Role of STAT3 activated NLRP3 inflammasomes in BV2 cell inflammatory response induced by maltol aluminum / 环境与职业医学

Background Aluminum activates signal transducer and activator of transcription 3 (STAT3), causing microglial nucleotide-binding and oligomerization domain-like receptors protein 3 (NLRP3) inflammasome activation and inflammatory responses and producing neurotoxicity. Objective To explore the role of STAT3 regulated NLRP3 inflammasomes in the inflammatory response of mouse microglia cell line (BV2) cells induced by maltol aluminum [Al(mal)3]. Methods BV2 cells were assigned to five groups: one control group, three Al(mal)3 exposure groups (low, medium, and high doses at 40, 80, and 160 μmol·L−1 Al(mal)3 respectively), and one C188-9 (STAT3 antagonist) intervention group [10 μmol·L−1 C188-9 +160 μmol·L−1 Al(mal)3]. Cell viability was detected by CCK8. The expression of M1/M2 type markers, i.e. CD68/CD206, STAT3, p-STAT3, NLRP3, cleaved-casepase-1, and apoptosis-associated speck-like protein (ASC) in BV2 cells were detected by Western blotting, and proinflammatory cytokines interleukin (IL)-1β and IL-18, and anti-inflammatory cytokine IL-10 were determined by ELISA. Results The results of cell viability assay showed that cell viability gradually decreased with the increase of Al(mal)3 dose. Compared with the control group, the cell viability of the Al(mal)3 high-dose group was decreased by 18% (P<0.05); compared with the Al(mal)3 high-dose group, the cell viability of the C188-9 intervention group was significantly elevated by 14% (P<0.05). Compared with the control group, the expression levels of CD68 in the Al(mal)3 low-, medium-, and high-dose groups were elevated by 19%, 20%, and 21%, respectively (P<0.05); the expression level of CD206 in the Al(mal)3 high-dose group was decreased by 25% (P<0.05). Compared with the Al(mal)3 high-dose group, the expression level of CD68 in the C188-9 intervention group was reduced by 9% (P<0.05), whereas the expression level of CD206 was elevated by 22% (P<0.05). Compared with the control group, the p-STAT3 protein expression and the p-STAT3/STAT3 ratio in the Al(mal)3 high-dose group increased by 129% and 127%, respectively (P<0.05). Compared with the Al(mal)3 high-dose group, the p-STAT3 protein expression and the p-STAT3/STAT3 ratio in the C188-9 intervention group were decreased by 55% and 54%, respectively (P>0.05). Compared with the control group, the expression level of NLRP3 protein increased by 75% in the Al(mal)3 high-dose group (P<0.05), the expression levels of cleaved-casepase-1 protein increased by 28% and 35% in the Al(mal)3 medium- and high-dose groups (P<0.05), and the expression levels of ASC increased by 22%, 25%, and 53% in the Al(mal)3 low-, medium- and high-dose groups (P<0.05), respectively. Compared with the Al(mal)3 high-dose group, the expression levels of NLRP3, cleaved-casepase-1, and ASC proteins in the C188-9 intervention group decreased by 30%, 19%, and 32%, respectively (P<0.05). Compared with the control group, the levels of IL-1β in the Al(mal)3 medium- and high-dose groups increased by 18% and 21%, respectively (P<0.05), and the level of IL-18 in the Al(mal)3 high-dose group increased by 10% (P<0.05). Compared with the Al(mal)3 high-dose group, the IL-18 levels were reduced by 23% in the C188-9 intervention group (P<0.05). The content of anti-inflammatory factor IL-10 did not differ significantly between groups (P>0.05). Conclusion Aluminum can induce inflammatory responses in BV2 microglia and is predominantly pro-inflammatory, and the mechanism may involve STAT3 regulation of NLRP3 inflammasome secretion of inflammatory factors.

