Indian Journal of Experimental Biology Vol. 42, March 2004, pp. 326-329 Evaluation of phytochemical and antimicrobial properties of leaf extract of Tapinanthus sessilifolius (P. Beauv) van Tiegh Florence D Tarfa"*, Obiageri 0 Obodozie a , Emmanuel Mshelia b , Kolo Ibrahim b & Temple V JC aDepartment of Medicinal Chemistry and Quality Control, bDepartment of Microbiology, Human Virology and Biotechnology, National Institute for Pharmaceutical Research and Development (NIPRD), ldu Industrial Area, P.M.B 21, Garki Abuja, Nigeria cMolecular Biology and Biochemistry Unit, School of Medical Sciences, University of Papua, New Guinea Received 1 JIIly 2003; revised 13 November 2003 Leaf extracts of T. sessi/ifolius growing on five different host plants (Psidium guajava. Citrus lemon. Vernonia amygdalina. Persea americana and Jatropa curcas) were evaluated for antimicrobial activity of the plant. Powdered leaves of T. sessilifolius collected from each host plant was divided into two portions. One portion was used for aqueous infusion and the other portion was successively extracted with hexane, ethylacetate and methanol. Infusion of aqueous extract of powdered leaves did not show antimicrobial effect even at the concentration of 1000 and 2000Jlg/ml on test microorganisms (Staph. at/reIlS, E. coli, Bacillus subtilis, Pseudomonas aerugil10sa and Candida albicalls). However in broth culture, methanolic and hexane extract had MIC range of 62.5-500Jlg/ml and ethyl acetate extract had 250-500 J.lg/ml. Phytochemical screening of leaf samples of T. sessilifolius collected from different h05t plants showed positive test for hydrolysable tannins, saponins, flavonoids, terpenes, cardiac glycoside, reducing sugars and proteins.LDso concentration was found to be > 1.500 mg/kg for samples from P. guajava; 489.89 mg/kg for J. curcas and C. lemon; and 692 mg/kg for V. amydalina in mice. Keywords: Antimicrobial property, Candida albicans, Leaf extract, Pseudomonas aerugillosa, Staphylococcus aI/reus, Tapillanthus sessillfolius African mistletoe, Tapinanthus sessilifolius P.Beauv Van Tiegh (Lorallthaceae) is a semi parasitic plant found growing on a variety of evergreen plants throughout Northern and Southern Nigeria l . Unlike true parasite that depends on its host for all nutrients, African mistletoe takes only water and minerals from its host plant 2 . The plant is ever green shrubby epiphytic and grows throughout the year on tree branches of its host with help of suckers. The characteristics of the leaves depend on the host plant *Correspondent author: E-mail :tarfaf@yahoo.co.uk that often have no botanical affinitl. T sessilifoLius has clusters of narrowly tubular flowers often brightly coloured called "matches stick /flower". In some parts of Africa, including Nigeria, aqueous extract made from the dried leaves is used as a remedy for hypertension, diabetes, infertility, epilepsy, varicose vein and other metabolic disorders 3 . s . Recently, effect of aqueous extract on gastrointestinal smooth muscle in rabbit has been reported 6 . The present study, therefore, was conducted to evaluate its anti-microbial activity and to study phyto-chemical nature of various extracts of Tapinanthus sessilifolius. Plant material- The leaves of Tapinanthus sessilifolius were harvested in the month of November 2000 in Jos, Plateau State of Nigeria. The leaf samples were harvested from different host plants namely, Psidium guajava, Citrus lemon, Vernonia amygdalina, Jatropha curcas and Persea americana. They were identified and authenticated by Professor Z.O. Gbile, a consultant taxonomist. The specimens with herbarium voucher number FHI 105336 were deposited at Forestry Research Institute Ibadan and National Institute for Pharmaceutical Research and Development (NIPRD) Abuja, Nigeria. Preparation of extract-The leaves of T. sessiLifolius from different host plants were air dried for 7 days and crushed into coarse powder. The powder thus obtained was successively extracted in soxhlet extractor with hexane, ethylacetate and methanol. For infusion, each plant sample (32g) was soaked in water (lL) for 18 hr, heated up to 70°C, allow to cool, filtered and freeze dried and weighed. Phytochemical screening - Standard methods were used for phytochemical screening of leaves extract as described earlier 7 ,8. Acute tOXIClty studies-Five groups, each consisting of 5 mice of both sexes were used for the test. Group 1 - 4 were injected (ip) with varying doses (10, 100, 1000 and 2000 mg/kg) of the extract, while group 5 served as control. Signs and symptoms of toxicity over a 24 hr period was observed. Death within this period was recorded. The LDso was estimated using the method of Lorke 9 • Microorganism and media - American typed cultures of StaphyLococcus aureus ATCC 13709, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 10231, Escherichia coli ATCC 8637 and Bacillus subtiLis from Ahmadu Bello University Zaria (ABU) were used in the study. Nutrient agar,