Orthogonal array design for optimizing extraction efficiency of active constituents from Jakyak-Gamcho Decoction, the complex formula of herbal medicines, Paeoniae Radix and Glycyrrhizae Radix.

A complex formula composed of Paeonia lactiflora PALL. and Glycyrrhiza uralensis Fisch., which is called as Jakyak-Gamcho Decoction (JGD), has been used for a pain-relieving function and muscle spasms due to blood deficiency in the traditional medicine. In this study, the anti-inflammatory activity of JGD was evaluated based on the quantitative determinations and the relative proportions of six major constituents in the decoction mixture extracted by orthogonal array methods. Our results suggest that the three parameters are all crucial factors. The optimized conditions for extraction were therefore established [solvent (water); pH value (4); extraction number (4)]. We also optimized the extraction conditions related to anti-inflammatory activity [solvent (70% EtOH); pH value (6); extraction number (4)]. So, we found that the bioactivity was responsible for mixed components but not individual one. It was proportionally associated with the amounts of some components in the extracts of herbal medicines. When the proportion of the active components was similar to each other, they had the similar functions. Furthermore, the results could establish a model system for the quality assurance of herbal preparations, and provided a new paradigm of active components-pharmacodynamics, which is used for illustrating the connections between the bioactivities and the proportion of active constituents in the extracts of herbal medicines.