Lower Barthel Index Is Associated with Higher Risk of Hospitalization-Requiring Pneumonia in Long-Term Care Facilities.

Pneumonia is an important infectious entity that affects residents in long-term care facilities (LTCFs), whereas hospitalization-requiring pneumonia (HRP) represents a more critical patient condition with worse outcomes. The evidence addressing the association between Barthel index and risk of HRP among LTCF residents is lacking. A multicenter, retrospective cohort study was conducted in three LTCFs enrolling adult patients who resided for 3 months or more and ever underwent Barthel index evaluation within a study period of January 1 to December 31, 2010. The endpoint was HRP after enrollment. A total of 299 patients (169 women; age, 79.0 ± 12.2 years) were enrolled and categorized into HRP Group (n = 68; 36 women; age, 79.1 ± 11.3 years) and Non-HRP Group (n = 231; 133 women; age, 79.0 ± 12.4 years) by the endpoint. The patients in HRP Group had significantly lower Barthel index (8.6 versus 25.8 points, p < 0.001) but higher proportion of chronic obstructive pulmonary disease (13.2% versus 3.9%, p = 0.004). By the multivariate analysis of logistic regression, we found that lower Barthel index (odds ratio (OR), 0.967; p < 0.001), existence of chronic obstructive pulmonary disease (OR, 4.192; p = 0.015), and feeding route (percutaneous endoscopic gastrostomy comparing with oral feeding; OR, 0.177; p = 0.012) were independently associated with HRP. In conclusion, a lower Barthel index is significantly associated with the occurrence of pneumonia that requires hospitalization in long-term care residents. Barthel index is a useful and reliable tool for risk evaluation in this population.

Arsenic trioxide induces unfolded protein response in vascular endothelial cells.

Chronic arsenic exposure has been linked to endothelial dysfunction and apoptosis. We investigate the involvement of unfolded protein response (UPR) signaling in the arsenic-mediated cytotoxicity of the SVEC4-10 mouse endothelial cells. The SVEC4-10 cells underwent apoptosis in response to As2O3 dose- and time-dependently, accompanied by increased accumulation of calcium, and activation of caspase-3. These phenomena were completely inhibited by α-lipoic acid (LA), which did not scavenge ROS over-production, but were only partially or not ameliorated by tiron, a potent superoxide scavenger. Moreover, arsenic activated UPR, leading to phosphorylation of eukaryotic translation initiation factor 2 subunit α (eIF2α), induction of ATF4, and processing of ATF6. Treatment with arsenic also triggered the expression of endoplasmic reticulum (ER) stress markers, GRP78 (glucose-regulated protein), and CHOP (C/EBP homologous protein). The activation of eIF2α, ATF4 and ATF6 and expression of GRP78 and CHOP are repressed by both LA and tiron, indicating arsenic-induced UPR is mediated through ROS-dependent and ROS-independent pathways. Arsenic also induced ER stress-inducible genes, BAX, PUMA (p53 upregulated modulator of apoptosis), TRB3 (tribbles-related protein 3), and SNAT2 (sodium-dependent neutral amino acid transporter 2). Consistent with intracellular calcium and cell viability data, ROS may not be important in arsenic-induced death, because tiron did not affect the expression of these pro-apoptotic genes. In addition, pretreatment with salubrinal, a selective inhibitor of eIF2α dephosphorylation, enhanced arsenic-induced GRP78 and CHOP expression and partially prevented arsenic cytotoxicity in SVEC4-10 cells. Taken together, these results suggest that arsenic-induced endothelial cytotoxicity is associated with ER stress, which is mediated by ROS-dependent and ROS-independent signaling.

Arsenic modulates heme oxygenase-1, interleukin-6, and vascular endothelial growth factor expression in endothelial cells: roles of ROS, NF-κB, and MAPK pathways.

