Investigation of bioactive components of plantain herb (Plantago lanceolata) plant extracts obtained by advanced and traditional methods

In this study, extracts of Plantago lanceolata (sinirli ot) were prepared using both traditional and advanced extraction methods (microwave-assisted and ultrasonic-assisted). The bioactive constituents of these extracts were evaluated for their antioxidant activities by three distinct assays: DPPH radical-scavenging capacity, ferric-reducing antioxidant power (FRAP) and ABTS radical neutralization. Total phenolic content was quantified against a gallic acid standard expressed as (mg/g GAE) and total flavonoid content was measured using a quercetin standard (mg/g QE). Among the antioxidant assays, the laboratory-scale microwave extract exhibited the highest activity in both the DPPH and ABTS tests, whereas in the FRAP assay, the aqueous extract showed the greatest reducing power (2.02 ± 0.02 A mg/g FeSO₄). The microwave extract also contained the highest phenolic content (2.70 ± 0.13 A mg/g GAE), while the methanolic extract had the highest flavonoid content (13.01 ± 0.27 A mg/g QE). These results indicate that advanced extraction techniques yield extracts richer in bioactive compounds compared to traditional methods. In addition to antioxidant profiling, the antimicrobial activity of P. lanceolata extracts was tested against Bacillus cereus, Escherichia coli, Yersinia enterocolitica, Pseudomonas aeruginosa, Salmonella typhimurium, and Candida albicans using the disk-diffusion method. All extracts showed no activity against C. albicans. The strongest antibacterial effect was observed against P. aeruginosa (17.6 ± 0.01 mm) inhibition zone, while the weakest was against S. typhimurium (6.6 ± 0.01 mm). Keywords: Antimicrobial activity, Antioxidant activity, Bioactive compounds, Extraction methods, Plantago lanceolata