ABSTRACT

 Piliostigmathonningii is one of the African plants with numerous medicinal values in ethnomedicine. It belongs to the family of Fabaceae and can he used for treating ailments like loose stooling in teething children, wound dressing, ulcer treatment, worms' infestation, hemorrhoids, inflammations, bacterial infections. gonorrhea, stomach ache and headache. This study probed the chemical constituents and antimicrobial properties of the leaf and seed of P. thonningii. Qualitative phytochemical screening of the leaf and seed extracts of the plant showed the presence of alkaloic.ls, flavonoids, tannins, saponins, terpenes, steroids, glycosides, and phenols.The quantitative aspect of the leaf showed that the alkaloid content was 15.5 %. tannins I 0.2 %, saponins 9.6 %, tlavonoids 4.3 %, terpenes 15.2 %, steroids 16.9 % and Phenols 12.9 %. The seed contained alkaloid 6.2%. tannins 4.2 %, saponins 4.8 %. flavonoids 2.5 %, terpenes 15.9 %, steroids 13.3 % and phenols 7.9 %. The vitamins detected in the leaf included Beta-carotene (10.428±0.000 mg/l00g). ascorbic acid ( 13.432±0.020 mg/I 00g), riboflavin (3.412±0.035 mg/1 00g). niacin (0.941±0.000 mg/l00g). thiamin (2.424±0.002 mg/l00g) while that of the seed included Beta-carotene (5.349±0.013 mg/l00g), ascorbic acid (8.4±0.040 mg/l00g), riboflavin (0.640±0.000 mg/1 00g), niacin (0.0131 ±0.000 mg/l00g) and thiamin (0.431±0.0031 mg/l00g). The mineral compositions detected in the leaf included calcium (2413.02±0.001 mg/I00g), magnesium (908±0.003 mg/l00g). potassium (1103.04±0.023 mg/l00g), sodium (53.01±0.018 mg/I 00g). phosphorus (46.24±0.000 mg/l00g), nitrogen ( 1842.03±0.002 mg/I 00g), iron (16.31±0.000 mg/I00g), zinc (0.243±0.001 mg/l00g) and copper (0.001±0.000 mg/l00g), while that of the seed included calcium (20 I 0.34±0.006 mg/I 00g). magnesium (728.84±0.023 mg/I 0Og). potassium ( 1004.02±0.011 mg/l00g). sodium (38.03±0.061 mg/l00g), phosphorus (20.02±0.00 I mg/l00g), nitrogen (785.01±0.003 mg/l00g), iron (2.02±0.001 mg/l0Og), zinc (0.01±0.000 mg/I 00g) and copper (0.0 1±0.000 mg/l00g). The GC-MS results or the chloroform extract of the leaf at different retention times showed a promising result of 17 probable structures with 14 of them, having medicinal values. In the same vein. the seed showed 9 probable structures with 7 of them having medicinal values. The antimicrobial activities of the chloroform extract of the leaf and seed were studied using hospital isolates of live pathogenic microorganisms. Its activity at a varying concentrations of 150 mg/ml. 75 mg/ml. 50mg/ml. 25 mg/ml. 12.5 mg/ml and 6.25 mg/ml was investigated against.S.aereus, B. cereus. E. coli, S. typhiand P.aeruginosa using agar well diffusion method. The result showed that the extract of the leaf exhibited activity against three micro-organisms in a concentration-dependent pattern. with the highest growth inhibition seen in S. aereus and the lowest growth in S. ryphi with MIC of 25 mg/ml and 75 mg/ml respectively while the seed showed inhibition activity against two microorganisms in a concentrationdependent manner, with the highest growth inhibition seen in S, aereus and the lowest growth in E. coli with MIC of 50 mg/ml and 75 mg/ml respectively. The result of this research work revealed that P. thonningii has a lot of phytochemicals which might be responsible for its therapeutic potentials in ethnomedicine.