In recent years, medicinal and aromatic herbs, which contain variety of antimicrobial compounds and have no risk to human health in terms of antibiotic resistance, are increasingly used as alternatives to antibiotics. In the study, chemical composition, total phenolic content, antioxidant and antimicrobial activity of essential oil and extract of Mentha x piperita L. growing wild in Eskisehir were investigated. Carvone (55.8%), limonene (12.8%), 1.8-cineole (8.7%) and trans-dihydrocarvone (6.4%) were determined as the main constituents of the essential oil, while the major components of the extract were carvone (56.4%), 1.8-cineole (14.1%) and trans-dihydrocarvone (8.4%). The total phenolic contents of essential oil (2204.33 µg GAE/g) were significantly higher than of extract (744 µg GAE/g). The essential oil and the extract were inhibited 84.08% and 42.59% by the DPPH radical, 91.87% and 48.40% by the ABTS radical, respectively. The highest inhibition zone was observed against S. aureus (23 mm). However, minimum inhibition concentration (MIC) values of the essential oil were ranged between 2.5% and 10% (v/v), while MIC values of the extract were determined as 10% and >10% (v/v). The present study demonstrated that M. piperita could be used in pharmaceutical and food applications as a natural antioxidant and antimicrobial substance.

This study aimed to evaluate the impact of varying doses of Zeatin, Kinetin, and Gibberellic Acid biostimulants on the growth and biochemical parameters of Mentha piperita L. Conducted in a greenhouse with three replications using a "Completely Randomized Experimental Design" design, the experiment assessed seedling and root lengths, fresh and dry weights of seedlings and roots, total phenolic content, and antioxidant activity (CUPRAC and FRAP). The results revealed that biostimulant applications significantly increased all growth and biochemical parameters compared to the control. Gibberellic acid at 200 mg/l produced the longest seedlings, while Kinetin at 50 mg/l resulted in the longest roots. The highest antioxidant activity (FRAP) and total phenolic content were observed with the 40 mg/l dose of Zeatin.