Quantitative analyses of sennosides A and B in eight ethical bofutsushosan extract products

AimCurrently, no information regarding the sennosides A and B content is provided on bofutsushosan extract products for ethical use. In this study, sennosides A and B in bofutsushosan extract products from eight different pharmaceutical companies and those in bofutsushosan decoction were quantitatively analyzed. Additionally, since it has been reported that sennoside A is unstable to heat, the relationship between the different decoction times of Rhubarb and the total extracted amounts of sennosides A and B was investigated. Finally, nuclear magnetic resonance (NMR)-based metabolomics analysis was performed on Rhubarb extracts to evaluate the variability in the quality of Rhubarb.MethodsSolutions of bofutsushosan extract products, bofutsushosan decoction, and Rhubarb decoction were subjected to solid-phase extraction, and then were analyzed using HPLC. The five Rhubarb extracts prepared from five different lots were subjected to NMR-based metabolomics analysis.ResultsThe quantities of sennosides A and B varied among the bofutsushosan extract products, with a maximum interproduct variation of approximately five-fold. Sennosides A and B were not significantly unstable to heat up to 60 min. The five Rhubarb samples were classified into three independent clusters.ConclusionIt is recommended that the quantities of sennosides A and B in Kampo extract products, including Rhubarb, be described in the package insert. When preparing Rhubarb-containing Kampo medicines, sennosides A and B decomposition can be ignored for decoction times of up to 60 min. Further studies on the biological activity of secondary metabolites other than sennosides A and B are necessary for Rhubarb quality control.