The characteristics of polysaccharide composition of red wines in China: Effects of grape varieties, origins and winemaking techniques.

In this work, the polysaccharide profile of different grapes and red wines in China was studied and the influences of two common winemaking techniques on the components of wine were analyzed. The soluble polysaccharide content in the skins of native grape species in China (non-Vitis vinifera grapes) was significantly higher than that of Vitis vinifera species, while the terroir effect on V. vinifera varieties was limited. The combination of the enzyme preparation and the addition of mannoproteins (MPs) at the beginning of alcoholic fermentation (MP1 + E) could increase the contents of MPs and acid polysaccharides (APS) compared to the control wines. Meanwhile, better color characteristics and higher level of anthocyanin derivatives were observed. However, MP1 + E treatment reduced the content of polysaccharides rich in arabinose and galactose (PRAGs) due to enzymatic hydrolysis. The study will provide useful information for winemakers to regulate the wine polysaccharide profile.

Sensitive and selective detection of Hg2+ in tap and canal water via self-enhanced ECL aptasensor based on NH2-Ru@SiO2-NGQDs.

In the present study, a novel self-enhanced electrochemiluminescence (ECL) aptasensor which combined self-enhanced ECL composite as signal response element and aptamer as the specific recognition element was firstly proposed for the sensitive and selective detection of Hg2+. Innovatively, the luminophore Ru(bpy)32+-doped silica nanoparticles functionalized with 3-aminopropyltriethoxysilane (NH2-Ru@SiO2) and the co-reactant nitrogen doped graphene quantum dots (NGQDs) were bound together to form the self-enhanced ECL composite, NH2-Ru@SiO2-NGQDs, by electrostatic adsorption. Satisfactorily, high and stable luminous efficiency of NH2-Ru@SiO2-NGQDs was obtained benefited from the short electron transfer distance and low energy loss of self-enhanced-typal ECL composite. For the fabrication of the self-enhanced ECL aptasensor for Hg2+ detection, the Hg2+ aptamer, of which one end was connected to NH2-Ru@SiO2-NGQDs, and the other end was fixed on glass carbon electrode (GCE) surface through Au-S bond, was served as a bridge. Upon the addition of Hg2+, the aptamer was bent due to the formation of thymine-Hg2+-thymine (T-Hg2+-T) specific structure, which caused the self-enhanced ECL composite was close to the GCE surface. On this basis, a linearly enhanced ECL signal was acquired with the concentration of Hg2+ in the range of 5.0 × 10-11 M - 1.0 × 10-6 M with excellent selectivity, repeatability and stability in 3 min for each assay. In addition, the proposed aptasensor showed satisfying accuracy and practicability for Hg2+ analysis in tap and canal water verified by the inductively coupled plasma-mass spectrometry (ICP-MS) method.

A FRET-based aptasensor for ochratoxin A detection using graphitic carbon nitride quantum dots and CoOOH nanosheets as donor-acceptor pair.

A new fluorescence aptasensor for Ochratoxin A (OTA) analysis in corn and barley flour was developed owing to the favourable quenching function of cobalt oxyhydroxide (CoOOH) nanosheets. The first combination of graphitic carbon nitride quantum dots (g-CNQDs) and CoOOH nanosheets as efficient energy donor-acceptor pair was reported, and the quenching mechanism was proved by investigating the fluorescence lifetime of g-CNQDs. The aptamer-modified g-CNQDs (g-CNQDs-apt) were adsorbed onto CoOOH nanosheets surface by van der Waals force. Consequently, the Förster resonance energy transfer (FRET) from g-CNQDs-apt to CoOOH nanosheets was initiated, leading to quenched fluorescence. With the addition of OTA, the linear aptamer specifically bound with OTA to form G-quadruplex, which had relatively weak interaction with the CoOOH nanosheets and separated from the nanosheets surface. Thus, the FRET process between g-CNQDs-apt and CoOOH nanosheets was hindered, leading to the fluorescence of g-CNQDs-apt recovered clearly. The developed aptasensor exhibited acceptable detection limit with 0.5 nM and desirable linear relationship from 1 nM to 140 nM. Meanwhile, the aptasensor possessed multiple advantages, including easy operation, rapid detection and high selectivity. Moreover, the aptamer sensing platform was favorably applied for OTA determination in cereal (barley and corn flour), in which the recoveries varied from 94.5% to 101% with the relative standard deviation under 2.24%.

