title: Discovery of molecular mechanisms of traditional Chinese medicinal formula Si-Wu-Tang using gene expression microarray and connectivity map.
abstract: To pursue a systematic approach to discovery of mechanisms of action of traditional Chinese medicine (TCM), we used microarrays, bioinformatics and the "Connectivity Map" (CMAP) to examine TCM-induced changes in gene expression. We demonstrated that this approach can be used to elucidate new molecular targets using a model TCM herbal formula Si-Wu-Tang (SWT) which is widely used for women's health. The human breast cancer MCF-7 cells treated with 0.1 µM estradiol or 2.56 mg/ml of SWT showed dramatic gene expression changes, while no significant change was detected for ferulic acid, a known bioactive compound of SWT. Pathway analysis using differentially expressed genes related to the treatment effect identified that expression of genes in the nuclear factor erythroid 2-related factor 2 (Nrf2) cytoprotective pathway was most significantly affected by SWT, but not by estradiol or ferulic acid. The Nrf2-regulated genes HMOX1, GCLC, GCLM, SLC7A11 and NQO1 were upregulated by SWT in a dose-dependent manner, which was validated by real-time RT-PCR. Consistently, treatment with SWT and its four herbal ingredients resulted in an increased antioxidant response element (ARE)-luciferase reporter activity in MCF-7 and HEK293 cells. Furthermore, the gene expression profile of differentially expressed genes related to SWT treatment was used to compare with those of 1,309 compounds in the CMAP database. The CMAP profiles of estradiol-treated MCF-7 cells showed an excellent match with SWT treatment, consistent with SWT's widely claimed use for women's diseases and indicating a phytoestrogenic effect. The CMAP profiles of chemopreventive agents withaferin A and resveratrol also showed high similarity to the profiles of SWT. This study identified SWT as an Nrf2 activator and phytoestrogen, suggesting its use as a nontoxic chemopreventive agent, and demonstrated the feasibility of combining microarray gene expression profiling with CMAP mining to discover mechanisms of actions and to identify new health benefits of TCMs.
authors.affiliation: National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, United States of America.
authors.forename: Zhining
authors.initials: Z
authors.lastname: Wen
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Wang
authors.forename: Steven
authors.initials: S
authors.lastname: Wang
authors.forename: Ranadheer
authors.initials: R
authors.lastname: Ravula
authors.forename: Lun
authors.initials: L
authors.lastname: Yang
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Charles
authors.initials: C
authors.lastname: Wang
authors.forename: Zhong
authors.initials: Z
authors.lastname: Zuo
authors.forename: Moses S S
authors.initials: MS
authors.lastname: Chow
authors.forename: Leming
authors.initials: L
authors.lastname: Shi
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D045744:Cell Line, Tumor; D016000:Cluster Analysis; D030541:Databases, Genetic; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D057075:Enzyme Assays; D004958:Estradiol / Q000494:pharmacology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008516:Medicine, Chinese Traditional; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics; D012015:Reference Standards; D015203:Reproducibility of Results; D020218:Response Elements / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012984:Software
chemical_list: D000975:Antioxidants; D004365:Drugs, Chinese Herbal; D051267:NF-E2-Related Factor 2; C403258:si-wu-tang; D004958:Estradiol; D008156:Luciferases