Cordycepin inhibits UVB-induced matrix metalloproteinase expression by suppressing the NF-��B pathway in human dermal fibroblasts

Cordycepin (3''-deoxyadenosine) has been shown to exhibit many pharmacological activities, including anti-cancer, anti-inflammatory, and anti-infection activities. However, the anti-skin photoaging effects of cordycepin have not yet been reported. In the present study, we investigated the inhibitory effects of cordycepin on matrix metalloproteinase-1 (MMP-1) and -3 expressions of the human dermal fibroblast cells. Western blot analysis and real-time PCR revealed cordycepin inhibited UVB-induced MMP-1 and -3 expressions in a dose-dependent manner. UVB strongly activated NF-κB activity, which was determined by IκBα degradation, nuclear localization of p50 and p65 subunit, and NF-κB binding activity. However, UVB-induced NF-κB activation and MMP expression were completely blocked by cordycepin pretreatment. These findings suggest that cordycepin could prevent UVB-induced MMPs expressions through inhibition of NF-κB activation. In conclusion, cordycepin might be used as a potential agent for the prevention and treatment of skin photoaging.     

Triptolide-induced suppression of phospholipase D expression inhibits proliferation of MDA-MB-231 breast cancer cells

In spite of the importance of phospholipase D (PLD) in cell proliferation and tumorigenesis, little is known about the molecules regulating PLD expression. Thus, identification of small molecules inhibiting PLD expression would be an important advance for PLD-mediated physiology. We examined one such here, denoted "Triptolide", which was identified in a chemical screen for inhibitors of PLD expression using cell assay system based on measurement of PLD promoter activity. Triptolide significantly suppressed the expression of both PLD1 and PLD2 with sub-µM potency in MDA-MB-231 breast cancer cells as analyzed by promoter assay and RT-PCR. Moreover, triptolide abolished the protein level of PLD in a time and dose-dependent manner. Triptolide-induced PLD1 downregulation was also observed in all the cancer cells examined, suggesting a general phenomenon detected in various cancer cells. Decrease of PLD expression by triptolide suppressed both basal and PMA-induced PLD activity. In addition, triptolide inhibited activation of NFκB which increased PLD1 expression. Ultimately, downregulation of PLD by triptolide inhibited proliferation of breast cancer cells. Taken together, we demonstrate that triptolide suppresses the expression of PLD via inhibition of NFκB activation and then decreases cell proliferation.     

Interleukin-1�� promotes the expression of monocyte chemoattractant protein-1 in human aorta smooth muscle cells via multiple signaling pathways

Monocyte chemoattractant protein-1 (MCP1) plays a key role in monocyte/macrophage infiltration to the sub-endothelial space of the blood vessel wall, which is a critical initial step in atherosclerosis. In this study, we examined the intracellular signaling pathway of IL-1β-induced MCP1 expression using various chemical inhibitors. The pretreatment of a phosphatidylcholine (PC)-specific PLC (PC-PLC) inhibitor (D609), PKC inhibitors, or an NF-κB inhibitor completely suppressed the IL-1β-induced MCP1 expression through blocking NF-κB translocation to the nucleus. Pretreatment with inhibitors of tyrosine kinase or PLD partially suppressed MCP1 expression and failed to block nuclear NF-κB translocation. These results suggest that IL-1β induces MCP1 expression through activation of NF-κB via the PC-PLC/PKC signaling pathway.     

A simple and sensitive chromium speciation procedure by hyphenating flow injection on-line preconcentration with catalytic spectrophotometry

A high sensitive chromium speciation procedure based on spectrophotometric detection was developed by coupling flow injection on-line preconcentration with a catalytic indicator reaction. Chromium(VI) is retained on a mini-column packed with polystyrene anion exchange resin (strong basic 717 resin), which was afterwards eluted with a small volume of NaNO₃ solution. The eluted Cr(VI) is then directed to catalyze the decoloration of alizarin cyanine green (ACG) in the presence of bromate as oxidizing reagent, and the absorbance change is proportional to the concentration of Cr(VI). With a sampling volume of 12 ml and a loading time of 120 s, an enrichment factor of 26.5 was achieved for the preconcentration. The most distinct feature of this procedure is characterized by its overall detection limit, i.e., 50 ng l⁻¹, which is much superior to those achieved by FAAS, and comparable to those obtained by inductively coupled plasma mass spectrometry (ICPMS) and electrothermal atomic absorption spectrometry (ETAAS). The procedure was validated with a certified reference material. It was also applied to the speciation of chromium in a series of surface water samples.     