Dietary Fatty Acids Alter Lipid Profiles and Induce Myocardial Dysfunction without Causing Metabolic Disorders in Mice.

Oversupply of bulk saturated fatty acids (SFA) induces metabolic disorders and myocardial dysfunction. We investigated whether, without causing metabolic disorders, the uptake of individual dietary SFA species alters lipid profiles and induces myocardial dysfunction. C57BL/6 mice were fed various customized long-chain SFA diets (40% caloric intake from SFA), including a beef tallow (HBD), cocoa butter (HCD), milk fat (HMD) and palm oil diet (HPD), for 6 months. An isocaloric fat diet, containing medium-chain triglycerides, served as a control (CHD). Long-term intake of dietary long-chain SFA differentially affected the fatty acid composition in cardiac phospholipids. All long-chain SFA diets increased the levels of arachidonic acid and total SFA in cardiac phospholipids. The preferential incorporation of individual SFA into the cardiac phospholipid fraction was dependent on the dietary SFA species. Cardiac ceramide content was elevated in all mice fed long-chain SFA diets, while cardiac hypertrophy was only presented in mice fed HMD or HPD. We have demonstrated that the intake of long-chain SFA species differentially alters cardiac lipid profiles and induces cardiac dysfunction, without causing remarkable metabolic disorders.

Antidiabetic Effect of Salvianolic Acid A on Diabetic Animal Models via AMPK Activation and Mitochondrial Regulation.

BACKGROUND/AIMS: Diabetes mellitus (DM) characterized by hyperglycemia contributes to macrovascular and microvascular complications. Salvianolic acid A (SalA) is a polyphenolic compound isolated from the root of Salvia miltiorrhiza Bunge, which is a traditional Chinese medicine widely used to treat cardiovascular diseases. However, little is known about its antidiabetic effect. Our study aimed to investigate the in vivo and in vitro antidiabetic effect of SalA and the underlying mechanisms. METHODS: Alloxan-induced type 1 diabetic mice and high-fat diet (HFD) and low-dose streptozotocin (STZ)-induced type 2 diabetic rats received SalA treatment. Blood glucose, oral glucose tolerance test (OGTT), 24-h food and water intake were monitored. In vitro, glucose consumption and uptake were measured in HepG2 cells and L6 myotubes. Mitochondrial function was detected in hepatic and skeletal muscle mitochondria. AMP-activated protein kinase (AMPK) and Akt were analyzed by western blot. RESULTS: In both type 1 and type 2 diabetic animals, SalA lowered fasting blood glucose (FBG) and fed blood glucose in dose-dependent manner, as well as reduced 24-h food and water intake. In vitro, SalA caused dose-dependent increase in glucose consumption and enhanced glucose uptake. SalA significantly increased ATP production from 10 min to 12 h in HepG2 cells and L6 myotubes. Interestingly, SalA decreased mitochondrial membrane potential (MMP) in HepG2 cells. Furthermore, SalA improved hepatic and skeletal muscle mitochondrial function, increased ATP production, and concurrently decreased MMP. In particularly, SalA activated AMPK phosphorylation through Ca(2+)/calmodulin-dependent protein kinase kinase ß (CaMKKß)/AMPK signaling pathway, independent of liver kinase 1 (LKB1)/AMPK pathway. However, SalA didn't show any effect on insulin secretagogue and activation of PI3K/Akt signaling pathway. CONCLUSION: SalA exhibits the antidiabetic effects in diabetic animal models through improving mitochondrial function, increasing ATP production, and decreasing MMP via CaMKKß/AMPK signaling pathway.

Salvianolic Acid a prevents the pathological progression of hepatic fibrosis in high-fat diet-fed and streptozotocin-induced diabetic rats.

