Analysis of 2′-hydroxyflavanone (2HF) in mouse whole blood by HPLC–MS/MS for the determination of pharmacokinetic parameters

Given the lack of investments, structure, and difficulty of metabolite isolation, promising natural product studies do not progress to preclinical studies, such as pharmacokinetics. 2′-Hydroxyflavanone (2HF) is a flavonoid that has shown promising results in different types of cancer and leishmaniasis. For accurate quantification of 2HF in BALB/c mouse blood, a validated HPLC-MS/MS method was developed. Chromatographic analysis was performed using C18 (5μm, 150 mm × 4.6 mm). The mobile phase consisted of water containing 0.1% formic acid, acetonitrile, and methanol (35/52/13 v/v/v) at a flow rate and total running time of 0.8 mL/min and 5.50 min, respectively, with an injection volume of 20 µL. 2HF was detected by electrospray ionization in negative mode (ESI-) using multiple reaction monitoring (MRM). The validated bioanalytical method showed satisfactory selectivity without significant interference for the 2HF and IS. In addition, the concentration range between 1 and 250 ng/mL showed good linearity (r = 0.9969). The method showed satisfactory results for the matrix effect. Precision and accuracy intervals varied between 1.89% and 6.76% and 95.27% and 100.77%, respectively, fitting the criteria. No degradation of 2HF in the biological matrix was observed since stability under freezing and thawing conditions, short duration, postprocessing, and long duration showed deviations less than 15%. Once validated, the method was successfully applied in a 2HF oral pharmacokinetic study with mouse blood, and the pharmacokinetic parameters were determined. 2HF demonstrated a Cmax of 185.86 ng/mL, a Tmax of 5 min, and a half-life (T1/2) of 97.52 min.

Pharmacological profiling of JME-173, a novel mexiletine derivative combining dual anti-inflammatory/anti-spasmodic functions and limited action in Na+ channels

Existing evidence suggests that the local anaesthetic mexiletine can be beneficial for patients with asthma. However, caution is required since anaesthesia of the airways inhibits protective bronchodilator neuronal reflexes, limiting applications in conditions of hyperirritable airways. Here, we describe the synthesis of a new series of mexiletine analogues, which were screened for reduced activity in Na⁺ channels and improved smooth muscle relaxant effects, that were evaluated using the patch-clamp technique and an isolated tracheal organ bath, respectively. JME-173 (1-(4-bromo-3,5-dimethylphenoxy)propan-2-amine) was the most effective among the four mexiletine analogues investigated. JME-173 was then studied in vivo using a murine model of lung inflammation induced by cigarette smoke (CS) and in vitro using neutrophil chemotaxis and mast cell degranulation assays. Finally, the JME-173 pharmacokinetic profile was assessed using HPLC-MS/MS bioanalytical method. JME-173 directly inhibited IL-8 (CXCL8)- and FMLP-induced human neutrophil chemotaxis and allergen-induced mast cell degranulation. After oral administration 1 h before CS exposure, JME-173 (50 mg/kg) strongly reduced the increased number of macrophages and neutrophils recovered in the bronchoalveolar effluent without altering lymphocyte counts. Pharmacokinetic experiments of JME-173 (10 mg/kg, orally) showed values of maximum concentration (C_max), maximum time (T_max), area under the blood concentration-time curve (AUC_0-t) and area under the blood concentration-time curve from 0-Inf (AUC_0-inf) of 163.3 ± 38.3 ng/mL, 1.2 ± 0.3 h, 729.4 ± 118.3 ng*h/ml and 868.9 ± 117.1 ng*h/ml (means ± S.E.M.), respectively. Collectively, these findings suggest that JME-173 has the potential to be an effective oral treatment for diseases associated with bronchoconstriction and inflammation.

Sofosbuvir shows a protective effect against vertical transmission of Zika virus and the associated congenital syndrome in rhesus monkeys

The outbreaks of Zika virus (ZIKV) infection in Brazil, 2015-2016, were associated with severe congenital malformations. Our translational study aimed to test the efficacy of the antiviral agent sofosbuvir (SOF) against vertical transmission of ZIKV and the associated congenital syndrome (CZS), using a rhesus monkey model. Eight pregnant macaques were successfully infected during the organogenesis phase with a Brazilian ZIKV strain; five of them received SOF from two to fifteen days post-infection. Both groups of dams showed ZIKV-associated clinical signals, detectable ZIKV RNA in several specimens, specific anti-ZIKV IgM and IgG antibodies, and maternal neutralizing antibodies. However, malformations occurred only among non-treated dam offspring. Compared to non-treated animals, all SOF-treated dams had a shorter ZIKV viremia and four of five neonates had undetectable ZIKV RNA in blood and tissue samples. These results support further clinical evaluations aiming for the prevention of CZS.

