Effects of astaxanthin on blood coagulation, fibrinolysis and platelet aggregation in hyperlipidemic rats.

CONTEXT: Astaxanthin (ASTX) is a xanthophyll carotenoid that reduces hemostasis in hyperlipidemic organisms. Its antihemostatic mechanisms remain unclear. OBJECTIVE: The effects of ASTX on coagulation, the fibrinolytic system and platelet aggregation were investigated in hyperlipidemic rats. MATERIALS AND METHODS: Different doses of ASTX (5, 10 and 30 mg/kg/day, p.o.) were administered for four weeks to high-fat diet-induced hyperlipidemic rats. Serum lipid and lipoprotein levels were measured with an automatic biochemical analyzer. The prothrombin time (PT), activated partial thromboplastin time (APTT) and maximum platelet aggregation rate (MAR) were determined by a coagulation analyzer. The activities of the tissue-type plasminogen activator (t-PA), type-1 plasminogen activator inhibitor (PAI-1) and endothelial nitric oxide synthase (eNOS), as well as the levels of thromboxane B(2) [TXB(2)], 6-keto prostaglandin F(1α) [6-keto-PGF(1α)] and platelet granule membrane protein (GMP-140), were measured with enzyme-linked immunosorbent assay kits. Gene and protein expression levels were analyzed by reverse transcriptase polymerase chain reaction and Western blot, respectively. RESULTS: ASTX (30 mg/kg) treatment in hyperlipidemic rats reduced serum TG (0.58 ± 0.14 versus 1.12 ± 0.24 mmol/L), serum TC (1.77 ± 0.22 versus 2.24 ± 0.21 mmol/L), serum LDL-C (1.13 ± 0.32 versus 2.04 ± 0.48 mmol/L), serum MDA (69%), plasma MAR (55%), serum TXB2/6-keto-PGF1α (34%) and serum GMP-140 levels (25%), plasma PAI-1 activity (48%) and downregulated the mRNA (33%) and protein (23%) expression of aorta eNOS, the mRNA (79%) and protein (72%) expression levels of aorta PAI-1. However, ASTX (30 mg/kg/d) treatment increased serum SOD activity (2.1 fold), serum GPx activity (1.8 fold), plasma PT (1.3 fold), plasma APTT (1.7 fold), serum NO (1.4-fold), serum 6-keto-PGF1α (1.3 fold). CONCLUSIONS: ASTX reduced blood coagulation and platelet aggregation and promoted fibrinolytic activity in hyperlipidemic rats. These activities were closely correlated with ASTX, maintaining the balance of t-PA/PAI-1, NO/ROS and TXA2/PGI2 in vivo.

Resveratrol alleviates vascular inflammatory injury by inhibiting inflammasome activation in rats with hypercholesterolemia and vitamin D2 treatment.

OBJECTIVE: Atherosclerosis (AS) is an inflammatory disease involved in vascular inflammatory injury. The inflammasome is an important part of inflammatory diseases and participates in the vascular inflammatory injury. Resveratrol (RSV) possesses anti-inflammatory activities, but its effects on inflammasomes during vascular injury remain unclear. This study focused on the effects and mechanisms of RSV on inflammasomes during vascular injury. METHODS: Male Sprague-Dawley rats were treated with a purified diet or cholesterol-enriched diet combined with vitamin D2 (VD; 1.8 million units/kg/days, Po) and saline or RSV (50 mg/kg/days, Po) daily for 5 weeks. The concentrations and enzyme activities of related indicators were measured by a spectrophotometer or ELISA kit. Their gene and protein expression levels were analyzed by reverse transcription-polymerase chain reaction and Western blot, respectively. RESULTS: Upon administration with RSV, rats with combined hyper cholesterol and VD demonstrated the following changes: the vascular histopathological changes were relieved, and the level of the von Willebrand factor decreased. The level of serum IL-1ß, a marker of inflammasome activation, significantly decreased. The mRNA and protein expression levels of the three components of inflammasomes, namely, NOD-like receptor pyrin domain containing 3, apoptosis-associated speck-like protein containing a caspase-recruitment domain, and caspase-1, were downregulated. The effects of RSV were closely related to hypolipidemia (decrease in the levels of total cholesterol, triglycerides, and low-density lipoprotein cholesterol combined with the expression of the lectin-like ox-LDL receptor and increase in high-density lipoprotein cholesterol), antioxidation (decrease in MDA levels and increase in SOD and GPx activities), and anti-inflammation (downregulation of the expression of IL-1ß, intracellular adhesion molecule-1, and monocyte chemotactic protein-1). The mechanisms for the downregulation of NF-κB p65 and p38 MAPK expression, as well as the upregulation of SIRT1 expression, were analyzed. CONCLUSION: This study proved that RSV inhibited inflammasome activation to protect vascular injury in vivo. RSV exhibited therapeutic potential in the treatment of vascular injury.

