The Keap1‐Nrf2/ARE signaling pathway is an important defense system against exogenous and endogenous oxidative stress injury. The dysregulation of the signaling pathway is associated with many diseases, such as cancer, diabetes, and respiratory diseases. Over the years, a wide range of natural products has provided sufficient resources for the discovery of potential therapeutic drugs. Among them, polyphenols possess Nrf2 activation, not only inhibit the production of ROS, inhibit Keap1‐Nrf2 protein–protein interaction, but also degrade Keap1 and regulate the Nrf2 related pathway. In fact, with the continuous improvement of natural polyphenols separation and purification technology and further studies on the Keap1‐Nrf2 molecular mechanism, more and more natural polyphenols monomer components of Nrf2 activators have been gradually discovered. In this view, we summarize the research status of natural polyphenols that have been found with apparent Nrf2 activation and their action modes. On the whole, this review may guide the design of novel Keap1‐Nrf2 activator.

No abstract

Sirtuins family is a class of NDA+ dependent protein deacetylases that play a key role in the regulation of several aspects of biological processes, such as cell cycle regulation, autophagy, immune and inflammatory response. Many studies have shown that sirtuins2 as a key player in the cancer pathway is of great significance in tumorigenesis. This review summarizes the newly discovered, in recent years, some SIRT2 inhibitors for cancer target structure, action mechanism, biological activity, substrate specificity, and signaling pathways.

The IL-6R/JAK2/STAT3 pathway mediated by interleukin-6 (IL-6) plays an important role in the occurrence and development of multiple myeloma (MM), which is associated with decreased microRNA-451a. However, the biological function of microRNA-451a in MM remains unclear. The bone marrow (BM) of patients with MM was sampled, and the plasma cells were enriched. BM miR-451a, IL-6 and IL-6R levels and Ki-67 expression intensity were evaluated using reverse transcription-quantitative PCR, ELISA and flow cytometry, respectively. U266 cell proliferation, viability and apoptosis were measured using BrdU, CCK-8 and Annexin V/propidium iodide assays, respectively. Total and phospo-(p-)JAK2 and p-STAT3 levels were measured by western blotting. Dual-luciferase reporter assays were performed to validate the predicted target binding sites. miR-451a expression was low in patients with MM and was associated with the Revised International Staging System (R-ISS) stage. IL-6 concentrations were significantly higher in patients with MM than in normal controls and were inversely associated with miR-451a levels (r=−0.96, P<0.0001). IL-6R levels were positively correlated with the R-ISS stage. miR-451a was downregulated, and IL-6R was upregulated in myeloma cell lines. Treatment with an miR-451a mimic inhibited viability and induced apoptosis in U266 cells. p-JAK2 and p-STAT3 levels were significantly lower in mimic-treated U266 cells than in control cells. Thus, miR-451a was shown to regulate myeloma cell proliferation and apoptosis via the IL-6R/JAK2/STAT3 pathway and may be used to predict patient prognosis.