Optimization of Extraction Process of Total Saponins from Rubus crataegifolius Bunge. Root by Response Surface Methodology and Its Antioxidant Activity

In this study, the extraction process of total saponins from Rubus crataegifolius Bunge. roots was investigated and optimized by response surface method. The effects of ethanol concentration, extraction time and solid-liquid ratio on the extraction rate of total saponins from pallets were investigated. The results showed that the optimal extraction conditions of the total saponins from the pallets were: extraction time 2 h, ethanol concentration 71%, liquid-solid ratio 28:1 mL/g, the predicted value was 3.49%. Under these conditions, the extraction rate of total saponins from R. crataegiolius Bunge. roots was 3.366%. The IC₅₀ (mg/mL) values of total saponins extract from R. crataegifolius Bunge. roots against DPPH·, ABTS⁺· and superoxide anion free radicals were 0.0782, 0.277 and 0.9954 mg/mL, respectively. Therefore, the response surface method to optimize the extraction process of total saponins from R. crataegifolius Bunge. roots was effective, reliable, stable and feasible, and this article would provide scientific basis for the development and utilization of total saponins from pallets as natural antioxidants.