Da-Yong Cai

Metabolic pathways involved in Xin-Ke-Shu protecting against myocardial infarction in rats using ultra high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

Xin-Ke-Shu (XKS) is a patent drug used for coronary heart diseases in China. This study evaluated the protective effect of XKS against isoproterenol (ISO)-induced myocardial infarction (MI). For its underlying mechanism in rats with MI, a metabonomic approach was developed using ultra high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/QTOF-MS). Plasma metabolites were profiled in MI rats, pretreated orally with or without XKS. Two genres of metabolic biomarkers were used to elucidate the pharmacological action of XKS: pathological biomarkers and pharmaco biomarkers. Fifteen metabolites significantly varying between MI rats and normal rats were characterized as potential pathological biomarkers related to MI, including L-acetylcarnitine (1), L-isoleucyl-L-proline (2), tyramine (3), isobutyryl-L-carnitine (4), phytosphingosine (5), sphinganine (6), L-palmitoylcarnitine (7), lysoPC(18:0) (8), uric acid (9), L-tryptophan (10), lysoPC(18:2) (11), lysoPC(16:0) (12), docosahexaenoic acid (13), arachidonic acid (14) and linoleic acid (15). Among them, eight (1-6, 9 and 10) were first reported as pathological biomarkers related to ISO-induced MI, which mainly involved into fatty acid β-oxidation pathway, sphingolipid metabolism, proteolysis, tryptophan metabolism and purine metabolism. The metabolites significantly varying between MI rats with and without XKS pretreatment were considered as pharmaco biomarkers. A total of 17 pharmaco biomarkers were recognized, including 15 pathological biomarkers (1-15), hexanoylcarnitine (16) and tetradecanoylcarnitine (17). The results suggested that pretreatment of XKS protected metabolic perturbations in rats with MI, major via lipid pathways, amino acid metabolism and purine metabolism, which also provided a promising approach for evaluating the pharmacodynamics and mechanism of traditional Chinese medicines (TCM) formulas.

UPLC-Q/TOF MS standardized Chinese formula Xin-Ke-Shu for the treatment of atherosclerosis in a rabbit model

Xin-Ke-Shu (XKS), a patent traditional Chinese medicine (TCM) preparation, has been commonly used for the treatment of coronary heart disease in China. In order to understand its mechanism of action, a metabonomic approach based on ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF MS) was utilized to profile the plasma metabolic fingerprints of atherosclerosis (AS) rabbits with and without XKS treatment. The metabolic profile of model group clearly separated from normal, and that of XKS group was closer to the control group. Metabolites with significant changes during atherosclerosis were characterized as potential biomarkers related to the development of atherosclerosis by using orthogonal partial least-squares-discriminate analysis (OPLS-DA). Twenty potential biomarkers, including l-acetylcarnitine (1), propionylcarnitine (2), unknown (3), phytosphingosine (4), glycoursodeoxycholic acid (5), LPC(14:0) (6), sphinganine (7), LPC(20:5) (8), LPC(16:1) (9), LPC(18:2) (10), LPC(18:3) (11), LPC(22:5) (12), LPC(16:0) (13), LPC(18:1) (14), LPC(22:4) (15), LPC(17:0) (16), LPC(20:2) (17), elaidic carnitine (18), LPC(18:0) (19) and LPC(20:1) (20), were identified by their accurate mass and MS(E) spectra. The derivations of those biomarkers can be regulated by administration of XKS, which suggested that the intervention effect of XKS against AS may involve in regulating the lipid perturbation including fatty acid β-oxidation pathway, sphingolipid metabolism, glycerophospholipid metabolism and bile acid biosynthesis. This study indicated that the UPLC-Q/TOF MS-based metabonomics not only gave a systematic view of the pathomechanism of AS, but also provided a powerful tool to study the efficacy and mechanism of complex TCM prescriptions.

Quercetin inhibits angiogenesis by targeting calcineurin in the xenograft model of human breast cancer

