A Simple and Economic Limewater-based Conversion of Spirostanol Saponins: Using Paridis Rhizoma as a case study

Abstract

Background Green and economic conversion of spirostanol saponins in the plant is considered as an attracting area in pharmaceutical applications. We aimed to provide a practical paradigm named limewater-based conversion of spirostanol saponins (LCSS), meanwhile, a widely-used traditional Chinese herbal medicine, Paridis Rhizoma (PR), was selected as a case study. Methods Based on single factor experiments, response surface methodology (RSM) using a Box-Behnken design (BBD) was employed to optimize processing time, limewater concentration and solvent volume to obtain a maximum total saponins yield from PR. H1299, A549 and HeLa cell lines was carried out to check pharmacological effect of Crude Paridis Rhizoma (CPR) and Processed Paridis Rhizoma (PPR), and the technology was reconfirmed by another herbal medicine, Anemarrhenae Rhizoma (AR). Results The optimal conditions were: processing time of 24 h, limewater concentration of 0.12% limewater and solvent volume of 60 mL/30 g. Under these conditions, the contents of polyphyllin VII, polyphyllin II, dioscin, gracillin, and polyphyllin I had 1.131 ± 0.448, 1.835 ± 0.479, 1.430 ± 0.550, 1.761 ± 0.571 and 1.668 ± 0.360 times increasing in four batches of PR, which was responsible for the increasing of total spirostanol saponins (TSS) in PPR. In addition, the extracts of PPR exhibited stronger antitumor potential than that of CPR on H1299, A549 and HeLa cell lines based on MTT test and cell scratch test. The efficiency of proposed LCSS was then reconfirmed by Anemarrhenae Rhizome (AR), indicating its capacity in broader application. Conclusion This study depicted a LCSS strategy that may have great potential in achieving effective and economic improvement of spirostanol saponin accumulation in herbal medicines.