Activités Antiproliférative et Antiradicalaire d’extraits Aqueux de Quatre Plantes Médicinales Congolaises

Le but de ce travail est d’évaluer les propriétés antiproliférative et antiradicalaire des extraits aqueux de quatre plantes médicinales congolaises dont Morinda lucida, Klainedoxa gabonensis, Tephrosia vogelii et Nauclea latifolia. L’activité antiproliférative de l’extrait aqueux de chacune des quatre espèces a été évaluée in vitro sur une lignée cellulaire cancéreuse (U87-MG) et une lignée cellulaire normale (Hek-293) en utilisant le test MTT. L’activité antiradicalaire a été évaluée en mesurant la capacité de piégeage du radical DPPH. Des analyses phytochimiques des extraits ont été réalisées par chromatographie sur couche mince et par HPLC-PDA. Les extraits aqueux de Klainedoxa gabonenis et de Tephrosia vogelii ont montré une activité antiproliférative contre les cellules cancéreuses U87-MG avec des valeurs de CI50 inférieures à 90 μg/ml. L’extrait aqueux de Klainedoxa gabonenis a montré également une activité antiradicalaire remarquable (CI50 = 4 ± 0,73 μg/ml) .En plus, le traitement des cellules cancéreuses U87-MG à la fois par l’extrait aqueux de Klainedoxa gabonensis (100 μg/ml) et par un inhibiteur de la protéine MEK (1μM) provoque une suppression totale de la prolifération des cellules U87-MG (glioblastome). L’analyse en HPLC–PDA de l’extrait aqueux Klainedoxa gabonenis a montré la présence des composés de type acide gallique (41, 9 %) et quercétine (2,17 %). Notre étude a permis d’identifier deux plantes médicinales aux propriétés antiprolifératives parmi les quatre plantes médicinales congolaises évaluées dont une possédant à la fois les propriétés antiproliférative et antiradicalaire. The purpose of this work is to evaluate antiprolifertive and DPPH radical scavenging activities of aqueous extracts from Morinda lucida Smith, Klainedoxa gabonensis Pierre ex Engl, Tephrosia vogelii Hook f and Nauclea latifolia Sm. The antiproliferative activity of the aqueous extract of each of the four species was evaluated in vitro on a cancer cell line (U87-MG) and a normal cell line (Hek-293) using the MTT assay. The antiradicalar activity was evaluated by measuring the scavenger capacity of the DPPH radical. Phytochemical analyzes of the extract were performed by thin layer chromatography and HPLC-PDA. The aqueous extracts of Klainedoxa gabonenis and Tephrosia vogelii showed antiproliferative activity against U87-MG cancer cells with IC50 values below 90 μg / ml. The aqueous extract of Klainedoxa gabonenis also showed remarkable antiradical activity (IC50 = 4± 0,73 μg/ml). In addition, the treatment of U87-MG cancer cells by both the aqueous extract of Klainedoxa gabonensis (100 μg / ml) and by an MEK protein inhibitor (1 μM) causes a total suppression of U87-cell proliferation. MG (glioblastoma). HPLC-PDA analysis of the aqueous extract Klainedoxa gabonenis showed the presence of gallic acid compounds (41.9%) and Quercetin (2.17%).: Our study identified two medicinal plants with antiproliferative properties among the four Congolese herbal medicines evaluated, one with both anti-proliferative and antiradical properties

<i>Pentaclethra eetveldeana</i> Leaves from Four Congo-Brazzaville Regions: Antioxidant Capacity, Anti-Inflammatory Activity and Proportional Accumulation of Phytochemicals

Oxidative stress and inflammation play a key role in the occurrence of neurodegenerative diseases. Traditionally, Pentaclethra eetveldeana leaves are used in dementia treatment. Therefore, this study aimed to evaluate the antioxidant and anti-inflammatory activities as well as the phytochemical composition of Pentaclethra eetveldeana leaves from four Congo-Brazzaville regions. The 1.2-diphenyl-1-picrylhydrazyl radical-scavenging, β-carotene bleaching and molybdenum reduction assays were used to assess the antioxidant activity. The protein denaturation and erythrocyte membrane stabilization tests were used to analyze the anti-inflammatory activity. Phytochemical screening, the quantification of polyphenols by spectrophotometry, as well as the determination of extraction yields were carried out. It was found that the extracts reduced molybdenum; furthermore, compared to ascorbic acid, they showed better antiradical activity and inhibited lipid peroxidation. Moreover, globally, the membrane-stabilizing power of the aqueous extracts was superior or comparable to diclofenac, while the same extracts were less effective for the inhibition of denaturation. All of the aqueous extracts contained polyphenols, saponins, alkaloids, anthraquinones, reducing sugar and cardiotonic glycosides. The total polyphenols, tannins and proanthocyanidins are produced proportionally from one region to another. Finally, the leaves from Brazzaville and Boundji contain flavonols, while those from Makoua and Owando contain flavones. Thus, Pentaclethra eetveldeana leaves contribute to traditional dementia treatment through their antioxidant and anti-inflammatory properties

Efficacy of sulfadoxine-pyrimethamine, amodiaquine, and sulfadoxine-pyrimethamine-amodiaquine combination for the treatment of uncomplicated falciparum malaria in the urban and suburban areas of Brazzaville (Congo)

Congo-Brazzaville has recently adopted artesunate-amodiaquine as the first-line antimalarial drug to replace chloroquine. Before the implementation of this new strategy, we conducted several clinical studies to assess the therapeutic efficacy of former, classical first-line antimalarial drugs in the city of Brazzaville, in which reside about 30% of the Congolese population. From 2003 to 2005, non-randomised trials were conducted to evaluate the efficacy of sulfadoxine-pyrimethamine (SP) (n = 97 patients), amodiaquine (AQ) (n = 62 patients), and the combination of sulfadoxine-pyrimethamine-amodiaquine (n = 54 patients) in children aged between 6 months and 5 years with uncomplicated malaria using the 2003 WHO guidelines during the 28-day follow-up period. After excluding new infections by PCR, the proportion of treatment failure on day 28 was 30.2% (95% confidence interval, 19.2-43.0%) for sulfadoxine-pyrimethamine, 34.8% (95% confidence interval, 21.4-50.2%) for amodiaquine, and 14.2% (95% confidence interval, 5.9-27.2%) for sulfadoxine-pyrimethamine + amodiaquine combination. Treatment with sulfadoxine-pyrimethamine was associated with an increase of gametocyte charge. These results suggest that neither sulfadoxine-pyrimethamine nor amodiaquine is efficacious as monotherapy and that their combination may not remain effective in the coming years. Based on our results, the implementation of artemisinin-based combination therapy appears to be urgent in the country