S‐Allyl cysteine,S‐ethyl cysteine and S‐propyl cysteine alleviate oxidative stress‐induced damage within PC12 cells

BACKGROUND: The PC12 cell line is a suitable model for the investigation of neurodegenerative diseases. In this study, PC12 cells were used to examine in vitro antioxidative and antiapoptotic protection by S‐allyl cysteine (SAC), S‐ethyl cysteine (SEC) and S‐propyl cysteine (SPC). PC12 cells were treated with these agents at 5 and 10 µmol L^?1 before exposure to hydrogen peroxide (H₂O₂). RESULTS: H₂O₂ treatment significantly decreased mitochondrial membrane potential (MMP) and cell viability and increased lactate dehydrogenase (LDH) release and DNA fragmentation (P < 0.05). The pre‐treatments with SAC, SEC and SPC significantly and concentration‐dependently elevated cell viability and MMP and lowered LDH release and DNA fragmentation (P < 0.05). H₂O₂ treatment also significantly increased levels of malondialdehyde (MDA), reactive oxygen species (ROS) and oxidised glutathione (GSSG) and decreased glutathione (GSH) content (P < 0.05). The pre‐treatments with SAC, SEC and SPC significantly decreased subsequent H₂O₂‐induced formation of MDA, ROS and GSSG (P < 0.05) and also alleviated H₂O₂‐induced GSH depletion (P < 0.05). Finally, H₂O₂ treatment significantly decreased Na⁺‐K⁺‐ATPase activity and elevated caspase‐3 activity (P < 0.05). The pre‐treatments with SAC, SEC and SPC significantly attenuated H₂O₂‐induced Na⁺‐K⁺‐ATPase activity reduction and caspase‐3 activity elevation (P < 0.05). CONCLUSION: The results obtained support that the three cysteine‐containing compounds studied are potent neuroprotective agents. Copyright © 2008 Society of Chemical Industry     

Antiinflammatory and antifibrogenic effects of s-ethyl cysteine and s-methyl cysteine in the kidney of diabetic mice

Protective effects of s-ethyl cysteine (SEC) and s-methyl cysteine (SMC) in kidney of diabetic mice were examined. SEC and SMC at 0.5, 1, 1.5, 2 g/L were added to the drinking water for 6 wk. Results showed that the intake of SEC or SMC alleviated body weight loss and urine output, as well as markedly decreased plasma blood urea nitrogen (BUN) and creatinine clearance (CCr) in diabetic mice (P < 0.05). The intake of SEC caused significantly dose-dependent increase in insulin and decrease in blood glucose, urinary albumin and type IV collagen (P < 0.05). SEC and SMC intake significantly and dose-dependently decreased malondialdehyde level and increased glutathione content in kidney (P < 0.05). The intake of these agents also increased renal GPx activity (P < 0.05), but there was no dose-dependent effect. SEC treatments dose-dependently decreased IL-6 and TNF-alpha levels, increased IL-4 and IL-10 levels, as well as upregulated IL-10 mRNA expression (P < 0.05). SMC treatments significantly suppressed renal IL-6 and TNF-alpha levels (P < 0.05), but did not affect IL-4 and IL-10 levels (P < 0.05). SEC or SMC intake significantly suppressed renal TGF-beta1 level and renal PKC activity (P < 0.05); however, only SEC treatments showed dose-dependent effect. SEC and SMC treatments significantly down-regulated mRNA expression of renal TGF-beta1 (P < 0.05), only SEC treatments had dose-dependent effects. Based on the observed antioxidative, antiinflammatory, and antifibrogenic effects, the supplement of SEC or SMC might be helpful for the prevention or treatment of diabetic kidney diseases.     

Antioxidative and Anti-Inflammatory Neuroprotective Effects of Astaxanthin and Canthaxanthin in Nerve Growth Factor Differentiated PC12 Cells

