Messanvi Gbeassor

Comparative study of the toxic effects of fumonisin B1 in rat C6 glioma cells and p53-null mouse embryo fibroblasts

The present experiments have been carried out in order to study (comparatively) oxidative stress and its consequences (i.e. modifications of DNA bases and/or DNA fragmentation), cell cycle progression (through two generations) and apoptosis in C6 glioma cells (with normal p53 status) and p53-null mouse embryonic fibroblasts (MEF) after incubation with fumonisin B(1) (FB(1)). Further endpoints, including protein and DNA syntheses as well as cytotoxicity, have been also studied. The results show that FB(1) (incubation) produced a significant increase of malondialdehyde (MDA) production (suggestive of lipid peroxidation) which was prevented by antioxidant agents in both cell types. Moreover, FB(1) induced a significant and dose-related increase of 8-OH-dG and DNA fragmentation in both C6 glioma and MEF cells. Unlike MEF cells, apoptotic C6 glioma cells were observed after FB(1) incubation. Moreover, suppression of cell cycle progression was observed in C6 glioma but not in MEF cell incubated with FB(1). The results suggest a possible loss of protective mechanisms (such as p53-dependent apoptosis and cell cycle arrest) in FB(1)-damaged MEF cells and confirm that cells lacking of mechanisms governed by p53 gene would be more susceptible to neoplastic cascade or mutation following DNA lesions induced by this mycotoxin.

An ethnobotanical study of antimalarial plants in Togo Maritime Region

BACKGROUND Malaria continues to be of great concern in Togo, as it accounts for high mortality rates, principally in children. Although plant-based medicines are the only means in major malarious regions of the country, still very little is known about the medicinal plants and medical practices of the indigenous people. OBJECTIVE The present study aimed to document the indigenous medicinal plant utilization for the management of malaria and related symptoms in Togo Maritime Region. METHODOLOGY Fifty Traditional Healers (TH) were selected with the help leaders of Togolese Traditional Healers Associations and information on their knowledge on the use of plants for malaria therapeutic purposes was gathered using a semi-structured interviews. RESULTS After enquiries, 52 plant species belonging to 49 genera and 29 families were recorded. The most represented families were Rubiaceae and Rutaceae with four species each. Traditional healers agreed more in the treatment of malaria (ICF=0.70), fever (ICF=0.33) and anemia (ICF=0.20). For the treatment of malaria, 38.46% (20/52) of the species cited in the study were of high fidelity level (FL=100%). The leaves (58.22%), leafy stem (33.78%) and fruits (8.52%) were the most used parts in concoctions. The main mode of preparation was decoction (69%) and the administration was essentially by oral route (79%) and body-bath (14%). CONCLUSION The issue of the study showed that Togo Maritime Region TH have a good knowledge of antimalarial plants. However the study must be extend to the whole country to lead to innovative strategies in malaria control. Such results could be a starting point for in vitro antimalarial screenings.

In vitro inhibitory effect of West African medicinal and food plants on human cytochrome P450 3A subfamily

AIM OF THE STUDY In Africa, medicinal plants are used intensively and concomitantly with allopathic medicines in the treatment of opportunity diseases by many patients or by healthy person to prevent diseases. However, there is little information about the interactions between medicines and botanical products used currently in West Africa area. Therefore, the aim of the present investigation is to study the effect of some plant products on CYP3A4, CYP3A5 and CYP3A7, three individual enzymes of CYP3A subfamily, in vitro. MATERIALS AND METHODS Teas and ethanolic extracts of medicinal, food and co-administered plants were evaluated on CYP3A4, CYP3A5 and CYP3A7 individual enzymes in vitro using fluorometric assays. RESULTS Extracts of adjuvant plants such as Aframomum cuspidatum, and Aframomum melegueta, as well as one medicinal plant (Harrisonia abyssinica) inhibited CYP3A4, CYP3A5 and CYP3A7 activity more than 90%. Phyllanthus amarus showed high inhibition of CYP3A5 and CYP3A7. Food plants (Solanum macrocarpon and Talinum triangulare) inhibited CYP3A4 and CYP3A5 less than 20%. CONCLUSION These results indicate that plants tested in this study affect in vitro the activity of the main three CYP3A subfamily enzymes. These active plants could interfere with the metabolism at phase I of conventional drugs in vivo as well act as pharmacoenhancers in herbal mixtures.

Effect of Tectona grandis on phenylhydrazine-induced anaemia in rats.

Traditional oral report indicates that Tectona grandis is used in the treatment of anaemia in Togo. For this purpose, the extract of T. grandis leaves is evaluated on anaemia model of rat induced by intraperitoneal injection of phenylhydrazine at 40 mg/kg for 2 days. Oral administration of T. grandis extract at 1 g/kg/day and 2 g/kg/day, to the rats previously treated with phenylhydrazine, increased the concentration of haemoglobin, red blood cells number, haematocrit and reticulocytes rate. Moreover, the extract of T. grandis enhanced the osmotic resistance of the red blood cells that confirm the important presence of young red blood cells. These results support partially the traditional use of T. grandis in the treatment of anaemia.