Vascular endothelial growth factor receptor 2 (VEGFR2) mediated calcineurin/nuclear factor of activated T-cells (NFAT) pathway is crucial in the angiogenesis of human breast cancer. Quercetin (Qu), a flavonoid known to possess anti-angiogenesis and antitumor properties, inhibited calcineurin activity in vitro. Herein, we performed a study in vivo to evaluate the effects of Qu on the angiogenesis in breast cancer. Female BALB/c nude mice were injected with MCF-7 cells into the mammary fat and were randomly divided into four groups. The animals were treated with vehicle solution, tamoxifen (TAM, 5.6mg/kg), tacrolimus (FK506, 3mg/kg), or Qu (34mg/kg) for 21 days, respectively. The results showed that, similar to TAM and FK506, Qu decreased tumor growth, limited oncocyte proliferation and promoted tumor necrosis. Anti-angiogenic actions of Qu were demonstrated as decreased serum VEGF (P<0.01), and sparse microvessel density (P<0.05). Qu significantly inhibited tumor calcineurin activities, and the inhibitory rate was 62.73% in Qu treated animals, compared to that was 72.90% in FK506 group (P>0.05). Effects of Qu on calcineurin/NFAT pathway were confirmed as decreased subcellular located levels of VEGF (P<0.05), VEGFR2 (P<0.05) and NFATc3 (P<0.01), downregulated gene expression of VEGF (P<0.05), VEGFR2 (P<0.05) and NFATc3 (P<0.01), reduced protein levels of VEGF (P<0.05), VEGFR2 (P<0.05), and NFATc3 (P<0.01) in tumor tissues. These findings indicate that Qu inhibit angiogenesis of human breast cancer xenograft in nude mice, which was associated with suppressing calcineurin activity and its regulated pathway activation.

Glycyrrhizinate reduces portal hypertension in isolated perfused rat livers with chronic hepatitis

AIM To investigate the effects of diammonium glycyrrhizinate (Gly) on portal hypertension (PHT) in isolated portal perfused rat liver (IPPRL) with carbon tetrachloride (CCl₄)-induced chronic hepatitis. METHODS PHT model was replicated with CCl₄ in rats for 84 d. Model was identified by measuring the ascetic amounts, hepatic function, portal pressure in vivo, splenic index, and pathological alterations. Inducible nitric oxide synthase (iNOS) in liver was assessed by immunohistochemistry. IPPRLs were performed at d₀, d₂₈, d₅₆, and d₈₄. After phenylephrine-induced constriction, Gly was geometrically used to reduce PHT. Gly action was expressed as median effective concentration (EC₅₀) and area under the curve (AUC). Underlying mechanism was exploited by linear correlation between AUC values of Gly and existed iNOS in portal triads. RESULTS PHT model was confirmed with ascites, splenomegaly, serum biomarkers of hepatic injury, and elevated portal pressure. Pathological findings had shown normal hepatic structure at d₀, degenerations at d₂₈, fibrosis at d₅₆, cirrhosis at d₈₄ in PHT rats. Pseudo lobule ratios decreased and collagen ratios increased progressively along with PHT development. Gly does dose-dependently reduce PHT in IPPRLs with CCl₄-induced chronic hepatitis. Gly potencies were increased gradually along with PHT development, characterized with its EC₅₀ at 2.80 × 10⁻¹⁰, 3.03 × 10⁻¹¹, 3.77 × 10⁻¹¹ and 4.65×10⁻¹¹ mol/L at d₀, d₂₈, d₅₆ and d₈₄, respectively. Existed iNOS was located at hepatocyte at d₀, stellate cells at d₂₈, stellate cells and macrophages at d₅₆, and macrophages in portal triads at d₈₄. Macrophages infiltrated more into portal triads and expressed more iNOS along with PHT development. AUC values of Gly were positively correlated with existed iNOS levels in portal triads. CONCLUSION Gly reduces indirectly PHT in IPPRL with CCl₄-induced chronic hepatitis. The underlying mechanisms may relate to rescue NO bioavailability from macrophage-derived peroxynitrite in portal triads.

