International Journal of Medicinal Plants Research

International Journal of Medicinal Plant Research Vol. 1 (4), pp. 032-037, September, 2012. © International Scholars Journals

Full Length Research Paper

Phytochemical characterization, antibacterial screening and toxicity evaluation of Dichrostachys cinerea

Johnstone Omukhulu Neondo^1*, Cecilia Mweu Mbithe¹, Peter Kariuki Njenga², Catherine Wangari  Muthuri³

¹Institute for Biotechnology Research- Jomo Kenyatta University of Agriculture and Technology. P.O. Box 62000-00200, Nairobi

²Botany-Jomo Kenyatta University of Agriculture and Technology. P.O. Box 62000-00200, Nairobi

³ICRAF World Agroforestry Centre (ICRAF) P.O Box 30677-00100, Nairobi

*Corresponding author’s E-mail: [email protected]

Received 3 September 2012; Accepted 18 September, 2012

Absract

To provide scientific rationale to the traditional use of Dichrostachys cinerea as medicinal plant in Kenya, phytochemical analysis, antimicrobial screening and evaluation of toxic concentration levels of D. cinerea extracts were done. Qualitative assessment of phytochemicals, in vitro antimicrobial (selected bacteria and fungus) and brine shrimp toxicity assays were done. Explants (leaves, bark of stems and roots) were collected from D. cinerea trees growing in Jomo Kenyatta University of Agriculture and Technology (JKUAT) fallow land behind Botany laboratory. They were washed and then air dried under light exposure (27°C − 30°C for 14 days). A portion of each extracts was used for phytochemical screening. Sensitivity of different bacterial strains to various extracts was measured in terms of zone of inhibition using disc diffusion assay. Brine shrimps lethality test (BST) was used to predict the presence of bioactive compounds in the extracts. Methanol extracts contained all the tested phytochemicals while hot water extracts lacked steroids. Methanol and hot water extracts had no significant difference in terms of antibacterial screening. The LC₅₀ value was found to be 2000ppm (parts per million). The results suggest that extracts of D. cinerea contain potential antibacterial and antifungal agents.

Keywords: Extracts; Phytochemical; microorganisms; antimicrobial activity; Toxicity bioassay.