Maytenus octogona Superoxide Scavenging and Anti-Inflammatory Caspase-1 Inhibition Study Using Cyclic Voltammetry and Computational Docking Techniques.

The relationship between oxidative stress and inflammation is well known, and exogenous antioxidants, primarily phytochemical natural products, may assist the body's endogenous defense systems in preventing diseases due to excessive inflammation. In this study, we evaluated the antioxidant properties of ethnomedicines from Peru that exhibit anti-inflammatory activity by measuring the superoxide scavenging activity of ethanol extracts of Maytenus octogona aerial parts using hydrodynamic voltammetry at a rotating ring-disk electrode (RRDE). The chemical compositions of these extracts are known and the interactions of three methide-quinone compounds found in Maytenus octogona with caspase-1 were analyzed using computational docking studies. Caspase-1 is a critical enzyme triggered during the activation of the inflammasome and its actions are associated with excessive release of cytokines. The most important amino acid involved in active site caspase-1 inhibition is Arg341 and, through docking calculations, we see that this amino acid is stabilized by interactions with the three potential methide-quinone Maytenus octogona inhibitors, hydroxytingenone, tingenone, and pristimerin. These findings were also confirmed after more rigorous molecular dynamics calculations. It is worth noting that, in these three compounds, the methide-quinone carbonyl oxygen is the preferred hydrogen bond acceptor site, although tingenone's other carbonyl group also shows a similar binding energy preference. The results of these calculations and cyclovoltammetry studies support the effectiveness and use of anti-inflammatory ethnopharmacological ethanol extract of Maytenus octogona (L'Héritier) DC.

CYP2D6 and CYP2C19 Genes Associated with Tricontinental and Latin American Ancestry of Pe-ruvians.

Precision medicine seeks to individualize the dose from the beginning of phar-macological therapy based on the characteristics of each patient, genes involved in the metabolic phenotype, ethnicity or miscegenation, with the purpose to minimize adverse effects and optimize drug efficacy. The objective was to re-view studies that describe the association of the CYP2D6 and CYP2C19 genes with the tricontinental and Latin American ancestry of Peruvians. A biblio-graphic search was carried out in PubMed/Medline and SciELO, with various descriptors in Spanish and English. The results of this review confirm that the ethnic origin of Peruvians is triconti-nental due to European (mainly Spanish), African and Asian migration, in addi-tion to Latin American migration, being 60.2% mixed, 25.8% Amerindian, 5.9% white, 3.6% African descent, 1.2% Chinese and Japanese descent, and 3.3% unspecified. Studies on CYP2C19*3, CYP2D6*2, *3 and *6 have been reported in Peruvians, and the frequency is similar to that studied in Ecuadori-ans and Colombians. The CYP2C19*3, CYP2D6*3, and CYP2D6*6 alleles found in Peruvians are common in Europeans, Africans, and Asians; while CYP2D6*4 in Africans and CYP2D6*2 related to Asians. In some studies, the ethnic/gene association has not been demonstrated; while others have shown a significant association, which is why further investigation is warranted. It is concluded that the studies on CYP2D6 and CYP2C19 genes associated with the tricontinental and Latin American ancestry of Peruvians are little, and ac-cording to what has been investigated, the CYP2C19*3, CYP2D6*2, *3, *4 and *6 alleles have more related to their ancestry.

Interacciones farmacocinéticas de la azitromicina e implicación clínica / Pharmacokinetic interactions of azithromycin and clinical implication