Epiafzelechin from the Root Bark of Cassia sieberiana: Detection by DART Mass Spectrometry, Spectroscopic Characterization, and Antioxidant Properties

The root bark of Cassia sieberiana was analyzed using direct analysis in real time mass spectrometry, and a main flavonoid component with an [M + H](+) mass of 275 was identified. The flavonoid, epiafzelechin, was isolated and fully characterized with the concerted use of NMR spectroscopy, circular dichroism, and optical rotation. Electronic circular dichroism and optical rotation TDDFT calculations were also performed, and their agreement with the experimental results confirmed the enantiomeric identity of the isolated natural product. The antioxidant activity of the compound was also investigated.

Sida acuta Burm. f.: a medicinal plant with numerous potencies

Sida acuta is shrub belonging to Malvaceae family. The plant is widely distributed in the subtropical regions where it is found in bushes, in farms and around habitations. Surveys conducted in indigenous places revealed that the plant had many traditional usages that varied from one region to another. The most cited illnesses are fever, headache and infections diseases. Indeed, many laboratory screening have been conducted to show the scientific rationale behind these usages and many compounds have been isolated from the plant. In the present review we listed the plant usages in folk medicine in some regions where the plant grows and we discussed on the confirmed in vitro activities after laboratory screenings. The review ended with the pharmacological properties of several compounds isolated from S. acuta principally alkaloids.

Acute and sub-chronic (28days) oral toxicity evaluation of hydroethanolic extract of Bridelia ferruginea Benth root bark in male rodent animals.

The present investigation was carried out to evaluate the safety of hydro-ethanol extract of Bridelia ferruginea Benth (Euphorbiaceae) root bark. For acute toxicity study, a single dose of 2000 and 5000 mg/kg of the B. ferruginea root bark extract was given orally to healthy male Wistar rats and Balb/c mice. The animals were observed for mortality and clinical signs for 3 h and then daily for 14 days. In the sub-chronic toxicity study, the extract was administered orally at doses of 250, 500 and 1000 mg/kg/day for 28 days to male Wistar rats. Animals were sacrificed to examine their organs, and urine and blood serum were analyzed. In the acute toxicity study, B. ferruginea root bark extract caused neither significant visible signs of toxicity, nor mortality in Wistar rats and Balb/c mice. In sub-chronic toxicity study, administration of the B. ferruginea root bark extract at 250, 500, and 1000 mg/kg for 28 consecutive days to Wistar rats did not produce mortality. No significant differences were found in relative organ weights, biochemical studied parameters in treated groups compared to control group. No obvious histological changes were observed in organs of B. ferruginea extract treated animals compared to controls.

The effect of Mangifera indica stem bark and Pluchea ovalis roots on tracheal smooth muscle in vitro

Aqueous extract of the stem bark of Mangifera indica and ethanolic extract of the roots of Pluchea ovalis has been studied on rat tracheal smooth muscle in vitro. The extract of M. indica at 1, 2 and 4 mg/ml and that of P. ovalis at 0.25, 0.5 and 1 mg/ml relaxed, dose-dependently, the rat tracheal smooth muscle strip previously contracted by acetylcholine at 0.055 mmol/l.

Evaluation of the Quality of Artemisinin-Based Antimalarial Medicines Distributed in Ghana and Togo

This study, conducted as part of our overall goal of regular pharmacovigilance of antimalarial medicines, reports on the quality of 132 artemisinin-based antimalarial medicines distributed in Ghana and Togo. Three methods were employed in the quality evaluation—basic (colorimetric) tests for establishing the identity of the requisite active pharmaceutical ingredients (APIs), semi-quantitative TLC assay for the identification and estimation of API content, and HPLC assay for a more accurate quantification of API content. From the basic tests, only one sample totally lacked API. The HPLC assay, however, showed that 83.7% of the ACTs and 57.9% of the artemisinin-based monotherapies failed to comply with international pharmacopoeia requirements due to insufficient API content. In most of the ACTs, the artemisinin component was usually the insufficient API. Generally, there was a good correlation between the HPLC and SQ-TLC assays. The overall failure rates for both locally manufactured (77.3%) and imported medicines (77.5%) were comparable. Similarly the unregistered medicines recorded a slightly higher overall failure rate (84.7%) than registered medicines (70.8%). Only two instances of possible cross-border exchange of medicines were observed and there was little difference between the medicine quality of collections from border towns and those from inland parts of both countries.

Ethnobotanical Knowledge of Sterculiasetigera Del. in the Sudanian Zone of Togo (West Africa)

Ethnobotanical knowledge is useful in development of management and conservation of plant genetic resources. In this study, ethnobotanical investigations were conducted in Sudanian zone of Togo to identify use values knowledge of Sterculia setigera tree. Information was obtained with the aid of semistructured interviews. Three (3) ethnic groups: Bassar, Moba, and Konkomba belonging to ten (10) localities were investigated. Use knowledge of Sterculia setigera through these ethnic groups was assessed using four use indices: reported use (RU), plant part value (PPV), specific reported use (SU), and intraspecific use value (IUV). Sixty (60) informants of 43 years old were interviewed. The plant parts values and specific uses are raised more in the Moba’s ethnic group. The main quoted uses are medicinal, religious, food, and cosmetic. Thus, fourteen (14) treatments of ailments are assigned to it. Considering the various uses, it is crucial to validate scientifically the therapeutic uses and safety of these plants through phytochemical screening, different biological activity tests, and toxicological studies.