Punicalagin Attenuates Disturbed Flow-Induced Vascular Dysfunction by Inhibiting Force-Specific Activation of Smad1/5.

BACKGROUND: Pathophysiological vascular remodeling in response to disturbed flow with low and oscillatory shear stress (OSS) plays important roles in atherosclerosis progression. Pomegranate extraction (PE) was reported having anti-atherogenic effects. However, whether it can exert a beneficial effect against disturbed flow-induced pathophysiological vascular remodeling to inhibit atherosclerosis remains unclear. The present study aims at investigating the anti-atherogenic effects of pomegranate peel polyphenols (PPP) extraction and its purified compound punicalagin (PU), as well as their protective effects on disturbed flow-induced vascular dysfunction and their underlying molecular mechanisms. METHODS: The anti-atherogenic effects of PPP/PU were examined on low-density lipoprotein receptor knockout mice fed with a high fat diet. The vaso-protective effects of PPP/PU were examined in rat aortas using myograph assay. A combination of in vivo experiments on rats and in vitro flow system with human endothelial cells (ECs) was used to investigate the pharmacological actions of PPP/PU on EC dysfunction induced by disturbed flow. In addition, the effects of PPP/PU on vascular smooth muscle cell (VSMC) dysfunction were also examined. RESULTS: PU is the effective component in PPP against atherosclerosis. PPP/PU evoked endothelium-dependent relaxation in rat aortas. PPP/PU inhibited the activation of Smad1/5 in the EC layers at post-stenotic regions of rat aortas exposed to disturbed flow with OSS. PPP/PU suppressed OSS-induced expression of cell cycle regulatory and pro-inflammatory genes in ECs. Moreover, PPP/PU inhibited inflammation-induced VSMC dysfunction. CONCLUSION: PPP/PU protect against OSS-induced vascular remodeling through inhibiting force-specific activation of Smad1/5 in ECs and this mechanism contributes to their anti-atherogenic effects.

Study on the Inhibitory Effects of Naringenin-Loaded Nanostructured Lipid Carriers Against Nonalcoholic Fatty Liver Disease.

Naringenin (NGN) can be used to inhibit the progression of nonalcoholic fatty liver disease (NAFLD) in mice, but its poor water solubility limits its applications. Nanostructured lipid carriers (NLCs) have recently attracted much attention in the field of nanodrug delivery systems because they increase the drug loading capacity and impressively enhance the solubility of indissolvable drugs. Herein, a thin-film dispersion method was used to prepare naringenin-loaded nanostructured lipid carriers (NGN-NLCs). These NGN-NLCs have a narrow size distribution of 171.9 ±2.0 nm, a high drug loading capacity of 23.7 ± 0.3%, a high encapsulation efficiency of 99.9 ± 0.0% and a drug release rate of 86.2 ± 0.4%. NGN- NLCs elevated the pharmacokinetic parameters (Cmax and AUC0→t) of NGN, accelerated NGN transepithelial transport in MDCK cells and intestinal absorption in the jejunum and ileum, and reduced hepatic lipid accumulation in an oleic acid (OA) plus lipopolysaccharide (LPS)-induced lipid deposition cell model in primary hepatocytes and in a methionine/choline deficient (MCD) diet-induced NAFLD mouse model. A detailed study of the mechanism showed that this NLC formulation elevated the drug release rate in simulated intestinal solutions in vitro, the transepithelial transport in MDCK cells, the oral absorption in mice and the ex vivo intestinal absorption of NGN. Thus, NGN-NLCs significantly enhanced the inhibitory effects of NGN on MCD diet induced mouse NAFLD.

Formulation and intestinal absorption of naringenin loaded nanostructured lipid carrier and its inhibitory effects on nonalcoholic fatty liver disease.

In this study, we prepared naringenin (NGN) loaded nanostructured lipid carrier (NGN-NLC) and investigated its characterizations, transepithelial transport, intestinal absorption and inhibitory effects on nonalcoholic fatty liver disease (NAFLD) induced by a methionine choline deficient (MCD) diet in mice. The NGN-NLC, prepared by a method of emulsion-evaporation plus low temperature-solidification, displayed high drug loading capacity of 22.5 ± 1.7%. Compared to the NGN crude drug, the NGN-NLC, at an equal NGN dose, improved NGN release rate by 3.5-fold and elevated NGN transepithelial transport and intestinal absorption through enhancing intracellular transport of clathrin pathway and escaping p-gp efflux; at an 8-fold lower NGN dose, showed comparable pharmacokinetic parameters, but elevated liver NGN distribution by 1.5-fold, reduced MCD diet-induced hepatic lipid deposition by 3-fold. These results suggest that the NLC formulation significantly increased the inhibitory effects of NGN on NAFLD because of the improved drug release rate, transepithelial transport and intestinal absorption, and the elevated oral bioavailability and liver NGN distribution.