Two new maltol glycosides from roots of Psammosilene tunicoides / 中草药

Objective: To investigate the chemical constituents from the roots of Psammosilene tunicoides. Methods: Chemical constituents were separated by column chromatography over silica gel, Sephadex LH-20, and reverse-phase silica gel (ODS), and chemical structures were determined by analysis of HR-ESI-MS, 1D, and 2D NMR spectroscopic data. Results: Two new maltol glycosides were isolated from the 80% aq. Ethanol extract from the roots of P. tunicoides, and their structures were determined as maltol-3-O-[6-O-(4-O-α-L-rhamnopyranosyl)-Z-p-coumaroyl]-β-D-glucopyranoside (1) and maltol-3-O-[6-O-(4-O-α-L- rhamnopyranosyl)-E-p-coumaroyl]-β-D-glucopyranoside (2). Conclusion: Compounds 1 and 2 are identified as new maltol glycosides, and named as tunicosides A and B, respectively.

Establishment of human ApoE4 gene transfected PC12 cell line and the effect of maltol aluminum on its cell viability / 中国职业医学

OBJECTIVE: To establish a PC12 cell line with stable expression of human apolipoprotein E( ApoE4) gene by transfection with a lentiviral vector carrying human ApoE4 gene and to investigate the effect of maltol aluminum on the viability of transfected PC12 cells. METHODS: The lentiviral vector carrying human ApoE4 gene was transfected into PC12 cells. PC12 cells with overexpression of ApoE4 gene and negative control vector were obtained after puromycin screening.The mRNA relative expression of R-Apo E and( or) H-Apo E-FLAG of cells in PC12,PC12-NC and PC12-ApoE4 groups were detected by real-time fluorescent quantitative polymerase chain reaction,and the effect of cell construction was identified. PC12-ApoE4 cells and PC12 cells were exposed to maltol aluminum solution at concentrations of 0. 00,100. 00,200. 00 and 400. 00 μmol/L respectively for 24 hours,and cell viability was detected by Cell Counting Kit-8( CCK-8)assay. RESULTS: PC12-ApoE4 and PC12-NC cells under the fluorescence microscope showed fluorescence expression,suggesting that transfection was successful. The expression of PC12 cells showed no fluorescence. The relative expression of H-Apo E-FLAG gene mRNA( the median amount) of PC12-ApoE4 cells was 148. 74,which was higher than the R-Apo E gene in PC12 cells( 1. 00) and PC12-NC cells( 1. 01)( P < 0. 01). After exposure to maltol aluminum,the cell survival rates in terms of the main effect and interaction effect of dose and cell type were statistically significant( P < 0. 01),among them,the cell viabilities were decreased in the concentration range of 0. 00-400. 00 μmol/L with the dose of maltol aluminum exposure increased,showing dose-effect relationship( P < 0. 01). CONCLUSION: The cell line stably expressed human ApoE4 gene was constructed successfully. There was interaction between the effects of maltol aluminum and ApoE4 gene on the survival rate of PC12 cells,and ApoE4 gene could enhance the cytotoxicity of maltol aluminum on PC12 cells.

Chemical Constituents of Ethyl Acetate Fraction from Cynodon dactylon / 中国药学杂志

OBJECTIVE: To isolate and identify the chemical constituents from Cynodon dactylon. METHODS: The chemical constituents of the alcohol extract of C. dactylon. were isolated and purified by various chromatography methods, and their structures were identified by physical and chemical properties and spectral data. RESULTS: Fourteen compounds were isolated from C. dactylon and their structures were examined by physicochemical characteristics and spectral data and identified as vanillin (1), arctigenin (2), maltol (3), (+)-dehydrovomifoliol (4), (3R, 6R, 7E)-3-hydroxy-4, 7-megastigmadien-9-one (5), (-)-loliolide (6), zhebeiresinol (7), 1-indole-3-carboxaldehyde (8), ferulic acid (9), matairesinol (10), pinoresinol (11), ethyl caffeate (12), traxillagenin (13), and impecylenolide (14). CONCLUSION: Compounds 1-14 are isolated from C. dactylon for the first time.