ABSTRACT: Nerve growth factor differentiated PC12 cells were used to examine the antioxidative and anti‐inflammatory effects of astaxanthin (AX) and canthaxanthin (CX). PC12 cells were pretreated with AX or CX at 10 or 20 μM, and followed by exposure of hydrogen peroxide (H₂O₂) or 1‐methyl‐4‐phenylpyridinium ion (MPP⁺) to induce cell injury. H₂O₂ or MPP⁺ treatment significantly decreased cell viability, increased lactate dehydrogenase (LDH) release, enhanced DNA fragmentation, and lowered mitochondrial membrane potential (MMP) (P < 0.05). The pretreatments from AX or CX concentration‐dependently alleviated H₂O₂ or MPP⁺‐induced cell death, LDH release, DNA fragmentation, and MMP reduction (P < 0.05). Either H₂O₂ or MPP⁺ treatment significantly increased malonyldialdehyde (MDA) and reactive oxygen species (ROS) formations, decreased glutathione content, and lowered glutathione peroxidase (GPX) and catalase activities (P < 0.05). The pretreatments from AX or CX significantly retained GPX and catalase activities, and decreased MDA and ROS formations (P < 0.05). H₂O₂ or MPP⁺ treatment significantly decreased Na⁺‐K⁺‐ATPase activity, elevated caspase‐3 activity and levels of interleukin (IL)‐1, IL‐6, and tumor necrosis factor (TNF)‐α (P < 0.05); and the pretreatments from these agents significantly restored Na⁺‐K⁺‐ATPase activity, suppressed caspase‐3 activity and release of IL‐1, IL‐6, and TNF‐α (P < 0.05). Based on the observed antioxidative and anti‐inflammatory protection from AX and CX, these 2 compounds were potent agents against neurodegenerative disorder.     

Dietary Trans Fats Enhance Doxorubicin‐Induced Cardiotoxicity in Mice

This study investigated the combined effects of trans fat diet (TFD) and doxorubicin upon cardiac oxidative, inflammatory, and coagulatory stress. TFD increased trans fatty acid deposit in heart (P < 0.05), and decreased protein C and antithrombin‐III activities in circulation (P < 0.05). TFD plus doxorubicin treatment elevated activities of plasminogen activator inhibitor‐1, lactate dehydrogenase, and creatine phosphokinase (P < 0.05). This combination also raised xanthine oxidase activity, and enhanced cardiac levels of reactive oxygen species, interleukin (IL)‐6, IL‐10, tumor necrosis factor‐alpha, and monocyte chemoattractant protein‐1 than TFD or doxorubicin treatment alone (P < 0.05). TFD alone increased cardiac nuclear factor kappa B (NF‐κB) activity (P < 0.05), but failed to affect expression of NF‐κB and mitogen‐activated protein kinase (MAPK) (P > 0.05). Doxorubicin treatment alone augmented cardiac activity, mRNA expression, and protein production of NF‐κB and MAPK (P < 0.05). TFD plus doxorubicin treatment further upregulated cardiac expression of NF‐κB p65, p‐p38, and p‐ERK1/2 (P < 0.05). These findings suggest that TFD exacerbates doxorubicin‐induced cardiotoxicity.     

Suppressive effects of extracts from the aerial part of Coriandrum sativum L. on LPS‐induced inflammatory responses in murine RAW 264.7 macrophages

BACKGROUND: Coriandrum sativum is used not only as a spice to aid flavour and taste values in food, but also as a folk medicine in many countries. Since little is known about the anti‐inflammatory ability of the aerial parts (stem and leaf) of C. sativum, the present study investigated the effect of aerial parts of C. sativum on lipopolysaccharide (LPS)‐stimulated RAW 264.7 macrophages. We further explored the molecular mechanism underlying these pharmacological properties of C. sativum. RESULTS: Ethanolic extracts from both stem and leaf of C. sativum (CSEE) significantly decreased LPS‐induced nitric oxide and prostaglandin E₂ production as well as inducible nitric oxide synthase, cyclooxygenase‐2, and pro‐interleukin‐1β expression. Moreover, LPS‐induced IκB‐α phosphorylation and nuclear p65 protein expression as well as nuclear factor‐κB (NF‐κB) nuclear protein–DNA binding affinity and reporter gene activity were dramatically inhibited by aerial parts of CSEE. Exogenous addition of CSEE stem and leaf significantly reduced LPS‐induced expression of phosphorylated mitogen‐activated protein kinases (MAPKs). CONCLUSION: Our data demonstrated that aerial parts of CSEE have a strong anti‐inflammatory property which inhibits pro‐inflammatory mediator expression by suppressing NF‐κB activation and MAPK signal transduction pathway in LPS‐induced macrophages. Copyright © 2010 Society of Chemical Industry     