Type 2 diabetes patients have an increased risk of developing hepatic fibrosis. Salvianolic acid A (SalA) has been reported to be a strong polyphenolic anti-oxidant and free radical scavenger. The aim of the present study was to evaluate the effect of SalA on the pathological progression of hepatic fibrosis in high-fat diet (HFD)-fed and streptozotocin (STZ)-induced diabetic rats and to clarify the underlying mechanisms. Type 2 diabetic animal model with hepatic fibrosis was developed by a high-sucrose, HFD and low-dose STZ injection (i.p.). Diabetic rats were randomly divided into SalA group (0.3 mg/kg/day) and diabetic control groups fed with a HFD. After administration for four months, SalA reversed the hyperlipidemia and reduced hepatic triglyceride (TG). Hematoxylin-Eosin (HE) and Picro acid-Sirius red staining results indicated that SalA significantly alleviated the lesions of hepatic steatosis and fibrosis, with the reduction of type I and III collagens. The expression of α-smooth-muscle-actin (α-SMA) and transforming growth factor ß1 (TGF-ß1) in the liver were markedly down-regulated by SalA treatment. TUNEL staining showed that SalA reduced apoptosis in hepatocytes. In addition, SalA improved hepatic mitochondrial respiratory function in diabetic rats. Taken together, these findings demonstrated that SalA could prevent the pathological progression of hepatic fibrosis in HFD-fed and STZ-induced diabetic rats. The underlying mechanisms may be involved in reducing oxidative stress, suppressing α-SMA and TGF-ß1 expression, as well as exerting anti-apoptotic and mitochondria-protective effects.

Inhibition of calpain reduces oxidative stress and attenuates endothelial dysfunction in diabetes.

AIMS: The present study was to investigate the role of calpain in reactive oxygen species (ROS) production in endothelial cells and endothelium-dependent vascular dysfunction under experimental conditions of diabetes. METHODS AND RESULTS: Exposure to high glucose activated calpain, induced apoptosis and reduced nitric oxide (NO) production without changing eNOS protein expression, its phosphorylation and dimers formation in primary human umbilical vein endothelial cells (HUVECs). These effects of high glucose correlated with intracellular ROS production and mitochondrial superoxide generation. Selectively scavenging mitochondrial superoxide increased NO production in high glucose-stimulated HUVECs. Inhibition of calpain using over-expression of calpastatin or pharmacological calpain inhibitor prevented high glucose-induced ROS production, mitochondrial superoxide generation and apoptosis, which were concurrent with an elevation of NO production in HUVECs. In mouse models of streptozotocin-induced type-1 diabetes and OVE26 type-1 diabetic mice, calpain activation correlated with an increase in ROS production and peroxynitrite formation in aortas. Transgenic over-expression of calpastatin reduced ROS production and peroxynitrite formation in diabetic mice. In parallel, diabetes-induced reduction of endothelium-dependent relaxation in aortic ring was reversed by over-expression of calpastatin in mouse models of diabetes. However, the protective effect of calpastatin on endothelium-dependent relaxation was abrogated by eNOS deletion in diabetic mice. CONCLUSIONS: This study suggests that calpain may play a role in vascular endothelial cell ROS production and endothelium-dependent dysfunction in diabetes. Thus, calpain may be an important therapeutic target to overcome diabetes-induced vascular dysfunction.

Evaluation of hippocampal injury and cognitive function induced by embolization in the rat brain.

Embolism is responsible for at least 20% of all stroke and half of cerebral infarctions. A number of animal models have been developed to mimic thromboembolic stroke. However, little aimed directly at hippocampal damage and cognitive function. In the present study, three sizes of emboli (150-178 µm, 74-124 µm, and 48-74 µm) were employed to induce thromboembolic stroke model in rats. Results showed that the diameter of the particle was critical for animal behavioral and histopathological consequences. Hematoxylin-eosin (HE) staining revealed that CA1 and CA2-3, which are two of the main hippocampal subdivisions were injured seriously, especially induced by emboli(48-74 µm) . At 24 hr, the neurological deficit scores showed that emboli injection could cause significant neurological deficit, and the increase of neurological deficit scores correlated well to the diameter of emboli. At 60 days, emboli(150-178 µm) and emboli(48-74 µm) lead to obvious cognitive impairment, which correlated well to the hippocampal CA1 injury. Our research might be helpful to choose suitable size of emboli to induce animal model to research subcortical ischemia and vascular dementia. However, cognitive alterations and cerebral injury following different sizes of emboli injection in rats remains a topic for future investigation.

