Xiao-Qiang Li

Characterizations and anti-tumor activities of three acidic polysaccharides from Angelica sinensis (Oliv.) Diels.

In this study, three acidic polysaccharides (APS-3a, APS-3b and APS-3c) were obtained from Angelica sinensis (Oliv.) Diels. They displayed different structural features and anti-tumor activities. APS-3b and APS-3c significantly inhibited the growth of S180 tumors and increased the life spans of S180 tumor-bearing mice, whereas APS-3a had no significant effect. Further experiments showed that APS-3b and APS-3c could cause a concentration-dependent proliferation of the splenocytes, up-regulate IFN-gamma, IL-2 and IL-6 mRNA expressions in splenocytes and stimulate the productions of NO and TNF-alpha in peritoneal macrophages. Taken together, the three acidic polysaccharides displayed different anti-tumor activities which were associated with their different structural characteristics.

Amlodipine inhibits TNF-α production and attenuates cardiac dysfunction induced by lipopolysaccharide involving PI3K/Akt pathway

Calcium channel blockers (CCBs) are widely used in the therapy of cardiovascular diseases. Recent studies have shown that several CCBs exerted distinct anti-inflammatory effect in myocardial dysfunction models. The purpose of the present study was to evaluate therapeutic effect and possible mechanism of action of amlodipine, one of the widely used CCBs, on rat cardiac dysfunction during sepsis induced by lipopolysaccharide (LPS). Pretreatment of the rats with amlodipine (10 or 30 mg/kg, i.v.) delayed the fall of mean arterial blood pressure caused by LPS. Amlodipine also significantly inhibited the elevation of plasma tumor necrosis factor alpha (TNF-alpha) and decreased levels of inducible nitric oxide synthase (iNOS) in response to LPS challenge. To investigate the mechanism of the action of amlodipine, neonatal rat cardiomyocytes were used as a model. Amlodipine concentration-dependently decreased the release of TNF-alpha and iNOS protein expression, and suppressed the degradation and phosphorylation of inhibitor of kappaB-alpha (IkappaB-alpha) in LPS-activated neonatal rat cardiomyocytes. Further studies revealed that amlodipine markedly activated phosphatidylinositiol 3-kinase (PI3K) and Akt, downstream of the PI3K signal cascade. Application of PI3K inhibitors, wortmannin and LY294002 attenuated the depression of TNF-alpha and iNOS expression by amlodipine in LPS-induced cardiomyocytes. These findings may explain some cardioprotective effects of amlodipine in LPS-mediated sepsis and suggest that the inhibition of TNF-alpha and iNOS expression by amlodipine is, at least in part, dependent on PI3K/Akt signaling pathway.

Madecassoside suppresses LPS-induced TNF-α production in cardiomyocytes through inhibition of ERK, p38, and NF-κB activity

Madecassoside (MA) is a major triterpenoid component of Centella asiatica that has a wide range of biological activities, including wound-healing and antioxidative activities. In the present study, we evaluated the therapeutic effect of MA on rat cardiac dysfunction during sepsis induced by lipopolysaccharide (LPS), as well as the possible mechanism. Pretreatment of the neonatal rat cardiomyocytes with MA inhibited LPS-induced TNF-alpha production in a concentration-dependent manner. In addition, pretreatment of the rats with MA (20 mg/kg, i.g.) significantly inhibited the elevation of plasma TNF-alpha, delayed the fall of mean arterial blood pressure, and attenuated the tachycardia induced by LPS. We further observed that MA prevented the LPS-induced nuclear factor-kappa B (NF-kappaB) translocation from the cytoplasm into the nucleus, and inhibited the LPS-induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and p38. These results suggest that MA inhibits LPS-stimulated TNF-alpha production through the blocking of ERK1/2, p38 and NF-kappaB pathways in cardiomyocytes. MA may have cardioprotective effects in LPS-mediated sepsis.

