Determination of antibacterial properties of some plant extracts

Throughout history, humans have used plants in the treatment of diseases. Herbal remedies have come to the forefront due to microorganisms developing resistance to synthetic drugs and the resulting failures in treatment. Plant extracts and phytochemicals are of great importance in therapeutic applications because of their antimicrobial properties. The antimicrobial activities of plants are attributed to their secondary metabolites. Studies on the antimicrobial activity of plant extracts and plant-derived products have shown that plants can be an important source in the search for new antibiotics. In this study, the leaves of Galium aparine L. (cleavers), Cichorium endivia L. (endive), and Rumex acetosella L. (red sorrel) were dried and powdered, then extracted using a Soxhlet apparatus with five different solvents: chloroform, ethyl acetate, acetone, ethanol, and methanol. The antibacterial effects of the obtained extracts were determined against 11 standard bacterial strains (Staphylococcus aureus ATCC 6538, Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 3166 09:K35:K99, Escherichia coli ATCC 25922, Escherichia coli ATCC 25923, Escherichia coli ATCC 29988, Bacillus cereus ATCC 11778, Streptococcus salivarius RSHE 606, Pseudomonas aeruginosa ATCC 29853, Pseudomonas aeruginosa ATCC 15442, Proteus mirabilis ATCC 43071) using the microdilution method. C. endivia showed the highest antibacterial activity against P. aeruginosa ATCC 15442 with ethanol and ethyl acetate extracts (2 mg/ml). None of the C. endivia extracts exhibited antibacterial activity against S. aureus ATCC 6538 at the concentrations tested. R. acetosella showed the highest antibacterial activity with its ethyl acetate extract against B. cereus ATCC 11778 (0.5 mg/ml). The chloroform extract of R. acetosella did not show any bacteria at the concentrations we studied except P. aeruginosa ATCC 15442 (32 mg/ml). G. aparine showed its highest antibacterial activity against P. aeruginosa ATCC 15442 with the methanol extract (4 mg/ml). Among the studied plant extracts, the strongest antibacterial effect was observed in the ethyl acetate extract of R. acetosella against B. cereus ATCC 11778. The control antibiotic chloramphenicol exhibited higher antibacterial activity against all tested bacteria compared to the plant extracts. The results obtained from this study may contribute to future research in this field. Keywords: Antibacterial, extract, Cichorium endivia, Galium aparine, mikrodilüsyon, Rumex acetosella.