The Neuroprotective Effect of Maltol against Oxidative Stress on Rat Retinal Neuronal Cells

PURPOSE: Maltol (3-hydroxy-2-methyl-4-pyrone), formed by the thermal degradation of starch, is found in coffee, caramelized foods, and Korean ginseng root. This study investigated whether maltol could rescue neuroretinal cells from oxidative injury in vitro. METHODS: R28 cells, which are rat embryonic precursor neuroretinal cells, were exposed to hydrogen peroxide (H2O2, 0.0 to 1.5 mM) as an oxidative stress with or without maltol (0.0 to 1.0 mM). Cell viability was monitored with the lactate dehydrogenase assay and apoptosis was examined by the terminal deoxynucleotide transferase-mediated terminal uridine deoxynucleotidyl transferase nick end-labeling (TUNEL) method. To investigate the neuroprotective mechanism of maltol, the expression and phosphorylation of nuclear factor-kappa B (NF-kappaB), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 were evaluated by Western immunoblot analysis. RESULTS: R28 cells exposed to H2O2 were found to have decreased viability in a dose- and time-dependent manner. However, H2O2-induced cytotoxicity was decreased with the addition of maltol. When R28 cells were exposed to 1.0 mM H2O2 for 24 hours, the cytotoxicity was 60.69 ± 5.71%. However, the cytotoxicity was reduced in the presence of 1.0 mM maltol. This H2O2-induced cytotoxicity caused apoptosis of R28 cells, characterized by DNA fragmentation. Apoptosis of oxidatively-stressed R28 cells with 1.0 mM H2O2 was decreased with 1.0 mM maltol, as determined by the TUNEL method. Western blot analysis showed that treatment with maltol reduced phosphorylation of NF-kappaB, ERK, and JNK, but not p38. The neuroprotective effects of maltol seemed to be related to attenuated expression of NF-kappaB, ERK, and JNK. CONCLUSIONS: Maltol not only increased cell viability but also attenuated DNA fragmentation. The results obtained here show that maltol has neuroprotective effects against hypoxia-induced neuroretinal cell damage in R28 cells, and its effects may act through the NF-kappaB and mitogen-activated protein kinase signaling pathways.

Chemical constituents from leaves of Acanthopanax evodiaefolius / 中草药

Objective: To study the chemical constituents from the leaves of Acanthopanax evodiaefolius. Methods: The compounds were isolated and purified by silica gel and Sephadex LH-20 column chromatography. Their structures were identified on the basis of their physicochemical properties and spectroscopic data. Results: Thirteen compounds were isolated from the methanol extract of A. evodiaefolius and their structures were identified as heptadecanoic acid (1), heptacosanol (2), trans-cinnamic acid (3), ursolic acid (4), oleanolic acid (5), betulinic acid (6), corosolic acid (7), apigenin (8), naringenin (9), maltol (10), syringic acid (11), stigmasterol (12), and daucosterol (13), respectively. Conclusion: Compounds 1-3 and 7-10 are obtained from the plans in genus Acanthopanax Miq. for the first time and all the compounds are obtained from A. evodiaefolius for the first time.

Taste-modifying technology of Jinzhen Oral Liquid / 中草药

Objective: To study the optimal method for taste-modifying of Jinzhen Oral Liquid (JOL). Methods: Active carbon adsorption method was optimized through L9(34) orthogonal test and with the change rate of concentration of bilirubin as index, and the different taste-modifying prescriptions were evaluated by the fuzzy mathematics synthetic evaluation system. Results: The optimal adsorption conditions were as follows: The pH value of the mixture of Cornu Bubali and artificial Calculus ovis was adjusted to 7.0 at 50 °C with 0.25% activated carbon, and stirring for 10 min. The optimal formula ingredient was as follows: 15.0 mg ethyl maltol, 5.0 g CMC-Na, 1.0 g steviosin, and 0.5 g orange flavor in 1 000 mL JOL. Conclusion: The taste-modifying prescriptions provide great value for further scale production.

