Glutathione Supplementation Prevents Neonatal Parenteral Nutrition-Induced Short- and Long-Term Epigenetic and Transcriptional Disruptions of Hepatic H2O2 Metabolism in Guinea Pigs.

The parenteral nutrition (PN) received by premature newborns is contaminated with peroxides that induce global DNA hypermethylation via oxidative stress. Exposure to peroxides could be an important factor in the induction of chronic diseases such as those observed in adults who were born preterm. As endogenous H2O2 is a major regulator of glucose-lipid metabolism, our hypothesis was that early exposure to PN induces permanent epigenetic changes in H2O2 metabolism. Three-day-old guinea pigs were fed orally (ON), PN or glutathione-enriched PN (PN+GSSG). GSSG promotes endogenous peroxide detoxification. After 4 days, half the animals were sacrificed, and the other half were fed ON until 16 weeks of age. The liver was harvested. DNA methylation and mRNA levels were determined for the SOD2, GPx1, GCLC, GSase, Nrf2 and Keap1 genes. PN induced GPx1 hypermethylation and decreased GPx1, GCLC and GSase mRNA. These findings were not observed in PN+GSSG. PN+GSSG induced Nrf2 hypomethylation and increased Nrf2 and SOD2 mRNA. These observations were independent of age. In conclusion, in neonatal guinea pigs, PN induces epigenetic changes, affecting the expression of H2O2 metabolism genes. These changes persist for at least 15 weeks after PN. This disruption may signify a permanent reduction in the capacity to detoxify peroxides.

Clinical efficacies, underlying mechanisms and molecular targets of Chinese medicines for diabetic nephropathy treatment and management.

Diabetic nephropathy (DN) has been recognized as a severe complication of diabetes mellitus and a dominant pathogeny of end-stage kidney disease, which causes serious health problems and great financial burden to human society worldwide. Conventional strategies, such as renin-angiotensin-aldosterone system blockade, blood glucose level control, and bodyweight reduction, may not achieve satisfactory outcomes in many clinical practices for DN management. Notably, due to the multi-target function, Chinese medicine possesses promising clinical benefits as primary or alternative therapies for DN treatment. Increasing studies have emphasized identifying bioactive compounds and molecular mechanisms of reno-protective effects of Chinese medicines. Signaling pathways involved in glucose/lipid metabolism regulation, antioxidation, anti-inflammation, anti-fibrosis, and podocyte protection have been identified as crucial mechanisms of action. Herein, we summarize the clinical efficacies of Chinese medicines and their bioactive components in treating and managing DN after reviewing the results demonstrated in clinical trials, systematic reviews, and meta-analyses, with a thorough discussion on the relative underlying mechanisms and molecular targets reported in animal and cellular experiments. We aim to provide comprehensive insights into the protective effects of Chinese medicines against DN.

Antitumor effects of Andrographis via ferroptosis-associated genes in gastric cancer.

The overall prognosis of advanced/metastatic gastric cancer (GC) remains poor despite the development of pharmacotherapy. Therefore, other treatment options, such as complementary and alternative medicine, should be considered to overcome this aggressive malignancy. Andrographis, which is a generally unharmful botanical compound, has gained increasing interest for its anticancer effects in multiple malignancies via the regulation of cancer progression-associated signaling pathways. In the present study, a series of in vitro experiments (cell proliferation, colony formation and apoptosis assays) was designed to elucidate the antitumor potential and mechanism of Andrographis in GC cells. The present study demonstrated that Andrographis exerted antitumor effects in GC cell lines (MKN74 and NUGC4) by inhibiting proliferation, reducing colony formation and enhancing apoptotic activity. Furthermore, it was demonstrated that the expression levels of the ferroptosis-associated genes heme oxygenase-1, glutamate-cysteine ligase catalytic and glutamate-cysteine ligase modifier were significantly upregulated after Andrographis treatment in both GC cell lines in reverse transcription-quantitative PCR experiments (P<0.05); this finding was further confirmed by immunoblotting assays (P<0.05). In conclusion, to the best of our knowledge, the present study was the first to demonstrate that Andrographis possessed antitumor properties by altering the expression levels of ferroptosis-associated genes, thereby providing novel insights into the potential of Andrographis as an adjunctive treatment option for patients with metastatic GC.

Crocin attenuates cigarette smoke-induced lung injury and cardiac dysfunction by anti-oxidative effects: the role of Nrf2 antioxidant system in preventing oxidative stress.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) has been emerging as a great health problem in world. Cigarette smoke is known to cause oxidative stress and deplete glutathione (GSH) levels. Nuclear erythroid-related factor 2 (Nrf2) is involved in transcriptional regulation of glutamate-cysteine ligase catalytic subunit (GCLc). Antioxidant compounds may be of therapeutic value in monitoring disease progression. Crocin demonstrates antioxidant and anti-inflammatory functions. The aim of this study was to investigate the protective role of crocin against CSE-mediated oxidative stress, inflammatory process, Nrf2 modifications and impairment of cardiac function in rats with COPD. METHODS: Eighty rats were divided into four groups: Control, Cigarette smoke exposure (CSE), Crocin, Crocin+CS. Each group was divided into the two parts: 1) to evaluate lung inflammatory and oxidative process, 2) to evaluate the effect of Cigarette smoke induced-lung injuries on cardiac electrocardiogram (such as heart rate and QRS complex) and hemodynamic parameters (such as perfusion pressure and left ventricular developed pressure). RESULTS: CSE rats showed a significant increase in cotinine concentration (17.24 ng/ml), and inflammatory parameters and a decrease in PO2 (75.87 mmHg) and expression of PKC (0.86 fold), PI3K (0.79 fold), MAPK (0.87 fold), Nrf2 (0.8 fold) and GCLc (0.75 fold) genes, antioxidant activity, and finally cardiac abnormalities in electrocardiogram and hemodynamic parameters. Co-treatment whit crocin could restore all these values to normal levels. CONCLUSIONS: CS induced-COPD in rat model provides evidence that chronic CS exposure leads to lung injury and mediated cardiac dysfunction. Crocin co-treatment by modulating of Nrf2 pathway protected lung injury caused by COPD and its related cardiac dysfunction. In this study, we showed the importance of Nrf2 activators as a therapeutic target for the development of novel therapy for lung oxidative injuries.

