Research on "Erchen" in Erchen decoction

Traditional Chinese Medicine has a long history of aging medicines,with the Erchen decoction(it is a traditional Chinese botanical formula),produced by Chenpi(Citri Reticulatae Pericarpium)(CRP)and Banxia(Pinelliae Rhizoma)(PR),as having the most research value.While modern pharmacological studies have found that the main active components of CRP are flavonoids and volatile oils.The relative contents of 30 CRP flavonoids increase with aging time.However,the expectorant effect of CRP is not proportional to its aging time,and its volatile oil composition is thought to be negatively correlated with its aging time,yet this correlation has not yet been established by research.In addition,different experimental measurement methods have found that aging has a reduced effect on the toxic components of different processing types of PR,such as calcium oxalate needle crystals and protein substances.These research also noted that different processing methods also resulted in differences in the efficacy of PR.For example,during the aging process of Jiangbanxia(Pinelliae Rhizoma Praeparatumcum Zingibere Et Alumine)and auxiliary materials,6-gingerol was produced,which enhanced the anti-vomiting effects of PR but weakened its expectorant and cough function.Using a method of Alum processed PR,increases the contents of Inosine,Guanosine,Adenosine and Succinate,which thus enhances its expectorant effect.Finally,the contents of 6-Gingerol,Glycyrrhizin,Ammonium Glycyrrhizate,and other substances produced in the aging process of PR,can be used as base compounds for producing additional products of PR.The research on the efficacy and uses of Erchen decoction,particularly compounds made with CRP and PR is voluminous,but no standards currently exist for effective and standardized application of these substances.This paper reviews the research with an aim to establish standardization of methods and of compound aging time.