Multifaceted Study of Medicago marina Essential Oil: Chemical Composition, Antidiabetic, and Phytotoxic Insights via In Vitro and In Silico Approaches

The essential oil of Medicago marina was subjected to analysis at vegetative and reproductive stages of development, with a particular emphasis on its chemical composition, α-amylase inhibition, and allelopathic activities. The results of the gas chromatography and molecular docking studies demonstrated alterations in oil yield and composition throughout the developmental stages. Before blooming, hydrocarbons were the predominant compounds, while monoterpenes were abundant during the reproductive stage, with higher concentrations of eugenol (8.86%) and β-ionone (17.67%) compared to earlier stages. The α-amylase activity exhibited variation across the growth stages, with the highest enzyme inhibition (87.33 ± 0.001%) observed at 1.25 mg/mL during the reproductive stage. The essential oil demonstrated pronounced allelopathic effects, markedly reducing radish stem elongation (94.09 ± 0.62%) and root growth (95.71 ± 0.2%). Furthermore, molecular docking analysis confirmed that five principal oil components exhibited strong inhibitory activity against human pancreatic α-amylase and 4-hydroxyphenylpyruvate dioxygenase (HPPD). These findings underscore the potential of M. marina essential oil as a hypoglycemic and allelopathic agent, influencing seed germination and the growth of radish and lettuce.