 5‐LO active site.
Upon prolonged thermal exposure under vacuum, a well-defined single-site surface species (triple bond, length as m-dashSi-O-)Zr(NEt2)3 () evolves into an ethylimido complex (triple bond, length as ...m-dashSi-O-)Zr(double bond, length as m-dashNEt)NEt2 (). Reactions of with an imine substrate result in imido/imine (double bond, length as m-dashNRi, R: Et, Ph) exchange (metathesis) with the formation of (triple bond, length as m-dashSi-O-)Zr(double bond, length as m-dashNPh)NEt2 (). Compounds and effectively catalyze imine/imine cross-metathesis and are thus considered as the first heterogeneous catalysts active for imine metathesis.
Propolis was collected from honeybee hives in three geographically distinct Algerian climates and extracts were characterized for composition and bioactivity. Bees were identified as native ...subspecies using an in‐silico DraI mtDNA COI‐COII test. Over 20 compounds were identified in extracts by LC‐MS. Extracts from the Medea region were more enriched in phenolic content (302±28 mg GAE/g of dry extract) than those from Annaba and Ghardaia regions. Annaba extracts had the highest flavonoid content (1870±385 mg QCE/g of dry extract). Medea extracts presented the highest free‐radical scavenging activity (IC50=13.5 μg/mL) using the DPPH radical assay while Ghardaia extracts from the desert region were weak (IC50>100 μg/mL). Antioxidant activities measured using AAPH oxidation of linoleic acid were similar in all extracts with IC50 values ranging from 2.9 to 4.9 μg/mL. All extracts were cytotoxic (MTT assay) and proapoptotic (Annexin‐V) against human leukemia cell lines in the low μg/mL range, although the Annaba extract was less active against the Reh cell line. Extracts inhibited cellular 5‐lipoxygenase product biosynthesis with IC50 values ranging from 0.6 to 3.2 μg/mL. Overall, examined propolis extracts exhibited significant biological activity that warrant further characterization in cellular and in vivo models.
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