Article Sidebar
Published:
Jan 7, 2015Keywords:
Article Details
Open access articles published in the Journal of Agriculture, Science and Technology are under the terms of the Creative Commons Attribution (CC BY) License which permits use, distribution and reproduction in any medium, provided the original work is properly cited. The CC BY license permits commercial and non-commercial re-use of an open-access article, as long as the author is properly attributed.
Copyright on any research article published in the Journal of Agriculture, Science and Technology is retained by the author(s). The authors grant the Journal of Agriculture, Science and Technology with a license to publish the article and identify itself as the original publisher. Authors also grant any third party the right to use the article freely as long as its original authors, citation details and publisher are identified.
Use of the article in whole or in part in any medium requires proper citation as follows:
Title of Article, Names of the Author, Year of Publication, Journal Title, Volume (Issue) and page. Links to the final article on the JSRE website are encouraged.
The Creative Commons Attribution License does not affect any other rights held by authors or third parties in the article, including without limitation the rights of privacy and publicity. Use of the article must not assert or imply, whether implicitly or explicitly, any connection with, endorsement or sponsorship of such use by the author, publisher or any other party associated with the article.
For any reuse or distribution, users must include the copyright notice and make clear to others that the article is made available under a Creative Commons Attribution license, linking to the relevant Creative Commons web page. Users may impose no restrictions on the use of the article other than those imposed by the Creative Commons Attribution license.
To the fullest extent permitted by applicable law, the article is made available as is and without representation or warranties of any kind whether express, implied, statutory or otherwise and including, without limitation, warranties of title, merchantability, fitness for a particular purpose, non-infringement, absence of defects, accuracy, or the presence or absence of errors.
Main Article Content
Phytochemical Screening and Antimicrobial Studies of Green, Orthodox and Black Kenyan Tea
Abstract
This study evaluated the phytochemical and antimicrobial activities of green, orthodox and black Kenyan tea on five microorganisms with the possible purpose of determining their pharmacological significance/ medicinal value. The in vitro antimicrobial activities of three extracts of tea was done using humanly isolated strains of Staphylococcus aureus, Salmonella typhimurium, Escherichia coli, Streptococcus faecalis, and, Candida albicans. The assays were carried out by agar well diffusion. Streptomycin and cefadroxilserved asthe control drugs. Aqueoustea extracts were used for the assays. The aqueous tea extracts were found to be more effective against the tested bacteria than fungi at high concentration. Orthodox tea had no antimicrobial activity against Salmonella typhimurium and Candida albicans. Extracts of green tea, orthodox and black tea showed activity on Staphylococcus aureus at concentrationsranging from 100‐200mgml‐1having comparable diameters of zones of inhibition of 10.0±0.0, 4±0.2 and 6.5±0.0 respectively. The first two tea extracts demonstrated activities on Escherichia coli and Streptococcus faecalis at concentrationsranging from 100‐400mgml‐1 with relatively close diameters ofzones of inhibition of 14mm and 12mm respectively. Only black tea inhibited the growth of Candida albicans at the MIC of 100mgml‐1 whereas, Salmonella typhimurium was inhibited by green tea and black tea extracts at the MIC of 200mgml‐1 . Black tea also inhibited growth of Escherichia coli, but at concentration ranging from 200‐ 400mgml‐1 with diameter zones of inhibition from 3.5±0.0‐ 4.0±0.0 and a MIC of 150mgml‐1 . Phytochemical screening of the three extracts of tea showed the presence of cardiac glycosides, alkaloids,saponins, flavanoids, terpenes and tannins. Green tea lacked anthraquinones while orthodox tea lacked cardenolides. Results were interpreted according to Kirby‐Bauer technique. The results obtained in this study provide preliminary evidence of the significance of secondary metabolites of tea and and their pharmacological effects.
