The antioxidant and antimicrobial activities of Melissa officinalis essential oil (MOEO) were investigated in order to evaluate its potential as a natural bioactive compound with practical applications. The antioxidant capacity of the essential oil was assessed using the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay, a widely used method for determining free radical neutralization ability. The results revealed a clear concentration -dependent effect, with higher concentrations of MOEO leading to a greater percentage of radical inhibition, indicating strong antioxidant potential. The antimicrobial activity of MOEO was evaluated using the broth microdilution method against several Gram-negative bacterial strains, including Escherichia coli, Salmonella typhimurium, and Haemophilus influenzae. The findings demonstrated of MOEO increased, a progressive reduction in microbial proliferation was observed. Minimum inhibitory concentrations (MIC) values were determined for each train, highlighting a relatively high sensitivity of the tested bacteria to the essential oil. The biological effects observed in this study are primarily attributed to the presence of bioactive constituents such as citral, citronelall, and other phenolic compounds. These molecules are known to disrupt bacterial cell membranes, interfere with cellular metabolism, and neutralize free radicals. Overall, the results support the potential use of Melissa officinalis essential oil as a natural antioxidant and antimicrobial agent, with promising applications in agriculture, food preservation, and alternative therapeutic strategies.

Melissa officinalis, antioxidant, antimicrobial activity, minimum inhibitory concentrations

agronomy

Presentation: poster