Keap1 as Target of Genistein on Nrf2 Signaling Pathway Antagonizing Aβ induced Oxidative Damage of Cerebrovascular Endothelial Cells

Ebselen alleviates white matter lesions and improves cognitive deficits by attenuating oxidative stress via Keap1/Nrf2 pathway in chronic cerebral hypoperfusion mice

Oxidative stress is crucial in cerebral white matter lesions (WMLs) induced by chronic cerebral hypoperfusion. Therefore, ameliorating oxidative damage is considered to be a beneficial strategy for the treatment of WMLs. Ebselen (EbSe), a small lipid organoselenium compound, its lipid peroxidation activity is mediated through the glutathione peroxidase-mimetic properties. This study aimed to investigate the role of EbSe in WMLs after bilateral common carotid artery stenosis (BCAS). The BCAS model can moderately reduce cerebral blood flow, and mimics white matter damage caused by chronic cerebral hypoperfusion or small vessel disease. Laser Speckle Contrast Imaging (LSCI) was used to monitor the cerebral blood flow of mice. The spatial learning and memory were tested by using the eight-arm maze. LFB staining was used to detect demyelination. The expression of MBP, GFAP and Iba1 was assayed by immunofluorescence. The demyelination was assessed by Transmission Electron Microscope (TEM). The activities of MDA, SOD and GSH-Px were detected by assay kits. The mRNA levels of SOD, GSH-Px and HO-1 was detected by realtime PCR. The activation of the Nrf2/ARE pathway and the expression of SOD, GSH-Px and HO-1was assessed by Western blot. EbSe ameliorated cognitive deficits and white matter lesions induced by bilateral common carotid artery stenosis (BCAS). The expression of GFAP and Iba1 was decreased in the corpus callosum of BCAS mice after EbSe treatment. Moreover, EbSe alleviated the level of MDA by elevating the expression and mRNA of SOD, GSH-Px and HO-1 in BCAS mice. Furthermore, EbSe promoted the dissociation of the Keap1/Nrf2 complex, resulting in the accumulation of Nrf2 in the nucleus. This study demonstrates a favorable effect of EbSe on cognitive impairment in a chronic cerebral hypoperfusion model, and the improvement of EbSe's antioxidant property is mediated by Keap1/Nrf2 pathway.

The protective activity of genistein against bone and cartilage diseases

Genistein, a natural isoflavone rich in soybean and leguminous plants, has been shown various biological effects, such as anti-inflammation, anti-oxidation, anti-cancer, and bone/cartilage protection. Due to the structural similarity to estrogen, genistein exhibits estrogen-like activity in protecting against osteoporosis and osteoarthritis. Furthermore, genistein has been considered as an inhibitor of tyrosine kinase, which has been found to be dysregulated in the pathological development of osteoporosis, osteoarthritis, and intervertebral disc degeneration (IDD). Many signaling pathways, such as MAPK, NF-κB, and NRF2/HO-1, are involved in the regulatory activity of genistein in protecting against bone and cartilage diseases. The potential molecular mechanisms of genistein in therapeutic management of bone and cartilage diseases have been investigated, but remain to be fully understood. In this article, we mainly discuss the current knowledge of genistein in protecting against bone and cartilage diseases, such as osteoporosis, osteoarthritis, rheumatoid arthritis (RA), and IDD.