A comparative study on antibacterial effects of Hagenia abyssinica oil extracted from different parts of the plant using different solvents against two selected and standardized human pathogens

Hagenia abyssinica is an important medicinal plant that the traditional society relied on for generations as a traditional medicine for various types of worm infections. The tree is a multipurpose dioecious tree and can grow up to 20 m in length. This research work is designed to investigate the antibacterial activity of H. abyssinica oils extracted using three different kinds of solvent and from three different parts of the plant on two standard bacterial isolates obtained from Pasteur Institute located at Addis Ababa, Ethiopia. The solvents used to extract the oils are ethyl acetate, n-hexane and methanol. Accordingly, the antibacterial activity of all the oils were tested and the oil extracted using methanol from all parts of the plants was characterized by having a higher mean of zone of inhibition (which is 1.710 in centimeter diameter) as compared to the two other oils (n-hexane, which is 0910 and that of ethyl acetate, which is 0.842). The data obtained from this research work showed that the oils extracted from the different parts of the plant using the three different solvents exhibited a higher mean zone of inhibition on Staphylococcus aureus (which is 1.279) than that of Escherichia coli (which is 1.029). In addition, oil extracted from root of the plant has a higher mean of zone of inhibition (which is 1.415) as compared to the leaf (which is 1.14) and bark (which is 0.908). Generally, oils extracted from root, leaf and bark of H. abyssinica have an antibacterial property even if they exhibit difference.