Burn-induced apoptosis of cardiomyocytes is survivin dependent and regulated by PI3K/Akt, p38 MAPK and ERK pathways

Survivin belongs to the family of genes known as inhibitors of apoptosis, and although it has been implicated in the prevention of cancer, its potential role in burn-induced cardiac injury is unknown. In this study, we investigated the effects of survivin blockade on burn-induced cardiac apoptosis. Using a standardized Sprague-Dawley rat model of third-degree burn injury over 40% of total body surface area, apoptosis was measured in vivo followed by in vitro assessment of burn serum-stimulated cardiomyocytes. Based on the Western blot analyses, real-time PCR, ELISA, and TUNEL, apoptosis and caspase activation both in vivo and in vitro were significantly increased after severe burn injury, while survivin expression was increased (up to 2.90-fold) during the early stage of burn injury and was almost completely abolished 8xa0h after the burn. Survivin-deficient cardiomyocytes, as well as hearts from rats treated with the survivin inhibitor YM155, exhibited increased caspase-3 protein and mRNA expression and apoptosis ratio at different times after the burn. Furthermore, inhibition of ERK, phosphoinositol 3-kinase contributed the burn serum-induced increase in apoptosis and caspase-3 protein expression, and decreased survivin expression, whereas burn serum-induced increase in apoptosis was attenuated by P38 mitogen-activated protein kinase inhibition. These data identify survivin as a critical anti-apoptotic regulator of cardiomyocytes after burn injury. ERK, P38 MAPK and PI3K were found to be upstream regulators of survivin.

The comparison of α-bromo-4-chlorocinnamaldehyde and cinnamaldehyde on coxsackie virus B3-induced myocarditis and their mechanisms

Early experiments showed cinnamaldehyde had obvious therapeutic effect on viral myocarditis, but cinnamaldehyde was unstable in vivo. To overcome this limitation, we used cinnamaldehyde as a lead compound to synthesize α-bromo-4-chlorocinnamaldehyde (BCC). In the present study, we compared the therapeutic effects of BCC with cinnamaldehyde on coxsackie virus B3 (CVB3)-induced viral myocarditis (VMC), as well as investigated the possible mechanism. The antiviral and cytotoxic effects in vitro were evaluated on HeLa cells infected by CVB3 and rat cardiomyocytes respectively. Our results showed that IC50 were 0.78±0.13 μM and 48.16±5.79 μM in BCC and cinnamaldehyde-treated cells. 50% toxic concentration (TC) in BCC-treated cells was 22-fold higher than in the cinnamaldehyde group. In vivo BALB/c mice were infected with CVB3 for establishing VMC models. The results demonstrated that BCC reduced the viral titers and cardiac pathological changes in a dose-dependent manner. Myocardial virus titers were significantly lower in the 50 mg/kg BCC-treated group than in cinnamaldehyde groups. In addition, BCC could significantly inhibit the replication of CVB3 mRNA and the secretion of inflammatory cytokines TNF-α, IL-β and IL-6 in CVB3-infected cardiomyocytes. We further observed that BCC suppressed CVB3-induced NF-κB activation, IκB-α degradation and phosphorylation in a concentration-dependent manner, and reduced Toll like receptor (TLR) 4 protein level in hearts. These results suggest that BCC had a promising therapeutic effect on VMC with a highly significant favorable effects and less toxicity than cinnamaldehyde. Furthermore, the effect of BCC on VMC might be through inhibition of inflammatory signaling.

Corosolic acid inhibits the proliferation of glomerular mesangial cells and protects against diabetic renal damage

Diabetic nephropathy (DN) is one of the major complications of diabetes mellitus (DM). This study aimed to explore the effects of corosolic acid (CA) on the renal damage of DM and the mechanisms behind these effects. The renoprotective effect of CA was investigated in type 1 diabetic rats and db/db mice. The kidneys and glomerular mesangial cells (GMCs) were used to study the proliferation of GMCs by immunostaining and MTT assay. Further immunoblotting, siRNA, qPCR analysis, and detecting of NADPH oxidase activity and reactive oxygen species (ROS) generation were performed to explore relevant molecular mechanisms. In CA-treated diabetic animals, diabetes-induced albuminuria, increased serum creatinine and blood urea nitrogen were significantly attenuated, and glomerular hypertrophy, mesangial expansion and fibrosis were ameliorated. Furthermore, CA significantly inhibited proliferation of GMCs and phosphorylation of ERK1/2 and p38 MAPK in both diabetic animals and high glucose (HG)-induced GMCs. CA also normalized Δψm and inhibited HG-induced NADPH oxidase activity, ROS generation and NOX4, NOX2, p22phox and p47phox expression. More importantly, CA inhibited GMC proliferation mediated by NADPH/ERK1/2 and p38 MAPK signaling pathways. These findings suggest that CA exert the protective effect on DN by anti-proliferation resulted from inhibition of p38 MAPK- and NADPH-mediated inactivation of ERK1/2.

