Twelve medicinal plants were screened, namely Abrus precatorius L., Caesalpinia pulcherrima Swartz., Cardiospermum halicacabum L., Casuarina equisetifolia L., Cynodon dactylon (L.) Pers., Delonix regia L., Euphorbia hirta L., Euphorbia tirucalli L., Ficus benghalensis L., Gmelina asiatica L., Santalum album L., and Tecomella undulata (Sm.) Seem, for potential antibacterial activity against 5 medically important bacterial strains, namely Bacillus subtilis ATCC6633, Staphylococcus epidermidis ATCC12228, Pseudomonas pseudoalcaligenes ATCC17440, Proteus vulgaris NCTC8313 and Salmonella typhimurium ATCC23564. The antibacterial activity of aqueous and methanol extracts was determined by agar disk diffusion and agar well diffusion method. The methanol extracts were more active than the aqueous extracts for all 12 plants studied. The plant extracts were more active against Gram-positive bacteria than against Gram-negative bacteria. The most susceptible bacteria were B. subtilis, followed by S. epidermidis, while the most resistant bacteria were P. vulgaris, followed by S. typhimurium. From the screening experiment, Caesalpinia pulcherrima Swartz. showed the best antibacterial activity; hence this plant can be further subjected to isolation of the therapeutic antimicrobials and further pharmacological evaluation.
medicinal plants, antibacterial activity, aqueous extracts, methanol extracts
PAREKH, JIGNA; JADEJA, DARSHANA; and CHANDA, SUMITRA (2005) "Efficacy of Aqueous and Methanol Extracts of Some Medicinal Plants for Potential Antibacterial Activity," Turkish Journal of Biology: Vol. 29: No. 4, Article 3. Available at: https://journals.tubitak.gov.tr/biology/vol29/iss4/3