Ginsenoside Rb1 attenuates intestinal ischemia-reperfusion-induced liver injury by inhibiting NF-��B activation

Intestinal ischemia-reperfusion (I/R) is an important event in the pathogenesis of multiple organ dysfunction syndrome (MODS). The aim of this study is to determine the effects of ginsenoside Rb1 on liver injury induced by intestinal I/R in rats. Adult male Wistar rats were randomly divided into four groups: (1) a control, sham-operated group (sham group); (2) an intestinal I/R group subjected to 1 h intestinal ischemia and 2 h reperfusion (I/R group); (3) a group treated with 20 mg/kg ginsenoside Rb1 before reperfusion (Rb1-20 group); and (4) a group treated with 40 mg/kg ginsenoside Rb1 before reperfusion (Rb1-40 group). Liver and intestinal histology was observed. Aspartate aminotransferase (AST), alanine aminotransferase (ALT) level in serum and malondialdehyde (MDA) level in intestinal tissues were measured. Myeloperoxidase (MPO), TNF-α, MDA level and immunohistochemical expression of NF-κB and intracellular adhesion molecale-1 (ICAM-1) in liver tissues was assayed. In addition, a western blot analysis of liver NF-κB expression was performed. Results indicated intestinal I/R induced intestinal and liver injury, which was characterized by increase of AST and ALT in serum, MDA level in intestine, MPO, TNF-α and MDA level and ICAM-1 and NF-κB expression in the liver tissues. Ginsenoside Rb1 (20, 40 mg/kg) ameliorated liver injury, decreased MPO, TNF-α and MDA level, NF-κB and ICAM-1 expression in liver tissues. In conclusion, ginsenoside Rb1 ablated liver injury induced by intestinal I/R by inhibiting NF-κB activation.     

束状保留间隙接口在常规柱反相高效液相色谱／毛细管气相色谱在线联用中的应用

用自行设计制作的新型束状保留间隙高效液相色谱（ＨＰＬＣ）／毛细管气相色谱（ＣＧＣ）接口与常规柱反相ＬＣ联用;采用沸点蒸发方式,在柱后流速为１．０～１．５ｍＬ／ｍｉｎ时成功地转移了８００～１０００μＬ含水ＬＣ流动相,用标准样品对该接口性能进行了测试,并对环丁砜样品进行了分离。结果表明,束状保留间隙的性能优于单根保留间隙,与反相常规柱更加匹配。     

On-line simultaneous pre-concentration procedure for the determination of cadmium and lead in drinking water employing sequential multi-element flame atomic absorption spectrometry

An on-line pre-concentration system for the sequential determination of cadmium and lead in drinking water by using fast sequential flame atomic absorption spectrometry (FS-FAAS) is proposed in this paper. Two minicolums of polyurethane foam loaded with 2-(6-methyl-2-benzothiazolylazo)-orcinol (Me-BTAO) were used as sorptive pre-concentration media for cadmium and lead. The analytical procedure involves the quantitative uptake of both analyte species by on-column chelation with Me-BTAO during sample loading followed by sequential elution of the analytes with 1.0?mol?L^?1 hydrochloric acid and determination by FS-FAAS. The optimisation of the entire analytical procedure was performed using a Box–Behnken multivariate design utilising the sampling flow rate, sample pH and buffer concentration as experimental variables.

The proposed flow-based method featured detection limits (3σ) of 0.08 and 0.51?µg?L^?1 for cadmium and lead, respectively, precision expressed as relative standard deviation (RSD) of 1.63% and 3.87% (n?=?7) for cadmium at the 2.0?µg?L^?1 and 10.0?µg?L^?1 levels, respectively, and RSD of 6.34% and 3.26% (n?=?7) for lead at the 5.0?µg?L^?1 and 30.0?µg?L^?1 levels, respectively. The enrichment factors achieved were 38.6 and 30.0 for cadmium and lead, respectively, using a sample volume of 10.0?mL. The sampling frequency was 45 samples per hour. The accuracy was confirmed by analysis of a certified reference material, namely, SRM 1643d (Trace elements in natural water). The optimised method was applied to the determination of cadmium and lead in drinking water samples collected in Santo Amaro da Purificação City, Bahia, Brazil.     

Determination of nine emerging pesticides at trace level in aqueous samples using fully automated on-line solid phase extraction coupled with liquid chromatography-mass spectrometry

On-line solid phase extraction (SPE) coupled to liquid chromatography-mass spectrometry (LC-MS) offers an easy and fast strategy to analyze the organic contaminants in environmental samples with high sensitivity and selectivity. This paper described an in-house designed on-line SPE system and an on-line SPE-LC-MS method for the determination of pesticides at trace levels in water samples. The system was assembled from an eight-position valve, a piston pump, a six-port valve and a C18 SPE column, and significantly reduced analysis time by achieving full automation. Moreover, the use of a large enrichment volume (50?mL) significantly enhanced method sensitivity. Using this on-line SPE system, an on-line SPE-LC-MS method was developed for the determination of nine pesticides at trace levels in lake water and seawater sample. Under optimized conditions, method detection limits (MDLs) were 1.00–10.0?ng?L^?1.