Polygonum viviparum L. inhibits the lipopolysaccharide‐induced inflammatory response in RAW264.7 macrophages through haem oxygenase‐1 induction and activation of the Nrf2 pathway

BACKGROUND: Polygonum viviparum L. (PV) is a member of the family Polygonaceae and is widely distributed in high‐elevation areas. It is used as a folk remedy to treat inflammation‐related diseases. This study was focused on the anti‐inflammatory response of PV against lipopolysaccharide (LPS)‐induced inflammation in RAW264.7 macrophages. RESULTS: Treatment with PV did not cause cytotoxicity at 0–50 µg mL^?1 in RAW264.7 macrophages, and the IC₅₀ value was 270 µg mL^?1. PV inhibited LPS‐stimulated nitric oxide (NO), prostaglandin (PG)E₂, interleukin (IL)‐1β and tumour necrosis factor (TNF)‐α release and inducible NO synthase (iNOS) and cyclooxygenase (COX)‐2 protein expression. In addition, PV suppressed the LPS‐induced p65 expression of nuclear factor (NF)‐κB, which is associated with the inhibition of IκB‐α degradation. These results suggest that, among mechanisms of the anti‐inflammatory response, PV inhibits the production of NO and these cytokines by down‐regulating iNOS and COX‐2 gene expression. Furthermore, PV can induce haem oxygenase (HO)‐1 protein expression through nuclear factor E2‐related factor 2 (Nrf2) activation. A specific inhibitor of HO‐1, zinc(II) protoporphyrin IX, inhibited the suppression of iNOS and COX‐2 expression by PV. CONCLUSION: These results suggest that PV possesses anti‐inflammatory actions in macrophages and works through a novel mechanism involving Nrf2 actions and HO‐1. Thus PV could be considered for application as a potential therapeutic approach for inflammation‐associated disorders. © 2012 Society of Chemical Industry     

Riboflavin at High Doses Enhances Lung Cancer Cell Proliferation,Invasion, and Migration

The influence of riboflavin (vitamin B₂) upon growth, invasion, and migration in non‐small cell lung cancer cell lines was evaluated. Riboflavin at 1, 10, 25, 50, 100, 200, or 400 μmol/L was added into A549, H3255, or Calu‐6 cells. The effects of this compound upon level and/or expression of reactive oxygen species (ROS), inflammatory cytokines, intercellular adhesion molecule (ICAM)‐1, fibronectin, matrix metalloproteinase (MMP)‐9, MMP‐2, focal adhesion kinase (FAK), nuclear factor kappa B (NF‐κB), and mitogen‐activated protein kinase (MAPK) were examined. Results showed that riboflavin at test doses did not affect the level of ROS and glutathione. Riboflavin at 200 and 400 μmol/L significantly enhanced cell growth in test lung cancer cell lines, and at 400 μmol/L significantly increased the release of interleukin‐6, tumor necrosis factor‐alpha, and vascular endothelial growth factor. This agent at 200 and 400 μmol/L also upregulated protein production of ICAM‐1, fibronectin, MMP‐9, MMP‐2, NF‐κB p50, p‐p38 MAPK, and FAK; and at 400 μmol/L enhanced invasion and migration in test cell lines. These findings suggested that riboflavin at high doses might promote lung cancer progression.     

Lactobacillus plantarum AR501 Alleviates the Oxidative Stress of D‐Galactose‐Induced Aging Mice Liver by Upregulation of Nrf2‐Mediated Antioxidant Enzyme Expression

Lactic acid bacteria (LAB) have been used as ingredients of functional foods to promote health and prevent diseases because of their beneficial effects. This study aimed to investigate the antioxidative effects of LAB on the hepatotoxicity in D‐galactose‐induced aging mice. LAB were isolated from the traditional Chinese fermented foods and screened by the tolerance of hydrogen peroxide (H₂O₂). Male ICR (Institute of Cancer Research) mice were subcutaneously injected with D‐galactose for 5 weeks and then gastric gavage with LAB for 6 weeks. The results showed that Lactobacillus plantarum AR113 and AR501, and Pediococcu pentosaceus AR243 could tolerate up to 1.5 mM H₂O₂ in vitro, and they could live through simulated gastrointestinal tract (GIT) to colonizing the GIT of host. In vivo, oral administration of L. plantarum AR113 and AR501 improved the antioxidant status of D‐galactose‐induced oxidative stress mice such as alleviated liver damages and reduced abnormal activities of superoxide dismutase, glutathione peroxidase, and catalase to normal levels. In addition, L. plantarum AR501 markedly elevated the gene expression of nuclear factor erythroid‐2‐related factor 2 and upregulated the expressions of several antioxidant genes such as glutathione reductase, glutathione S‐transferase, glutamate‐cysteine ligase catalytic subunit, glutamate‐cysteine ligase modifier subunit, and NAD(P)H quinone oxidoreductase 1 in the liver of an aging mice. Therefore, L. plantarum AR501 could be a good candidate for producing antiaging functional foods.     