Pinocembrin inhibits angiotensin II-induced vasoconstriction via suppression of the increase of [Ca2+]i and ERK1/2 activation through blocking AT(1)R in the rat aorta.

Pinocembrin (5,7-dihydroxyflavanone) is one of the primary flavonoids in propolis. Angiotensin II (AngII) is a biologically active peptide that induces vasoconstriction via the activation of the angiotensin type 1 receptor (AT1R). In the present study, we investigated the vasorelaxant effect of pinocembrin on AngII-induced vasoconstriction and the molecular mechanism of action. Pinocembrin was observed to inhibit AngII-induced vasoconstriction in rat aortic rings with either intact or denuded endothelium. In endothelium-denuded tissues, pinocembrin (pD́'2pD2(') 4.28±0.15) counteracted the contractions evoked by cumulative concentrations of AngII. In a docking model, pinocembrin showed effective binding at the active site of AT1R. Pinocembrin was shown to inhibit both AngII-induced Ca(2+) release from internal stores and Ca(2+) influx. Moreover, the increase in the phosphorylation of extracellular signal-regulated kinase (ERK1/2) and myosin light chain 2 (MLC2) induced by AngII was blocked by pinocembrin. These results demonstrate that pinocembrin inhibits AngII-induced rat aortic ring contraction, and these inhibitory effects may be related to the reduction of the AngII-induced increase in [Ca(2+)]i and ERK1/2 activation via blocking AT1R.

[Effects of the effective components group of xiaoshuantongluo formula on rat acute blood stasis model].

Effects of the effective components group of Xiaoshuantongluo formula (XECG) on rat acute blood stasis model were studied under the guidance of the concept of effective components group. Rat acute blood stasis model was induced by subcutaneous injection of epinephrine combined with ice water bath. Hemorheology indices such as whole blood viscosity, plasma viscosity, erythrocyte aggregation index and platelet aggregation rate; coagulation parameters including PT, APTT, TT and FIB; 6-keto-PGF1alpha, TXB2 and D-dimer levels were determined to evaluate the effects of XECG. The results showed that XECG significantly reduced ADP-induced platelet aggregation, but showed little influence on the whole blood viscosity, plasma viscosity and erythrocyte aggregation rate. XECG extended PT and TT slightly, but had no effects on APTT and FIB content. D-dimer levels significantly decreased after administration of XECG with a little decrease of TXB2, but the content of 6-keto-PGF1alpha did not change significantly. The results suggest that the role of XECG of anti-aggregation is more prominent.

Effect of valsartan on the pathological progression of hepatic fibrosis in rats with type 2 diabetes.

Currently there is no effective treatment for nonalcoholic fatty liver disease (NAFLD), especially hepatic fibrosis induced by type 2 diabetes. Valsartan maybe has beneficial effect on the liver disease. The aim of the present study was to investigate the effect of valsartan on the pathological progression of hepatic fibrosis in rats with type 2 diabetes. An animal model of hepatic fibrosis with type 2 diabetes was developed using a high-sucrose, high-fat diet and low-dose streptozotocin. Valsartan (15 mg/kg/day, i.g.) was orally administered for four months. The livers were removed to make hematoxylin-eosin (HE) staining and Picric acid-Sirius red staining, and immunohistochemistry staining of α-smooth-muscle-actin (α-SMA), transforming growth factor ß1 (TGF-ß1), tumor necrosis factor (TNF-α) and monocyte chemotactic protein-1 (MCP-1). Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining was performed to detect hepatocyte apoptosis. The liver mitochondria were isolated to measure the mitochondrial respiratory function. The results showed that valsartan significantly alleviated the lesion of hepatic steatosis and hepatic fibrosis by HE staining and Picric acid-Sirius red staining. Immunohistochemical staining suggested that the expression of α-SMA, TGF-ß1, TNF-α and MCP-1 in liver tissue of diabetic rats was markedly reduced by valsartan. TUNEL staining showed that there were fewer TUNEL-positive apoptotic hepatocytes in valsartan group. In addition, valsartan restored the injured hepatic mitochondrial respiratory function. The findings demonstrated that valsartan prevented the pathological progression of hepatic fibrosis in type 2 diabetic rats, correlated with reducing α-SMA, TGF-ß1, TNF-α and MCP-1 expression, also anti-apoptosis and mitochondria-protective potential.