Chronic arsenic exposure has been linked to an increased risk of vascular diseases. To clarify the molecular mechanisms through which arsenic causes injuries to blood vessels, we analyzed the effects of arsenic trioxide on the cytotoxicity, intracellular reactive oxygen species (ROS), the expression of related genes, and signaling pathways involved in the SVEC4-10 mouse endothelial cells. Arsenic dose-dependently caused SVEC4-10 cell death, which is completely inhibited by α-lipoic acid (LA), a thioreductant, but partially ameliorated by Tiron, a potent superoxide scavenger. The mRNA levels of heme oxygenase-1 (HO-1), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and vascular endothelial growth factor (VEGF) were significantly increased by arsenic. The up-regulation of these can be blocked by LA instead of Tiron, suggesting ROS is not important in their increase. HO-1 competitive inhibitor zinc protoporphyrin improved the cytotoxicity of arsenic in an inverted-U dose-response curve, indicating the biphasic hormetic effect of HO-1. HO-1 siRNA decreased VEGF expression in response to arsenic. Arsenic exposure also enhanced NF-E2-related factor 2 (Nrf2) expression and increased activation of nuclear factor-κB (NF-κB). NF-κB inhibitor Bay 11-7082 reduced arsenic-mediated expression of HO-1 and IL-6. Selective blocking of the MAPK pathways with p38 inhibitor SB203580 significantly decreased arsenic-induced HO-1 and VEGF expression, while JNKs inhibitor SP600125 increased IL-6 expression. These results suggest that in arsenic-treated SVEC4-10 cells, HO-1 expression is mediated through Nrf2-, NF-κB-, and p38 MAPK-dependent signaling pathways and serves as an upstream regulator of VEGF. IL-6 expression is regulated by NF-κB and JNKs. In conclusion, oxidative stress may be associated with arsenic-induced cytotoxicity and endothelial gene up-regulation, but signaling transduction dominates the direct effects of ROS.

Magnetic-bead-based microfluidic system for ribonucleic acid extraction and reverse transcription processes.

This paper presents a new integrated microfluidic chip that automatically performs ribonucleic acid (RNA) extraction and reverse transcription (RT) processes. The microfluidic system consists of a microfluidic control module and a magnetic bio-separator. The microfluidic control module can perform pumping and mixing of small amount of fluids and subsequent purification and concentration of RNA samples by incorporating with the magnetic bio-separator consisting of 2-dimension twisted microcoils. Notably, the magnetic bio-separators are developed either to generate the required magnetic field to perform the separation of magnetic beads or to work as a micro-heater to control the temperature field for the following RT process. Experimental results show that the total RNA can be successfully purified and extracted by using magnetic beads and the subsequent RT processing of the RNA can be performed automatically. Total RNA is successfully extracted and purified from T98 cells utilizing the microfluidic system, which is comparable with the conventional methods. The whole automatic procedure of RNA sample extraction only takes 35 min, which is much faster than the conventional method (more than 2 h). As a whole, the developed microfluidic system may provide a powerful platform for rapid RNA extraction and RT processes for further biomedical applications.

Purple urine bag syndrome: a community-based study and literature review.

AIM: Purple urine bag syndrome (PUBS) is considered as an uncommon phenomenon. This cohort study aimed to figure out the causative factors and the potential risks of PUBS. METHODS: We recruited 84 patients with long-term urinary catheterization from seven nursing institutions and home care centre, then compared the differences of demographic, clinical, urine test and bacteriological data between the patients with and without PUBS. RESULTS: The 2-month period prevalence of PUBS in chronic catheterized patients was 16.7%. PUBS-affecting patients had significantly higher proportion of female gender (P = 0.034), self oral intake (P = 0.036) and eating self-prepared food (P = 0.007). Otherwise, no statistical associations were found. Five different bacterial species were isolated from the urine of PUBS-affecting patients. No sequelae were found after forward follow-up for 6 months. We further discuss the associations between certain factors and PUBS according to literature review and the results of our study. CONCLUSION: PUBS is not as rare as we thought before. The causative factors of PUBS have not been clearly characterized. It may be the combination of several factors that cause the PUBS. Female gender and food content were found to be associated factors of PUBS in our study. Asymptomatic PUBS is unnecessary to be treated by antibiotics.

