Toxicological investigation of acute and chronic treatment with Gnidia stenophylla Gilg root extract on some blood parameters and histopathology of spleen, liver and kidney in mice.

BACKGROUND: In southeast Ethiopia, people locally use the roots of Gnidia stenophylla Gilg (Thymelaeaceae) to cure malaria and other diseases with no literature evidence substantiating its safety. The aim of this study was, therefore, to investigate the safety of the aqueous root extract of G. stenophylla after acute (single dose) and repeated sub chronic oral administration in mice. RESULTS: A single oral administration of the extract at 500, 1000, 2000 and 4000 mg/kg body weight did not induce any behavioral change and mortality in both sexes. The oral LD50 of the extract was found to be above 6000 mg/kg body weight in mice. Chronic treatment with the extract for 13 weeks did not induce any sign of illness and/or death and had no adverse effect on the body weight. Dose-related elevations of erythrocytes, hematocrit, hemoglobin, platelets and neutrophils differential and significant decrease in the number of lymphocyte were observed. Liver sections of mice treated with 800 mg/kg body weight, revealed mild inflammations around the portal triads and central veins; whereas the spleen and kidneys appeared normal with no detectable gross morphological and histopathological alteration at both doses. CONCLUSIONS: The results of this study revealed that aqueous root extract of G. stenophylla Gilg at antimalarial dose is safe even when taken for a longer period. At a higher dose, the extract may have a potential to increase some hematological indices but may induce mild hepatotoxicity as a side effect.

Effect of Oral Administration of Gnidia Stenophylla Gilg Aqueous Root Extract on Food Intake and Histology of Gastrointestinal Tract in Mice.

BACKGROUND: Aqueous preparations of a medicinal plant, Gnidia stenophylla Gilg (Thymelaeaceae) are commonly used to cure malaria and other ailments in Ethiopia. This study evaluated the safety of the plant extract by determining its effects on food intake and histology of gastrointestinal tract (GIT) after oral administration for 13 weeks in albino mice. METHODS: Thirty mice were equally assigned to three groups. Group I served as control and received a vehicle while groups II and III were given 400 and 800 mg/kg body weight/day plant extract respectively, orally, for 13 weeks. At the end of the study, the mice were scarified and postmortem gross and histopathological evaluations were performed on their stomachs and intestines. RESULTS: Chronic oral treatment with the extract for 13 weeks did not induce any sign of illness and death and had no effect on food intake of the mice. Furthermore, extract treatment at both doses did not produce any detectable gross morphological change in GIT. Microscopic evaluation of sections of the stomach, duodenum and jejunum of the mice treated with 400 mg/kg body weight did not show any histopathological change. In the mice treated with 800 mg/kg body weight, however, the GIT sections revealed cytoplasmic vacuolation, hydropic degeneration and excessive erosion of the surface mucosal cells. CONCLUSION: The results of this study revealed that aqueous root extract of G. stenophylla at effective antimalarial dose is safe even when taken for a longer period in mice. At a higher dose, however, the extract may induce gastrointestinal irritation. Further studies on other vital organs and non-rodent species including humans are recommended.

Insecticidal Activity of Some Traditionally Used Ethiopian Medicinal Plants against Sheep Ked Melophagus ovinus.

Twelve medicinal plants and a commercially used drug Ivermectin were examined for insecticidal activity against Melophagus ovinus sheep ked at different time intervals using in vitro adult immersion test. The findings show that at 3.13 µL/mL, 6.25 µL/mL and 12.5 µL/mL concentration of Cymbopogon citratus, Foeniculum vulgare and Eucalyptus globulus essential oils respectively, recorded 100% mortalities against M. ovinus within 3 hour of exposure. Significantly higher insecticidal activity of essential oils was recorded (P = 0.00) when compared to 10 µ g/mL Ivermectin after 3-hour exposure of M. ovinus at a concentration of ≥1.57 µ L/mL, ≥3 µ L/mL, and ≥12.7 µ L/mL essential oils of C. citratus, F. vulgare, and E. globulus, respectively. Among essential oils, C. citratus has showed superior potency at a three-hour exposure of the parasite (P = 0.00) at a concentration of ≥0.78 µ L/mL. Strong antiparasitic activity was recorded by aqueous extract of Calpurnia aurea (80% mortality) at a concentration of 200 mg/mL within 24 h among aqueous extracts of 9 medicinal plants. The results indicated all the four medicinal plants, particularly those tested essential oils, can be considered as potential candidates for biocontrol of M. ovinus sheep ked.

