Mise en évidence de l’activité anti-inflammatoire des sous-fractions méthanoliques des feuilles de Moringa oleifera Lam. (Moringaceae) chez le rat

Moringa oleifera est une plante de la pharmacopée africaine, très utilisée en médecine traditionnelle pour ses nombreuses applications thérapeutiques. L’objectif de la présente étude était de fractionner la fraction méthanolique de l’extrait hydro-alcoolique de ses feuilles dont les propriétés anti-inflammatoires avaient été démontrées antérieurement et d’identifier la sous-fraction méthanolique la plus active. La méthode de séparation liquide-liquide a été utilisée pour partitionner la fraction méthanolique. Trois sous-fractions méthanoliques (F1, F2 et F3) sont obtenues à l’issue du fractionnement. L’activité anti-inflammatoire de ces extraits a été testée sur un modèle pharmacologique d’oedème aigu de la patte de rat induit par la carraghénine en comparaison à celle de l’aspirine utilisée comme substance de référence. Après administration par gavage, l’aspirine (30 mg/kg) et les extraits (15 et 30 mg/kg) préviennent de manière significative, l’oedème de la patte des rats de la 1ère à la 5ème heure de l’expérience. L’étude montre globalement une activité anti-inflammatoire des sous-fractions F1, F2 et F3. L’effet le plus important est observé avec la F3 durant les trois 1ères heures de l’expérience avec une cinétique d’inhibition de l’oedème comparable à celle de l’aspirine. Ces résultats suggèrent que les feuilles de Moringa oleifera pourraient constituer une source potentielle d’antiinflammatoires dans le traitement des pathologies ayant une composante inflammatoire.© 2016 International Formulae Group. All rights reserved.Mots clés: Moringa oleifera, feuilles, anti-inflammatoire, sous-fractions méthanoliquesEnglish Title: Study of the anti-inflammatory activity of methanolic sub-fractions of the leaves of Moringa Oleifera Lam. (Moringaceae) in ratEnglish AbstractMoringa oleifera is an African pharmacopoeia plant, widely used in traditional medicine for its many therapeutic applications. This study aimed at partitioning the methanolic fraction of hydro-alcoholic leaves extract of which anti-inflammatory properties have been previously demonstrated and to identify the most active methanolic sub-fraction. The liquid/liquid fractionation method was used to partition the methanolic  fraction. Three methanolic sub-fractions (F1, F2 and F3) were obtained from the fractionation. Antiinflammatory activity of extracts was tested using pharmacological model of carrageenan-induced acute paw oedema in rats compared to that of aspirin (reference). After oral administration, aspirin (30 mg/kg) and extracts (15 and 30 mg/kg) significantly prevented carrageenan-induced paw oedema in rats from the 1st to 5th hours of experimentation. Study showed overall anti-inflammatory activity of methanolic sub-fractions. The most important effect was observed with the F3 during the first three hours with a kinetic inhibition of oedema similar to that of aspirin. These results suggest that the leaves of Moringa oleifera could be a potential source of anti-inflammatory drugs in treatment of diseases with an inflammatory component.© 2016 International Formulae Group. All rights reserved.Keywords: Moringa oleifera, leaves, anti-inflammatory, methanolic sub-fraction

Optimization of a magnetic bead-based assay (MAGPIX®-Luminex) for immune surveillance of exposure to malaria using multiple Plasmodium antigens and sera from different endemic settings

Abstract Background Serological markers are potentially useful tools for monitoring the progress of malaria control programs, but a better understanding of antibody response dynamics is necessary. The use of a magnetic bead-based immunoassay (MBA) is advantageous compared to ELISA, due to its multiplexing capacity, but limited information is available on the standardization and validation of this assay. Methods Several parameters for multiplex testing of antibodies to Plasmodium antigens were analysed using a set of 4 antigens and 98 sera from Senegalese rural asymptomatic and urban symptomatic individuals. The 4 antigens included Plasmodium falciparum CSP and PfAMA1 peptides, recombinant P. falciparum MSP4p20 and a Plasmodium malariae CSP (PmCSP) peptide. Comparisons with ELISA were done using MSP4p20 and whole schizont extract (SE) antigens. Results The use of fewer beads (1000 beads per well instead of 2000) and 5 µg of antigen per 106 bead were validated as lower amounts. The use of a carrier protein (BSA) was shown to be critical when using peptides and the effect of a 24 h delayed measures was evaluated (5–25% signal decrease). Analysis of Ab responses showed almost equally high levels and prevalence in all transmission settings. Clear distinctions between rural and urban malaria were noted using PmCSP and SE antigens. Conclusions This study underlines the importance of further optimization of the MBA technique and highlights the interest of using multistage/multispecies antigens for surveillance of malaria in endemic settings