Determination of Two Constituents in Compound Streptomycin Cream / 中国药房

OBJECTIVE:To determine streptomycin sulfate and sulfonamide in compound streptomycin cream by UV spectrophotometry.METHODS:The maltol-ammonium ferric sulfate colourimetry was adopted in which the ammonium ferric sulfate was taken as the developer,the absorbability of streptomycin sulfate was determined with the wavelength at521nm;The absorbability of sulfonamide was determined at a wavelength of251nm with0.1%mol/L NaOH taken as the sol-vent.RESULTS:The linear ranges of streptomycin sulfate and sulfonamide were200～950?g/ml(r=0.9994)and1.464～7.784?g/ml(r=0.9998)respectively;Their respective average recovery were99.1%(RSD=1.90%)and99.7%(RSD=1.60%).CONCLUSION:The method can be used as the quality control for compound streptomycin cream.

An experimental study on the effect of maltol against oxygen toxicity / 예방의학회지

Since the widespread application of hyperbaric oxygenation in clinical medicine, the problems of oxygen toxicity have been attracting a deep interest from the researchers on hyperbaric medicine as a practical issue. Among extensive research trials, the study on the protective agents oxygen toxicity occupied one of the most challenging field. As the mechanisms of oxygen toxicity, the role of the oxygen free radicals produced by peroxidation process are strongly accepted by the leading researchers on oxygen toxicity, the probable protective effects of antioxidant against oxygen toxicity are sustaining a sufficient rational. Maltol(2-methyl-3-hydroxy-gamma-pyrone) which is known to be a component of Korean red ginseng has been reporting to have an antioxidant action. But, further study is needed to provide definite evidence for this compound to be an antioxidant, since the action was based on the results which were obtained under in vitro experiment. In this study, the author attempted to evaluate the effect of maltol as protective agent against oxygen toxicity through the observation of death rate, convulsion rate, time to convulsion and microscopic pathological changes in some organs of experimental rats exposed to various conditions. The findings observed are as follows: 1) The death rate, convulsion rate, time to convulsion, lung/weight ratio and microscopic pathological finding of lung were identified as reliable objective and quantitative indices for oxygen toxicity. 2) Maltol showed excellent protective effect against pulmonary oxygen toxicity as an antioxidant.

THE ANTIOXIDATIVE ACTION OF MALTOL ON AUTO-OXIDATION OF ERYTHROCYTES / 中国药理学通报

The effect of maltol to prevent erythrocyte from auto-oxidation is presented. When erythrocytes were incubated at 37 ℃ for 24 h in vitro, oxyhemoglobin was decreased, methemoglobin, superoxide freeradical, lipofuscin and Heinz's body were increased as well as membrane proteins were changed. These reactions could be inhibited by maltol.

THF TOXICITY OF MALTOL AND ITS EFFECT ON ANTIOXIDATIVE ENZYME ACTIVITIES OF ERYTHROCYTES IN MICE / 中国药理学通报

According to our previous experimental results, maltol is a powerful antioxidant against autoxidation and oxidative stress of eryth-rocytes. In this report, the toxicity and antioxidative action of maltol in mice was investigated. The results indicated that maltol was not toxic in mice when fed in a dose of 50mg/kg?d-1 (body weight) for 1 month. The antioxidative enzymes ( SOD and Cat ) activities and GSH content of erythrocytes were significantly increased. In addition, the lifespan of houseflies fed with maltol was prolonged.

THE ANTIOXIDANT ACTION OF MALTOL ON ERYTHROCYTE MEMBRANE / 中国药理学通报

Maltol is a chemical derived from Chinese herb Panax Ginseng. The effect of maltol on hemolysis and hydroperoxidation of erythro-cytes induced by active oxygen radical is presented. Maltol could protect hemolysis induced by H2O2 in vitro. When erythrocyte membrane protein was exposed to butylhydroperoxide in vitro, membrane protein was polymerized, and membrane lipids were oxidized to hydroperoxide compound. These oxidative reactions could inhibited by maltol. The results showed that maltol might act as a scavenger of superoxide of hydroxy radical as demonstrated by biochemical method and ESR spin method。