Antibacterial and cytotoxic activity of Kenyan medicinal plants
Wagate G Cyrus, Gakuya W Daniel, Mark O Nanyingi, Francis K Njonge, James M Mbaria
Department of Public Health, Pharmacology and Toxicology 1Department of Clinical Studies, Faculty of Veterinary Medicine, University
of Nairobi, PO Box 29053, 00625 Nairobi, Kenya 2Department of Chemistry, Jomo Kenyatta University of Agriculture and Technology,
Nairobi, Kenya
Abstract
Seven medicinal plant extracts traditionally used in Kenya, mainly for management of infectious conditions, were chosen and screened for their antibacterial activity against Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Bacillus cereus and Staphylococcus aureus) bacteria. Antibacterial activity was tested using the broth dilution method. Harrisonia abyssinica and Terminalia kilimandscharica extracts showed significant activity against Gram+ and Gram- bacteria. The methanolic extracts of T. kilimandscharica bark and H. abyssinica bark and leaves showed minimum inhibitory activity against all tested bacteria, with minimal inhibitory concentrations ranging from 25-150 mg/mL. Ajuga remota and Amaranthus hybridus, which are lethal to brine shrimp nauplii,
showed significantly lower antibacterial activity than those that were relatively non-toxic.
Key words: antibacterial - cytotoxicity - medicinal plants
link www.scielo.br/pdf/mioc/v103n7/04.pdf
Thursday, January 22, 2009
Monday, January 19, 2009
6th Biennial Scientific Conference and Exhibition
Acaricidal activity of Psiadia punctulata (Compositae) against Boophilus decolaratus and Rhipicephalus appendiculatus (Acari: ixodidae)
Mark O. Nanyingi1,*, James M. Mbaria1, Cyrus G. Wagate1, Stephen Mwaura2 ,Adamson L. Lanyasunya3 , Kipsengeret B. Koros1,5 , Jacob O. Midiwo4 , William O. Ogara1
1Department of Public Health, Pharmacology and Toxicology, University of Nairobi, P.O. Box 29053-00625, Nairobi, Kenya
2International Livestock Research Institute, P.O. Box 30709-00100, Nairobi, Kenya
3Samburu Integrated Resource Aids Network P.O Box 26, Maralal, Kenya
4Department of Chemistry, University of Nairobi, P.O. Box 30197, Nairobi, Kenya
5 Center for Public Health Research, Kenya Medical Research Institute, P.O. Box 54840, 00200 Nairobi, Kenya
Abstract
Psiadia punctulata (Compositae) is an endemic plant species used for medicinal purposes in Samburu District. Previous studies revealed the presence of flavonoids, diterpenes and phenylpropenoids compounds that possess insecticidal properties. This study reports the larvicidal activity of crude methanol extract (CME) of the aerial parts of this plant on cattle ticks Rhipicephalus appendiculatus and Boophilus decoloratus. A stock solution of 5000 ppm was prepared by dissolving the ME in two parts trichloroethylene (TCE) and one part olive oil. The respective tick larvae were separately exposed to filter papers impregnated with different concentrations of the CME in triplicates. Thirty larvae of both species ranging 14-21 days old were fasted and enclosed in the envelopes. In vitro Larval packet Test (LPT) was conducted at 27-28°C and 90-95% RH for 24 h at 12:12 hour photoperiod. Larval mortality was observed after 48 hours. Triplicates for each concentration of the ME against individual larvae were evaluated to determine the lethal concentrations. The CME was larvicidal at LC50 (3.918mg/ml) and LC99 (8.771mg/ml) on R. appendiculatus and LC50 (1.857mg/ml) and LC99 (8.347mg/ml) B. decoloratus, respectively. The potential tick control use of this extracts is discussed. The plant extract possess potential novel acaricidal compounds.
Keywords: Psiadia punctulata; acaricidal; Tick control; Rhipicephalus appendiculatus; Boophilus decoloratus
Mark O. Nanyingi1,*, James M. Mbaria1, Cyrus G. Wagate1, Stephen Mwaura2 ,Adamson L. Lanyasunya3 , Kipsengeret B. Koros1,5 , Jacob O. Midiwo4 , William O. Ogara1
1Department of Public Health, Pharmacology and Toxicology, University of Nairobi, P.O. Box 29053-00625, Nairobi, Kenya
2International Livestock Research Institute, P.O. Box 30709-00100, Nairobi, Kenya
3Samburu Integrated Resource Aids Network P.O Box 26, Maralal, Kenya
4Department of Chemistry, University of Nairobi, P.O. Box 30197, Nairobi, Kenya
5 Center for Public Health Research, Kenya Medical Research Institute, P.O. Box 54840, 00200 Nairobi, Kenya
Abstract
Psiadia punctulata (Compositae) is an endemic plant species used for medicinal purposes in Samburu District. Previous studies revealed the presence of flavonoids, diterpenes and phenylpropenoids compounds that possess insecticidal properties. This study reports the larvicidal activity of crude methanol extract (CME) of the aerial parts of this plant on cattle ticks Rhipicephalus appendiculatus and Boophilus decoloratus. A stock solution of 5000 ppm was prepared by dissolving the ME in two parts trichloroethylene (TCE) and one part olive oil. The respective tick larvae were separately exposed to filter papers impregnated with different concentrations of the CME in triplicates. Thirty larvae of both species ranging 14-21 days old were fasted and enclosed in the envelopes. In vitro Larval packet Test (LPT) was conducted at 27-28°C and 90-95% RH for 24 h at 12:12 hour photoperiod. Larval mortality was observed after 48 hours. Triplicates for each concentration of the ME against individual larvae were evaluated to determine the lethal concentrations. The CME was larvicidal at LC50 (3.918mg/ml) and LC99 (8.771mg/ml) on R. appendiculatus and LC50 (1.857mg/ml) and LC99 (8.347mg/ml) B. decoloratus, respectively. The potential tick control use of this extracts is discussed. The plant extract possess potential novel acaricidal compounds.
Keywords: Psiadia punctulata; acaricidal; Tick control; Rhipicephalus appendiculatus; Boophilus decoloratus
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