Enhancement of bioactive compound extraction from Rhus chinensis leaves using the polyol-based ultrasound-assisted method: Antioxidant anti-melanogenesis, and pollution defense properties

This study investigates the optimization of polyol-based ultrasound-assisted extraction (UAE) for Rhus chinensis (RC) leaves to enhance the extraction of bioactive compounds with antioxidant, anti-melanogenesis, and pollution defense properties. Through a mixture design, the highest total phenolic content (TPC) was achieved using a solvent composed of 33.29 % butylene glycol, 33.39 % glycerin, and 33.31 % water. The effects of extraction time and solvent-to-material ratio on TPC, total tannin content (TTC), and antioxidant activities (DPPH, ABTS, FRAP) were evaluated using a central composite design (CCD). Optimal conditions were found to be 15 min of extraction time and a solvent-to-material ratio of 32.29:1, resulting in the highest recovery of bioactive compounds. The polyol-based UAE method outperformed traditional extraction techniques, yielding superior antioxidant activities and demonstrating strong potential for cosmeceutical applications. Analysis of the RC extract revealed several bioactive compounds, including myrsinone, verbasoside, 6-pentadecyl salicylic acid, and salicyl alcohol. The RC extract exhibited significant free radical scavenging, melanogenesis inhibition, and pollution defense properties, positioning it as a promising ingredient in skincare formulations aimed at combating oxidative stress while promoting skin lightening, and offering environmental protection. These results provide a scientific foundation for the development of natural, high-performance skincare products, showcasing the efficacy of polyol-based UAE as an advanced technique for extracting functional compounds from botanicals.