Aqueous and Ethanol Extracts of Daylily Flower (Hemerocallis fulva L.) Protect HUVE Cells Against High Glucose

The content of several phenolic acids and flavonoids in aqueous extract (AE) and ethanol extract (EE) of daylily flower (Hemerocallis fulva L.) was analyzed. The effects of AE or EE at 0.5%, 1%, or 2% in HUVE cells against high glucose‐induced cell death, oxidative, and inflammatory damage were examined. Results showed that seven phenolic acids and seven flavonoids could be detected in AE or EE, in the range of 29 to 205 and 41 to 273 mg/100 g, respectively. Compared with the control groups, high glucose raised the activity of caspase‐3 and caspase‐8; suppressed Bcl‐2 mRNA expression and increased Bax mRNA expression; and induced HUVE cells apoptosis. The pretreatments from AE or EE at 1% or 2% reduced caspase‐3 activity and Bax mRNA expression, and enhanced cell viability. High glucose decreased glutathione content; stimulated the production of reactive oxygen species, interleukin‐6, tumor necrosis factor‐alpha, and prostaglandin E₂; raised the activity of cyclooxygenase‐2 and nuclear factor kappa B p50/65 binding; and reduced the activity of glutathione peroxidase, glutathione reductase, and catalase in HUVE cells. AE pretreatments at 1% and 2% reversed these changes. These novel findings suggested that daylily flower was rich in phytochemicals, and could be viewed as a potent functional food against diabetes.     

Salvianolic Acid B Inhibits High‐Fat Diet‐Induced Inflammation by Activating the Nrf2 Pathway

Salvianolic acid B (Sal B) is a major water‐soluble bioactive component of Salvia miltiorrhiza, which is a traditional Chinese medicine. We investigated the ways in which Sal B affects high‐fat diet (HFD)‐induced immunological function disorder remission using a C57BL/6 mouse model. We gave groups of C57BL/6 mice a normal diet (Control), a normal diet supplemented with Sal B (Control + Sal B), a high‐fat diet (HF), and a high‐fat diet supplemented with Sal B (HF + Sal B) for 10 wk. Sal B supplementation decreased the body weight and plasma lipids, increased the fecal excretion of lipids, prevented the accumulation of chronic oxidative stress, and reversed the disproportionality of CD3⁺CD4⁺ and CD3⁺CD8⁺ T lymphocytes compared to HFD. We found an increase in IL‐6 and TNF‐α, while IL‐10 decreased in plasma after the HFD and Sal B reversed the deregulation of the Thl/Th2 ratio. In addition, HFD‐induced inflammation was stopped by Sal B through the downregulation of nuclear factor‐κB (NF‐κB), cyclooxygenase‐2 (COX‐2), and inducible NO synthesis (iNOS), and the upregulation of nuclear factor‐erythroid 2‐related factor 2 (Nrf2)‐regulated genes. These findings demonstrated that Sal B could effectively attenuate inflammation by activating the Nrf2‐mediated antioxidant defense system.     

