Antioxidant Potential of Natural Extract of L. in Relation to Chorioallantoic Membrane (CAM) Vessels of Chicken Embryo.

The chicken chorioallantoic membrane (CAM) model is an embryonic blood capillary system considered a suitable "in vivo" model for studying the irritation effect of plant extracts on the vascular system, including impacts on hemostasis, hyperemia, hemorrhage, and coagulation. The main aim of the present work was to investigate the irritation effects of different concentrated alcohol extracts of L. (GBE) leaves on the blood vessels of the CAM model during early embryogenesis, evaluated using the Luepke scoring system. The antioxidant properties of GBE were assessed using DPPH radical scavenging and the FRAP method, alongside HPLC-DAD analysis to confirm the presence of major therapeutically relevant metabolites, revealing a strong therapeutic potential of the extract. On embryonic day 9, different concentrations of GBE as well as the controls (saline solution and 30% ethanol) were applied to the CAM surface. Vascular changes were observed immediately after application, with vasoconstriction leading to the temporary "disappearance" of blood vessels. At 30 s post-application, all GBE concentrations and ethanol induced hyperemia and mild hemorrhage, which gradually diminished over time. No changes were observed with saline application. The extent of morphometric changes in the vessels was also influenced by the concentration of GBE used. Concentrations of 20% and 30% GBE induced vasoconstriction. Lower concentrations of GBE induced vasodilation, with maximum values recorded after 240 s for 1% and 15% GBE. The results of this study may help to better characterize the vascular effects of natural under in vivo conditions and promote greater interest in the use of alternative animal models in pharmacological and biomedical research.