Polyphenolic composition of Lantana camara and Lippia chevalieri, and their Antioxidant and Antimicrobial Activities

In the present study, the antioxidant and antibacterial activities of methanolic extracts of two Verbenaceae (Lantana camara L. and Lippia chevalieri Moldenke: aerial part) were investigated. Their polyphenolic composition in the ethyl acetate and aqueous fractions were characterized by HPLC-DAD. The antioxidant capability of the methanolic extracts was assessed by the Ferric Reducing Antioxidant Power (FRAP) and the scavenging activity of the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). The Minimum Inhibitory Concentrations (MIC) of the methanolic extracts (25 µg mL-1), and the minimum bactericidal concentrations (MBC) (12.5 µg mL-1) against 13 pathogenic bacteria and four serotyped bacteria from the American Type Culture Collection (ATCC) were also determined by the agar-well diffusion method. The results indicated that the L. chevalieri extracts are rich in phenolic compounds (among the 27 polyphenolic compounds detected, 20 belong to L. chevalieri) and showed the highest antioxidant activities, simultaneously on iron (III) to iron (II)-reducing activity and the radical scavenging activity. However, L. camara displayed the best and the broadest antimicrobial spectrum, especially on Shigella flexneri and Pantoea sp. (two Gram-negative strains of bacteria). The nature of polyphenolics compounds detected (phenol acid and flavone) in the L. camara can justify this activity.Key words: Verbenaceae, HPLC-DAD, antioxidant activity, antimicrobial activity, polyphenolic compound

Anti-proliferative effect of Scoparia dulcis L. against bacterial and fungal strains

Scoparia dulcis L. was sequentially extracted with hexane, chloroform and methanol and soaked with aqueous-acetone (80%) to check for its antimicrobial activities against five bacterial and four fungal strains.250μg of each extract loaded on a whatman paper disc exhibited significant antimicrobial activities on all the fungus and against Gram-negative and Gram-positive bacteria. Therefore, P. mirabilis is less sensitive to all the extracts while B. cereus, a â-lactamase producer bacterium, was resistant to the activity of the polar methanol and aqueous-acetone extracts. By the microdilution method, the most active extracts were chloroform extract on B. cereus with minimal inhibitory concentration (MIC) of 1.56 mg/ml and Aqueous-acetone extract on S. typhimurium (MIC = 1.56 mg/ml); the antifungal activity was strongest for hexane extract (MIC = 6.25 mg/ml) on both A. niger and P. roquefortii.Keywords: Scoparia dulcis, Antibacterial, Antifungal, Polyphenols

Do floristic composition, plant species abundance and vegetation structure in Sudanian wetlands vary according to conservation status?

In Sahel, wetlands are particularly endangered hence practical knowledge for their sustainable management is needed. The aim of this study was to compare plant community structure between protected and unprotected wetland bank stands in eastern Burkina Faso. Phytosociological and dendrometrical parameters were carrying out in adult trees, seedling individuals and herbaceous species. Discrimination of plant communities and diversity indices were calculated for each group. Weibull distribution was used to compare the diameter structures. The results shows that plant communities located in riverbanks of unprotected wetlands have a greater specificheterogeneity. They are rich inannual speciesand in species with a wide distribution. Finally their woody stands are characterized by lower basal areas than unprotected wetland riverbank stands. Plant community stands in riverbanks of protected wetlands were better preserved but some disturbances were noticed. Furthermore, juvenile plants of the two sites were threatened and this may affect in long term, the relative stability of these trees stands as revealed by Weibull distribution. Further study should focus on wetlands riverbanks seedling status in order to propose restoration strategies

Long-Term Vegetation Change in Central Africa: The Need for an Integrated Management Framework for Forests and Savannas

peer reviewedTropical forests and savannas are the main biomes in sub-Saharan Africa, covering most of the continent. Collectively they offer important habitat for biodiversity and provide multiple ecosystem services. Considering their global importance and the multiple sustainability challenges they face in the era of the Anthropocene, this chapter undertakes a comprehensive analysis of the past, present, and future vegetation patterns in central African forests and savannas. Past changes in climate, vegetation, land use, and human activity have affected the distribution of forests and savannas across central Africa. Currently, forests form a continuous block across the wet and moist areas of central Africa, and are characterized by high tree cover (>90% tree cover). Savannas and woodlands have lower tree cover (<40% tree cover), are found in drier sites in the north and south of the region, and are maintained by frequent fires. Recent tree cover loss (2000–2015) has been more important for forests than for savannas, which, however, reportedly experienced woody encroachment. Future cropland expansion is expected to have a strong impact on savannas, while the extent of climatic impacts depends on the actual scenario. We finally identify some of the policy implications for restoring ecosystems, expanding protected areas, and designing sustainable ecosystem management approaches in the region

Profiles de Substrat des &beta; - Lactamases Extraites D'Isolats Cliniques au Centre Hospitalier Saint Camille de Ouagadougou/Burkina Faso