Ginseng essence, a medicinal and edible herbal formulation, ameliorates carbon tetrachloride-induced oxidative stress and liver injury in rats.

BACKGROUND: Ginseng essence (GE) is a formulation comprising four medicinal and edible herbs including ginseng (Panax ginseng), American ginseng (Panax quinquefolius), lotus seed (Nelumbo nucifera), and lily bulb (Lilium longiflorum). This study was aimed at investigating the hepatoprotective effect of GE against carbon tetrachloride (CCl4)-induced liver injury in rats. METHODS: We treated Wistar rats daily with low, medium, and high [0.625 g/kg body weight (bw), 1.25 g/kg bw, and 3.125 g/kg bw, respectively] doses of GE for 9 wk. After the 1st wk of treatment, rats were administered 20% CCl4 (1.5 mL/kg bw) two times a week to induce liver damage until the treatment ended. RESULTS: Serum biochemical analysis indicated that GE ameliorated the elevation of aspartate aminotransferase and alanine aminotransferase and albumin decline in CCl4-treated rats. Moreover, CCl4-induced accumulation of hepatic total cholesterol and triglyceride was inhibited. The hepatoprotective effects of GE involved enhancing the hepatic antioxidant defense system including glutathione, glutathione peroxidase, glutathione reductase, glutathione S-transferase, superoxide dismutase, and catalase. In addition, histological analysis using hematoxylin and eosin and Masson's trichrome staining showed that GE inhibited CCl4-induced hepatic inflammation and fibrosis. Furthermore, immunohistochemical staining of alpha-smooth muscle actin indicated that CCl4-triggered activation of hepatic stellate cells was reduced. CONCLUSION: These findings demonstrate that GE improves CCl4-induced liver inflammation and fibrosis by attenuating oxidative stress. Therefore, GE could be a promising hepatoprotective herbal formulation for future development of phytotherapy.

Ganoderma lucidum mycelia enhance innate immunity by activating NF-kappaB.

Ganoderma lucidum is a popular medicinal mushroom in China and Japan for its immunomodulatory and antitumor effects. The goal of this research is to investigate the effect of dried mycelia of Ganoderma lucidum produced by submerged cultivation on the enhancement of innate immune response. We found that Ganoderma lucidum mycelia (0.2-1.6 mg/ml) stimulated TNF-alpha and IL-6 production after 8h treatment in human whole blood. IFN-gamma release from human whole blood was also enhanced after 3 day-culture with Ganoderma lucidum mycelia (0.2-1.0mg/ml). However, Ganoderma lucidum mycelia did not potentiate nitric oxide production in RAW264.7 cells. To better understand the possible immuno-enhancement mechanisms involved, we focused on nuclear factor (NF)-kappaB activation. Electrophoretic mobility shift assay revealed that the Ganoderma lucidum mycelia (1.6 mg/ml) activated kappaB DNA binding activity in RAW264.7 cells. These results provide supporting evidences for the immunomodulatory effect of Ganoderma lucidum mycelia.

Immunomodulatory effect of Glossogyne tenuifolia in murine peritoneal macrophages and splenocytes.

