Antibacterial and Antifungal Activity of Ethanol Extract of Different Parts of Medicinal Plants in Jordan

Agar diffusion assay and Minimum Inhibitory Concentration (MIC) determinations, in vitro were used to evaluate antimicrobial activity of plant extracts against nine bacteria and four fungi. Fourteen ethanolic extracts of different plant parts from Tecoma capensis Thunb. Lindl (Bignoniaceae), Lavandula angustifolia Mill. (Lamiaceae), Rosmarinus officinalis L. (Lamiaceae), Jasminum sambac Ait. (Oleaceae), Populus alba L. (Salicaceae), Populus nigra L. (Salicaceae), Sonchus oleraceus L. (Asteraceae), and Laurus nobilis L. (Lauraceae) were assayed. Ethanolic extract yields varied among plants and parts of the same plant. The highest yields (18% w/w) were from L. nobilis bark, the lowest (4%) from P. nigra leaves. Other yields ranged from 7- 17%. Antimicrobial activity at 3 mg per disc varied between 8-25 mm inhibition zones. L. nobilis leaf extract exhibited highest antibacterial activity (22 mm and 0.5 mg per disc MIC) against Bacillus subtilis and the highest antifungal towards Aspergillus niger (25 mm and 0.5 mg MIC). S. oleraceus aerial parts, P. nigra, P. alba leaves and L. nobilis fruit extracts were the least active against bacteria and fungi (8-10 mm and 2.0-3.0 MICs). Interestingly, T. capensis flower extract exhibited strong antifungal activity (17 mm and 0.5 mg MIC) and inhibited moderately methicillin resistant Staphylococcus aureus which is reported for the first time. These plant extracts showed interesting antimicrobial activity against bacteria and fungi, thus validating their use and further investigations are needed.