&beta;-lactamases extracted from clinical isolates were analysed. Most of them are active on usual b-lactam antibiotics in Burkina Faso. 2 main types of substrate patterns are emerging from our studies. The danger of therapeutic failures in using the &Beta;-lactam antibiotics may occur in medium or long term. Key Words: Antibiotics, &beta;-lactams, &beta;-lactamases, substrate patterns, Burkina Faso. Résumé Des &beta;-lactamases extraites d'isolats cliniques ont été et analysées. Bon nombres de ces enzymes sont actifs sur les antibiotiques usuels renfermant le noyau &Beta;-lactame au Burkina. Globalement deux types de profiles de substrat se dégagent de nos analyses. Des échecs thérapeutiques faisant appel à ces molécules sont à craindre à court ou à moyen terme. Mots-clefs: Antibiotiques &beta;-lactames, &beta;-lactamases, profiles de substrat, Burkina Faso. West Afr. J. Pharmacol. Drug Res. Vol.19 (1&2) 2003: 28-3

Pratiques avicoles et gestion de la fertilité des sols dans les exploitations agricoles de l’Ouest du Burkina Faso

Objectif : l’article montre la place de la volaille dans la production de fumure organique (FO) et la fertilisation des champs des exploitations agricoles (EA).Méthodologie et résultats : Une enquête d’exploitation agricole a été réalisée avec une approche globale des caractéristiques structurelles et des activités d’élevage de l’exploitation, et la collecte de données déclarées par le chef d’exploitation. L’enquête a été réalisée en 2016 sur un échantillon de 300 EA dans les régions des Cascades et des Hauts-Bassins du Burkina Faso. Les résultats mettent en évidence 5 types d’EA : 2 types d’agriculteurs (type 1 : 8,92 ha, 129 volailles, 4 bovins et 6 petits ruminants ; type 2 : 5,48 ha, 31 volailles, 3 bovins et 7 petits ruminants) et 3 types d’agro-éleveurs (type 3 : 10,57 ha, 42 volailles, 11 bovins et 16 petits ruminants ; type 4 : 6,58 ha, 68 bovins et 26 petits ruminants ; type 5 : 36,40 ha, 117 volailles, 44 bovins, 47 petits ruminants). L’élevage extensif de volaille qui est le système dominant (plus de 70 % des EA enquêtées) apporte près de 26 % du revenu des EA du type 1. Ce système extensif permet de produire dans l’année 4,67 kg de fiente par volaille contre 19,21 et 5,08 kg/volaille/an respectivement pour la claustration et le système semi-intensif. La fiente de volaille représente entre 26,46 et 35,72 % de la production de fumure organique et contribue à fertiliser près de 4,50 % des superficies totales cultivées des EA.Conclusions et application des résultats : Cette contribution de la volaille dans la production de la FO et la fertilisation des champs peut être améliorée en réduisant les pertes durant le processus de production et de collecte des déjections. Le système d’élevage semi-intensif et la claustration se présentent comme des perspectives intéressantes à explorer.Mots clés : typologie, système d’élevage, volaille, substrat organique, Hauts-Bassins, Cascades

Major enzymatic factors involved in bacterial penicillin resistance in Burkina Faso

peer reviewedMany clinical species of bacteria were isolated from biological samples such as urines, blood and wound in Saint Camille medical centre of Ouagadougou. Among the concerned species, the most important members were Escherichia coli and Klebsiella pneumoniae. These β-lactamases producing isolates were directly screened by PCR to identify the nature of the amplified genes responsible for penicillin destroying activity. Therefore specific TEM and SHV primers were used. The PCR products were sequenced. The sequencing results indicated that the parental forms blaTEM-1 and blaSHV-1 were the most common determinants of β-lactamase found, respectively in Escherichia species and Klebsiella pneumoniae. The bacterial susceptibility analysis by MICs measurement clearly correlated the presence of concerned β-lactamase determinants and their resistance patterns. This study is part of a set of investigations carried out by our laboratory to assess the β-lactamase incidence in the failure of β-lactam therapy. In particular, the purpose of this study was to determine the precise nature of β-lactamase supporting the low susceptibility of host bacteria towards penicillins. © 2007 Asian Network for Scientific Information

Antibacterial Potential of Aqueous Acetone Extracts from Five Medicinal Plants Used Traditionally to Treat Infectious Diseases in Burkina Faso

Abstract: Polyphenol contents, in vitro antioxidant and antimicrobial activities of leaves and barks from of Anogeissus leiocarpus, Khaya senegalensis, Sterculia setigera, Solanum incanum and Pterocarpus erinaceus extracts obtained with aqueous acetone 80% (WAE) were investigated in this study. The present study was conducted to evaluate the total phenolic contents, in vitro antioxidant and antibacterial properties. Folinciocalteu and AlCl 3 methods, respectively were used for polyphenol contents. The antioxidant potential of the samples was evaluate using two separate methods, inhibition of free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Iron (III) to iron (II) reduction activity (FRAP). In vitro antibacterial capacity of aqueous acetone extracts were investigated by agar disc diffusion, micro-well dilution (MIC) and Minimum Bactericidal Concentration (MBC) assay against five bacteria. Our extracts contained high levels of phenolics and exhibited antibacterial activity against bacteria. S. aureus and B. cereus were the most sensitive; while E. coli was the most resistant. There were highly positive relationships (R 2 = 0.8454-0.9780) between phenolic contents and antioxidant, activity antibacterial capacity and phenolic contents of the tested extracts against each bacterium. This suggested that the antibacterial activity of the tested extracts was closely associated with their phenolic constituents. In this study, the extract of Anogeissus leiocarpus leaves was presented the best results among all extracts