Glossogyne tenuifolia Cass., a medicinal plant native to Taiwan, is traditionally used as an anti-inflammatory remedy. Oleanolic acid and luteolin-7-glucoside have been previously identified as active components of Glossogyne tenuifolia in the murine macrophage-like cell line, RAW264.7. Current study investigates the effect and mechanism of the ethanol extract of Glossogyne tenuifolia (GT) and its major constituents on the release of inflammatory mediators in activated elicited murine peritoneal macrophages and splenocytes. Our results showed that GT (up to 0.15 mg/ml) inhibited the production of proinflammatory mediators, TNF-alpha, IL-1beta, IL-6, nitric oxide (NO) and prostaglandin E(2) (PGE(2)) in LPS-activated macrophages, and IFN-gamma in PHA-activated splenocytes. GT also inhibited LPS-activated murine iNOS and COX-2 promoter activities in transiently transfected RAW264.7 cells. The major constituents, oleanolic acid and luteolin-7-glucoside, as well as its aglycone, luteolin, inhibited the release of NO, PGE(2), TNF-alpha and IL-1beta in activated peritoneal macrophages. However, only luteolin-7-glucoside and luteolin were able to reduce IFN-gamma release in PHA-stimulated splenocytes. To further investigate the possible mechanisms that interfere with LPS- and PHA-signaling, this study focused on nuclear factor-kappaB activation signaling pathways. Our results demonstrate that GT (0.075-0.15 mg/ml) treatment reduces nuclear factor-kappaB (NF-kappaB) DNA binding activity, as demonstrated by electrophoretic mobility shift assay (EMSA). Collectively, the results suggest that GT inhibits proinflammatory mediator synthesis in activated murine peritoneal macrophages and splenocytes, in part through NF-kappaB-dependent pathways.

Anti-inflammatory and antiviral effects of Glossogyne tenuifolia.

Glossogyne tenuifolia (Hsiang-Ju) is a traditional antipyretic and hepatoprotective herb used in Chinese medicine. The aim of this research is to investigate the pharmacological activities and potent components of the ethanol extract of Glossogyne tenuifolia (GT) in human primary cells and cell line. We found that GT (0.1 approximately 0.25 mg/ml) exerted dose-dependent inhibitions on the release of TNF-alpha and IL-6 in LPS-activated human whole blood and peripheral blood mononuclear cells (PBMC), and IFN-gamma in PHA-stimulated human whole blood. The lack of cytotoxicity indicated that the inhibitory effects of GT on cytokine production were not due to cell death. Luteolin, the deglycosylated derivative of one of the major compositions, luteolin-7-glucoside, exerted inhibitory effects on TNF-alpha, IL-6 and IFN-gamma production in activated human whole blood with estimated IC(50)s of 42.73 microM, 44.86 microM and 3.34 microM, respectively. Furthermore, GT had potent anti-hepatitis B virus (HBV) effects on the human hepatocellular carcinoma cell line, PLC/PRF/5. GT exhibited a dose-dependent inhibition on the release of hepatitis B surface antigen (HBsAg) by repressing the expression of HBsAg with IC(50) of 0.093 mg/ml. We concluded that GT exerted combinatorial anti-inflammatory and antiviral effects, and the multiple actions may underlie its traditional hepatoprotective function.

Immunomodulatory mechanism of the aqueous extract of sword brake fern (Pteris ensiformis Burm.).

Sword brake fern (Pteris ensiformis Burm.) is an ingredient in most of the traditional herbal beverage formulas in Taiwan; however, no information is available to explain its bioactivity. The aim of this study is to elucidate the molecular pharmacological activity in the aqueous extract of sword brake fern (SBF). We found that SBF (0.05-0.25 mg/ml) slightly induced TNF-alpha, IL-6, NO (nitric oxide) and PGE2 (prostaglandin E2) production in unstimualted murine macrophages, RAW264.7 cells. Furthermore, SBF (0.05-0.25 mg/ml) dose-dependently suppressed LPS-induced TNF-alpha, IL-1beta, IL-6, NO and PGE2 in activated RAW264.7 cells without exerting cytotoxicity. Further analysis of molecular mechanisms revealed that SBF prominently repressed LPS-induced iNOS (inducible nitric oxide synthase) and COX-2 (cyclooxygenase-2) promoter activities. Activation of the transcription factor NF-kappaB, which is one of the important pathways for transduction of LPS-stimulated inflammatory mediator producing signals, was suppressed by SBF in a dose-dependent manner, as demonstrated by both electrophoretic mobility shift assay (EMSA) and transfection with pNF-kappaB-Luc plasmid. These results suggest that SBF attenuates inflammatory mediator synthesis of activated macrophages partially through a NF-kappaB-dependent pathway. The immunomodulatory activity of SBF supports its traditional health promotion effect.