Introducción: El síndrome respiratorio agudo grave (por la COVID-19) es en la actualidad la primera causa de muerte en el Perú, por lo que se requiere de fármacos eficaces y seguros para mitigar la enfermedad. Se realizó una búsqueda bibliográfica en SciELO y PubMed/ Medline; se seleccionaron 37 de 58 artículos sobre el tema. Objetivos: Revisar e integrar la información sobre las interacciones farmacocinéticas de la azitromicina que se prescriben en el tratamiento ambulatorio de la COVID-19 en el Perú, y evaluar su implicación clínica. Desarrollo: La azitromicina es usada en la COVID-19, por su actividad antiinflamatoria, al inhibir a las interleucinas (IL1, 6, 8 y TNF-α), y a las moléculas de adhesión intracelular 1 (ICAM1); y por inducir la producción de interferón tipo I (IFN-α, IFN-β) y III (IFN-λ) en células de pacientes con enfermedad pulmonar obstructiva crónica. Los estudios de tres brazos, aleatorizado y abierto, indican que la azitromicina no genera cambios en los parámetros farmacocinéticos de la ivermectina, sildenafilo, rupatadina y desloratadina; los estudios de un solo centro, abierto, sin ayuno y de dos períodos, evidencian que la azitromicina influye en los parámetros farmacocinéticos de venetoclax y de los psicotrópicos. Conclusiones: Basado en la evidencia de los estudios clínicos revisados e integrados, se concluye que estas son limitadas y de poca relevancia clínica, sin embargo, se propone usar el antibiótico bajo el criterio científico del médico, para evitar las interacciones farmacocinéticas y las reacciones adversas de los fármacos(AU)

Introduction: The severe acute respiratory syndrome (due to COVID-19) is currently the leading cause of death in Peru, so effective and safe drugs are required to mitigate the disease. A bibliographic search was carried out in SciELO and PubMed/Medline; 37 of 58 articles on the topic were selected. Objectives: Review and integrate the information on the pharmacokinetic interactions of azithromycin that are prescribed in the outpatient treatment of COVID-19 in Peru, and evaluate their clinical implication. Development: Azithromycin is used in COVID-19, due to its anti-inflammatory activity, by inhibiting interleukins (IL1, 6, 8 and TNF-α), and intracellular adhesion molecules 1 (ICAM1); and by inducing the production of type I interferon (IFN-α, IFN-β) and III (IFN-λ) in cells of patients with chronic obstructive pulmonary disease. The three-arm, randomized and open-label studies indicate that azithromycin does not cause changes in the pharmacokinetic parameters of ivermectin, sildenafil, rupatadine, and desloratadine; single-center, open-label, non-fasting, and two-period studies show that azithromycin influences the pharmacokinetic parameters of venetoclax and psychotropics. Conclusions: Based on the evidence from the reviewed and integrated clinical studies, it is concluded that these are limited and of little clinical relevance, however, it is proposed to use the antibiotic under the scientific criteria of the doctor, to avoid pharmacokinetic interactions and adverse reactions of drugs(AU)

Deglycosylation is a key step in biotransformation and lifespan effects of quercetin-3-O-glucoside in Caenorhabditis elegans.

Due to their purported healthful activities, quercetin and other flavonoids are being increasingly proposed as nutraceuticals. Quercetin occurs in food as glycosides; however, most assays on its activity have been performed with the aglycone, despite glycosylation deeply affects compound bioavailability. In this work, the uptake and lifespan effects of quercetin-3-O-glucoside (Q3Glc) and quercetin have been assessed in Caenorhabditis elegans. Q3Glc was taken up by this nematode in a concentration-dependent manner and rapidly deglycosylated to quercetin, which was accumulated in the worm and partially biotransformed to conjugated metabolites. Significant mean lifespan extension up to 23% compared to controls was observed in wild type worms cultivated in the presence of low concentrations of Q3Glc (10 µM and 25 µM), whereas exposure to greater concentrations of Q3Glc (50-200 µM) caused a reduction in mean and maximum lifespan compared with the control. By contrast, treatment of klo-1 and klo-2 mutant worms lacking ß-glucosidase activity with 200 µM of Q3Glc led to extended mean lifespan (up to 39%), similar to quercetin aglycone at the same concentration levels. In those mutants, Q3Glc was accumulated without important deglycosylation to quercetin was produced. Taken together, these findings indicated that Q3Glc was taken up by the nematode in greater extent than quercetin, and that deglycosylation and subsequent aglycone accumulation in the worm appeared as key points to explain the observed lifespan effects. The obtained results also suggested that facilitated absorption should be more important for the uptake of quercetin derivatives than passive diffusion.

