ANTIPROLIFERATIVE EFFECT OF ALCOHOLIC EXTRACTS OF SOME GABONESE MEDICINAL PLANTS ON HUMAN COLONIC CANCER CELLS

Extracts from Piptadeniastrum africanum Brenan (Mimosaceae), Petersianthus macrocarpus (Breauv) L. (Lecydaceae), Cissus debilis Planch (Vitaceae) and Dieffenbachia seguine Jacq. (Araceae) were tested in vitro for their antiproliferative activity on human colon cancer cell line (CaCo-2). The highest antiproliferative activities were obtained with the alcoholic extracts of the roots of Piptadeniastrum africanum (G-PAR), the leaves of Petersianthus macrocarpus (G-PMF) and the stem of Cissus debilis (G-CDL), with 50% inhibition concentrations (IC50) of 15 µg/ml, 17 µg/ml and 25 µg/ml respectively. Only one extract (leaves of Dieffenbachia seguine (G-DSF)) exhibited weak antiproliferative activity with 50% inhibition concentration (IC50) higher than 50 µg/ml

An overview of anti-diabetic plants used in Gabon: Pharmacology and Toxicology

© 2017 Elsevier B.V. All rights reserved.Ethnopharmacological relevance: The management of diabetes mellitus management in African communities, especially in Gabon, is not well established as more than 60% of population rely on traditional treatments as primary healthcare. The aim of this review was to collect and present the scientific evidence for the use of medicinal plants that are in currect by Gabonese traditional healers to manage diabetes or hyperglycaemia based here on the pharmacological and toxicological profiles of plants with anti-diabetic activity. There are presented in order to promote their therapeutic value, ensure a safer use by population and provide some bases for further study on high potential plants reviewed. Materials and methods: Ethnobotanical studies were sourced using databases such as Online Wiley library, Pubmed, Google Scholar, PROTA, books and unpublished data including Ph.D. and Master thesis, African and Asian journals. Keywords including ‘Diabetes’ ‘Gabon’ ‘Toxicity’ ‘Constituents’ ‘hyperglycaemia’ were used. Results: A total of 69 plants currently used in Gabon with potential anti-diabetic activity have been identified in the literature, all of which have been used in in vivo or in vitro studies. Most of the plants have been studied in human or animal models for their ability to reduce blood glucose, stimulate insulin secretion or inhibit carbohydrates enzymes. Active substances have been identified in 12 out of 69 plants outlined in this review, these include Allium cepa and Tabernanthe iboga. Only eight plants have their active substances tested for anti-diabetic activity and are suitables for further investigation. Toxicological data is scarce and is dose-related to the functional parameters of major organs such as kidney and liver. Conclusion: An in-depth understanding on the pharmacology and toxicology of Gabonese anti-diabetic plants is lacking yet there is a great scope for new treatments. With further research, the use of Gabonese anti-diabetic plants is important to ensure the safety of the diabetic patients in Gabon.Peer reviewedFinal Accepted Versio

The Antiplasmodial Agents Of The Stem Bark Of Entandrophragma Angolense (Meliaceae).

In the search of active principles from the stem bark of Entandrophragma angolense , we submitted the compounds isolated from the dichloromethane – methanol (1:1) extract of the stem bark to antimalarial test against chloroquine resistant strain W2 of Plasmodium falciparum malaria parasite. Only 7α- obacunyl acetate and a cycloartane derivative exhibited a good activity, with IC50s of 2 and 5.4 μg/ml respectively. Other compounds were moderately active

Comparative study of the anti-oxidant activity of the total polyphenols extracted from Hibiscus Sabdariffa L., Glycine max L. Merr., yellow tea and red wine through reaction with DPPH free radicals

The present study is part of the evaluation of extracts of Glycine max L. Merr and Hibiscus L. Sabdariffa as antioxidants. A comparative study was performed with extracts of yellow tea and commercial red wine, two foods known for their antioxidant activity. The method applied is free radical scavenging using the 1,1-diphenyl-2-picrylhydrazyl (DPPH°). The antioxidant properties were identified and measured by the determining the anti-radical activity reducing index, expressed in percentage % RSA (Radical Scavenger Activity), and by the determination of the colouring intensity (IC50). All results are compared to those of ascorbic acid as reference antioxidant. The results indicate the following order for the antioxidant power of the extracts tested. % RSA (tea) > % RSA (Glycine max) % > RSA (red wine) % > RSA (Sabdariffa Hibiscus), and colouring intensities (IC50) ranging from 4.62 μM (ascorbic acid) to 1.10 μM (Hibiscus sabdariffa) correlated with their chemical structure and the content of phenolic compounds

The Antiplasmodial Agents of the Stem Bark of Entandrophragma Angolense (Meliaceae)