Laboratory investigation of epidemic dropsy in Addis Ababa, Ethiopia.

BACKGROUND: Food adulteration including adulteration of edible oils may cause serious health problems. One of the most common edible adulterants is argemone oil. An outbreak of epidemic dropsy occurred in Addis Ababa during May-June, 2008. One hundred and eighty two cases were recorded with twelve confirmed deaths. Dietary history of the cases revealed that vegetable oils were the usual cooking medium. OBJECTIVE: The aim of the study was hence to investigate the causes of this outbreak. METHODS: Contaminant identification was done using standard chemical tests, complemented with TLC. Toxicity study was done using Swiss albino mice feed with contaminated and non contaminated standard diet for 30 days. RESULTS: Laboratory investigation of the edible oils has indicated that 47 of the 280 edible oils analyzed were adulterated with argemone oil. About 81% of the edible oil samples collected from Lideta sub-city were adulterated with argemone oil. Toxicological investigation of the adulterated oils also indicated typical features of argemone alkaloid poisoning in mice. CONCLUSION: Results of both laboratory analysis and toxicological studies confirmed consumption of edible oils adulterated with argemone oil as the cause of epidemic dropsy in Addis Ababa.

Evaluation of in vivo antihypertensive and in vitro vasodepressor activities of the leaf extract of Syzygium guineense (Willd) D.C.

The aim of this work was to evaluate the antihypertensive activity of the hydroalcohol extract of the leaves of Syzygium guineense (Willd) D.C. (Myrtaceae) in a 1-kidney-1-clip rat model and its vasorelaxant effect on isolated aorta. The extract reduced blood pressure in a dose and time dependent fashion. Following 3 days of treatment, single oral daily doses of 50, 100 and 150 mg/kg caused an overall reduction (p < 0.05) of systolic blood pressure by 6.9, 34.0 and 40.8 mmHg, respectively. The diastolic blood pressure was, however, significantly reduced (p < 0.05) by 100 mg/kg (10.3 mmHg) and 150 mg/kg (18.4 mmHg) doses only. The mean blood pressure was reduced by 5.0, 18.3 and 25.9 mmHg by the respective doses. The extract also caused a dose-dependent relaxation of aorta precontracted with KCl at a concentration of 5-70 mg/mL, with a maximum relaxation of 56.22% achieved at 70 mg/mL concentration. The relaxation mechanism was found to be independent of the endothelium system, muscarinic receptors, histamine receptors, ATP dependent K(+) channels, cyclooxygenase enzymes and cGMP/NO pathway. The findings suggest that the extract had an antihypertensive effect most likely caused by dilation of the blood vessels, a confirmation for the folkloric use of the plant.

Anti-malarial activity of withania somnifera L. Dunal extracts in mice.

OBJECTIVE: This study aims at investigating the in vivo antiplasmodial activity of a traditionally used medicinal plant, Withania somnifera, L. Dunal, (Solanaceae). METHODS: Rodent malaria parasite, Plasmodium berghei, 0.2 ml of x l0(7) parasites, was inoculated into Swiss albino mice intraperitoneally. Extracts were administered by intra gastric tube daily for four days starting from the day of parasite inoculation. Negative controls received the same amount of solvent used to suspend the exracts and the positive controls were given chloroquine by the same route. Parasite suppressive effect and effects on body weight, packed cell volume (PCV) and body temperature were determined. RESULTS: Parasitemia percent inhibition of W. somnifera roots and root barks were 50.43% and 29.13% respectively, with 600 mg/kg dose. Inhibition was statistically significant at all dose levels, compared to the negative controls (p < 0.05), and maximum inhibition was seen at 600 mg/kg. CONCLUSION: Extracts of the leaves and root barks of W. somnifera showed parasite suppressive effect and a protective effect on PCV drop (at higher doses), both in dose-related fashions. However, the effects on body weight and body temperature falls are inconclusive.