Antioxidant activity of methanol extract of the lotus leaf (Nelumbo nucifera Gertn.).

In this study, hydrogen peroxide (H2O2)-mediated Caco-2 cytotoxicity was employed to investigate the potential antioxidant activity of the methanol extract from the lotus leaf (Nelumbo nucifera Gertn.). A dose-dependent protective effect against reactive oxygen species (ROS)-induced cytotoxicity was observed when Caco-2 cells were treated with 10 mM H2O2 in combination with the methanol extract of the lotus leaf (0.1-0.3 mg/ml). However, no significant effect was found when co-treating Caco-2 cells with 10 mM H2O2 and alpha-tocopherol. In vitro assay revealed that the extract exhibited scavenging activities on free radicals and hydroxyl radicals, and metal binding ability as well as reducing power, which may explain in part the mechanism behind the extract's ability to protect cells from oxidative damage. In addition, the extract also exhibited concentration-dependent antioxidant activities against hemoglobin-induced linoleic acid peroxidation and Fenton reaction-mediated plasmid DNA oxidation.

Antioxidant activity of Porcelainberry (Ampelopsis brevipedunculata (Maxim.) Trautv.).

The stem and root of Porcelainberry (Ampelopsis brevipedunculata (Maxim.) Trautv.) (AB) was traditionally used as an anti-inflammatory, diuretic and anti-hepatotoxic agent in folk medicine. In this study, cell-free and cell culture systems were employed to investigate the antioxidant activity of the methanol extract of AB (MEAB). The cell-free system showed that the MEAB exhibited dose-dependent antioxidant activities against linoleic acid peroxidation and plasmid DNA oxidation. We also demonstrated that the MEAB possessed strong reducing power and scavenging effects of hydroxyl radicals and DPPH free radicals. The harmful effects of reactive oxygen metabolites on HepG2 cells and the possible antioxidant effects of the MEAB were also investigated. Pretreatment or cotreatment of HepG2 cells with the MEAB could significantly protect cells from H2O2-induced oxidative stress. This implies that the antioxidant effects in cell culture may result from the direct interaction between the MEAB and exogenous oxidant sources, as these occur in cell free systems, as well as from the induction of cellular stress gene expression. The antioxidant activity of the MEAB may partially explain its anti-inflammatory and anti-hepatotoxic effects.

Lipid peroxidation end product 4-hydroxy-trans-2-nonenal triggers unfolded protein response and heme oxygenase-1 expression in PC12 cells: Roles of ROS and MAPK pathways.

This study investigates the roles of ROS overproduction and MAPK signaling pathways in the induction of unfolded protein response (UPR) and the expression of Phase II enzymes in response to 4-hydroxy-trans-2-nonenal (4-HNE) in a neuronal-like catecholaminergic PC12 cells. Our results showed that 4-HNE triggered three canonical pathways of UPR, namely IRE1-XBP1, PERK-eIF2α-ATF4 and ATF6, and induced the expression of UPR-targeted genes, GRP78, CHOP, TRB3, PUMA, and GADD34, as well as Phase II enzymes, HO-1 and GCLC. 4-HNE also induced apoptosis, intracellular calcium accumulation, caspase-3 activation, and G0/G1 cell cycle arrest, which was correlated with the increased expression of GADD45α. The addition of tiron, a cellular permeable superoxide scavenger, scavenged 4-HNE-mediated ROS formation, but did not alleviate cytotoxicity, or the expression of UPR-targeted genes or Phase II enzymes, indicating that ROS overproduction per se did not play a major role in 4-HNE-caused deleterious effects. HO-1 expression was attenuated by Nrf2 siRNA and chemical chaperone 4-phenylbutyrate (4-PBA), suggesting HO-1 expression was regulated by Nrf2-ARE, which may work downstream of ER stress. 4-HNE treatment promptly induced ERK, JNK and p38 MAPK activation. Addition of p38 MAPK specific inhibitor SB203580 attenuated HO-1 upregulation, but enhanced expression of CHOP, PUMA and TRB3, and cytotoxicity. These results indicate that 4-HNE-induced transient p38 MAPK activation may serve as an upstream negative regulator of ER stress and confer adaptive cytoprotection against 4-HNE-mediated cell injury.

