[Optimization of extraction process of Children's Qingfei Zhisou Syrup based on pharmacodynamics]

This study determined the extraction rates of indirubin in Indigo Naturalis by ethanol reflux extraction method and water extraction method. The pharmacodynamic study against cough induced by ammonia water in the mouse model and the cough induced by citric acid in the guinea pig model were performed to optimize the extraction process of the sovereign medicinal Indigo Naturalis and the whole prescription of Children's Qingfei Zhisou Syrup. The extraction rate of indirubin by the ethanol reflux method was 51.89%, and indirubin was not detected in the product of water extraction. Two samples of Children's Qingfei Zhisou Syrup prepared with different methods can prolong the incubation period of cough and suppress the frequency of coughs in pharmacodynamic experiments. In terms of prolonging the incubation period of cough, the two samples prepared with different methods had no significant difference. In terms of reducing the frequency of coughs, the high-dose Five kinds of ethanol extracts such as indigo naturalis and three kinds of water extracts such as gypsum had better effect against the citric acid-induced cough of guinea pigs than other samples(P<0.05). The extraction rate of indirubin in Children's Qingfei Zhisou Syrup sample prepared with ethanol was higher than that with water. The two samples of Children's Qingfei Zhisou Syrup prepared with the two methods showed good antitussive effects. The sample prepared with 5 ingredients(including Indigo Naturalis) extracted with ethanol and 3 ingredients(including Gypsum Fibrosum) extracted with water had better alleviation effect on the citric acid-induced cough of guinea pig than the whole water extract sample. In conclusion, the optimum extraction scheme is ethanol extraction for 5 ingredients including Indigo Naturalis in combination with water extraction for 3 ingredients including Gypsum Fibrosum, and the Children's Qingfei Zhisou Syrup produced in this manner has better antitussive efficacy.