Anti‐Diabetic Effects of Gynura Bicolor Aqueous Extract in Mice

The effects of Gynura bicolor aqueous extract (GAE) upon glycemic control, coagulation disorder, lipid accumulation, and glycative, oxidative, and inflammatory stresses in diabetic mice were investigated. Mice were treated with streptozotocin to induce type 1 diabetes. Diabetic mice were divided into four groups, consumed GAE at 0%, 0.25%, 0.5%, or 1%. Normal group consumed standard mouse basal diet. After 8‐week treatments, mice were sacrificed after overnight fasting. Results showed that GAE supplement at 0.5% and 1% decreased plasma glucose level and increased plasma insulin level. Diabetes lowered plasma level of protein C and anti‐thrombin III; and raised plasminogen activator inhibitor‐1 activity and fibrinogen level in plasma. GAE supplement at 0.5% and 1% reversed these alterations. Histological data, assayed by Oil Red O stain, indicated that GAE supplement decreased lipid accumulation in liver. GAE supplement at 0.5% and 1% reduced aldose reductase activity in heart and kidney; and lowered the levels of carboxymethyllysine and pentosidine in plasma and two organs. Diabetes decreased glutathione content, and increased reactive oxygen species, interleukin (IL)‐1β, IL‐6, and tumor necrosis factor‐α production in heart and kidney. GAE supplement at three test doses reversed these changes. Diabetes upregulated the mRNA expression of p38 and nuclear factor kappa (NF‐κ)B in heart and kidney. GAE supplement suppressed the mRNA expression of both p38 and NF‐κB. These novel findings suggest that Gynura bicolor is a potent functional food for diabetic prevention or alleviation.     

Sesamin attenuates intercellular cell adhesion molecule‐1 expression in vitro in TNF‐α‐treated human aortic endothelial cells and in vivo in apolipoprotein‐E‐deficient mice

Sesame lignans have antioxidative and anti‐inflammatory properties. We focused on the effects of the lignans sesamin and sesamol on the expression of endothelial‐leukocyte adhesion molecules in tumor necrosis factor‐α (TNF‐α)‐treated human aortic endothelial cells (HAECs). When HAECs were pretreated with sesamin (10 or 100 μM), the TNF‐α‐induced expression of intercellular cell adhesion molecule‐1 (ICAM‐1) was significantly reduced (35 or 70% decrease, respectively) by Western blotting. Sesamol was less effective at inhibiting ICAM‐1 expression (30% decrease at 100 μM). Sesamin and sesamol reduced the marked TNF‐α‐induced increase in human antigen R (HuR) translocation and the interaction between HuR and the 3'UTR of ICAM‐1 mRNA. Both significantly reduced the binding of monocytes to TNF‐α‐stimulated HAECs. Sesamin significantly attenuated TNF‐α‐induced ICAM‐1 expression and cell adhesion by downregulation of extracellular signal‐regulated kinase 1/2 and p38. Furthermore, in vivo, sesamin attenuated intimal thickening and ICAM‐1 expression seen in aortas of apolipoprotein‐E‐deficient mice. Taken together, these data suggest that sesamin inhibits TNF‐α‐induced extracellular signal‐regulated kinase/p38 phosphorylation, nuclear translocation of NF‐κB p65, cytoplasmic translocalization of HuR and thereby suppresses ICAM‐1 expression, resulting in reduced adhesion of leukocytes. These results also suggest that sesamin may prevent the development of atherosclerosis and inflammatory responses.     

Red mold dioscorea‐induced G2/M arrest and apoptosis in human oral cancer cells

BACKGROUND: Monascus‐fermented products are among the most commonly used traditional food supplements. Dioscorea is known to exhibit anticancer properties. In this study the effects of the ethanol extract of red mold dioscorea (RMDE) on cell proliferation, cell cycle and apoptosis in human oral cancer cells were investigated. RESULTS: RMDE exercised growth inhibition on squamous cell carcinoma‐25 (SCC‐25) cells. RMDE‐mediated G2/M phase arrest was associated with the down‐regulation of NF‐κB, resulting in the inhibition of cyclin B1 and CDK1 expression; this may be the mechanism by which RMDE inhibits cancer cells. Furthermore, the proapoptotic activity of RMDE was revealed by the Annexin V‐FITC/PI double‐staining assay. In addition, the proapoptotic effect of RMDE was evident by the inhibition of Bax expression in the mitochondria, resulting in the activation of caspase‐9 and caspase‐3 and subsequent triggering of the mitochondrial apoptotic pathway. RMDE also enhanced caspase‐8 activity, indicating the involvement of the death receptor pathway in RMDE‐mediated SCC‐25 cell apoptosis. CONCLUSION: RMDE treatment inhibited the growth of SCC‐25 cells by arresting cell cycle at the G2/M phase and induced apoptosis in a time‐ and dose‐dependent manner. Therefore RMDE may be a good candidate for development as a dietary supplement against oral cancer. Copyright © 2010 Society of Chemical Industry