In the search of active principles from the stem bark of Entandrophragma angolense, we submitted the compounds isolated from the dichloromethane - methanol (1:1) extract of the stem bark to antimalarial test against chloroquine resistant strain W2 of Plasmodium falciparum malaria parasite. Only 7α-obacunyl acetate and a cycloartane derivative exhibited a good activity, with IC50s of 2 and 5.4 µg/ml respectively. Other compounds were moderately active

Antiproliferative Effect Of Alcoholic Extracts Of Some Gabonese Medicinal Plants On Human Colonic Cancer Cells

Extracts from Piptadeniastrum africanum Brenan (Mimosaceae), Petersianthus macrocarpus (Breauv) L. (Lecydaceae), Cissus debilis Planch (Vitaceae) and Dieffenbachia seguine Jacq. (Araceae) were tested in vitro for their antiproliferative activity on human colon cancer cell line (CaCo-2). The highest antiproliferative activities were obtained with the alcoholic extracts of the roots of Piptadeniastrum africanum (G-PAR), the leaves of Petersianthus macrocarpus (G-PMF) and the stem of Cissus debilis (G-CDL), with 50% inhibition concentrations (IC50) of 15 μg/ml, 17 μg/ml and 25 μg/ml respectively. Only one extract (leaves of Dieffenbachia seguine (G-DSF)) exhibited weak antiproliferative activity with 50% inhibition concentration (IC50) higher than 50 μg/ml

Antimalarial Activity in Crude Extracts of Some Cameroonian Medicinal Plants

Fifteen crude extracts from the stem bark and seeds of four medicinal plants, viz: Entandrophragma angolense, Picralima nitida, Schumanniophyton magnificum and Thomandersia hensii were tested in vitro for their antimalarial activity against the chloroquine-resistant Plasmodium falciparum W2 strain. The results showed that the extracts of these plants possessed some antimalarial activity, the methanol extract of Picralima nitida demonstrating the highest activity in vitro. Further isolation and identification of some active compounds from these plants will justify their common use in traditional medicine for the treatment of malaria or fever in Cameroon

Dynamic Adsorption on Fixed-Bed Column of Manganese Oxoanions (MnO<SUB>4</SUB><SUP>-</SUP>) in Aqueous Media on Activated Carbon Prepared from Palm Nut Shells

International audienceThe study of the influence of operating parameters of dynamic adsorption on fixed-bed column of manganese oxoanions (MnO 4-) in aqueous media on granular activated carbon (GAC), prepared from the shells palm nuts of Gabon, was carried out. The operating parameters studied were the particle size, the concentration of the initial solution (C 0) of MnO 4-, the flow rate (D) and the pH of the media. The results obtained on the study of the influence of operating parameters show that the best adsorption capacities at saturation (Q sat) of MnO 4-ion on the CAG were obtained with particle size between 0.04 < x < 0.1 (5.90 mg.g-1); with flow rate of 3 mL.min-1 (8.36 mg.g-1) and when the pH of the initial solution was equal to 3.5 (27.01 mg.g-1). Also, these results showed that the bed of prepared GAC appeared more effective when C 0 was low (10 mg.L-1). The kinetic models of the different studies carried out show that the pseudo-first-order kinetic model best describes the adsorption of MnO 4-ions on the GAC. The results of the intraparticle diffusion model indicate that the adsorption of MnO 4-follows a multi-step process and that the intraparticle diffusion is not the limiting step. In addition, the surface adsorption plays a predominant role in the adsorption mechanism of MnO 4-ions on activated carbon studied in fixed-bed column dynamics

Constituents from Nauclea latifolia with Anti-Haemophilus influenzae Type b Inhibitory Activities.

Kezetas Bankeu JJ, Kenou Kagho DU, Fotsing Fongang YS, et al. Constituents from Nauclea latifolia with Anti-Haemophilus influenzae Type b Inhibitory Activities. Journal of Natural Products. 2019;82(9):2580-2585.Three previously undescribed indole alkaloids, named latifolianine A (1) and latifoliaindoles A and B (2 and 3), along with 10 known compounds (4-13), were isolated from the heartwood of Nauclea latifolia. Their structures were elucidated based on the analysis of their NMR and MS data. Latifolianine A (1) represents an unusual and unprecedented monoterpene indole alkaloid unit condensed with an ursane-type pentacyclic triterpenoid moiety. Plausible biogenetic routes toward latifolianine A (1) and latifoliaindoles A and B (2 and 3) were proposed. All the isolates were assessed in vitro for their inhibitory effects on Haemophilus influenzae. Naucleidinal (7) exhibited potent antibacterial activity (MIC value of 3.1 mug/mL) as compared to a reference drug, ciprofloxacin (MIC value of 1.6 mug/mL)