Amegnona Agbonon

Ethnobotanical study of medicinal plants used in the management of diabetes mellitus and hypertension in the Central Region of Togo

Context: The Tem tribe in the Central Region of Togo is a population with an extensive knowledge of medicinal plants. However, little is known about their medical practices, principally the use of plants in the management of diabetes mellitus (DM) and hypertension (HTN). Objective: The present study documented the indigenous medicinal plant utilization for the management of DM and HTN in the Togo Central Region. Methodology: From March to October 2010, 55 traditional healers were interviewed about their knowledge on the use of plants for DM and HTN treatment. Results: The results revealed that 35/55 (63.64%) healers had treated at least one case of DM and/or HTN. They highlighted the use of 64 species belonging to 31 families in the treatment of DM and/or HTN. The most used plants against diabetes were Psidium guajava L. (Myrtaceae), Khaya senegalensis A. Juss. (Meliaceae), Sarcocephalus latifolius (Sm.) E.A. Bruce (Rubiaceae), Annona muricata L. (Annonaceae), Bridelia ferruginea Benth. (Phyllanthaceae), and Securidaca longepedunculata Fresen. (Polygalacae), while Allium sativum L. (Liliaceae) and Parkia biglobosa Benth. (Fabaceae), followed by Khaya senegalensis A. Juss. (Meliaceae), Gardenia ternifolia Schumach. (Rubiaceae), and Persea americana Mill. (Lauraceae) were the most commonly cited as antihypertensive. Conclusion: The issue revealed that traditional healers of the above mentioned region have basic knowledge regarding herbal medicine for DM and HTN in comparison with previous published reports. Further pharmacological screening of the identified plants should be conducted to ascertain the effectiveness of these plants.

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.

Antimicrobial, antiplasmodial, haemolytic and antioxidant activities of crude extracts from three selected Togolese medicinal plants

OBJECTIVE To investigate the antioxidant, antimicrobial, antiplasmodial, acute toxicity and haemolytic activities of methanolic extracts of three plants. Phytochemical analysis to determine the phenolic contents was also carried out. METHODS The 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical scavenging, NCCLS broth microdilution and Plasmodium Lactate Dehydrogenase (pLDH) assays were used to determine antioxidant, antimicrobial and antiplasmodial activities, respectively. Haemolysis assay was conducted on A(+) human red blood cells and acute toxicity on male Swiss albino mice. Phenolics were quantitatively determined using spectrophotometric methods. RESULTS The DPPH assay yielded interesting antioxidant activities of methanolic extract of Parinari curatellifolia (P. curatellifolia) and Entada africana (E. africana) (IC(50) were 0.20±0.01 μg/mL and 0.47±0.01 μg/mL, respectively). This activity was highly correlated with phenolic contents of extracts. The antimicrobial tests displayed minimal inhibitory concentrations (MICs) values ranging from 0.90 to 1.80 mg/mL for Serratia marcescens (S. marcescens) the most susceptible bacterial strain. MIC value was 1.20 mg/mL for susceptible fungal strains including Mucor rouxi (M. rouxi), Fusarium oxyporum (F. oxyporum) and Rhizopus nigricans (R. nigricans). pLDH assay showed moderate antiplasmodial activity of Balanites aegyptiaca (B. aegyptiaca) (IC(50) = 24.56±3.45 μg/mL), however this extract was highly haemolytic and toxic in mice (LD(50) = 625±128 mg/kg). CONCLUSIONS Our results support in part the use of the selected plants in the treatment of microbial infections. In addition the plant showed interesting antioxidant activity that could be useful in the management of oxidative stress.

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.

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.

Mangifera indica. Stem Bark Effect on the Rat Trachea Contracted by Acetylcholine and Histamine

Abstract Experiments were designed to determine the effect of Mangifera indica. Linn stem bark aqueous extract on rat trachea previously incubated in presence of indomethacin, propranolol, and atropine or promethazine with histamine or acetylcholine as agonist. The strips of trachea were suspended for isometric tension recording at 37°C. M. indica. aqueous extract at 2 mg/ml impair the contraction induced both by histamine and acetylcholine in all three experimental conditions. The contractile responses (% maximum effect) induced by histamine at 12 × 10−4 g/ml, in the presence of extract, were respectively 69.18 ± 3.05% (indomethacin), 74.18 ± 1.03% (indomethacin + propranolol), and 45.54 ± 1.7% (indomethacin + propranolol + atropine) versus 100 ± 5.15% for control. The extract also reduced the contraction induced by acetylcholine, but this inhibitory effect is lightly decreased when the tissues were contracted by acetylcholine after incubation in presence of indomethacin + propranolol. These experiments suggest that the aqueous extract of M. indica. could block both the histaminic and muscarinic receptors on rat trachea; and the results corroborate with the traditional use of M. indica. stem bark in the treatment of asthma.

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.