Oxidative status of stressed Caenorhabditis elegans treated with epicatechin.

The aim of this work was to examine the mechanisms involved in the in vivo antioxidant effects of epicatechin (EC), a major flavonoid in the human diet. The influence of EC in different oxidative biomarkers (reactive oxygen species (ROS) production, intracellular glutathione, activity of catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD)) was studied in the model organism Caenorhabditis elegans . Under thermal stress condition, exposure of the worms (wild type N2 strains) to EC (200 µM) significantly reduced ROS levels (up to 28%) and enhanced the production of reduced glutathione (GSH). However, no significant changes were appreciated in the activities of GPx, CAT, and SOD, suggesting that further activation of these antioxidant enzymes was not required once the concentration of ROS in the EC-treated worms was restored to what could be considered physiological levels.

Characterization of sulfated quercetin and epicatechin metabolites.

Different monosulfates of quercetin and epicatechin with metabolic interest were obtained by hemisynthesis and characterized regarding their chromatographic behavior and absorption and mass spectra. Three of these compounds were further isolated, and their structures were elucidated by mass spectrometry and (1)H and (13)C nuclear magnetic resonance using one- and two-dimensional techniques (heteronuclear single-quantum coherence and heteronuclear multiple-bond correlation). The calculation of the proton and carbon shifts caused by sulfation allowed for the assignment of the position of the sulfate group in the flavonoids, so that the compounds were identified as quercetin-3'-O-sulfate, quercetin 4'-O-sulfate, and epicatechin 4'-O-sulfate. It was found that sulfation at position 3' induced a large upfield shift in the carbon bearing the sulfate group and downfield displacements of the adjacent carbons, whereas no significant upfield or downfield shifts were observed with respect to the parent flavonoid when sulfation was produced at position 4'.

Effects of O-methylated metabolites of quercetin on oxidative stress, thermotolerance, lifespan and bioavailability on Caenorhabditis elegans.

Quercetin is a major flavonoid in the human diet and the most commonly used in studies of biological activity. Most of the knowledge about its biological effects has originated from in vitro studies while in vivo data are scarce. Quercetin mostly occurs in foodstuffs as glycosides that are deglycosylated during absorption and further submitted to different conjugation reactions. Methylation to isorhamnetin (quercetin 3'-O-methylether) or tamarixetin (quercetin 4'-O-methylether) seems to be an important conjugation process in quercetin metabolism. In this work, the effects of quercetin and its 3'- and 4'-O-methylated metabolites on the phenotypic characteristics, stress oxidative resistance, thermotolerance and lifespan of the model organism Caenorhabditis elegans have been assessed. The three assayed flavonols significantly prolonged the lifespan of this nematode with an increase from 11% to 16% in the mean lifespan with respect to controls. However, only quercetin significantly increased the reproductive capacity of the worm and enlarged the body size. Exposure to the assayed flavonols also increased significantly the resistance against thermal and juglone-induced oxidative stress, although differences were found depending on the stage of development of the worm. Thus, quercetin offered greater protection when thermal stress was applied in the 1st day of adulthood, whereas tamarixetin was more efficient in worms submitted to stress in the 6th day of adulthood. Similarly, significantly greater protection was provided by quercetin than by its methylated derivatives at the 1st day of adulthood, whilst quercetin and isorhamnetin were equally efficient when the oxidative stress was induced in the 6th of day of adulthood. Further evidence of antioxidant protection was obtained checking the oxidation status of proteins by the OxyBlot™ detection kit. Analyses by HPLC-DAD-ESI/MS confirmed that the three flavonols were taken up by C. elegans leading to the formation of some glycosylated, sulfated and methylated metabolites, and that demethylation of these latter to quercetin was also produced. Quantification of the levels of quercetin, isorhamnetin and tamarixetin, as well as their detected metabolites indicated a greater uptake of quercetin than its methylated derivatives by the nematode.