Phytochemical and Antimicrobial Constituents of the Leaf Extracts of Pterocarpus Santalinoides (Nturukpa), a Nigerian Common Food and Herb

Plants have formed the basis of traditional medicine system which has been used for thousands of years. In Nigeria Pterocarpus santalinoides is used as food as well as medicine. The study was carried out to assess the antimicrobial potential and phytochemical composition of Nturukpa (Pterocarpus santalinoides) leaf extracts on selected test organisms. Fresh leaf samples were collected and screened using standard methods for phytochemicals using methanol and aqueous solvents. Antimicrobial activity of two extracts (Methanol and Aqueous) was performed using Agar well diffusion method against the selected test organisms at different concentrations. Determination of Minimum Inhibitory Concentration (MIC) and Minimum Bacteriocidal/Fungicidal concentration (MBC/MFC) of the extracts were also carried out. Phytochemical analysis indicated the presence of alkaloids, tannins, flavonoids, proteins, glycoside, saponin, steroid, terpernoid and phenol in both extracts. The methanolic extract demonstrated a higher antimicrobial activity than the aqueous extract. The zones of inhibition for the methanolic extract of the leaf range from 11.00mm – 23.67mm while the zones of inhibition for the aqueous extract of the leaf range from 6.00mm – 16.33mm. The Minimum Inhibitory Concentration (MIC) for the aqueous extract was 50% for all test organisms but had no Minimum Bacteriocidal and Fungicidal concentration (MBC/MFC) effect while the MIC for the methanolic extract on the test organism was at 25% concentration except for Staphylococcus aureus that was at 50% concentration and its Minimum Bactericidal and Fungicidal Concentration was at 50% for Escherichia coli and Candida albicans. Statistical test using ANOVA showed that there was significance difference (P<0.05) in the zones of inhibition at different concentration between the Methanolic and Aqueous extract of the leaf. The results of the investigation clearly indicated that Pterocarpus santalinoides leaf extracts have a potential antimicrobial activity against various microorganisms due to the presence of various phytochemicals. The demonstration of antimicrobial activity of Pterocarpus santalinoides leaf against the test organisms is an indication that there is possibility of sourcing alternative antibiotic substances in this plant for the development of newer antimicrobial agents and further studies should be carried out on the safety and efficacy of this plant extract to establish whether they can offer therapeutic benefit alone or in synergy with other conventional antimicrobials.