Effect of different helminth extracts on the development of asthma in mice: The influence of early-life exposure and the role of IL-10 response

It is not currently clear whether different parasites have distinct effects on the airway inflammatory response in asthma and whether exposure in early life to helminths have a stronger impact in a potential inhibitory effect on asthma. The aim of this study is to evaluate the effect of exposure to different helminth extracts on the development of allergic pulmonary response in mice, including early-life exposure. Different helminth extracts (Angiostrongylus costaricensis, Angiostrongylus cantonensis and Ascaris lumbricoides) were studied in female adult BALB/c and C57BL/6 IL-10-deficient mice in a protocol of murine asthma, injected intraperitoneally in different periods of exposure (early, pre-sensitization and post-sensitization). Cell counts in bronchoalveolar lavage (BAL), eosinophil peroxidase (EPO) from lung tissue, cytokine levels from BAL/spleen cell cultures, and lung histology were analyzed. Airway cellular influx induced by OVA was significantly inhibited by extracts of A. cantonensis and A. lumbricoides. Extracts of A. lumbricoides and A. costaricensis led to a significant reduction of IL-5 in BAL (p < 0.001). Only the exposure to A. lumbricoides led to an increased production of IL-10 in the lungs (p < 0.001). In IL-10-deficient mice exposed to A. costaricensis pre-sensitization, eosinophil counts and IL-5 levels in BAL and EPO in lung tissue were significantly reduced. In the early exposure to A. cantonensis, lung inflammation was clearly inhibited. In conclusion, different helminth extracts inhibit allergic lung inflammation in mice. IL-10 may not play a central role in some helminth-host interactions. Early exposure to helminth extracts could be a potential strategy to explore primary prevention in asthma.

Antinociceptive and anti-inflammatory activities of ethanolic extracts of Lychnophora species

Extracts from Lychnophora species are traditionally used in Brazil as anti-inflammatory, and to treat bruise, pain and rheumatism. The ethanolic extract of aerial parts of five species of Lychnophoras and one specie of Lychnophoriopsis were examined for the antinociceptive (hot-plate and writhing tests) and anti-inflammatory (carrageenan-induced paw oedema test) activity in mice, by oral and topical routes, respectively. In the hot-plate test, the Lychnophora pinaster (0.75 g/kg) and Lychnophora ericoides (1.50 g/kg) extracts significantly increased the time for licking of the paws. The species Lychnophora passerina, Lychnophoriopsis candelabrum and Lychnophora pinaster, using the dose of 0.75 g/kg, and Lychnophora ericoides and Lychnophora trichocarpha in both doses evaluated (0.75 and 1.50 g/kg) significantly reduced the number of writhes induced by acetic acid. The administration of Lychnophora pinaster and Lychnophora trichocarpha ointments, in both concentrations evaluated (5 and 10%, w/w), and Lychnophora passerina and Lychnophoriopsis candelabrum, in the concentration of 10%, significantly reduced the paw oedema measured 3 h after carrageenan administration, suggesting, for the first time, an anti-inflammatory activity upon topical administration of these species. The present work comparatively demonstrated the antinociceptive and anti-inflammatory activities of some Brazilian Lychnophoras.

Synthesis and schistosomicidal activity of new substituted thioxo-imidazolidine compounds

Synthesis and physico-chemical properties of 3-benzyl-5-(4-fluoro-benzylidene)-1-methyl-2-thioxo-imidazolidin-4-ones, 5-benzylidene-3-(4-nitro-benzyl)-2-thioxo-imidazolidin-4-ones and 4-acridin-9-ylmethylene-1-benzyl-5-thioxo-imidazolidin-2-ones compounds are described. These thioxo-imidazolidine derivatives were prepared by alkylation and condensation with 4-fluoro-benzaldehyde or nucleophilic Michael addition with cyanoacrylates. The schistosomicidal activity of 3-benzyl-5-(4-fluoro-benzylidene)-1-methyl-2-thioxo-imidazolidin-4-one compounds was evaluated.