Protective role of lycopene against salinity-induced oxidative stress in Medicago sativa L. seedlings

Soil salinization is one of the major challenges to agriculture, reducing productivity and directly affecting plant growth, germination, and physiology, especially in economically important crops such as Medicago sativa. Conventional soil management methods are not always sufficient to mitigate the adverse effects of salinity, highlighting the need for alternative and sustainable strategies. This study evaluated the phytoprotective potential of lycopene (LCP) against NaCl-induced stress in M. sativa. Seeds were treated with 256 µg/mL and 512 µg/mL of LCP combined with 50 mM NaCl and compared to a control group containing NaCl only. The combination of 256 µg/mL LCP with NaCl significantly increased germination, root and leaf growth, and reduced oxidative stress markers such as TBARS and iron content level, demonstrating a protective antioxidant effect. In contrast, the combination with 512 µg/mL LCP showed a lower protective effect, indicating that higher concentrations may induce additional oxidative stress. In silico molecular analysis revealed LCP affinity with the target protein (–5.062 kcal/mol), involving hydrogen bonds and hydrophobic interactions, suggesting stability and functional effects on the protein. The results demonstrate that LCP exerts a dose-dependent phytoprotective effect, especially when associated with NaCl, promoting resistance to salt stress and improving morphological and biochemical parameters in M. sativa. These findings indicate the potential of LCP as a promising natural compound to mitigate the adverse effects of salinity in agriculture.