Abstract: Nine medicinal plants growing in Palestine were screened in vitro for potential antibacterial activity against 6 bacterial strains by well diffusion and micro-dilution techniques. Both aqueous and organic solvents were used. The dried extracts of Sacropoterium spinosum (Rosaceae) (seed), Ruta chalepensis L (Rutaceae) (leaf), Cassia senna (Ligumenosa) (leaf), Lawsonia inermis (Lythraceae) (leaf), Psidium guajava (Myrtaceae) (Leaf), Carataegus azerullus (Rosaceae) (Leaf), Ranunclus asiaticus(Ranunculaceae) (Flowers), Calendula officinalis (Composita) (Flowers),and Salvia syriaca (Labiatae) (leaf) were screened. The bacterial strains tested were; Methicillin-resistant Staphylococcus aureus (MRSA); three strains (1, 2 & 3), multidrug resistant Pseudomonas aeruginosa, Proteus vulgaris and Klebsiella pneumonia. The average diameter of inhibition zones ranged from 9 to 30 mm and 11 to 28 mm for aqueous and ethanol extract, respectively. Methicillin-resistant Staphylococcus aureus (MRSA) was the most inhibited microorganism. Sacropoterium spinosum extract was the most active against Methicillinresistant Staphylococcus aureus (MRSA) and multidrug resistant Pseudomonas aeruginosa. The MIC value of ethanol extract was 0.781 mg/ml against MRSA while 0.390 mg/ml against Pseudomonas aeruginosa. The combination effect of ethanol extracts of (Sacropoterium spinosum with Lawsonia Inermis) on bacterial species tested exhibited a higher effect than that of any individual extract.
Such results lead to an interesting promise for further investigation to design potentially active antibacterial augmentative agents of natural sources.