Antibacterial and antioxidant properties of crude extract, fractions and compounds from the stem bark of Polyscias fulva Hiern (Araliaceae)

In our previous work, the dichloromethane-methanol (1:1v/v) extract, fractions and isolated compounds from Polyscias fulva stem bark showed interesting antifungal activity. As a continuity of that work, this study aimed to bring out complementary informations about the antimicrobial properties of P. fulva stem bark that may be useful in the standardization of phytomedicine from this plant. The antibacterial activities of the crude extract, fractions and isolated compounds were assayed by broth microdilution techniques. Their antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), pyrogallol and �?²-carotene-linoleic acid assays. The extract presented antibacterial activities against S. typhi, E. aerogenes, P. aeruginosa and E. coli strains with MIC values of 2000 to 8000 �?¼g/mL. The fractionation led the ethyle acetate and n-butanol fractions relatively more active (MIC=500 to 1000 �?¼g/mL). �?²-sitosterol and 3-O-�?±-L- arabinopyranosyl-hederagenin were the most active compounds with MIC values ranging from 6.25 to 100 �?¼g/mL. The most sensitive bacterium was P. aeruginosa on which all the tested compounds were active (MIC=6.25 to 400 �?¼g/mL). Among all the tested substances, the crude extract (RSa50=84.86 �?¼g/mL) and the methyl atrarate (RSa50=14.77 �?¼g/mL), showed the highest scavenging activities against DPPH free radicals and those arising from the oxidation of the linoleic acid respectively. The results obtained revealed that the stem bark of P. fulva possesses antibacterial and antioxidant activities. It may then be useful in the development of an antimicrobial phytomedicine with a large spectrum of actvity endowed with antioxidant properties which can be standardised based on the isolated compounds.

Biography :

Guy Sedar Singor Njateng has completed his PhD from Dschang University. He is a Senior Lecturer/Senior Researcher at the University of Dschang-Cameroon. He is an Awardee of the 2011 CAS-TWAS Post-graduate Fellowship in Kunming Institute of Botany, China and of the 2016 CIIT-TWAS Post-doctoral Fellowship in Centre for Advanced Drug Research, COMSATS Institute of Information Technology (CIIT), Abbottabad, Pakistan. He has published more than 20 papers in reputed journals.

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