A pharmacodynamic model of portal hypertension in isolated perfused rat liver

AIM To develop a pharmacodynamic model of portal hypertension from chronic hepatitis. METHODS Pathological changes and collagen depositions were analyzed using morphometry to confirm CCl₄-induced chronic hepatitis. At d₀, d₂₈, d₅₆ and d₈₄ of the process, the portal perfused velocities (μL/min) in isolated rat livers were exactly controlled with a quantified pump. The pressure (mmHg) was monitored with a Physiological System. The geometric concentrations of phenylephrine or acetylcholine were added to a fixed volume (300 mL) of the circulating perfusate. The equation, the median effective concentration and its 95% confidence intervals of phenylephrine or acetylcholine were regressed with Prism-4 software in non-linear fit and various slopes. In the isolated perfused rat livers with chronic hepatitis, both median effective concentrations were defined as the pharmacodynamic model of portal hypertension. RESULTS At d₀, d₂₈, d₅₆ and d₈₄, the equations of portal pressure potency from the concentrations of phenylephrine used to constrict the portal vein in isolated perfused rat livers were Y = 0.1732 + 0.3970/[1 + 10((-4.3061-0.4407 X))], Y = -0.004934 + 0.12113/[1 + 10((-3.1247-0.3262 X))], Y = 0.0104 + 0.2643/[1 + 10((-8.8462-0.9579 X))], and Y = 0.01603 + 0.12107/[1 + 10((-5.1134-0.563 X))]; the median effective concentrations were 1.69 × 10⁻¹⁰ mol/L, 2.64 × 10⁻¹⁰ mol/L, 5.82 × 10⁻¹⁰ mol/L, and 8.24 × 10⁻¹⁰ mol/L, respectively. The equations from the concentrations of acetylcholine used to relax the portal vein were Y = -0.4548 + 0.3274/[1 + 10((6.1538 + 0.5554 X))], Y = -0.05391 + 0.06424/[1 + 10((3.8541 + 0.3469 X))], Y = -0.2733 + 0.22978/[1 + 10((3.0472 + 0.3008 X))], and Y = -0.0559 + 0.053178/[1 + 10((5.6336 + 0.5883 X))]; the median effective concentrations were 8.40 × 10⁻¹⁰ mol/L, 7.73 × 10⁻¹² mol/L, 5.98 × 10⁻¹¹ mol/L, and 2.66 × 10⁻¹⁰ mol/L, respectively. CONCLUSION A pharmacodynamic model of portal hypertension in isolated perfused rat livers with chronic hepatitis was defined as the median effective concentrations of phenylephrine and acetylcholine.

Diammonium glycyrrhizinate alleviates hepatopulmonary syndrome via restoring superoxide dismutase 3 activity in rats

Abstract Hepatopulmonary syndrome (HPS) has a fatal hypoxemia from pulmonary shunts. Superoxide dismutase 3 (SOD3) deficiency involves in this pathogenesis. The purpose of this study was to investigate the underlying mechanisms of diammonium glycyrrhizinate (DG) on HPS via SOD3. Carbon tetrachloride induced HPS rats were treated with captopril or DG for 56 days. Blood gas, pulmonary artery pressures, and histological changes were measured. Molecule dynamics of inducible (iNOS), endothelial (eNOS), neuronal nitric oxide synthase (nNOS) and SOD3 were assessed by immunohistochemistry, quantitative RT‐PCR and western blot. The results showed that DG significantly increased partial pressure of oxygen (P<0.01), decreased alveolar‐arterial oxygen gradient (P<0.01), and improved hypoxemia. In HPS model rats, anatomical pulmonary shunts were demonstrated as both constricted arterioles and dilated metarterioles, while physiological shunts were demonstrated by lowered pulmonary artery pressure in vivo. DG significantly reversed the vascular pathological changes. Elevated iNOS or eNOS, and decreased SOD3 expression in model rats indicated imbalance of nitric oxide (NO) bioavailability. Partial SOD3 potencies correlated with circulative events and NOSs, indicating that restorable SOD3 regulated arteriole constriction and metarteriole dilatation. DG reduced iNOS or eNOS, increased SOD3 expression, especially significantly increased the partial SOD3 located in pulmonary arteries (P<0.05), arterioles (P<0.05) and alveolus (P<0.05). These results suggested that DG relieved HPS shunts and limited HPS pathogenesis may associate with restoring SOD3 activity. Graphical abstract Figure. No Caption available.

Ling-Yang-Gou-Teng-decoction prevents vascular dementia through inhibiting oxidative stress induced neurovascular coupling dysfunction

ETHNOPHARMACOLOGICAL RELEVANCE Vascular dementia (VaD) is the common cognitive disorder derived mainly from lacunar stroke (LS). The oxidative stress induced neurovascular coupling (NVC) dysfunction involves in the pathogenesis of VaD. Currently, there is no specific drug for VaD. Ling-Yang-Gou-Teng -Decoction (LG), a well-known traditional Chinese formula, has been used for preventing VaD in clinic. AIM OF THE STUDY In this study, we aimed to investigate the underlying mechanism of LG on VaD in rats. MATERIALS AND METHOD VaD was replicated with autologous micro-thrombi against the background of hypercholesterolemia induced with high fatty diet. PTX (68.90 mg/kg/day), LG with three dosages (2.58, 8.14, 25.80 g/kg/day) was orally administrated to VaD rats, respectively. The NVC sensitivity was defined as the ratio of the microcirculative cerebral blood velocity (CBV) to the electroencephalograph (EEG) before and after penicillin stimulation. Behavioral performance, pathological changes of brain and oxidation related molecules were detected to assess the effects of LG on VaD. RESULTS LG exhibited beneficial effects on the VaD, which was demonstrated as improved exploratory, learning and memory abilities, relieved vascular or neural pathological changes in cerebral cortex or hippocampus. LG maintained NVC sensitivity, which was confirmed as significantly increased ΔCBV and the elevated ratio of ΔCBV/ΔqEEG. The underlying mechanisms of LG was associated with antioxidant effects, which was confirmed as significantly decreased nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) expression, and increased superoxide dismutase 3 (SOD3) expression. LG also reduced iNOS, increased nNOS and eNOS expression to restore NO bioavailability. CONCLUSIONS The results suggested that LG prevented VaD may associate with inhibiting oxidative stress, protecting NO bioavailability, and then maintaining NVC sensitivity.

