Optimizing the extraction of Sasa quelpaertensis Nakai to develop natural cosmetics with antioxidant and whitening activities

Optimization of the extraction procedure was performed to enhance the antioxidant activity and whitening effect of Sasa quelpaertensis Nakai extract using response surface methodology (RSM). The central composite design, a component of RSM, was utilized to optimize and validate the ethanol extract for antioxidant activity and the hot water extract for the whitening effect, respectively. Activities of antioxidant and whitening were determined by DPPH and tyrosinase inhibition assays. The antioxidant activity was notably influenced by ethanol concentration (p = 0.0344) more than other factors. The optimal conditions for the antioxidant effect were 54% ethanol concentration, 52 °C, and 3 h extraction time, yielding an antioxidant activity of 83.65±1.56%. On the other hand, the whitening effect was significantly impacted by ultrasonic irradiation time (p = 0.0175) compared to other factors. The optimal conditions for whitening were 41 °C, 1:19 of sample-to-solvent ratio, and 8 min of ultrasonic irradiation, achieving a tyrosinase inhibition activity of 51.00±1.80%. High-performance liquid chromatography (HPLC) analysis was conducted to identify compounds such as tricin with antioxidant activity and p-coumaric acid, arbutin with whitening effect under the optimized conditions. The results suggest that the optimized extracts from S. quelpaertensis could be utilized as beneficial cosmeceutical materials.