Screening of some kenyan medicinal plants for antibacterial activity

Phytother Res. 2009 Jun 22

Wagate CG, Mbaria JM, Gakuya DW, Nanyingi MO, Kareru PG, Njuguna A, Gitahi N, Macharia JK, Njonge FK.

Department of Public Health, Pharmacology and Toxicology, Faculty of Veterinary Medicine, University of Nairobi, P.O. Box 29053-00625, Nairobi, Kenya.

Eleven medicinal plants used by traditional healers in Machakos and Kitui District were screened, namely: Ajuga remota Benth, Aloe secundiflora Engl, Amaranthus hybridus L, Cassia didymobotrya Fes, Croton macrostachyus Del, Entada leptostachya Harms, Erythrina abyssinica DC, Harrisonia abyssinica Oliv, Schkuhria pinnata O. Ktze, Terminalia kilimandscharica Engl and Ziziphus abyssinica Hochst for potential antibacterial activity against four medically important bacterial strains, namely: Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, Micrococcus lutea ATCC 9341 and Pseudomonas aeruginosa ATCC 27853. The antibacterial activity of methanol extracts was determined as the minimum inhibitory concentration (MIC). The plant extracts were more active against Gram-positive (G+) than Gram-negative (G-) bacteria. The positive controls were streptomycin and benzylpenicillin for G- and G+ bacteria, respectively, both had a significant MIC at <1 mg/mL. The most susceptible bacteria were B. cereus, followed by M. lutea, while the most resistant bacteria were Ps. aeruginosa, followed by E. coli. The present study supports the use of these plants by the herbalists in the management of bacterial ailments. H. abyssinica and T. kilimandscharica showed the best antibacterial activity; hence these plants can be further subjected to phytochemical and pharmacological evaluation

Kenya Scientific Analysts

Background Information

Kenya Scientific Analysts (KSA) is a non-profit, organization committed to conducting high quality and policy-relevant scientific consultation.
KSA was established in 2006 with its headquarters in Nairobi, Kenya and satellite offices in Mombasa and Busia, Kenya.

Evolution
KSA was formerly known as Kenya Data Analysts (KDA) before expansion of its activities. KSA is registered with the Registrar of Companies in Kenya, giving it distinct legal status in the country.

Objectives
KSA has a wider aim to reach establish collaboration with reputable research institutes, individual researchers, doctoral students and other post graduates in undertaking relevant scientific research.
It has specific objectives:
 Contribute to Science through high impact research projects and publications.
 Provision of evidence based research finding to policy makers.

Research Focus
KSA research focuses on improving understanding of Epidemiology and Public Health of tropical and infectious diseases through development and implementation of innovative, policy-oriented research programs to address the health challenges. KSA particularly focuses on areas where there are considerable knowledge gaps.
Our methods include primary research projects where we collect new data; secondary analysis of existing data; synthesis of evidence; scenario building; and monitoring and evaluation of interventions. We also seek to develop and use new methodologies, partnering with other institutions as needed.

Collaborators

 Kenya Medical Research Institute, Nairobi
 International Livestock Research Institute
 University of Nairobi, Department of Public Health, Pharmacology and Toxicology
 University of Nairobi, Department of Chemistry
 Great Lakes University, Kisumu.
 African Medical Research Institute.
 Maseno University.
 Masinde Muliro University of Science and Technology
 Victoria Institute of Science and Technology

A Survey of Bovine Cysticercosis / Human Taeniosis in Northern Turkana District, Kenya

PREVENTIVE VETERINARY MEDICINE MARCH 2009
Lucas L Asaava, BVM; Philip M kitala, BVM., MSc., PhD; Peter B Gathura,
BVM.,MSc.,PhD; Mark O Nanyingi, BVM.,MSc; Gerald M Muchemi, BVM.,MSc.,PhD; Esther
Schelling , DVM, PhD

ABSTRACT
Bovine cysticercosis is a zoonosis that is mainly of socioeconomic and public health importance. A survey of this disease was carried out in northern Turkana District, Kenya to estimate the prevalence through both serology and meat inspection, to determine the prevalence of the adult tapeworm in the human definitive host, and to determine risk factors for cattle seropositivity. This information is of public health importance and will be of use in assessing economic losses due to down grading, refridgeration or condemnation of infested carcasses.The study area was stratified into the three livestock grazing regions of Oropoi to the south,
Lokichoggio-Mogilla centrally and Kibish in the north for the purposes of the serological and questionnaire (n=53 herd owners) data. Five adakaars (grazing units) were selected and 34, 63, 49, 75, and 571 cattle serum samples obtained from these. The slaughter slabs of Lokichoggio and Kakuma were visited and 188 serum samples were obtained from slaughter cattle and compared to results of meat inspection. Human stool samples were collected in each of the three grazing areas
and 66, 97,and 78 samples were obtained. The seroprevalence of cysticercosis in cattle was estimated at 16.7% (95%CI 13%-20.9%) using a secretory-excretory antigen detection ELISA. There was poor agreement between meat inspection and serology (k = 0.025; P=0.2797). The prevalence of taeniosis was estimated as 2.5% (95%CI
0.8%-5.6%) by microscopy. A backwards elimination logistic regression analysis indicated that the grazing unit (Adakaar), the deworming history of household members and the distance (>2km) of grazing fields from the homestead were significant explanatory variables for cattle being found to be positive on serology.
An intra-cluster correlation coefficient (ICC) of 0.07 (0.02 - 0.12); p<0.0001 was calculated for bovine cysticercosis in this area.

Keywords: Cattle-Cestoda; Taenia saginata; ELISA; Epidemiology-cestoda; Kenya-Turkana

Victoria institute of Science and Technology

Many antipoverty crusaders believe that closing the Digital Divide is not a top priority, arguing instead that the poor need clean water,good roads, electricity and jobs before they need computers. However, what they do not realize is that access to digital technology greatly enhances the effectiveness and affordability of efforts to improve the water supply, improve rural health and education, generate jobs and address any of the other interrelated problems of poverty. Closing the digital divide is not a silver bullet for reducing poverty. But there is a much lower likelihood of large scale and sustainable poverty reduction without doing so.
The emerging market countries of Asia are now major drivers of the digital economy and, in that vast region, the spread of wireless networks is stimulating all other dimensions of economic growth. In fact, the biggest technological growth is occurring outside big cities in these countries. As broadband networks spread into the countryside in Kenya, costs throughout the supply chain will drop. By adjusting their policies to close the digital divide, the major IT and telecom companies are achieving innovations that could spur growth in the advanced countries as well.
one prototype initiative is by a kenyan Harvard professor. Calestous Juma from the shores of Lake victoria in Budalangi. Calestous Juma is Professor of the Practice of International Development and the Director of the Science, Technology and Globalization Project at the Harvard Kennedy School He volunteers as a member of the International Advisory Council of World Computer Exchange (WCE).Professor Juma is now contacting his friends and colleagues to explore if they might be willing to join him in financially Sponsoring part of the $30,000 for content materials, sourcing the computers and other items as well as the logistical and shipping costs.
Victoria Institute of Science and Technology (VIST)will be key in bridging the digital divide and improve livelihoods of the rural communities of Bunyala Distirct in Kenya.

Antibacterial and cytotoxic activity of Kenyan medicinal plants

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

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