Salvianolic acid A protects human SH-SY5Y neuroblastoma cells against H2O2-induced injury by increasing stress tolerance ability.

Salvianolic acid A (Sal A) is a polyphenol extracted from the root of the Salvia miltiorrhiza bunge. Hydrogen peroxide (H(2)O(2)) is a major reactive oxygen species (ROS), which has been implicated in stroke and other neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. In this study, we investigated the neuroprotective effects of Sal A in human SH-SY5Y neuroblastoma cells against H(2)O(2)-induced injury. Our results showed that cells pretreated with Sal A exhibited enhanced neuronal survival and that this protection was associated with an increase in adenosine triphosphate (ATP) and the stabilization of mitochondrial membrane potential. In addition, Sal A markedly decreased the excessive activation AMP-activated protein kinase (AMPK) and the serine-threonine protein kinase, Akt, in SH-SY5Ycells induced by H(2)O(2). In conclusion, our results demonstrated that Sal A protects SH-SY5Y cells against H(2)O(2)-induced oxidative stress and these protective effects are related to stress tolerance and not energy depletion via inhibition of the AMPK and Akt signaling pathway.

Vasorelaxant effect of formononetin in the rat thoracic aorta and its mechanisms.

The purpose of the present study was to investigate the effect of formononetin and the related mechanisms on isolated rat thoracic aorta. Formononetin concentration dependently relaxed aortic rings precontracted with norepinephrine (NE, 1 µM) or KCl (80 mM). Pretreatment with formononetin noncompetitively inhibited contractile responses of aortas to NE and KCl. The vasorelaxant effect of formononetin partially relied on intact endothelia, which was significantly attenuated by incubation with N(ω)-nitro-L-arginine methyl ester (100 µM). In endothelium-denuded rings, glibenclamide (10 µM) and tetraethylammonium (5 mM) showed slight reduction in the vasorelaxant effect of formononetin. Moreover, formononetin reduced NE-induced transient contraction in Ca²âº-free solution and inhibited the vasocontraction induced by increasing external calcium in medium plus 80 mM KCl. Our results suggested that formononetin induced relaxation in rat aortic rings through an endothelium-dependent manner via nitric oxide synthesis pathway, and also involving an endothelium-independent vasodilatation by the blockade of Ca²âº channels. The opening of K⁺ channels might also be one of the mechanisms of formononetin-induced vasorelaxation.

[Effect of pinocembrin on brain mitochondrial respiratory function].

There are growing evidences that pinocembrin has better neuroprotective effect. In the present study, the effect of pinocembrin on mitochondrial respiratory function was evaluated in global brain ischemia/ reperfusion (4-vessel occlusion, 4-VO) rats. The results showed that pinocembrin improved the respiratory activity of 4-VO brain mitochondria, through increasing ADP/O, state 3 respiration state (V3), respiration control rate index (RCI) and oxidative phosphorylation rate (OPR). And then, the effect of pinocembrin on brain mitochondria was verified in vitro. The results showed that pinocembrin increased ADP/O, state 3 respiration state, respiration control rate index, oxidative phosphorylation rate in NADH/FADH2 dependent respiratory chain and decreased state 4 respiration state (V4) in NADH dependent respiratory chain. Pinocembrin improved ATP content in brain mitochondria in vitro and in SH-SY5Y cells.

The characteristics of therapeutic effect of pinocembrin in transient global brain ischemia/reperfusion rats.

