Optimization of Extraction Conditions for Antioxidant Activity of Acer tegmentosum Using Response Surface Methodology

Extraction from edible plants is a highly important process that has various biological functions. To maximize biological activity, extraction methods should facilitate optimal extraction of functional phytochemicals. In this study, the optimal hydrothermal extraction conditions of Acer tegmentosum were determined using response surface methodology (RSM), and HepG2 cells were treated with optimized extract and hydrogen peroxide. In a central composition design, the independent variables were extraction temperature (X1: 70–90 °C), extraction time (X2: 2–6 h), and solvent-to-solid ratio (X3: 50–150). The maximum total phenolic contents (276.70 ± 10.11 mg GAE/g) and DPPH (2,2-diphenyl-1-pictylhydrazyl) activity (33.45 ± 2.20%) of A. tegmentosum were estimated at optimized extraction conditions, as follows: X1: 89.34 °C, X2: 7.36 h, X3: 184.09. Using the calculated extraction conditions, functional phytochemicals were extracted by hydrothermal extraction and freeze-dried. A. tegmentosum treatment (>10 μg/mL) of HepG2 cells remarkably attenuated hydrogen-peroxide-inducible hepatic cellular death and reactive oxygen species production in vitro.