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Novel series of pyrazole derivatives were synthesized and tested for their in vivo anti-malarial activity using mice infected with chloroquine sensitive P. berghei at a dose level of 50 µmol/kg. The most active compounds were further tested in vitro against chloroquine resistant (RKL9) strain of P. falciparum. The in vivo anti-malarial activity study indicated that compounds 2a, 2b, 8a and 8b had mean percent suppression of 85%, 83%, 95% and 97%, respectively at equimolar dose level of the standard drug chloroquine diphosphate. Moreover, compounds 2a, 2b, 8a and 8b showed in vitro IC(50) values lower (p

The present study investigated the presence and level of pesticide residues in wheat and khat samples collected from various localities of Ethiopia. The khat samples from Galemso and Aseno had p,p'-DDT concentrations ranged from 141.2 to 973.0 μg/Kg and 194.3-999.0 μg/Kg, respectively. Diazinon was detected in all the khat samples from BadaBuna (173.9-686.9 μg/Kg) but not in any of the samples from Galemso and Aseno. Diazinon was detected in all the wheat samples obtained from both Arsi and Bale (125.8 and 125.6 μg/Kg, respectively) and aldrin levels in these samples were below the quantification limit. Khat may be a contributing factor in the pathological diseases found among khat users.

The chemical composition of the volatile oil from berries of Croton macrostachyus Hochst. ex Del. was determined by GC and GC/MS. The oil was tested for its in vitro antileishmanial activity on two Leishmania strains, and its toxicity on the human monocytic leukemia (THP-1) cell line and erythrocytes from sheep blood. The main constituents of the oil were benzyl benzoate (51.8%), linalool (10.1%), γ-muurolene (9.3%), ( E,E)-α-farnesene (3.2%), δ-cadinene (2.8%) and α-curcumene (2.7%). The oil was effective against L. donovani and L. aethiopica promastigotes (MIC = 0.08 μL/mL and 0.16 μL/mL, respectively) and axenic amastigote stages (EC50 = 20.00 nL/mL and 6.66 nL/mL, respectively). The CC50 value for the oil was 10.00 nL/mL on THP-1 cells with selectivity index values of 0.5 for L. donovani and 1.5 for L. aethiopica. The median lethal concentration (LC50) of the oil was 2.45 μL/mL. Thus the observed high efficacy and moderate toxicity of the volatile oil from C. macrostachyus, makes the plant a promising source of new lead compounds in the search for safe and effective antileishmanial drugs.

There has been a considerable interest in the development of novel compounds with anti-inflammatory and /or antimicrobial activities. Several economical and social merits have been prospected for compounds with dual effects. Pyrazoles are an important class of compounds for new drug development that attracted much attention. Several pyrazole derivatives have been synthesized as target structures and evaluated for their biological activities. This review describes the synthesis and the development of new pyrazoles that possess anti-inflammatory and /or antimicrobial activities. The cytotoxicity of the reported compounds indicates good safety associated with many of the pyrazole derivatives. However, the need for standardized method for cytotoxicity evaluation is required for better understanding of the compounds safety and the safety-structure relationships.

Though use of herbal medicine is increasing dramatically worldwide, environmental pollution especially with heavy metals poses serious problem on quality of medicinal plants and their products. In Ethiopia, where more than 85% of the population relies on traditional medicine, data on heavy metals level of plants is unavailable. The purpose of this study was to assess Pb and Cd in plants grown in different parts of Ethiopia. Out of 26 samples analyzed, four for lead (15.4%; 11.56 +/- 1.07 to 98.19 +/- 1.05 mg/kg) and seventeen for cadmium (65.4%; 0.38 to 1.83 +/- 0.06 mg/kg) were found to contain concentrations above WHO limits (10 mg/kg and 0.3 mg/kg respectively).

The hexane fraction from the roots of Echinops ellenbeckii O. Hoffm. from Ethiopia yielded seven acetylenic thiophenes of which five compounds (1, 3, 4, 6, 7) are reported for the first time in this species: the monothiophenes 5-(penta-1,3-diynyl)-2-(but-3-en-1-ynyl)-thiophene (1), 5-(penta-1,3-diynyl)-2-(4-acetoxy-but-1-ynyl)-thiophene (2), 5-(penta-1,3-diynyl)-2-(3-hydroxy-4-acetoxy-but-1-ynyl)-thiophene (3), 5-(penta-1,3-diynyl)-2-(3,4-diacetoxy-but-1-ynyl)-thiophene (4), 5-(penta-1,3-diynyl)-2-(3-chloro-4-acetoxy-but-1-ynyl)-thiophene (5), 5-(penta-1,3-diynyl)-2-(3,4-epoxy-but-1-ynyl)-thiophene (6) and the dithiophene 5-[(5-acetoxymethyl-2-thienyl)-2-(but-3-en-1-ynyl)]-thiophene (7). Additionally, four fatty acids (C14, C15, C16 and C18), seven fatty acid esters and three long-chain hydrocarbons could be identified. All the structures were elucidated on the basis of spectral data by GC-MS, HRMS and the NMR techniques.

Members of the genus Echinops in the family of Asteraceae are widely used in Ethiopian herbal medicine for the treatment of various diseases and illness such as migraine, diarrhea, heart pain, different forms of infections, intestinal worm infestation and hemorrhoid. Hydroalcoholic extracts of the root, flower head, leaf and stem of Echinops ellenbeckii O. Hoffm. and Echinops longisetus A. Rich were investigated for their chemical constituents and biological activities. The presence of alkaloids, saponins, phytosterols, polyphenols and carotenoids in the different parts of the plants was observed whilst anthraquinones were not detected. The leaf extracts of both plants and stem extract of E. longisetus showed strong inhibitory activity against cultures of Staphylococcus aureus. None of the extracts were found to be active against Gram-positive organisms. The flower extract of E. ellenbeckii showed strong inhibitory activity against Candida albicans. Root and flower extracts of the plants investigated showed lethal activity against earthworms. Moreover, the extracts of the roots of both plants showed molluscicidal activity against schistosome-transmitting snail hosts. The biological activities observed were dose dependent.

The antibacterial activity of volatile fractions from Artemesia abyssinthium, Croton macrostachyus, Echinops kebericho and Satureja punctata has been tested against selected Gram-positive and Gram-negative bacterial strains. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of five essential oils were investigated for their antibacterial activities against four gram-positive (Staphylococcus aureus (ATCC 25923), Streptococcus pyogenes, Listeria monocytogenes and Bacillus cereus) and seven gram-negative (Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Salmonella paratyphi, Shigella dysenteriae, Citrobacter sp., Klebsiella pneumonia and Proteus mirabilis) bacterial species. All the essential oils were active against all tested bacterial species. L. monocytogenes, B. cereus, and S. aureus were the three most sensitive bacteria with a mean concentration of 0.14, 0.8 and 0.62µg/ml, respectively. Almost all the essential oils have shown least activities against L. monocytogenes. In contrast, antibacterial activities were highest against S. paratyphi, P. mirabilis and E. coli with a mean concentration of 20.8, 18.8 and 15.7µl/ml, respectively. P. aeruginosa was found to be the most sensitive bacteria to all essential oils showing MIC of 0.1 to 1.6 with overall mean values of 0.62µl/ml while K. pneumonia ranked next with MIC mean values of 1.36µl/ml. The mean MIC values of the essential oils against B. cereus were significantly higher than the control (P= 0.013) whereas the essential oils against L. monocytogenes and S. aureus had comparable antibacterial activity with the control drug (P>0.05). The mean of MIC values were significantly higher against Gram-positive than Gram-negative bacteria (P