Activity

New flavonoid glycoside, kaempferol 3-O-α-[(6-P-coumaroyl galactopyranosyl-O-β-(→4)-O-α-rhamnopyranosyl-(1→4)]-O-α-rhamnopyranoside 1, in addition to five known flavonoid glycosides (2-6) kaempferol 3-O-[α-rhamnopyranosyl-(1→4)-O-α-rhamnopyranosyl-(1→6)-O]-β-galactopyranoside (kaempferol 3-O-β-isorhamninoside) 2, quercetin 3-O-[(2,3,4-triacetyl-α-rhamnopyranosyl)-(1 → 6)-β-galactopyranoside 3, quercetin 3-O-[(2,4-diacetyl-α-rhamnopyranosyl)-(1 → 6)]-3,4-diacetyl-β-galactopyranoside 4, quercetin 3-O-[(2,4-diacetyl-α-rhamnopyranosyl)-(1→6)]-2,4-diacetyl-β-galactopyranoside 5, quercetin 3-O-[(2,3,4-triacetyl-α-rhamnopyranosyl)-(1 → 6)-3-acetyl-β-galactopyranoside 6 were isolated from bell pepper (Capsicum annum L.) fruits and tested for both anti-inflammatory activity through cytokine production (TNF-α and IL-1β) and antioxidant activity through scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Compounds 1-3 significantly suppressed production of TNF-α / IL-1β in cultured THP-1 cells previously co-stimulated by LPS in a dose-dependent manner (10.2/49.1, 28.1/55.7, and 35.2/57.5 μM respectively) whereas compounds 4-6 have relatively weaker inhibitory activity. (45.3/73.5, 48.2/65.6, and 42.2/67.4 μM respectively). selleck chemicals All compounds 1-6 showed no cytotoxic activity against the growth of THP-1where the percentage of cell viability was (127.4, 108.5, 105.4, 103.9, 103.4, and 104.2 μM respectively). All isolated compounds exhibited higher radical scavenging activity than ascorbic acid in (DPPH) assay. These results indicated that bell pepper fruits could be an effective candidate for ameliorating inflammatory-associated complications.Chronic obstructive pulmonary disease (COPD) is estimated to be the sixth major cause of disability, and the third main cause of death in the world by 2020. Although both inflammation and oxidative stress are well known to be the key predisposing factors in the pathogenesis of COPD, other elements, including metabolism, may also contribute to the exacerbation of the disease. However, the therapeutic approach which alters metabolism against COPD has yet been fully developed. Therefore, here we provide a novel therapeutic strategy for COPD patients. We first screened out the known nuclear factor erythroid-2-related factor 2 (Nrf2) activators, CPUY192018, which inhibits glycolysis, boosts antioxidative stress simultaneously and delivers satisfying therapeutic effect in macrophages from COPD patients and cigarette smoke extract induced COPD mice. Furthermore, we clarify that CPUY192018 not only disrupts the interaction between Kelch-like ECH-associated protein 1 (Keap1) and Nrf2, which liberates Nrf2 to activate the antioxidative pathway but also disrupt the interaction between Keap1 and actin which downregulates glycolysis, boosting the phagocytic function of alveolar macrophage in lung tissue. Taken together, CPUY192018 demonstrates notable effects on counteracting oxidative stress and reprogramming metabolism via Nrf2 activation; hence, being a raising potential therapeutic approach against COPD.Methicillin-resistant Staphylococcus aureus (MRSA) is the leading cause of bacterial pneumonia, featured with exuberant inflammatory cytokine production, extensive oxidative stress and tissue injury. The Keap1/Nrf2 system is the major apparatus essential for host defense against oxidative and electrophilic stresses of both exogenous and endogenous origins, representing a logical target for host-directed strategy to treat severe inflammatory diseases including MRSA-induced pneumonia. In an effort to search therapeutics for bacterial pneumonia, we identify rosmarinic acid (RA) as a covalent modifier of Keap1 and hence an activator of Nrf2. Specifically, RA forms a covalent bond with the cysteine 151 of Keap1 in BTB domain, and blocks its association with Nrf2 for proteasome-mediated degradation. Consequently, RA treatment caused the increased Nrf2 nuclear translocation to initiate antioxidant and mitochondrial biogenic programs, as well as macrophage bactericidal activity through inducing autophagic pathway, which eventually led to expedited bacterial eradication, inflammation resolution, and disease recovery. Collectively, our findings establish RA as a specific inducer of Nrf2 and show its potential to prevent MRSA pneumonia.The reduction of insulin resistance or improvement of insulin sensitivity is the most effective treatment for type 2 diabetes (T2D). We previously reported that Nogo-B receptor (NGBR), encoded by the NUS1 gene, is required for attenuating hepatic lipogenesis by blocking nuclear translocation of liver X receptor alpha, suggesting its important role in regulating hepatic lipid metabolism. Herein, we demonstrate that NGBR expression was decreased in liver of obesity-associated T2D patients and db/db mice. NGBR knockout in mouse hepatocytes resulted in increased blood glucose, insulin resistance and beta-cell loss. High-fat diet (HFD)/streptozotocin (STZ)-treated mice presented the T2D phenotype by showing increased non-esterified fatty acid (NEFA) and triglyceride (TG) in liver and plasma, and increased insulin resistance and beta-cell loss. AAV-mediated NGBR overexpression in the liver reduced NEFA and TG in liver and circulation, and improved liver functions. Consequently, HFD/STZ-treated mice with hepatic NGBR overexpression had increased insulin sensitivity and reduced beta-cell loss. Mechanistically, NGBR overexpression restored insulin signaling of AMPKα1-dependent phosphorylation of AKT and GSK3β. NGBR overexpression also reduced expression of endoplasmic reticulum stress-associated genes in liver and skeletal muscle to improve insulin sensitivity. Together, our results reveal that NGBR is required to ameliorate T2D in mice, providing new insight into the role of hepatic NGBR in insulin sensitivity and T2D treatment.In murine and bovine photoreceptors, guanylate cyclase activating-protein 2 (GCAP2) activates retinal guanylate cyclases (GC) at low Ca2+ levels, thus contributing to the Ca2+/cGMP negative feedback on the cyclase together with its paralog GCAP1, which has the same function but different Ca2+ sensitivity. In humans, a GCAP2 missense mutation (G157R) has been associated with inherited-retinal degeneration (IRD) via an unknown molecular mechanism. Here, we characterized the biochemical properties of human GCAP2 and the G157R variant, focusing on its dimerization and the Ca2+/Mg2+-binding processes in the presence or absence of N-terminal myristoylation. We found that human GCAP2 and its bovine/murine orthologs significantly differ in terms of oligomeric properties, cation binding, and GC regulation. Myristoylated GCAP2 endothermically binds up to three Mg2+ ions with high affinity and forms a compact dimer that may reversibly dissociate in the presence of Ca2+. Conversely, non-myristoylated GCAP2 does not bind Mg2+ over the physiological range, and remains as a monomer in the absence of Ca2+.