Simvastatin nanoliposome induces myocardial and hepatic toxicities due to its absorption enhancement in mice.

Nanoliposome is a useful dosage form to increase solubility and absorption of simvastatin (SMV), and consequently improves its therapeutic effects. However, in vivo toxicity of SMV could also be elevated accompanied by the absorption enhancement, which is a decisive factor for the clinical application of SMV nanoliposome (SMV-Lipo), but has not been studied systematically and reported so far. In this study, organ toxicity of SMV-Lipo was evaluated in mice in the presence and absence of isoproterenol and compared to those of free SMV. Results demonstrated that compared to free SMV, the SMV-Lipo administrated at an equal dose of 25 mg/kg/d led to severe myocardiotoxicity, hepatotoxicity at baseline and more pronounced liver injury with elevation of alanine aminotransferase. In addition, muscular adverse effect was also observed in SMV-Lipo treated group but not in SMV group. Pharmacokinetic studies revealed that compared to free SMV, the SMV-Lipo administration significantly improved the plasma SMV concentration, and the oral bioavailability was 6.5 times of free SMV. Notably, when the dosage of free SMV increased to 50 mg/kg/d, yielding the comparable plasma concentration as SMV-Lipo given at 25 mg/kg/d, the myocardiotoxicity was observed in free SMV treated mice as well, which further confirmed that the enhanced absorption of SMV by the nanoliposomal formulation resulted in more severe myocardiotoxicity than the equal dose of free SMV.

Grape Seed Polyphenols Ameliorated Dextran Sulfate Sodium-Induced Colitis via Suppression of Inflammation and Apoptosis.

BACKGROUND: Ulcerative colitis (UC) is an inflammatory bowel disease. Its onset is typically gradual, usually followed by periods of spontaneous remission and subsequent relapses. Grape seed polyphenols (GSP), a natural product extracted from grape seeds, have strong anti-inflammatory functions. OBJECTIVES: In this study, we investigated whether GSP has an inhibitory effect on UC and its related mechanism or not. METHODS: We induced UC by 2.5% dextran sulfate sodium (DSS) and GSP at different doses (500 and 750 mg/kg body weight per day) was administrated to the mice by gavage. Body weight, diarrhea, and bloody stool were recorded every day to evaluate disease activity index. Hemotoxylin-eosin staining and immunohistochemical staining were used to identify the histological damages and inflammatory infiltration in colon tissues. Real-time polymerase chain reaction was used to evaluate mRNA expression of interleukin (IL)-6, IL-1ß, and tumor necrosis factor (TNF)-α and the expression of phosphorylated-signal transducer and activator of transcription 3 (STAT3) and STAT3 were assessed by western blot. The immunofluorescent assay was used to evaluate the apoptosis of intestinal epithelial cells (IECs). RESULTS: GSP could alleviate the loss of body weight, diarrhea, bloody stool, the mucosal damage, and inflammatory infiltration. GSP could also downregulate the mRNA expression of inflammatory cytokines IL-6, IL-1ß, and TNF-α as well as the phosphorylation of STAT3 and ameliorate the apoptosis of IECs. CONCLUSIONS: Our study suggests that GSP has protective effects against DSS-induced UC, which may through suppression of inflammation and apoptosis.

Atheroprotective Mechanisms of Tilianin by Inhibiting Inflammation Through Down-Regulating NF-κB Pathway and Foam Cells Formation.

Tilianin, a representative flavonoid ingredient of Dracocephalum moldavica L., has been used to treat several diseases for centuries, including atherosclerosis (AS). However, pharmacological mechanisms underlying its biological functions remain elusive. In the present study, we investigated the anti-AS mechanisms of tilianin through establishing in vitro models using three types of cells that contributed to AS progression, including macrophage, vascular smooth muscle cells and human umbilical vein endothelial cells, which were proved to be involve in LPS/TNF-α/oxidized low density lipoprotein (ox-LDL)-induced inflammation and ox-LDL induced foam cell formation. Our results indicate that tilianin significantly suppressed LPS induced inflammatory responses on macrophage and remarkably inhibited TNF-α induced VSMCs proliferation and migration. Furthermore, the anti-inflammatory effect of tilianin on macrophages and VSMCs was proved to be mainly by downregulating TNF-α/NF-κB pathway. Moreover, our results demonstrate that tilianin significantly ameliorated ox-LDL induced macrophages oriented foam cells formation through repressing mRNA expression of SR-A1 and inducting the expression of genes related to cholesterol efflux including SRB-1 and ABCA1. However, tilianin had no effect on ox-LDL induced HUVECs injury.

Rosa rugosa flavonoids alleviate myocardial ischemia reperfusion injury in mice by suppressing JNK and p38 MAPK.

