Antibacterial effects of celandine oil and extracts derived from roots and stalks of greater celandine (Chelidonium majus L.) collected from central Pomeranian region

A convincing number of studies indicating that alkaloids such as chelidonine and sanguinarine together with other secondary metabolites exhibit potent antibacterial, antifungal, and antiparasitic properties prompted us to examine the antimicrobial efficacy of Chelidonium majus L., a representative of the Papaveraceae family, against Staphylococcus aureus subsp. aureus Rosenbach (ATCC® 29213™) (mecA negative, Oxacillin sensitive, weak β-lactamase producing strain), S. aureus NCTC® 12493™ (mecA positive, Methicillin-resistant, EUCAST QC strain for cefoxitin), Escherichia coli (Migula) Castellani and Chalmers (ATCC® 25922™), E. coli (Migula) Castellani and Chalmers (ATCC® 35218™). In the current work, we decided to evaluate the antimicrobial efficacy of ethanolic extracts derived from stalks and roots of C. majus, as well as commercial 100% natural fatty celandine oil (Botanica, Russia) against different S. aureus and E. coli strains. Fresh stalks and roots were washed, weighed, crushed, and homogenized in 96% ethanol (in proportion of 1:19, w/w) at room temperature. The extracts were then filtered and investigated for their antimicrobial activity. Antimicrobial activity was determined using the agar disk diffusion assay. The extracts obtained from roots and stalks of C. majus and commercial natural fatty celandine oil exhibited different antibacterial activities against tested strains. The ethanolic extracts of C. majus revealed weak antibacterial activity against both E. coli (Migula) Castellani and Chalmers (ATCC® 25922™) and E. coli (Migula) Castellani and Chalmers (ATCC® 35218™) strains. The highest antibacterial activity was demonstrated for stalk extracts of C. majus against S. aureus NCTC® 12493™ compared to the control samples. We observed similar trends when measuring the zones of growth inhibition according to S. aureus subsp. aureus Rosenbach (ATCC® 29213™) strain. Since the antimicrobial efficacy of medicinal plants varies according to the accumulation of secondary metabolites (i.e., alkaloids, flavonoids, tannins, etc.), it is not surprising that differences in this efficacy have been noted even using samples taken from the same plant but different parts of the plant (stalks, roots). The antimicrobial activity of crude ethanolic extracts obtained from stalks and roots of greater celandine can be attributed to specific compounds or a combination of compounds. The current study lays the foundation for future research to confirm the potential use of C. majus as a candidate for the treatment of infections caused by S. aureus and E. coli in human and veterinary medicine.