Abstract
Background: Interest in medicinal plants has recently risen as a consequence of its therapeutic capabilities, which require further investigation. Aristolochia longa (A. longa) roots are commonly employed in traditional Moroccan medicine as an anticancer agent and against some cutaneous infections, but little is known about their antibacterial capabilities.
Methods: The disc-diffusion and minimal inhibitory concentration (MIC) methods were carried out to determine the antibacterial activity of aqueous and methanol extracts of A. longa roots against several reference bacterial strains.
Results: Both aqueous and methanolic extracts had antibacterial activity to varying degrees with the disc-diffusion assay, however the methanolic extract shown significant activity at a higher dosage (200 mg/ml). Escherichia coli (22.0 mm) was the most sensitive bacterium tested, followed by Staphylococcus aureus (16.0 mm) and Bacillus subtilis (12.0 mm). The bacteria with the lowest susceptibility were Klebsiella pneumonia, Pseudomonas aeruginosa, and Micrococcus luteus, which all had a 10.0 mm zone of inhibition. The MIC values corroborated these observations, with E. coli MICs of 6.25 +/- 1.5 mg/ml, S. aureus MICs of 25 +/- 1.02 mg/ml, M. luteus MICs of 12.5 +/- 1.25 mg/ml, K. pneumonia MICs of 50.0 +/- 0.75 mg/ml, and B. subtilis MICs of 100 +/- 0.6 mg/ml, respectively. The findings of the methanolic extract were statistically significant and equivalent to those of the antibiotics studied.
Conclusion: Roots of A. longa have significant broad-spectrum antibacterial agents, notably in the methanolic extract, which validated their applications in Moroccan folkloric medicine to treat soft-tissue and skin infections.