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 <i>Erica carnea</i> 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 <i>Ea</i> = (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 <i>Erica carnea</i> L. is a promising natural source of multifunctional bioactive compounds with therapeutic potential.