Kuwanon G attenuates atherosclerosis by upregulation of LXRα-ABCA1/ABCG1 and inhibition of NFκB activity in macrophages

Background: Atherosclerosis is characterized by chronic inflammation in vascular wall. Previous studies suggest that Kuwanon G (KWG) exerts anti‐inflammatory activities. However, the effect of KWG on atherosclerosis remains unexplored. Aims: To explore whether KWG affects macrophage foam cell formation in vitro and atherogenesis in vivo. Methods: RAW 264.7 macrophages were stimulated with ox‐LDL for 24 h to induce foam cell formation and treated with KWG. Foam cell formation was determined by ORO staining and enzymatic analysis. Pro‐inflammatory cytokines mRNA levels were tested by Real‐time PCR method. Further molecular mechanism was investigated using Western blot. In vivo, ApoE−/− mice were fed with high‐fat diet and intraperitoneally injected with KWG. Atherosclerotic lesion was accessed by H&E and ORO staining. Plaque composition was evaluated by immunohistochemistry and Sirius Red staining. Serum lipid profile and inflammatory cytokines were evaluated by enzymatic method and ELISA. Results: KWG significantly decreased intracellular lipid accumulation and inflammatory cytokines mRNA levels in macrophages through enhancing LXR&agr;‐ABCA1/ABCG1 pathway and inhibiting NF&kgr;B activation. Administrated with KWG remarkably reduced the atherosclerotic lesion areas and macrophage content in the plaque of high‐fat diet fed ApoE−/− mice. KWG also reduced hyperlipidemia and serum inflammatory cytokines in vivo. Conclusion: Taken together, these data highlight that KWG can attenuate atherosclerosis through inhibiting foam cell formation and inflammatory response. HighlightsKWG prevents macrophage foam cell formation by up‐regulating LXR&agr;‐ABCA1/ABCG1.KWG attenuates inflammatory response by diminishing NF&kgr;B activity.KWG attenuates atherosclerosis development in ApoE−/− mice fed with HFD.

Wound-healing activity of Zanthoxylum bungeanum maxim seed oil on experimentally burned rats

Background: The seed oil of Zanthoxylum bungeanum Maxim (ZBSO) is considered to be rich source of fatty acids, mainly oleic and linoleic acids, and has been used for the treatment of burns in Chinese medicine. Objective: We evaluated the healing efficacy of ZBSO and explored its possible mechanism on scalded rats. Materials and Methods: Sprague-Dawley rat models with deep second-degree burns were set up, and ZBSO (500 and 1000 μl/wound) was topically applied twice daily for 7 days and then once daily until wound healing. The therapeutic effects of ZBSO were evaluated by observing wound closure time, decrustation time, wound-healing ratio, and pathological changes. Collagen type-III, matrix metalloproteinase-2 (MMP-2), MMP-9, phospho-nuclear factor-κB (p-NF-κB) p65, inhibitor of NF-κB subunit α p-IκBα, and inhibitor of NF-κB subunit α (IκBα) expression were determined using Western blotting. Results: The ZBSO-treated group showed a higher wound-healing ratio and shorter decrustation and wound closure times than the untreated group. The topical application of ZBSO increased collagen synthesis as evidenced by an increase in hydroxyproline level and upregulated expression of collagen type-III on days 7, 14, and 21 posttreatment. A reduction in MMP-2 and MMP-9 expressions also confirmed the collagen formation efficacy of ZBSO. Furthermore, there was a significant increase in superoxide dismutase levels and a decrease in malondialdehyde levels in ZBSO-treated wounds. ZBSO also decreased tumor necrosis factor alpha, interleukin-1 (IL-1) β, and IL-6 levels in serum, upregulated IκBα, and downregulated p-NF-κB p65 and p-IκBα expression in vivo, indicating the anti-inflammatory action of ZBSO. Conclusion: ZBSO has significant potential to treat burn wounds by accelerating collagen synthesis and the anti-inflammatory cascade of the healing process. Abbreviations used: ECL: Enhanced chemiluminescence; ECM: Extracellular matrix; ELISA: Enzyme-linked immunosorbent assay; GC-MS: Gas chromatography-mass spectrometry; HRP: Horseradish peroxidase; HYP: Hydroxyproline; IκBα: Inhibitor of NF-κB subunit α; IL: Interleukin; MDA: Malondialdehyde; MMP: Matrix metalloproteinase-2; NF-κB: Nuclear factor-κB; SFE: Supercritical fluid extraction; SOD: Superoxide dismutase; SSD: Silver sulfadiazine; TCM: Traditional Chinese medicine; TNF: Tumor necrosis factor.