Screening of some medicinal plants of Ethiopia for their anti-microbial properties and chemical profiles.

In the indigenous health care delivery system of Ethiopia, numerous plant species are used to treat diseases of infectious origin. Regardless of the number of species, if any of such claims could be verified scientifically, the potential significance for the improvement of the health care services would be substantial. The objective of this study was, therefore, to determine the presence of anti-microbial activity in the crude extracts of some of the commonly used medicinal plants as well as to identify the class of compounds in the plants that were subjected to such screening. Thus, the crude methanol, petroleum ether and aqueous extracts of 67 plant species were subjected to preliminary screening against 10 strains of bacterial species and 6 fungal strains using the agar dilution method. A sample concentration of 250-2000 microg/ml and 500-4000 microg/ml were used for the bacterial and fungal pathogens, respectively. The results indicated that 44 different plant species exhibited activity against one or more of the bacteria while one species, viz., Albizzia gummifera showed activity against all the 10 bacteria at different gradient of dilution. Twenty three species inhibited or retarded growth of one or more organisms at dilution as low as 250 microg/ml. Extracts of same plants species were also tested against six different fungal pathogenic agents of which eight species showed growth inhibition against one or more of the organisms. Trichila emetica and Dovyalis abyssinica, which inhibited growth of four and five fungal strains at 100 microg/ml concentration, respectively, were the most promising plants. Chemical screening conducted on the extracts of all the plants showed the presence of several secondary metabolites, mainly, polyphenols, alkaloids, tannins sterols/terpenes, saponins and glycosides. The plants containing more of these metabolites demonstrated stronger anti-microbial properties stressing the need for further investigations using fractionated extracts and purified chemical components.

Diuretic effect of the crude extracts of Carissa edulis in rats.

Carissa edulis (forssk) vahl (Apocynaceae) is used traditionally for the treatment of headache, chest complaints, rheumatism, gonorrhoea, syphilis, rabies and as a diuretic. In the present study, the diuretic activity of different extracts of Carissa edulis was investigated. The diuretic activity of the different extracts of Carissa edulis in a dose range of 50-1000 mg/kg was assessed orally in rats using hydrochlorothiazide as a standard drug. The root bark maceration extract showed no effect on the urine output up to a dose of 1000 mg/kg, while the root bark soxhlet extract produced a significant increase (P < 0.05) in urine output at a dose of 1000 mg/kg. The root wood maceration and root wood soxhlet extracts produced a significant increase in urine output at a dose of 50 mg/kg, with a P-value of <0.05. Urinary electrolyte excretion was also affected by the extracts: the root bark soxhlet extract increased urinary excretion of sodium, potassium and chloride ions; root wood maceration extract increased excretion of sodium and potassium, while root wood soxhlet extract increased excretion of potassium ion. These findings support the traditional use of Carissa edulis as a diuretic agent.

Investigation on the antibacterial properties of garlic (Allium sativum) on pneumonia causing bacteria.

The antibacterial activity of the crude aqueous extract of garlic was investigated against some pneumonia causing bacteria by an agar dilution technique. The results revealed that Streptococcus pneumoniae standard test organism was completely inhibited by 7.8 mg/ml of media and the clinical isolate of Klebsiella pneumoniae was completely inhibited by 24.38 mg/ml of media, indicating that Streptococcus pneumoniae is the most sensitive and Klebsiella pneumoniae the least. Garlic could be used as an effective antibacterial agent for these pathogenic microorganisms.