| dc.description.abstract | In Kenya, over 70% of the population relies on traditional medicine as source of primary
healthcare due to its accessibility, affordability and acceptance. Traditional medicine and western
medicine are used side by side depending on the cost of conventional medicine. The cost, side
effects, toxicity and emerging resistance to antimicrobials has led to natural products being
investigated as promising agents for the treatment of diseases.
Meru Central District has inequitable distribution of health facilities and people have to walk at
least 7 kilometers to these facilities. High HIV /AIDS prevalence and low doctor / patient ratio
means many people seek medical services from TMP. This study aimed at identifying and
screening medicinal plants from this area for their pharmacological, toxicological and
phytochemical properties.
Twenty three (23) herbal practitioners identified 86 plants from 37 plant families of
ethnomedical interest. The plants were botanically identified by a plant taxonomist at the
Department of Land Resource Management and Agricultural Technology (LARMAT),
University of Nairobi. Selection of plants for this study was based on the informant consensus
among the identified herbal medicine practitioners on their use for treating microbial infections
inhuman.
Five (5) plants and seven (7) plant parts were selected and evaluated for their antimicrobial
activity, cytotoxicity and phytochemical properties. They are Piliostigma thonningit (leaves and
stem bark), Ajuga remota (leaves), Ocimum suave (leaves), Erythrina abyssinica (root bark and
stem bark) and Harissonia abyssinica {whole plant). Standard bacteria cultures of Staphylococcus aureus, Bacillus cereus, Escherichia coli and
Pseudomonas aeruginosa were used to determine the minimum bactericidal concentration
(MBC) and minimum inhibitory concentration (MIC) of the plants' methanolic and water
extracts through standard microbial techniques at the Department of Public Health,
Pharmacology and Toxicology University of Nairobi. Comparison was computed for
susceptibility of bacterial species and considered significant at p<0.05.
Cytotoxicity of the methanolic extracts was determined using brine shrimp lethality test with
serial dilutions of 1000Jlg/ml, l Oflug/ml and l Oug/ml. Lethal concentration 50 (LCso) at 95%
confidence intervals was determined using Probit analysis. Established phytochemical tests were
performed to show the presence or absence of secondary metabolites.
All the plants showed activity against the test bacteria except Erythrina abyssinica stem bark.
Piliostigma thonningii stem bark was most active against the test bacteria. There was no
difference in antibacterial activity between the methanolic and water extracts. Gram positive
bacteria were more susceptible to the extracts than gram negative bacteria. Bacillus cereus was
most susceptible while Escherichia coli most resistant. All the extracts had significant bioactivity
at LC50<1000Jlg/ml. Ajuga remota was most toxic with LCso of 69.24Jlg/ml. Tannins and
saponins were present in all extracts. Flavones and anthraquinones were absent.
The plants had appreciable antibacterial activity. The results of this study support the use of these
plants by the herbalists. Piliostigma thonningii stem bark exhibited the most antibacterial
activity. Further studies should be carried out on this plant regarding its antimicrobial potential.
More research is needed to document and scientifically validate the plants used by the Meru community. | en |