Antrodia salmonea inhibits TNF-α-induced angiogenesis and atherogenesis in human endothelial cells through the down-regulation of NF-κB and up-regulation of Nrf2 signaling pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Antrodia salmonea (AS) is known as a traditional Chinese medicine, but very few biological activities have been reported. MATERIALS AND METHODS: The present study was aimed to investigate the anti-angiogenic and anti-atherosclerotic potential of the fermented culture broth of AS against tumor necrosis factor-α (TNF-α)-stimulated human endothelial (EA.hy 926) cells. RESULTS: The non-cytotoxic concentrations of AS significantly inhibited TNF-α-induced migration/invasion and capillary-like tube formation in EA.hy 926 cells. Furthermore, AS suppressed TNF-α-induced activity and expression of matrix metalloproteinase-9 (MMP-9), and cell-surface expression of intercellular adhesion molecule-1 (ICAM-1), which was associated with abridged adhesion of U937 leukocytes to endothelial cells. Moreover, AS significantly down-regulated TNF-α-induced nuclear translocation and transcriptional activation of nuclear factor κB (NF-κB) followed by suppression of I-κB degradation and phosphorylation of I-κB kinase-α (IKKα). Notably, the protective effect of AS was directly correlated with the increased expression of hemeoxygenase-1 (HO-1) and γ-glutamylcysteine synthetase (γ-GCLC), which was reasoned by nuclear translocation and transactivation of NF-E2 related factor-2 (Nrf2)/antioxidant response element (ARE). Furthermore, HO-1 knockdown by HO-1-specific shRNA diminished the protective effects of AS on TNF-α-stimulated invasion, tube formation, and U937 adhesion in EA.hy 926 cells. CONCLUSIONS: Taken together, these results suggest that Antrodia salmonea may be useful for the prevention of angiogenesis and atherosclerosis.

Vitamin D upregulates glutamate cysteine ligase and glutathione reductase, and GSH formation, and decreases ROS and MCP-1 and IL-8 secretion in high-glucose exposed U937 monocytes.

INTRODUCTION: Glutathione is a major endogenous antioxidant and its deficiency is implicated in the etiology and progression of a number of human diseases. Vitamin D is important for the prevention of osteoporosis, cardiovascular disease, diabetes, autoimmune diseases, and some cancers. Using a monocyte cell model, this study examined the hypothesis that vitamin D upregulate glutamate cysteine ligase (GCLC) and glutathione reductase (GR), which catalyzes GSH biosynthesis. METHODS: U937 monocytes were pretreated with and without 1,25 (OH)2 vitamin D (10-25 nM) for 24 h and then exposed to control and high glucose (HG, 25 mM) for 4h. Levels of GSH determined using HPLC; GR activity by oxidation of NADPH; GCLC protein, MCP-1 and IL-8 using ELISA kits. RESULTS: 1,25 (OH)2 vitamin D supplementation significantly upregulated expression of GCLC and GR, levels of GCLC protein and GR activity, and formation of GSH in control and HG-treated monocytes. 1,25 (OH)2 vitamin D caused significantly (p<0.05) lower secretion of IL-8 and MCP-1, and lower ROS levels in monocytes exposed to control and HG-treated monocytes. CONCLUSIONS: This study demonstrates a positive link between vitamin D and GSH levels, and that some beneficial effects of vitamin D supplementation may be mediated by an improvement in the cellular GSH levels and a decrease in ROS and pro-inflammatory cytokines.

Willow bark extract increases antioxidant enzymes and reduces oxidative stress through activation of Nrf2 in vascular endothelial cells and Caenorhabditis elegans.

Willow bark extract (WBE) is listed in the European Pharmacopoeia and has been traditionally used for treating fever, pain, and inflammation. Recent studies have demonstrated its clinical usefulness. This study investigated the antioxidative effects of WBE in human umbilical vein endothelial cells (HUVECs) and Caenorhabditis elegans. WBE prevented oxidative-stress-induced cytotoxicity of HUVECs and death of C. elegans. WBE dose-dependently increased mRNA and protein expression levels of the nuclear factor erythroid 2-related factor 2 (Nrf2) target genes heme oxygenase-1, γ-glutamylcysteine ligase modifier and catalytic subunits, and p62 and intracellular glutathione (GSH) in HUVECs. In the nematode C. elegans, WBE increased the expression of the gcs-1::green fluorescent protein reporter, a well-characterized target of the Nrf2 ortholog SKN-1, in a manner that was SKN-1-dependent. WBE increased intranuclear expression and DNA binding of Nrf2 and the activity of an antioxidant response element (ARE) reporter plasmid in HUVECs. WBE-induced expression of Nrf2-regulated genes and increased GSH levels in HUVECs were reduced by Nrf2 and p38 small interfering (si) RNAs and by the p38-specific inhibitor SB203580. Nrf2 siRNA reduced the cytoprotective effect of WBE against oxidative stress in HUVECs. Salicin, a major anti-inflammatory ingredient of WBE, failed to activate ARE-luciferase activity, whereas a salicin-free WBE fraction showed intensive activity. WBE induced antioxidant enzymes and prevented oxidative stress through activation of Nrf2 independent of salicin, providing a new potential explanation for the clinical usefulness of WBE.