Oxidative stress and mitochondrial dysfunction are associated with disease and aging. Oxidative stress results from overproduction of reactive oxygen species (ROS), often leading to peroxidation of membrane phospholipids and production of reactive aldehydes, particularly 4-hydroxy-2-nonenal. Mild uncoupling of oxidative phosphorylation protects by decreasing mitochondrial ROS production. We find that hydroxynonenal and structurally related compounds (such as trans-retinoic acid, trans-retinal and other 2-alkenals) specifically induce uncoupling of mitochondria through the uncoupling proteins UCP1, UCP2 and UCP3 and the adenine nucleotide translocase (ANT). Hydroxynonenal-induced uncoupling was inhibited by potent inhibitors of ANT (carboxyatractylate and bongkrekate) and UCP (GDP). The GDP-sensitive proton conductance induced by hydroxynonenal correlated with tissue expression of UCPs, appeared in yeast mitochondria expressing UCP1 and was absent in skeletal muscle mitochondria from UCP3 knockout mice. The carboxyatractylate-sensitive hydroxynonenal stimulation correlated with ANT content in mitochondria from Drosophila melanogaster expressing different amounts of ANT. Our findings indicate that hydroxynonenal is not merely toxic, but may be a biological signal to induce uncoupling through UCPs and ANT and thus decrease mitochondrial ROS production.

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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 upreguated 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.

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Summary Purpose:  Monotherapy approvals have been difficult to obtain from the U.S. Food and Drug Administration (FDA), and have almost all been achieved using a trial design entitled “withdrawal to monotherapy” in treatment‐resistant patients, which employs a so‐called “pseudo‐placebo” as a comparator arm. The authors submitted a white paper to the FDA advocating use of a virtual placebo historical control as an alternative to pseudo‐placebo. Such an approach reduces patient risk that would result from exposure to pseudo‐placebo. In this article, we present the data submitted to the FDA to justify a historical control. Methods:  We analyzed individual patient data from eight previously completed withdrawal to monotherapy studies, which we determined had similar design. All studies employed percent meeting predetermined exit criteria (denoting worsening of seizure control) as the outcome measure. Kaplan‐Meier estimates of the percent exiting were calculated at 112 days. Results:  The percent meeting exit criteria were uniformly high, ranging from 74.9–95.9%. The eight studies appear to meet the criteria set forth for use of historical control. The estimate of the combined percent exit based on the noniterative mixed‐effects model is 85.1%, with a lower bound of the 95% prediction interval of 65.3%, and 72.2% for an 80% prediction interval. Conclusion:  There is justification for proposing that these data can serve as a historical control for future monotherapy studies, obviating the need for a placebo/pseudo‐placebo arm in trials intended to demonstrate the efficacy of approved drugs as monotherapy in treatment‐resistant patients.