Kwashie Eklu-Gadegbeku

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.

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.

In vivo and in vitro toxicological evaluation of the hydroalcoholic leaf extract of Ageratum conyzoides L. (Asteraceae)

ETHNOPHARMACOLOGICAL RELEVANCE In African traditional medicine, Ageratum conyzoides has been used as purgative, febrifuge, anti-ulcer and wound dressing. To date there is no safety information about long term use of Ageratum conyzoides which contains pyrrolizidine alkaloids, a class of hepatotoxic and carcinogenic phytochemicals. This study aims to evaluate the 90 days subchronic toxicity and in vitro toxicity of Ageratum conyzoides. MATERIALS AND METHODS Three groups of 8 rats (4 males and 4 females) received distilled water (control), 500 and 1000 mg/kg of the extract daily for 90 consecutive days by oral gavage. The animals were observed daily for abnormal clinical signs and death. Body weight, relative organ weight, haematological and biochemical parameters of blood as well as heart, kidney, liver and spleen tissues histology were evaluated. RESULTS After 90 days administration, Ageratum conyzoides increased significantly (p<0.05) the relative weight of the liver, the spleen and kidney as compared to control group. Ageratum conyzoides increased also significantly (p<0.05) ALP, ALT, AST and blood glucose. Furthermore, an increase in the number of platelets associated with a normocytic and normochromic anaemia was observed. The cytotoxicity, determined by the MTT test and neutral red assay, has shown that the cytotoxicity of hydroalcoholic extract of Ageratum conyzoides and its total alkaloids was very close. CONCLUSIONS Our results have shown that Ageratum conyzoides at 500 and 1000 mg/kg can induce liver, kidney and haematological disorders. These toxics effects can be attributed to its total alkaloids especially to pyrrolizidine alkaloids which are present in this plant.

Effets de Biophytum petersianum (Oxalidaceae) sur la pression artérielle chez le rat Wistar

RésuméLe présent travail évalue le potentiel hypotensif et les mécanismes d’action associés de l’extrait semi-éthanolique de Biophytum petersianum chez le rat Wistar normotendu. La méthode sanglante est utilisée pour mesurer la pression artérielle. L’extrait est administré par v.i. aux doses uniques de 27, 54 et 81 mg/kg. L’extrait à 54 mg/kg et la clonidine à 0,5 mg/kg sont administrés à des animaux différents, suivie d’une bi-occlusion carotidienne. La même dose d’extrait est administrée après bivagotomie et blocage des récepteurs muscariniques par l’atropine. Les résultats montrent que l’effet hypotenseur de l’extrait ne passe pas par l’inhibition du système nerveux sympathique mais implique partiellement la stimulation du système parasympathique puisque cet effet est bloqué par l’atropine. Ces résultats confirment l’utilisation traditionnelle de B. petersianum dans le traitement de l’hypertension.AbstractThe aim of the study was to investigate the hypotensive effect and the mechanism underlying a semiethanolic extract of Biophytum petersianum on normal Wistar rats. The invasive method was used to measure arterial blood pressure. The extract was administered by I.V. in single doses of 27, 54 and 81 mg/kg. An extract (54 mg/kg) and a clonidine (0.5 mg/kg) were administered to different rats, followed by double carotid occlusion. The same extract dose was used after bivagotomy and muscarinic receptor blockade.The results showed that the hypotensive effect of the extract was not a result of sympathetic nervous system inhibition but partially involved parasympathetic system stimulation, since this effect is blocked by atropine. These results confirm the traditional use of B. petersianum in the treatment of hypertension.

Effect of Bridelia ferruginea Benth (Euphorbiaceae) ethyl acetate and acetone fractions on insulin resistance in fructose drinking mice

