Antimicrobial and Phytochemical Studies of Hydroethanolic Extracts of Plumbago zeylanica (L.), a Medicinal Plant Used against Microbial Infections and Intestinal Disorders

Antibiotic resistance remains a real public health problem. The search for new molecules to effectively combat this problem is becoming a necessity. The objective of this study was to evaluate the in vitro antimicrobial effect of hydroethanolic extracts of leaves and roots of Plumbago zeylanica and to highlight the phytochemical compounds present in these extracts. Reference strains (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213 and Pseudomonas aeruginosa ATCC 27853) and clinical isolates (Escherichia coli ESBL, Shigella spp, Klebsiella spp, Acinetobacter spp, Pseudomonas aeruginosa, Enterococcus spp, Staphylococcus aureus MRSA and Candida albicans) were used. The agar well diffusion and broth microdilution methods were used to evaluate the antimicrobial effect. The susceptibility of the strains varied, depending on the extract, with a best inhibitory effect of the hydroethanolic extract of P. zeylanica roots on S. aureus ATCC 29213, S. aureus MRSA, Shigella spp and C. albicans. The MICs obtained was between 0.63 and 5 mg/ml. The most effective antimicrobial potential was obtained with the roots extract and staphylococcal strains were the most sensitive to the tested extracts. The tested extracts contain compounds such as flavonoids, tannins, phenolic compounds, triterpenes and sterols, saponosides and cardenolipid glycosides. These results support the use of P. zeylanica for the treatment of microbial diseases and contribute to the search for new bioactive molecules.