Curcuminoids distinctly exhibit antioxidant activities and regulate expression of scavenger receptors and heme oxygenase-1.

SCOPE: Curcumin (CUR), demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC) have been demonstrated as having antioxidant, anticarcinogenic, and hypocholesterolemic activities. We report the diverse antiatherogenic effects and mechanisms of curcuminoids. METHODS AND RESULTS: We found that CUR was the most potent antioxidant against copper-mediated LDL oxidation as measured by thiobarbituric acid-reactive substances assay, oxidized LDL (oxLDL) ELISA, and electrophoretic mobility. CUR upregulated heme oxygenase-1, modifier subunit of glutamate-cysteine ligase (GCLM), and CD36 expression in undifferentiated THP-1 cells, supporting the possible involvement of Nrf2 pathway in CD36 expression. Monocyte-to-macrophage differentiation plays a vital role in early atherogenesis. BDMC reduced oxLDL uptake most effectively, while CUR was the best inhibitor for CD36, scavenger receptor A, and lectin-like oxidized LDL receptor-1 expression during phorbol 12-myristate 13-acetate (PMA)-induced THP-1 differentiation. In PMA-differentiated THP-1 macrophages, CUR and DMC effectively induced heme oxygenase-1 expression, but attenuated oxLDL-induced CD36 expression, leading to decreased oxLDL uptake. CONCLUSION: This result indicates curcuminoids, despite structural similarities, exert different atheroprotective effects. Curcuminoids, especially CUR and DMC, are hormetic compounds, which induce Phase II enzyme expression and confer resistance to PMA- and oxLDL-induced scavenger receptor expression and activity.

Effects of citrus flavonoids, 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone and 3,5,6,7,8,3',4'-heptamethoxyflavone, on the activities of macrophage scavenger receptors and the hepatic LDL receptor.

Epidemiological and animal studies point to a possible protective effect of citrus flavonoids against cardiovascular diseases. The aim of this study is to investigate the effects of citrus flavonoids, 5-hydroxy-3,6,7,8,3',4'-hexamethoxyflavone (5-OH-HxMF) and 3,5,6,7,8,3',4'-heptamethoxyflavone (HpMF), on the activities and expressions of macrophage scavenger receptors and the hepatic LDL receptor. Treatment of HpMF (20 µM) during THP-1 differentiation successfully attenuated 12-myristate 13-acetate (PMA)-mediated DiI-labeled oxidized low-density lipoprotein (oxLDL) uptake as evidenced by flow cytometry, indicating that the functions of scavenger receptors were blocked. RT-Q-PCR analysis suggests that the decrease in oxLDL uptake was due to the down-regulation of PMA-induced SR-A mRNA expression. In terminally differentiated THP-1 macrophages, 5-OH-HxMF and HpMF could significantly reduce DiI-oxLDL uptake, with the former having a greater effect. 5-OH-HxMF attenuated oxLDL-mediated CD36 and SR-A expression; while HpMF only decreased CD36 expression. The effects of these two flavonoids on the activity and expression of the hepatic LDL receptor (LDLR) were further investigated in HepG2 cells. 5-OH-HxMF (10-20 µM) enhanced DiI-LDL uptake by 1.33-fold due to the enhanced LDLR expression. These results imply that HpMF is better at inhibiting PMA-induced oxLDL uptake during THP-1 differentiation, while 5-OH-HxMF is more powerful in attenuating oxLDL-induced scavenger receptor expression and activity in terminally differentiated THP-1 macrophages. Furthermore, 5-OH-HxMF may have hypolipidemic activity due to its up-regulating hepatic LDLR expression.