Protective effect of Lycium barbarum on doxorubicin-induced cardiotoxicity.

The objective of this work was to explore the hypothesis that Lycium barbarum (LB) may be protective against doxorubicin (DOX)-induced cardiotoxicity through antioxidant-mediated mechanisms. Male SD rats were treated with distilled water or a water extract of LB (25 mg/kg, p.o.) daily and saline or DOX (5 mg/kg, i.v.) weekly for 3 weeks. Mortality, general condition and body weight were observed during the experiment. DOX-induced cardiotoxicity was assessed by electrocardiograph, heart antioxidant activity, serum levels of creatine kinase (CK) and aspartate aminotransferase (AST) and histopathological change. The DOX group showed higher mortality (38%) and worse physical characterization. Moreover, DOX caused myocardial injury manifested by arrhythmias and conduction abnormalities in ECG (increased QT and ST intervals and ST elevation), a decrease of heart antioxidant activity, an increase of serum CK and AST, as well as myocardial lesions. Pretreatment with LB significantly prevented the loss of myofibrils and improved the heart function of the DOX-treated rats as evidenced from lower mortality (13%), normalization of antioxidative activity and serum AST and CK, as well as improving arrhythmias and conduction abnormalities. These results suggested that LB elicited a typical cardioprotective effect on DOX-related oxidative stress. Furthermore, in vitro cytotoxic study showed the antitumor activity of DOX was not compromised by LB. It is possible that LB could be used as a useful adjunct in combination with DOX chemotherapy.

[Purification of human VLDL apolipoproteins by middle pressure liquid chromatography].

OBJECTIVE: To purify human VLDL apolipoproteins by middle-pressure liquid chromatography. METHODS: Human VLDLs were isolated by one step density ultracentrifugation. Delipided human VLDL was separated by Sephacryl S-200 molecular sieve chromatography. ApoE was purified by heparin Sepharose CL-6B affinity chromatography. ApoC I ,C II and C III were purified from apoC. fraction by DEAE-Sephacel ion exchange chromatography: RESULTS: Purified apoE, apoC I, apoC II and apoC III were obtained. SDS-PAGE and immunodiffusion tests indicated the isolated proteins were pure. CONCLUSION: We have established a purification procedure for human VLDL apolipoproteins with highly efficiency and simplicity by MPLC.

Plasma very-low-density lipoprotein, low-density lipoprotein, and high-density lipoprotein oxidative modification induces procoagulant profiles in endogenous hypertriglyceridemia.

This study was to investigate whether oxidatively modified lipoproteins were associated with changes of pro- and anticoagulant profiles in hypertriglyceridemic subjects. Plasma VLDL, LDL, and HDL were isolated with the one-step density gradient ultracentrifugation method. The oxidation of the lipoproteins was identified. Prothrombin time (PT) and activated partial thrombplastin time (APTT), tissue plasminogen activator and plasminogen activator inhibitor-1, and platelet aggregation rate were determined with a reaction system consisting of mixed fresh normal plasma, in endogenous hypertriglyceridemic (HTG) patients, in in vitro modified lipoproteins from a normolipidemic donor, and in experimental rats. The results indicated that oxVLDL, oxLDL, and oxHDL occurred in the plasma of HTG patients. Compared with the control group, PT and APTT, incubated with plasma VLDL, LDL, or HDL from HTG patients, respectively, were significantly reduced, while platelet maximal aggregation rates were significantly higher (P < 0.05-0.01). Similar procoagulant profiles were observed in in vitro modified lipoprotein components and in rats with intrinsic hypertriglyceridemia as well. These results support our previous finding that LDL, VLDL, and HDL were all oxidatively modified in vivo in the subjects with HTG, and suggest that procoagulation state may result from the abnormal plasma lipoprotein oxidative modification in vivo.