Simultaneous Quantification of Uronic Acid, Amino Sugar, and Neutral Sugar in the Acidic Polysaccharides Extracted from the Roots of Angelica sinensis (Oliv.) Diels by HPLC

High-performance liquid chromatography (HPLC) is routinely used to analyze monosaccharide composition. This is the first report describing the simultaneous determination of uronic acid, amino sugar, and neutral sugar in the polysaccharide from Angelica sinensis using pre-column derivatization. We were able to analyze the monosaccharide composition of acidic Angelica polysaccharides (AAPS) using this method. Ten different monosaccharides, namely d-mannose, d-glucosamine, l-rhamnose, d-galactosamine, d-glucuronic acid, d-galacturonic acid, d-glucose, d-galactose, l-arabinose, and l-fucose were made into pre-column derivatives to serve as the standard for AAPS analysis. Samples were separated on a Hypersil BDS C18 column (4.6xa0mmu2009×u2009250xa0mm, i.d.) and detected by UV detection at 250xa0nm wavelength. The mobile phase was composed of aqueous ammonium acetate buffer (100xa0mM, pHxa05.0), acetonitrile, and tetrahydrofuran in the ratio of 81:17:2. Analytes were performed at 25xa0°C with a flow rate of 1.0xa0ml/min. Our study found that AAPS is composed of d-mannose, d-glucosamine, l-rhamnose, d-galactosamine, d-glucuronic acid, d-galacturonic acid, and d-glucose in a molar ratio of 1.5:14.1:1.7:1.6:2.0:2.3:1.

Cinnamaldehyde Derivatives Inhibited Coxsackievirus B3-Induced Viral Myocarditis.

The chemical property of cinnamaldehyde is unstable in vivo, although early experiments have shown its obvious therapeutic effects on viral myocarditis (VMC). To overcome this problem, we used cinnamaldehyde as a leading compound to synthesize derivatives. Five derivatives of cinnamaldehyde were synthesized: 4-methylcinnamaldehyde (1), 4-chlorocinnamaldehyde (2), 4-methoxycinnamaldehyde (3), α-bromo-4-methylcinnamaldehyde (4), and α-bromo-4-chlorocinnamaldehyde (5). Neonatal rat cardiomyocytes and HeLa cells infected by coxsackievirus B3 (CVB3) were used to evaluate their antiviral and cytotoxic effects. In vivo BALB/c mice were infected with CVB3 for establishing VMC models. Among the derivatives, compound 4 and 5 inhibited the CVB3 in HeLa cells with the half-maximal inhibitory concentrations values of 11.38 ± 2.22 μM and 2.12 ± 0.37 μM, respectively. The 50% toxic concentrations of compound 4 and 5-treated cells were 39-fold and 87-fold higher than in the cinnamaldehyde group. Compound 4 and 5 effectively reduced the viral titers and cardiac pathological changes in a dose-dependent manner. In addition, compound 4 and 5 significantly inhibited the secretion, mRNA and protein expressions of inflammatory cytokines TNF-α, IL-1β and IL-6 in CVB3-infected cardiomyocytes, indicating that brominated cinnamaldehyde not only improved the anti-vital activities for VMC, but also had potent anti-inflammatory effects in cardiomyocytes induced by CVB3.