ETHNOPHARMACOLOGICAL RELEVANCE The root of Bridelia ferruginea is traditionally used as a treatment for type 2 diabetes. The present study was investigated to evaluate the effect of Bridelia ferruginea root bark fractions on some markers of type 2 diabetes on fructose drinking mice. MATERIALS AND METHODS Mice received a solution of fructose 15% during 42 days ad libitum; at the 15th day to the 42nd day, they received distilled water for fructose drinking control group, metformin 50 mg/kg per day or fractions 50 mg/kg per day for treatment groups. The normal control group received only distilled water during the experiment. After 6 weeks of experiment, OGTT, fasting blood glucose, plasma insulin, triglycerides (TG), total cholesterol, AST and ALT levels were measured. RESULTS Fructose drinking control group (F) showed significant (p<0.001) increase of glucose tolerance, plasma levels of total cholesterol, triglycerides and insulin index for insulin resistance (Homeostasis Model Assessment ratio HOMA-IR) as compared to normal control mice. In treated groups, there was a significant reduction of glucose intolerance respectively 74% (p<0.001), 25% (p<0.5) and 92% (p<0.001) for ethyl acetate fraction, acetone fraction and metformin at the same dose of 50 mg/kg per day during 4 weeks administration. In ethyl acetate fraction and metformin treated groups, biochemical parameters and insulin index were significantly (p<0.001) lower than that of fructose drinking control group. CONCLUSIONS This indicates that Bridelia ferruginea root bark ethyl acetate fraction improved insulin resistance as metformin significantly in type 2 diabetes.

Activités antipyrétique et anti-inflammatoire d’extraits hydro-alcooliques des racines et feuilles de Nauclea latifolia Smith (Rubiaceae) chez le rat Wistar

RésuméNauclea latifolia Smith (Rubiaceae) est une plante dont les indications thérapeutiques sont nombreuses. Elle est couramment utilisée au Togo dans le traitement de diverses affections comme le paludisme, la fièvre et la douleur abdominale. Pour vérifier quelquesunes de ces propriétés, les extraits des racines et des feuilles sont évalués sur l’hyperthermie induite par la levure de bière à 20 % et l’œdème est provoqué par la carrageenan à 2 %. L’administration orale des extraits hydro-alcooliques des racines et des feuilles de Nauclea latifolia, à différentes doses, réduit significativement l’hyperthermie et l’œdème. Ces résultats supportent, du moins partiellement, certaines indications thérapeutiques traditionnelles de la plante.AbstractNauclea latifolia Smith (Rubiaceae) is used in traditional medicine in Togo to treat illnesses such as malaria, fever and stomach-ache. The present investigation was undertaken to evaluate the effect of leaf and root extracts on hyperthermia and paw oedema. The extract from the leaves and roots, at different doses, significantly reduced the hyperthermia and paw oedema. These results partially confirm the use of Nauclea latifolia in traditional medicine.

A model for promoting poultry industry development in Togo: feeding improvement, capacity building and extension

Although being the main bottlenecks for commercial poultry development in Togo, feeding and management practices retain little attention. Indeed, there is no proficient feed miller unit which can provide high quality feed according to the needs of the farmers. This is due to a lack of information on nutrition and relevant management tools or people trained as poultry farm managers. With the aim to alleviate poverty and hunger in Togo, an inter-university project [Catholic University of Leuven (KUL) and University of Lome (UL)] as a model for poultry development was being run from June 2006 to May 2012. Specific objectives of the project are 1) to provide insights and disseminate guidelines and information on adapted methods to improve poultry production and 2) to focus on development of new technologies in poultry production and implementation of research on better poultry nutrition, feeding and management practices.

Laying hen production and feeding practices in Togo: A survey

A survey was carried out, involving layer chicken farmers to identify and inventory the different feed components and to determine their rates of incorporation in poultry feed rations, as well as to inventory different layer lines or commercial crosses raised in Togo and finally to determine their production performances. During the survey, samples of feed ingredients and complete layer diets were collected for crude protein (CP) and gross energy (GE) levels determination. The survey indicated that 15 different feed components were used in the formulation of layer feed rations. Among these components, corn was the most important component (52.60±2.58%) followed by wheat bran (16.11±2.72%), roasted soya (11.40±1.91%), fish meal (8.29±1.64%) and cotton seed (7.57±1.58%). Rates of incorporation of these components in the feed ration varied according to the producer and the age of chickens, as there are no established standard requirements for layer feed in Togo currently. The survey revealed that average layer numbers per farm increased from 329 to 520 chickens between 2001 and 2005. Several layers strains or commercial crosses are present in Togo, however, only Isa Brown (IB), Harco and Hisex White (HW) were considered important. Productive performances were comparable between these three strains. It was concluded that promotion of the local egg industry in Togo should focus on the establishment of hatchery, proficient feed mill units, providing information about management practices and training those involved in the sector on appropriate technologies.