EVALUATION OF ANTIMICROBIAL PROPERTIES OF N-HEXANE EXTRACT OF THE LEAVES OF NAPOLEONEAE IMPERIALIS FAMILY LECYTHIACEAE

Napoleonaea imperialis is used to treat wounds in most parts of Nigeria. Against this background, N-hexane extract of the leaves were screened against some microorganisms to ascertain this claim and to recommend it for further investigation for possible inclusion into official compendium. The plant leaves were dried, powdered and extracted by cold maceration with N-hexane for 24hours. Phytochemical screening was done for alkaloids, saponin, steroidal nucleus, simple sugar, starch, glycoside, proteins and flavonoid using standard procedures. Antimicrobial screenings were carried out using agar diffusion technique. Antibacterial activity was conducted by screening against six pathogens comprising both Gram positive (B. subtilis and S. aureus) and Gram negative bacteria (P. aeruginosa, Klebsiella, E. coli and S. typhi) obtained from pharmaceutical Microbiology laboratory stock. The extract was screened against 24hour broth culture of bacteria seeded in the nutrient agar at concentrations 400, 200, 100, 50, 25, 12.5, 6.25and 3.125 mg/ml in DMSO and incubated at 37⁰C, for 24 hours and measuring the inhibition zone diameter – IZD. The positive controls were ampicillin 20µg/ml for bacteria. The organisms were very sensitive to ampicillin.  DMSO was used as negative control. The phytochemical screening showed the presence of alkaloids, saponins, tannins, glycosides and proteins whereas flavonoids, resins and steroids were absent. N-hexane extract exhibited activity against all the test bacteria at 400mg/ml and 200mg/ml. The N-hexane extract exhibited varying activity as the concentration is reduced, to Staphylococcus aureus, E. coli, B. subtilis, P. saeruginosa, Kleb pneumonia, Salmonella typhi with minimal inhibitory concentration of 50, 25, 200, 50, 400 and 200 mg/ml of N-hexane extract respectively. The extract demonstrated activities against certain bacteria confirming the use of the plant in ethno pharmacology and since the root extract are more often used, it is yet to be confirmed if it has more activity than the leaves against the test organisms. Taking the least inhibition zone diameter (IZD) of the standard (Ampicillin) as the breaking point, most of the extracts passed the breaking point.