Journal of Developmental Biology and Tissue Engineering Vol. 2(1), pp. 1-4, June 2010 Available online at http://www.academicjournals.org/jdbte ISSN 2141-2251 © 2010 Academic Journals Full Length Research Paper The antimicrobial activities and phytochemical screening of ethanolic leaf extracts of Hedranthera barteri Hook and Tabernaemontana pachysiphon Stapf. C. M. Duru 1 * and T. I. Mbata 2 1 Department of Biotechnology, Federal University of Technology, Owerri, Nigeria. 2 Department of Microbiology, Federal Polytechnic, Nekede, Owerri, Nigeria. Accepted 16 January, 2010 The antimicrobial efficacy and phytochemical screening of ethanolic leaf extracts of Hedranthera barteri and Tabernaemontana pachysiphon against Staphylococcus aureus, Escherichia coli and Fusarium phoseolida were determined using the Agar diffusion well method. Sensitivity in terms of zones of inhibition, minimum inhibitory concentration (MIC), minimum fungicidal and bactericidal concentration (MBC) and phytochemical composition of the leaf extracts were also determined. Results obtained showed that the ethanolic extracts of the leaf of H. barteri was the most potent inhibiting all isolates with diameters of zones of inhibition ranging between 2 - 15 mm, than the ethanolic leaf extracts T. pachysiphon which did not inhibit the growth of F. phoseolida. The extracts from both plants inhibited the growth of the bacterial isolates in a concentration dependent manner with MICs ranging between 25 - 100 mg/ml, while MFCs/MBCs gave a range of 6.25 - 100 mg/ml. Phytochemical screening of leaf extracts of both plants showed the presence of active principles such as alkaloids, saponins, resins, flavonoids, polyphenols and carbohydrates. Key words: Antimicrobial, Hedranthera barteri, Tabernaemontana pachysiphon, phytochemical, bacterial isolates. INTRODUCTION Hedranthera barteri and Tabernaemontana pachysiphon (Family Apocynaceae) are shrubs, found in damp situations of the closed forest in Ghana, North and South Nigeria, West Cameroon and also in Congo Brazzaville. The fruits of H. barteri and T. pachysiphon have been used traditionally to prevent miscarriages, treatment of sores and ulcers respectively (Thomas, 1910; Green, 1994). In Nigeria, H. barteri fruits have been implicated in herbal remedies against gonorrhoea, as a vermifuge and the exudates from the leaf used to suppress painful tumor (Ainslie, 1937). The leaf decoction is drunk by Igbos of South- Eastern Nigeria in treating dizziness (Thomas et al., 1967) while the bark and seeds of T. pachysiphon have been reported to contain conophargngine and alkaloids, and has been implicated in reducing breast *Corresponding author. E-mail: theoiyke@yahoo.com. Tel: +2348032618922. inflammation (Burkill, 1985). Chukwujekwu et al. (2005) and Onasanwo and Elegbe (2006) reported its use as anti-inflammatory, antimalarial, antibacterial and anti- nociceptive agents. This stimulated interest to further investigate these plants with a view of determing the antimicrobial properties and phytochemical composition of the leaf extracts of these plants. MATERIALS AND METHODS The fresh leaves of H. barteri and T. pachysiphon were collected from Enugu in South-Eastern Nigeria during the month of May 2008. The plants were identified by a plant taxonomist of the Department of Botany, Nnamdi Azikiwe University, Awka, Nigeria. Sample preparation and extraction The leaves were dried at room temperature (28°C) until completely dry and grounded into fine power using a motor laboratory plant mill (Christy and Norris Ltd, Chemsford England).