3',4'-didemethylnobiletin induces phase II detoxification gene expression and modulates PI3K/Akt signaling in PC12 cells.

Oxidative stress is considered a major cause of neurodegenerative disorders. In this work, we investigated the cytoprotective effects and mechanisms of the citrus flavonoid nobiletin (NOB) and its metabolite, 3',4'-didemethylnobiletin (3',4'-dihydroxy-5,6,7,8-tetramethoxyflavone; DTF), in PC12 cells. Both NOB and DTF exhibited strong potency in attenuating serum withdrawal- and H(2)O(2)-caused cell death and increased intracellular GSH level via upregulation of both catalytic and modifier subunits of glutamate-cysteine ligase (GCL). However, only DTF suppressed intracellular ROS accumulation in H(2)O(2)-treated cells, induced heme oxygenase-1 (HO-1) expression, and enhanced nuclear factor E2-related factor 2 (Nrf2) binding to the ARE. Nevertheless, DTF-mediated HO-1 upregulation was independent of Nrf2 activation because knockdown of Nrf2 expression by siRNA did not affect its expression. DTF suppressed NF-κB activation, and addition of NF-κB inhibitor, pyrrolidine dithiocarbamate or Bay 11-7082, synergistically enhanced DTF-mediated HO-1 expression, indicating that HO-1 induction is associated with NF-κB suppression. NOB and DTF also activated the ERK, JNK, and Akt pathways in PC12 cells that had undergone serum starvation. Addition of pharmacological kinase inhibitors, U0126, SP600125, and LY294002, caused cytotoxicity and the last significantly attenuated NOB- and DTF-mediated antiapoptotic actions, indicating the involvement of PI3K/Akt signaling in their cytoprotective effects. In conclusion, HO-1 and GCL upregulation and intrinsic ROS-scavenging activity may contribute to DTF-mediated cytoprotection. Furthermore, modulation of PI3K/Akt signaling is involved in channeling the DTF stimulus for cell survival against oxidative insults.

Lipoic acid ameliorates arsenic trioxide-induced HO-1 expression and oxidative stress in THP-1 monocytes and macrophages.

Inorganic arsenic is a common environmental contaminant; chronic exposure to arsenic can alter the physiology of various key immune cells, particularly macrophages. The aim of this research is to elucidate the key parameters associated with arsenic-induced toxicity and investigate the potential and mechanism of α-lipoic acid (LA), a potent thioreducant, for reducing the toxicity in human promonocytic THP-1 cells. We found that a non-lethal concentration of arsenic trioxide (1 µM) significantly induced the expression of heme oxygenase-1 (HO-1), a response biomarker to arsenic, without stimulating measurable superoxide production. Co-treatment of cells with the HO-1 competitive inhibitor zinc protoporphyrin (Znpp) potentiated arsenic-induced cytotoxicity, indicating that HO-1 confers a cytoprotective effect against arsenic toxicity. In addition, low concentrations of arsenic trioxide (1 and 2.5 µM) markedly inhibited monocyte-to-macrophage differentiation and expression of macrophage markers. Treatment of cells with LA attenuated arsenic trioxide-induced cytotoxicity and HO-1 over-expression and restored the redox state. In addition, LA neutralized arsenic trioxide-inhibition of monocyte maturation into macrophages and reversed the expression and activity of scavenger receptors. In conclusion, the cytotoxicity of arsenic trioxide is associated with an imbalance of the cellular redox state, and LA can protect cells from arsenic-induced malfunctions either through its reducing activity, direct interacting with arsenic or stimulating other unidentified signaling pathways.

