STUDIES ON THE ANTIMICROBIAL PROPERTIES OF BARK AND LEAVES OF MONKEY KOLA
(COLA MILLENII) ON SOME SELECTED PATHOGENS
This study is conducted to analyse the phytochemical component, evaluate the antimicrobial properties of the ethanolic, methanolic and water extracts of Cola millenii bark and leaves against some clinical Pathogens which are Staphylococcus aureus, Escherichia coli, Salmonella typhi and Candida albicans, to determine the minimum inhibitory concentration, minimum bactericidal concentration(MBC) and minimum fungicidal concentration(MFC). Cola millenii has been used in folk medicine and is a member of the family Sterculiaceae. The bark and leaves of Cola millenii K Schum were extracted using aqueous(water), ethanolic(organic), methanolic(organic) solvents and were investigated for antimicrobial activity against some pathogenic microorganisms using agar well diffusion method. The aqueous extract did not show any significant difference in their activities against the various organisms but the ethanolic extract and methanolic extract had significant activities, ethanolic leaf extract demonstrated the highest activity against the gram positive organism(Staphylococcus aureus) tested with the highest activity(18.00±0.5 mm), and also against the selected test fungi (Candida albicans) with activity (16.00±0.8 mm) zone of inhibition except for Salmonella typhi which did not show any zone of inhibition. Ethanolic bark extract demonstrated the highest activity against the gram negative organism tested (Escherichia coli) with the highest activity(13.00±0.8 mm), and also against the selected test fungi (Candida albicans) with activity (11.50±0.6 mm) zone of inhibition except for Salmonella typhi which did not show any zone of inhibition. The chloramphenicol and fungisol control showed large zones
of inhibition. The minimum inhibitory concentration(MIC) and minimum fungicidal concentration(MFC) of the extract ranges between 125 mg/ml to 250 mg/ml for both the bark and leaves of the plant. The antimicrobial property shown by the plant extract is an evidence of the ethno-medicinal uses of the plant. Cola millenii bark and leaves bioactive component may therefore be extracted and used as antibiotics as the result is comparable with commercially available antibiotics and incorporation of active compounds isolated from the ethanolic
extract of Cola millenii into conventional drug preparation`ns can also tackle the challenge posed by drug resistant microorganisms.