Unveiling Cytotoxic Bioactive Compounds from Erica carnea L.: Extraction Optimization, Kinetic Modeling, and Biological Activity Assessment.

The effects of temperature, time, and solvent concentration on the yield of bioactive compounds (BCs) with cytotoxic activity against three cell lines (Hep2c, RD, and L2OB) from Erica carnea L., as well as their influence on kinetic and thermodynamic parameters (enthalpy, entropy, and free energy), were investigated. The extract obtained at 30% ethanol, 50 °C, and 80 min showed the highest cytotoxic activity with IC50 values of 14.29, 13.93, and 22.23 µg/mL, respectively. The kinetics of BC extraction with cytotoxic activity was better described by the unsteady-state diffusion model compared to the Ponomarev model. The activation energy obtained was in the range of Ea = (4.92-26.57) kJ/mol. The thermodynamic parameters under transition theory at 50 °C were ∆S* = (-220.22)-(-285.15) J/Kmol, ∆H* = (2.24-23.88) kJ/mol, and ∆G* = (94.34-96.30) kJ/mol, indicating that the extraction of BCs with cytotoxic activity against the three cell lines is an irreversible and endothermic process. In addition to cytotoxic activity, the extracts demonstrated strong antioxidant activity (e.g., DPPH IC50 = 16.55 µg/mL) and antibacterial activity against multiple bacterial strains. Five antioxidant assays were applied, along with tests against eight bacterial strains for antibacterial activity. These findings suggest that Erica carnea L. is a promising natural source of multifunctional bioactive compounds with therapeutic potential.