Citrus flavonoid 5-demethylnobiletin suppresses scavenger receptor expression in THP-1 cells and alters lipid homeostasis in HepG2 liver cells.

SCOPE: Nobiletin, a polymethoxyflavone from the peel of citrus fruits, has been reported to inhibit modified LDL uptake in macrophages and enhance hepatic LDL receptor expression and activity. We report the anti-atherogenic effect and mechanism of 5-demethylnobiletin, an auto-hydrolysis product of nobiletin. METHODS AND RESULTS: 5-Demethylnobiletin significantly attenuated phorbol 12-myristate 13-acetate-induced gene expression and activity of scavenger receptors, CD36, scavenger receptor-A and lectin-like oxidized LDL receptor-1. The inhibitory effect is partly associated with the inhibition of protein-kinase C activity and c-Jun NH(2) -terminal kinase 1/2 phosphorylation, thereby inhibiting the activation of activator protein-1 and nuclear factor-κB. 5-Demethylnobiletin treatment also led to reduction of oxidized LDL-induced CD36 mRNA expression and blockade of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanide perchlorate-modified LDL uptake in THP-1-derived macrophages. In the human hepatoma cell line HepG2, 5-demethylnobiletin significantly induced LDL receptor activity and transcription, at least in part, through steroid-response element-binding protein-2 activation. 5-Demethylnobiletin also decreased the mRNA expression of acyl CoA:diacylglycerol acyltransferase 2, the key enzyme involved in the hepatic triacylglycerol biosyntheses. CONCLUSION: Current results suggest that 5-demethylnobiletin has diverse anti-atherogenic bioactivities. It is more potent in inhibiting monocyte-to-macrophage differentiation and foam cell formation than its permethoxylated counterpart, nobiletin. It exhibits similar hypolipidemic activity as nobiletin and both can enhance LDL receptor gene expression and activity and decreased acyl CoA:diacylglycerol acyltransferase 2 expression.

Glossogyne tenuifolia acts to inhibit inflammatory mediator production in a macrophage cell line by downregulating LPS-induced NF-kappa B.

Glossogyne tenuifolia (hsiang-ju) (GT) is a traditional antipyretic herb used in Chinese medicine; however, no information is available to explain its action. The objective of this research was to elucidate the molecular pharmacological activity and the effective components in the ethanol extract of GT. We found that GT had potent anti-inflammatory effects on the lipopolysaccharide (LPS)-activated murine macrophages, RAW264.7. GT downregulated LPS-induced expression of inducible nitric oxide synthase (iNOS) by blocking its transcription. GT also caused a dose-dependent inhibition of the release of prostaglandin E(2) by repressing the promoter activity of the inducible cyclooxygenase (COX-2) gene. Moreover, GT exerted a dose-dependent inhibition of the LPS-stimulated release of the proinflammatory cytokines, TNF-alpha, IL-1 beta, IL-6, and IL-12. To determine the mechanism by which GT inhibits LPS signaling, we focused on nuclear factor-kappa B (NF-kappa B) activation. Western blot analysis revealed that GT abolished LPS-induced inhibitor-kappa B phosphorylation. The electrophoretic mobility shift assay demonstrated that GT abolished LPS-mediated kappa B DNA binding activity. Moreover, macrophages were transfected with a vector coding for the luciferase reporter gene under the control of NF-kappa B cis-acting elements, and the transfected macrophages showed that the LPS-stimulated luciferase activity was GT-sensitive. These results suggest that GT attenuates inflammatory mediator synthesis of activated macrophages through an NF-kappa B-dependent pathway. The active components of GT were identified as oleanolic acid and luteolin-7-glucoside. Both of these compounds inhibited LPS-stimulated inflammatory mediator production and NF-kappa B activation. We conclude that GT inhibits NF-kappa B-mediated gene expression and downregulates inflammatory mediator production in murine macrophages.