Phytochemical Investigation and Antimicrobial Activity of Hexane, Ethyl Acetate and Methanol Fractions from Stem Bark of Icacina Trichantha Oliv. (Icacinaceae)

Abstract
Background: Micro-organisms are responsible for the transmission of a large number of diseases. It is hard to comprehend the amount of diseases, deaths and economic losses caused by micro-organisms alone. Plants are good sources of eco-friendly and readily available antimicrobial agents. Purpose: The aim of this study was to evaluate the chemical constituents and antimicrobial characteristics of three fractions from ethnomedicinal Icacina trichantha. Oliv. (Icacinaceae).Methods: Methanol extract from Icacina trichantha. Oliv was obtained by maceration and fractionated successively using hexane, and ethyl acetate. The antimicrobial properties of Icacina trichantha. Oliv was assessed using agar cup diffusion method on MRSA, P. aeruginosa, S. typhi, C. krusei, S. dysenteriae, S. pyrogenes, E. coli, K. pneumoniae, C. albicans, and C. tropicalis. Phytochemical screening on fractions was also evaluated using standard methods.Results: Phytochemical screening on fractions revealed the presence of saponins, alkaloids, steroids, tannins, and glycosides. Agar diffusion assay on fractions showed growth inhibitory effect on all the organisms except P. aeruginosa, S. typhi, and C. tropicalis. The MIC revealed that n-hexane fraction was active against MRSA, S. pyrogenes, E. coli, K. pneumonia, C. albicans and C. krusei at 10 mg/mL while S. dysenteriae was active at 5 mg/mL. The ethyl acetate fraction was active against all the organisms at a concentration of 5 mg/mL except P.aeruginosa, S.typhi and C.tropicalis. Methanol fraction showed activity of 5 mg/mL against MRSA, S. pyrogenes, E. coli, S. dysenteriae, C. albicans and C. krusei except for K. pneumoniae with activity at 10 mg/mL. Minimum bactericidal concentration/fungicidal concentration MBC/MFC evaluated on the n-hexane fraction revealed that MRSA, S. pyrogenes, E. coli, K. pneumoniae, S. dysenteriae, C. albicans, and C. krusei were activeat 20 mg/mL, while the ethyl acetate fraction had MBC/MFC of 10 mg/mL against all the organisms except P. aeruginosa, S. typhi, C. tropicalis. Methanol extract had MBC/MFC of 10 mg/mL against MSRA, E.coli and S. dysenteriae whereas S. pyrogenes, K. pneumoniae, C. albicans and C. krusei had MBC/MFC at 20 mg/mL.Conclusion: Icacina trichantha. Oliv. contain constituents with concentration dependent antimicrobial properties based on type of organism. The plant could be useful in the prevention and treatment of multi-resistant disease causing microorganisms.