OBJECTIVE: Although Rosa rugosa has been applied for preventing coronary artery disease, the pharmacological mechanism is little explored. In this study, the effects and mechanisms of Rosa rugosa flavonoids (RRF) on myocardial ischemia reperfusion injury (MIRI) were investigated. METHODS: Mice were pretreated by intragastric administration of 600 mg/kg RRF for 7 days. Then MIRI was induced by 45 minutes coronary artery ligation and 3 hours reperfusion. Myocardial infarct size (MIS) and histopathology, activities of myocardial enzymes, and effects of RRF on inflammation and apoptosis were evaluated. RESULTS: Pretreating the mice with RRF significantly reduced MIS and inhibited activity of plasma myocardial enzymes. Activity of the enzymes associated with anti-oxidation, SOD, and TEAC, and mRNA expression of NOX2 were significantly elevated. RRF pretreatment significantly decreased the translocation of p65 from the cytoplasm into the nucleus and reduced the expression of the pro-inflammatory cytokines, IL-6 and IL-1ß. RRF pretreatment also significantly prevented the expression of caspase-3 and Bax, and increased the expression of Bcl-2. And RRF inhibited the phosphorylation of JNK and p38 MAPK. CONCLUSIONS: RRF significantly inhibited MIRI through anti-oxidative, anti-inflammatory, and anti-apoptosis effects, and mechanisms were associated with its inhibition on phosphorylation of JNK and p38 MAPK.

Alpha-Tocopheryl Succinate-Conjugated G5 PAMAM Dendrimer Enables Effective Inhibition of Ulcerative Colitis.

Ulcerative colitis (UC) is a severe inflammatory disease in colon, however, the therapeutic efficacy of the standard-of-care in clinic for UC patients is unsatisfactory. To explore new drugs for effective and safe treatment of UC, alpha-tocopheryl succinate (α-TOS) is conjugated to generation 5 (G5) poly(amidoamine) (PAMAM) dendrimer to construct a nanodevice of G5-NH-acetamide (Ac)-TOS. The inhibitory effects of the G5-NH-Ac-TOS on UC are evaluated in vivo in a dextran sulfate sodium induced UC mouse model, and its mechanisms are explored in vitro in lipopolysaccharide stimulated mouse peritoneal macrophages. The results indicate that the G5-NH-Ac-TOS exhibits greater inhibitive effects on UC than free α-TOS, through significant attenuation of the disease activity index and reduction of macrophage infiltration in the colon tissues. The protective mechanisms of the G5-NH-Ac-TOS are revealed to be related to inhibition of expression of nuclear translocation of NF-κB, phosphorylation of Akt, and reduction of reactive oxygen species production in the macrophages.

Recent Advances in Dendrimer Research for Cardiovascular Diseases.

Dendrimers, as a type of artificially synthesized polymers, have been increasingly attracting attention in many research fields, including the material and medical sciences, due to their unique characteristics that include their highly branched and well-defined molecular architecture, multivalency and tunable chemical compositions. These advantages make dendrimers potential carriers for the delivery of therapeutic and diagnostic agents. Herein, we review the recent advances in dendrimer research for the prevention and treatment of cardiovascular diseases, with special focus on their applications as carriers for drug and gene delivery, as contrast agents, and as potential new drugs.

[Construction of baculovirus vector with WPRE regulatory element to express Newcastle disease virus F gene in primary chicken embryo cells].

OBJECTIVE: To construct the recombinant baculovirus with mammaliancell-specific promoter and woodchuck hepatitis virus post-transcriptional regulatory element (WPRE), to highly express Newcastle disease virus (NDV) F gene in the primary chicken embryo cells. METHOD: We extracted total RNAs from NDV La Sota strain. Then the F gene was amplified by reverse transcription polymerase chain reaction. We constructed the baculoviral vector (pCMV-WPRE-F) with F gene fused with the WPRE near its 3'end, which expressed under the control of the CMV promoter. The F gene recombinant bacmid was obtained by Bac-to-Bac system and transfected into sf9 insect cells to acquire F gene recombinant baculovirus. After amplification of recombinant baculovirus, the recombinant virus was transfected into chicken primary cells with 50 multiplicity of infection, and the proteins were harvested at 72 h after infection. The F protein expression levels mediated by WPRE regulatory element were analyzed. RESULTS: Western blot results show that the F gene was successfully expressed in chicken primary cells. The product was a 56kDa protein and could be recognized by anti-NDV serum. The WPRE fusion significantly improved the F gene expression as 10 mmol/L butyrate did, but different to butyrate, the WPRE regulatory element was nontoxic to cells. CONCLUSION: The optimized recombinant baculovirus could efficiently deliver NDV F gene into chicken primary cells and express the F antigen protein. In addition, the WPRE regulatory element could increase the expression levels of exogenous gene mediated by baculovirus in chicken primary cells. The research provides us a potential basis for the gene engineered vaccines of NDV and other avian infectious disease based on baculovirus vector.