PHYTOCHEMICAL INVESTIGATION AND ANTIMICROBIAL ACTIVITIES OF LEAF, STEM BARK AND ROOT BARK EXTRACTS OF BERSAMA ABYSSINICA FRESEN

Abstract

Bersama abyssinica is locally known as “Lolchisa” in Afan Oromo and its leaf part is traditionally used for the treatment of various human ailments including, cholera, diarrhea, dysentery, mycoses, skin infection, syphilis and toothache. The present study was carried out on the phytochemical investigation and antimicrobial activities of crude extracts of Bersama abyssinica leaf, stem bark and root bark. The different plant parts were extracted with solvents like n-hexane, chloroform:methanol (1:1) and methanol using Soxhlet extraction method. The qualitative analysis attested presence of alkaloids, flavonoids, glycosides, phenols, phytostrols, saponnins, steroids, tannins and terpenoids. GC-MS analysis revealed the presence of 8, 11 and 7 compounds in esterified n-hexane leaf, stem bark and root bark crude extracts, respectively. Methyl tetradecanoate, hexadecanoic acid methyl ester and 9,12,15-octadecatrienoic acid methyl ester were detected commonly in leaf, stem bark and root bark extracts with total percentage compositions 64.69%, 57.62% and 39.73%, respectively. Hexadecanoic acid methyl ester present with highest compositions in esterified n-hexane leaf, stem bark and root bark extracts respectively with compositions 38.65%, 35.91% and 32.36%. Total composition of fatty acids in leaf stem bark and root bark were 89.14%, 88.06% and 100%, respectively. The antimicrobial activities were tested against two gram positive bacteria (Staphylococcus aureus and Streptococcus agalactiae), two gram negative bacteria (Escherichia coli and Salmonella typhimurium) and two Fungi (Aspergillus niger and Fusarium verticilloides) using disc diffusion method. The extracts of methanol showed largest zone of inhibition and among parts of the plant leaf showed highest zone of inhibition for fungi and bacteria species tested. Thus the present study showed the chemical composition and antimicrobial activities varied with plant parts, solvents used for extraction and types of microbes. The appreciable antimicrobial activities against the tested bacterial and fungal species claim traditional uses of the plant as a medicine.