A review of pharmacological effects of xylopic acid

Xylopic acid (15β-acetyloxy-kaur-16-en-19-oic acid) is a kaurene diterpene that can be obtained from various Xylopia spp. Xylopic acid has demonstrated several pharmacological activities in vitro and in vivo. The compound has shown promising effect as a potent analgesic, anti-inflammatory and anti-allergic agent. Xylopic acid is a CNS depressant and was able to ameliorate anxiety-like symptoms in mice in addition to its neuroprotective effects. Deleterious effects of xylopic acid on the reproductive system of mice have been well documented but extensive toxicity study detailing effect of the acid upon chronic exposure needs to be determined. Due to the heavy consumption of X. aethiopica fruits, it is recommended that the pharmacokinetics of xylopic acid be determined to ascertain the possible food-drug interaction that may occur when conventional drugs are taken together with foods containing xylopic acid

Metabolomics profiling reveals new aspects of dolichol biosynthesis in Plasmodium falciparum

The cis-polyisoprenoid lipids namely polyprenols, dolichols and their derivatives are linear polymers of several isoprene units. In eukaryotes, polyprenols and dolichols are synthesized as a mixture of four or more homologues of different length with one or two predominant species with sizes varying among organisms. Interestingly, co-occurrence of polyprenols and dolichols, i.e. detection of a dolichol along with significant levels of its precursor polyprenol, are unusual in eukaryotic cells. Our metabolomics studies revealed that cis-polyisoprenoids are more diverse in the malaria parasite Plasmodium falciparum than previously postulated as we uncovered active de novo biosynthesis and substantial levels of accumulation of polyprenols and dolichols of 15 to 19 isoprene units. A distinctive polyprenol and dolichol profile both within the intraerythrocytic asexual cycle and between asexual and gametocyte stages was observed suggesting that cis-polyisoprenoid biosynthesis changes throughout parasite’s development. Moreover, we confirmed the presence of an active cis-prenyltransferase (PfCPT) and that dolichol biosynthesis occurs via reduction of the polyprenol to dolichol by an active polyprenol reductase (PfPPRD) in the malaria parasite

Influenza vaccine effectiveness against influenza A subtypes in Europe: Results from the 2021-2022 I-MOVE primary care multicentre study

Background: In 2021-2022, influenza A viruses dominated in Europe. The I-MOVE primary care network conducted a multicentre test-negative study to measure influenza vaccine effectiveness (VE). Methods: Primary care practitioners collected information on patients presenting with acute respiratory infection. Cases were influenza A(H3N2) or A(H1N1)pdm09 RT-PCR positive, and controls were influenza virus negative. We calculated VE using logistic regression, adjusting for study site, age, sex, onset date, and presence of chronic conditions. Results: Between week 40 2021 and week 20 2022, we included over 11 000 patients of whom 253 and 1595 were positive for influenza A(H1N1)pdm09 and A(H3N2), respectively. Overall VE against influenza A(H1N1)pdm09 was 75% (95% CI: 43-89) and 81% (95% CI: 45-93) among those aged 15-64 years. Overall VE against influenza A(H3N2) was 29% (95% CI: 12-42) and 25% (95% CI: -41 to 61), 33% (95% CI: 14-49), and 26% (95% CI: -22 to 55) among those aged 0-14, 15-64, and over 65 years, respectively. The A(H3N2) VE among the influenza vaccination target group was 20% (95% CI: -6 to 39). All 53 sequenced A(H1N1)pdm09 viruses belonged to clade 6B.1A.5a.1. Among 410 sequenced influenza A(H3N2) viruses, all but eight belonged to clade 3C.2a1b.2a.2. Discussion: Despite antigenic mismatch between vaccine and circulating strains for influenza A(H3N2) and A(H1N1)pdm09, 2021-2022 VE estimates against circulating influenza A(H1N1)pdm09 were the highest within the I-MOVE network since the 2009 influenza pandemic. VE against A(H3N2) was lower than A(H1N1)pdm09, but at least one in five individuals vaccinated against influenza were protected against presentation to primary care with laboratory-confirmed influenza.This project has received funding from the European Centre for Disease Prevention and Control with in the framework contract ECDC/2018/029.S

multicentre analysis, I-MOVE-COVID-19 and ECDC networks, July to August 2021

Funding Information: This project received funding from the European Centre for Disease Prevention and Control (ECDC) under the contract ECD.11486. Funding Information: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101003673. Publisher Copyright: © 2022 European Centre for Disease Prevention and Control (ECDC). All rights reserved.Introduction: In July and August 2021, the SARS-CoV-2 Delta variant dominated in Europe. Aim: Using a multicentre test-negative study, we measured COVID-19 vaccine effectiveness (VE) against symptomatic infection. Methods: Individuals with COVID-19 or acute respiratory symptoms at primary care/community level in 10 European countries were tested for SARS-CoV-2. We measured complete primary course overall VE by vaccine brand and by time since vaccination. Results: Overall VE was 74% (95% CI: 69-79), 76% (95% CI: 71-80), 63% (95% CI: 48-75) and 63% (95% CI: 16-83) among those aged 30-44, 45-59, 60-74 and ≥ 75 years, respectively. VE among those aged 30-59 years was 78% (95% CI: 75-81), 66% (95% CI: 58-73), 91% (95% CI: 87-94) and 52% (95% CI: 40-61), for Comirnaty, Vaxzevria, Spikevax and COVID-19 Vaccine Janssen, respectively. VE among people 60 years and older was 67% (95% CI: 52-77), 65% (95% CI: 48-76) and 83% (95% CI: 64-92) for Comirnaty, Vaxzevria and Spikevax, respectively. Comirnaty VE among those aged 30-59 years was 87% (95% CI: 83-89) at 14-29 days and 65% (95% CI: 56-71%) at ≥ 90 days between vaccination and onset of symptoms. Conclusions: VE against symptomatic infection with the SARS-CoV-2 Delta variant varied among brands, ranging from 52% to 91%. While some waning of the vaccine effect may be present (sample size limited this analysis to only Comirnaty), protection was 65% at 90 days or more between vaccination and onset.publishersversionpublishe

