Assessment Of The Antibacterial Activity Of Vernonia Amygdalina And Occimum Gratissimum Leaves On Selected Food Borne Pathogens
T Ibrahim, L Ajala, F Adetuyi, B Jude-Ojei
antibacterial, bioactive, concentration, extracts, gastrointestinal, pathogens
T Ibrahim, L Ajala, F Adetuyi, B Jude-Ojei. Assessment Of The Antibacterial Activity Of Vernonia Amygdalina And Occimum Gratissimum Leaves On Selected Food Borne Pathogens. The Internet Journal of Third World Medicine. 2008 Volume 8 Number 2.
The bioactive compounds activities of leaves extracts of two Nigerian edible vegetables were carried out by agar well diffusion method on selected food borne pathogens of medical significance. Both aqueous and ethanolic extracts of these plants leaves were tested against
The search for newer sources of antibiotics is a global challenge preoccupying research institution, pharmaceutical companies and academia, since many infection agents are becoming resistance to synthetic drugs(Latha and Kannabiran,2006).Plants have the major advantage of still being the most effective and cheaper alternative sources of drugs. The local use of natural plants as primary health remedies due to their pharmacological properties is quite common in Asia, Latin America and Africa (Bibitha
Traditional therapy involves the use of plant exacts or their active principles which may serve as a source of modern drugs and source of intermediate compounds for synthesizing analog drugs with more desirable properties (Akerele, 1993). The development of medicinal chemistry, as a major route for the discovery of novel and more active therapeutic agents, further investigation into the chemical and biological activities of the plants needed to be carried out (Rao & Roja, 2002). The work is to evaluate the antibacterial activity of these two Nigerian edible vegetables on selected food borne pathogens of medical significance as the results will increase the knowledge on the tradomedical use of these plants.
Materials And Methods
COLLECTION OF PLANT MATERIALS: Fresh, pesticide free leaves of both plants were collected from University of Agriculture, Abeokuta Ogun State.
TEST ORGANISMS: The test organisms used for the study were medical isolates collected from the microbiology unit of University of Lagos, Teaching Hospital, Idiaraba, Lagos. Their identification was re-affirmed using standard methods of Cheesebroug (1991).
EXTRACTION :( Aqueous and Ethanolic Extraction): The extracts were prepared as described by Madunagu
PHYTOCHEMICAL SCREENING: The extracts were re-screened for bioactive agent according to the methods described by Jigna
ANTIMICROBIAL SUSCEPTIBILITY TESTING: Five different concentrations of the extracts were prepared 10mg/ml, 20mg/ml, 30mg/ml, 40mg/ml, and 50mg/ml and tested against the tests organism by agar-well diffusion method of Aida
DETERMINATION OF MINIMUM INHIBITORY CONCENTRATION: The lowest concentration of the extracts that will inhibit the growth of test organisms (MIC) was determined by the methods of Atlas, (1995).
Results And Discussion
Table 1 indicated the result of the phytochemical screening of the two plants. None of the extracts contained steroid. Flavonoids and glycosides are more significant in the extracts of both plants. Table 2 showed the result of the antibacterial activity of the plants extracts at various concentrations .It was found out that the higher the concentration of the extract, the higher the diameter of zones of the inhibition. Table 3 showed the minimum inhibitory concentration (MIC) of the extracts. The MIC were determined to be 25mg/ml for aqueous extracts of the two plants on
Medicinal plants are used by a large proportion of developing nation. The reason for this may be a true improvement of disease conditions after herbal treatment. In these countries, the search for new drugs is centered upon the investigation of medicinal plants. The present research has tested the crude extracts of
The information provides by this study on MIC of the extracts will make it easier for dosage determination and chemotherapeutic index of the extract if they were to be processed into drugs. In the antibacterial susceptibility testing using the agar well diffusion method, absence of any clear zones of inhibition by the extract could be due to low concentration of diffusable compounds, time of collection of the plant material and climate which might in turn affect the amount of constituents of the plants. Thus treating gastroenteritis as a result of food intoxication with various crude preparations may not be effective because once the pathogens elucidate a sufficient amount of toxin in the food, it is the toxin and not the pathogen that cause the disease after ingestion of the contaminated food.In many cases, extracts of active constituents that are effective in vitro experiments may not show the same effectiveness when applied in-vivo. Therefore the fact that the extracts of these medicinal Plants inhibited some medically important bacteria proves that these plants might have some potential as an alternative source of antibacterial substances.