Seroepidemiology of Toxoplasmosis in Hemodialysis Patients in Senegal

Toxoplasmosis in immunocompromised patients results in either reactivation of latent toxoplasmosis or acute infection. In the framework of the kidney transplantation program in Senegal, the serological screening of potential pre-transplant and transplanted patients can prevent the disease. This study aimed to assess the seroprevalence of toxoplasmosis in a cohort of hemodialysis patients, candidates for kidney transplantation. To this end, a multicentre cross-sectional study was conducted in 2020 in six dialysis units from five regions. Blood samples and sociodemographic data were collected from each patient. IgG and IgM against T. gondii antibodies were assessed by a chemiluminescent method using Architect ci4100, and statistical analysis was performed using R software. Overall, 211 hemodialysis patients aged from 18 to 77 years were enrolled. The mean age was 42.62 years ± 13.6, and the sex ratio M/F was 1.24. The overall seroprevalence of T. gondii was 41.7%, with the highest value being recorded in the region of Kaolack (44.4%). Patients aged over 60 years were more typically infected, at a proportion of 56.0%. Regarding sex, males elicited a higher prevalence (44.4.%) than females did. Patients of an upper socioeconomic status were less affected, and contact with cats was not associated with toxoplasmosis. By education level, the illiterate group was most affected one. Overall, this first study of toxoplasmosis among Senegalese hemodialysis patients indicates high seroprevalence

Bland-Altman plot of the whole data.

<p>The x-axis represents the average of CD4 count between the PIMA and the BD FACSCount^TM, and the y-axis represents the bias (difference) between the PIMA^TM Alere and the BD FACSCount^TM. The solid blue line represents the mean of the difference between the two measurements, and the light black lines represent the upper and lower limits of agreement (ULA: mean differences plus and 1,96 x standard deviation of the mean difference; LLA: mean differences minus and 1,96 x standard deviation of the mean difference). Legend for CD4 categories: 1: CD4 T-cells < 200/mm³; 2: CD4 T-cells between 200 and 350/mm³; 3: CD4 T-cells between 351 and 500/mm³; 4: CD4 T-cells above 500/mm³.</p

Comparison of the mean difference between the CD4 PIMA^TM Alere and BD FACSCount^TM CD4 measurements.

<p>Comparison of the mean difference between the CD4 PIMA^TM Alere and BD FACSCount^TM CD4 measurements.</p

Analysis of the median CD4 counts between the PIMA and the FACSCount.

<p>Categories of absolute CD4+ T-cells counts (< 200/mm³, [200-350/mm³], [351-500/mm³], and > 500/mm³, in before-after scatter plots comparing the PIMA^TM Alere and the BD FACSCount^TM are shown. Data are shown as median values. P-values were calculated in SPSS 20 using nonparametric Mann-Whitney U test and the graphing was performed using GraphPad Prism software version 5.00.</p

Evaluation of PIMA^TM CD4 System for Decentralization of Immunological Monitoring of HIV-Infected Patients in Senegal

<div><p>Background</p><p>HIV infection is a concern in the army troupes because of the risk behaviour of the military population. In order to allow regular access to CD4⁺ T cell enumeration of military personnel as well as their dependents and civilians living with HIV, the Senegalese Army AIDS program is implementing PIMA^TM Alere technology in urban and semi-urban military medical centres. Validation such device is therefore required prior their wide implementation. The purpose of this study was to compare CD4⁺ T cell count measurements between the PIMA^TM Alere to the BD FACSCount^TM.</p><p>Methodology</p><p>We selected a total of 200 subjects including 50 patients with CD4⁺ T-cells below 200/mm³, 50 between 200 and 350/mm³, 50 between 351 and 500/mm³, and 50 above 500/mm³. CD4⁺ T-cell count was performed on venous blood using the BD FASCount^TM as reference method and the PIMA^TM Point of Care technology. The mean biases and limits of agreement between the PIMA^TM Alere and BD FACSCount^TM were assessed with the Bland-Altman analysis, the linear regression performed using the Passing-Bablok regression analysis, and the percent similarity calculated using the Scott method.</p><p>Results</p><p>Our data have shown a mean difference of 22.3 cells/mm³ [95%CI:9.1–35.5] between the BD FACSCount^TM and PIMA^TM Alere CD4 measurements. However, the mean differences of the two methods was not significantly different to zero when CD4⁺ T-cell count was below 350/mm³ (P = 0.76). The Passing-Bablok regression in categorized CD4 counts has also showed concordance correlation coefficient of 0.89 for CD4⁺ T cell counts below 350/mm³ whilst it was 0.5 when CD4 was above 350/mm³.</p><p>Conclusion</p><p>Overall, our data have shown that for low CD4 counts, the results from the PIMA^TM Alere provided accurate CD4⁺ T cell counts with a good agreement compared to the FACSCount^TM.</p></div

Passing-Bablok regression between PIMA^TM Alere CD4 and BD FACSCount^TM.

<p>The x-axis represents CD4 counts provided by the BD FACSCount^TM reference and the y-axis represents the CD4 counts provided by the PIMA^TM CD4. The solid line represents the regression line, and the dashed line represents the line y = x. The linear equation of the regression is y = 0.9347 x + 11.</p

Bland-Altman analysis.

<p>Bland-Altman plots of <b>(A)</b> CD4 T-cells < 200/mm³, <b>(B)</b> between 200 and 350/mm³, <b>(C)</b> between 350 and 500/mm³, and <b>(D)</b> above 500/mm³ according the CD4 cell count levels. For each plot, the x-axis represents the average of CD4 count between the PIMA and the BD FACSCount^TM, and the y-axis represents the bias (difference) between the PIMA^TM Alere and the BD FACSCount^TM. The solid red line represents the mean of the difference between the two measurements, and the light black lines represent the upper and lower limits of agreement (ULA: mean differences plus and 1,96 x standard deviation of the mean difference; LLA: mean differences minus and 1,96 x standard deviation of the mean difference)</p