AIMS: The therapeutic effect of pinocembrin, together with the therapeutic time window, in the transient global cerebral ischemia/reperfusion (I/R) rats was investigated. MAIN METHODS: Adult male Sprague-Dawley rats were subjected to global cerebral ischemia for 20 min by four-vessel occlusion. Pinocembrin (1 and 5mg/kg) was administrated intravenously 30 min before ischemia and 30 min, 2h, 6h after reperfusion, respectively. Neurological scores, brain edema and histological examination by Nissl staining were employed to assess the neuronal injury after ischemia and the neuroprotection by pinocembrin. The activities of superoxide dismutase (SOD), myeloperoxidase (MPO) and the content of malondialdehyde (MDA) in brain tissue were tested by colorimetric assays. Alterations of neurotransmitters were determined by a high performance liquid chromatography-electrochemical method. KEY FINDINGS: Pinocembrin significantly ameliorated neurological deficits and brain edema, and alleviated the degree of hippocampal neuronal loss at 24h after global cerebral I/R with a broad therapeutic time window. It was found that treatment with pinocembrin reduced the compensatory increase of SOD activity and decreased the MDA level and MPO activity in a dose-dependent manner. The metabolic balance between excitatory and inhibitory amino acids was modulated by pinocembrin treatment. SIGNIFICANCE: These findings suggest that pinocembrin provides neuroprotection against global cerebral ischemic injury with a wide therapeutic time window, which may be attributed to its antioxidative, antiinflammatory and antiexcitotoxic effects.

[Effect of metformin on the formation of hepatic fibrosis in type 2 diabetic rats].

The aim of this study is to investigate the effects of the metformin on the formation of hepatic fibrosis in type 2 diabetic rats and discuss its mechanism of liver-protecting activity. After SD rats were fed with high-fat and high-sucrose diet for four weeks, low-dose streptozotocin (STZ) was injected intraperitoneally to make the animal mode of type 2 diabetes. Then, all diabetic rats was fed with the high-fat diet and metformin (ig, 100 mg x kg(-1)) was given orally to metformin group for four months. After the last administration, fasting blood glucose was determined. The livers were removed to calculate the hepatic coefficient and to make HE and Picro acid-Sirius red staining, immunohistochemistry (alpha-SMA and TGFbeta1) and TUNEL staining in order to evaluate the effect of metformin on the hepatic fibrosis. The animal model of type 2 diabetes with hepatic fibrosis was successfully made. Metformin can significantly alleviate the lesions of hepatic steatosis and fibrosis, markedly reduce the expressions of alpha-SMA and TGFbeta1 in liver tissue of type 2 diabetic rats. However, TUNEL staining result suggested that metformin could not reduce apoptosis of hepatocytes. The results suggest that metformin can inhibit the formation of hepatic fibrosis in type 2 diabetes.

[Necroptosis: a new mechanism of cell death].

Traditionally, cell death has been categorized into apoptosis or necrosis. However, a growing number of research indicates necroptosis, distinct from apoptosis and necrosis, contributes to a range of human diseases as a new mechanism of cell death. In order to achieve a better understanding of different cell death models and an improvement for development of new drugs associated with this pathway, the mechanism of necroptosis, the differences among apoptosis, necrosis and necroptosis, as well as the role of necroptosis in human diseases and its relation to discovery of drug targets, are discussed in this article.

Cytotoxic activities of extracts and compounds from Viscum coloratum and its transformation products by Rhodobacter sphaeroides.

The bioassay-oriented fractionation of mistletoe crude extracts (MCEE) using 75% ethanol and culture products of mistletoe transformed by Rhodobacter sphaeroides, a photosynthetic bacterium (PSBT), revealed that the high cytotoxic activities were due to the petroleum ether extracts (PEs) and the acid-precipitated proteins from the aqueous extracts (AQs) of MCEE and PSBT. The isolated triterpenes may account for the activities of the PEs of MCEE and PSBT, respectively. Extraction of MCEE using petroleum ether led to the isolation of 3-epi-betulinic acid (1), betulonic acid (2), oleanolic acid (3), and beta-amyrin acetate (4), while petroleum ether extraction of PSBT led to the isolation of 1,3,4,betulinic acid (5), erythrodiol (6), and (3beta)-olean-12-ene-3,23-diol (7). The PE of PSBT exerted higher cytotoxicity than the PE of MCEE, which was due to the different triterpene contents of these two extracts. The cytotoxic activities of all compounds were tested, and the results revealed that compounds 1, 2, 3, 5, 6, and 7 contributed significantly to the cytotoxicities of both PEs. The AQ of the PSBT exerted almost the same cytotoxic activity and lower toxicity compared to the AQ of the MCEE. These findings indicate that mistletoe products biotransformed by R. sphaeroides could be used to treat cancers, since they have lower toxicities and higher antitumor activities compared to standard treatments.