RESUMO
In order to study the analgesic effect of Shaoyao Gancao Decoction, this paper discussed material basis and mechanism from the perspective of macromolecules in traditional Chinese medicine. Inspired by the phenomenon of turbidity after boiling Chinese medicine, this experiment took Shaoyao Gancao Decoction as the research object to study the formation process of precipitation during boiling. The results showed that aggregates with a certain shape were formed in the solvent during the boiling process, and the precipitate was obtained by standing and centrifuging. Analysis found that the precipitation was mainly composed of small molecules such as paeoniflorin, albiflorin, liquiritin, glycyrrhizic acid, isoliquiritin and gallic acid, and macromolecules such as protein and polysaccharide. The composition of precipitate was consistent with that of Shaoyao Gancao Decoction, but the analgesic effect of Shaoyao Gancao Decoction after removing the precipitate was significantly reduced. Based on these results, we isolated small molecular compounds, polysaccharides and protein from Shaoyao Gancao Decoction and their contents are 60.4, 700.7 and 207.2 mg·g-1 respectively. We get the ratio, polysaccharide: small molecule = 11.6∶1, protein: small molecule = 3.4∶1, the precipitate is prepared in the state of boiling. The characterization results showed that the particle size of the precipitate will change significantly after co-heating, and the content determination results showed that the content of the six small molecular compounds which was free in solvent was significantly reduced after the formation of the precipitate. The acetic acid writhing experiment proved that the precipitate has a good analgesic effect, and effectively reduced the levels of inflammatory factors prostaglandin E2 and nitric oxide, and increased the level of anti-inflammatory factor interleukin-10. These results proved that the precipitate in Shaoyao Gancao Decoction is an important material basis for analgesic effect, and macromolecules such as protein and polysaccharide are the main components of the precipitate. The study of macromolecules in the precipitate of Shaoyao Gancao Decoction not only provides new ideas and methods for elucidating the pharmacodynamic material basis of Shaoyao Gancao Decoction, but also provides a reference for analyzing the scientificity of traditional decoction.