Anti-angiogenic effects of Qingdu granule on breast cancer through inhibiting NFAT signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE Qingdu granule (QDG), a traditional Chinese herbal prescription, had anti-tumor effect on breast cancer. However the underlying mechanism of QDG was unclear. THE AIM OF THIS STUDY The present study aimed to investigate whether QDG could inhibit angiogenesis of breast cancer via acting on nuclear factor of activated T-cells (NFAT) signaling pathway. This was implicated in human umbilical vein endothelial cells (HUVECs) in vitro and breast cancer xenograft model in vivo. MATERIALS AND METHODS The VEGF165 (15.58 ng/mL) induced human umbilical vein endothelial cells (HUVECs) were treated with serum samples containing tamoxifen (TAM), tacrolimus (FK506), or QDG with three dosages. The migration and canalization capacities of HUVECs were evaluated by transwell migration and tube formation assay. In 72 h-cultured HUVECs, The gene expression, protein amount, and nuclear translocation of NFATc3 were measured. The anti-tumor and anti-angiogenic effects of QDG in vivo were investigated in breast cancer xenograft model. The serum VEGF levels, microvessel density, and protein expressions (immunohistochemistry and western blot) of VEGF, VEGFR2 and NFATc3 were detected. RESULTS The results showed that, QDG significantly inhibited HUVEC migration and tube formation. It downregulated NFATc3 gene expression, decreased NFATc3 protein amount, and reduced the ratio of NFATc3 nuclear translocation in HUVECs. In breast cancer xenograft model, QDG treatment significantly suppressed tumor growth, inhibited VEGF release, and decreased microvessel density. QDG reduced protein expressions of VEGF, VEGFR2 and NFATc3. CONCLUSION The results suggested that QDG showed anti-angiogenic effects of breast cancer both in vitro and in vivo. The mechanism might be partially associated with inhibiting NFAT signaling pathway.

A novel pharmacodynamic model in rats for preventing vascular dementia from maintaining neurovascular coupling sensitivity

Abstract Vascular dementia (VaD) is the common cognitive disorder derived mainly from lacunar stroke. The neurovascular coupling (NVC) dysfunction involves in its pathogenesis. VaD lacks suitable animal models for developing preventive therapies. This study aimed to confirm a model for preventing VaD via maintaining NVC sensitivity in rats. The model was replicated with autologous microthrombi against the background of hypercholesterolemia. A phosphodiesterase inhibitor (pentoxyfylline) was preventively administrated to confirm the role of NVC sensitivity. Cognitive function was evaluated as exploratory, learning and memorizing abilities. NVC sensitivity was defined as the ratio of microcirculative cerebral blood flow (&Dgr;CBF) to the quantitative electroencephalograph (&Dgr;qEEG) before and after penicillin stimulation. The pathogenesis of NVC dysfunction was explored as expressions of neuronal (nNOS), inducible (iNOS) and endothelial nitric oxide synthase (eNOS) in cerebral cortex. The model rats showed cognitive impairment, microvascular edema (2.54 ± 0.30%, P < 0.01), neuronal edema (1.24 ± 0.48%, P < 0.01) and nissl body loss (0.03 ± 0.003%, P < 0.01) in cerebral cortex, and neuronal necrosis in hippocampal CA1 region (neuronal cell number 41.76 ± 10.04 cells, P < 0.01) compared with sham group. The NVC dullness in model rats was confirmed as significantly decreased ratio of &Dgr;CBF/&Dgr;qEEG (0.05 ± 0.02%, P < 0.01) compared with sham group (0.20 ± 0.06%). The underlying mechanism of NVC dysfunction was found as imbalanced NOS expressions (decreased nNOS and eNOS, while increased iNOS levels in cerebral cortex). The NVC dullness was significantly relieved in pentoxyfylline administrated rats (0.12 ± 0.06%, P < 0.01). It indicated that this model was suitable to evaluate candidates for preventing VaD via maintaining NVC sensitivity.