*The traditional Chinese medicine processing change chemical composition and pharmacological effectiveness: Taking Atractylodes macrocephala Koidz. and honey bran-fried Atractylodes macrocephala Koidz. as examples

Background Atractylodes macrocephala Koidz. (Baizhu in Chinese, BZ) is a typical traditional edible-medicinal herb used for thousands of years. Known as “the spleen-reinforcing medicine”, it is often used clinically to treat reduced digestive function, abdominal distension, and diarrhoea, which are all caused by spleen deficiency. Among BZ's processing products, honey bran-fried BZ (HBBZ) is the only processed product recorded in BZ in the 2020 Chinese Pharmacopoeia (ChP). There are differences in effectiveness, traditional application, and clinical indications between them. Purpose This review reviewed BZ and its main product HBBZ from botany, ethnopharmacology, chemical compositions and pharmacological effectiveness. The changes in chemical compositions and pharmacological effectiveness of BZ induced by the processing of traditional Chinese medicine were emphatically described. Methods Keywords related to Atractylodes macrocephala Koidz., honey bran frying, essential oil, lactones, polysaccharide and combinations to include published studies of BZ and HBBZ from 2004-2023 were searched in the following databases: Pubmed, Chengdu University of TCM Library, Google Scholar, China National Knowledge Infrastructure (CNKI), and Wanfang database. All studies, published in English or Chinese, were included. However, in the process of chemical composition collection, we reviewed all available literature on the chemical composition of BZ and HBBZ. Conclusion Honey bran frying processing methods will affect BZ's chemical composition and pharmacological effectiveness. The types and contents of chemical components in the HBBZ showed some changes compared with those in BZ. For example, the content of volatile oil decreased and the content of lactones increased after stir-fried bran. In addition, new ingredients such as phenylacetaldehyde, 2-acetyl pyrrole, 6- (1,1-dimethylethyl) -3,4-dihydro-1 (2H) -naphthalone and 5-hydroxymethylfurfural appeared. Both BZ and HBBZ have a variety of pharmacological effectiveness. After stir-fried with honey bran, the "Zao Xing" is reduced, and the efficacy of tonify spleen is strengthened, which is more suitable for patients with weak spleen and stomach.