Vaccine effectiveness against symptomatic SARS-CoV-2 infection in adults aged 65 years and older in primary care: I-MOVE-COVID-19 project, Europe, December 2020 to May 2021

I-MOVE-COVID-19 primary care study team (in addition to authors above): Nick Andrews, Jamie Lopez Bernal, Heather Whitaker, Caroline Guerrisi, Titouan Launay, Shirley Masse, Sylvie van der Werf, Vincent Enouf, John Cuddihy, Adele McKenna, Michael Joyce, Cillian de Gascun, Joanne Moran, Ana Miqueleiz, Ana Navascués, Camino Trobajo-Sanmartín, Carmen Ezpeleta, Paula López Moreno, Javier Gorricho, Eva Ardanaz, Fernando Baigorria, Aurelio Barricarte, Enrique de la Cruz, Nerea Egüés, Manuel García Cenoz, Marcela Guevara, Conchi Moreno-Iribas, Carmen Sayón, Verónica Gomez, Baltazar Nunes, Rita Roquete, Adriana Silva, Aryse Melo, Inês Costa, Nuno Verdasca, Patrícia Conde, Diogo FP Marques, Anna Molesworth, Leanne Quinn, Miranda Leyton, Selin Campbell, Janine Thoulass, Jim McMenamin, Ana Martínez Mateo, Luca Basile, Daniel Castrillejo, Carmen Quiñones Rubio, Concepción Delgado-Sanz, Jesús Oliva.The I-MOVE-COVID-19 network collates epidemiological and clinical information on patients with coronavirus disease (COVID-19), including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virological characterisation in 11 European countries [1]. One component of I-MOVE-COVID-19 is the multicentre vaccine effectiveness (VE) study at primary care/outpatient level in nine European study sites in eight countries. We measured overall and product-specific COVID-19 VE against symptomatic SARS-CoV-2 infection among those aged 65 years and older. We also measured VE by time since vaccination.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101003673.info:eu-repo/semantics/publishedVersio

Chemical mechanism of UDP-galactopyranose mutase from Trypanosoma cruzi: a potential drug target against Chagas' disease.

UDP-galactopyranose mutase (UGM) is a flavoenzyme that catalyzes the conversion of UDP-galactopyranose to UDP-galactofuranose, the precursor of galactofuranose (Galf). Galf is found in several pathogenic organisms, including the parasite Trypanosoma cruzi, the causative agent of Chagas' disease. Galf) is important for virulence and is not present in humans, making its biosynthetic pathway an attractive target for the development of new drugs against T. cruzi. Although UGMs catalyze a non-redox reaction, the flavin must be in the reduced state for activity and the exact role of the flavin in this reaction is controversial. The kinetic and chemical mechanism of TcUGM was probed using steady state kinetics, trapping of reaction intermediates, rapid reaction kinetics, and fluorescence anisotropy. It was shown for the first time that NADPH is an effective redox partner of TcUGM. The substrate, UDP-galactopyranose, protects the enzyme from reacting with molecular oxygen allowing TcUGM to turnover ∼1000 times for every NADPH oxidized. Spectral changes consistent with a flavin iminium ion, without the formation of a flavin semiquinone, were observed under rapid reaction conditions. These data support the proposal of the flavin acting as a nucleophile. In support of this role, a flavin-galactose adduct was isolated and characterized. A detailed kinetic and chemical mechanism for the unique non-redox reaction of UGM is presented

Chemical mechanism of TcUGM.

<p>The reaction requires the oxidized flavin cofactor (<b>a</b>) to be reduced for activity. First, NADPH binds to the oxidized enzyme (<b>b</b>), and only after the flavin is reduced (<b>c</b>) will UDP-Gal<i>p</i> bind (<b>d</b>). The flavin then acts as a nucleophile attacking the C1 of galactose and forming a flavin sugar adduct (<b>e</b>), which occurs rapidly (<b>f</b>). This is followed by ring opening and recyclization (<b>g</b>). The rate limiting step in the reaction corresponds to either galactose isomerization or reattachment of the UDP (<b>f</b> to <b>g</b>). We postulate that the rate limiting step is the isomerization step. The final step is release of UDP-Gal<i>f</i>, which occurs rapidly. The enzyme can proceed to the next reaction cycle or be slowly oxidized by molecular oxygen (<b>h</b> to <b>a</b>).</p

Trapping of a covalent flavin intermediate.

<p>A) HPLC traces of the flavin sugar adduct from free FAD. The peak eluding at 22.5 min is the adduct, while the second peak at 23.6 min is FAD. B) Spectrum of the C4a- hydroxyflavin-galactose adduct. C) High resolution mass spectrometry results of the peak containing the flavin adduct. The inset shows the structure of the adduct with a hydroxyl group at the flavin C4a-position.</p

TcUGM Reduction by NAD(P)H^a.

a<p>Reactions were measured under anaerobic conditions at 15°C in 50 mM phosphate buffer pH 7.0.</p

Viscosity effect on k_cat.

<p>The effect of viscosity was determined by measuring the activity of TcUGM as a function of increasing concentrations of glycerol. The data was fit to a linear equation; the dashed line depicts the results of a diffusion controlled reaction. This line has a slope of 1.</p