Atherosclerosis and autoimmunity

Papain ameliorates monocyte-platelet aggregate formation-mediated inflammatory responses in monocytes by upregulating miRNA-146a transcription

BACKGROUND

MicroRNA-146a (miRNA-146a) is a nuclear factor κB (NF-κB)-inducible and inflammation-sensitive miRNA, while papain elicits anti-inflammatory effects by inhibiting monocyte-platelet aggregate (MPA)-mediated NF-κB pathway activation in monocytes. This study aimed to demonstrate the underlying effects of papain on MPA formation-initiated miRNA-146a expression and subsequent action in monocytes.

METHODS

THP-1 cells were exposed to papain, miRNA-146a mimic and inhibitor, NF-κB inhibitor (BAY11-7082), and platelets. Flow cytometry was used to measure the MPA formation-initiated monocyte activation. Levels of miRNA-146a, cyclooxygenase 2 (COX-2) mRNA and protein, and monocyte chemoattractant protein 1 (MCP-1) were analyzed in monocytes by RT-PCR, western blot, and ELISA.

RESULTS

The NF-κB inhibitor and miRNA-146a mimics upregulated miRNA-146a expression but suppressed subsequent monocyte activation and expression of COX-2 and MCP-1. Following exposure to papain, the enhanced miRNA-146a transcription induced by MPA-formation was found along with significant inhibition of monocyte activation in a dose-dependent manner. However, the inhibitory tendency was significantly reversed by miRNA-146a inhibitors. Expression of COX-2 mRNA and protein, as well as MCP-1, was inhibited in monocytes by papain, whereas miRNA-146a inhibitors promoted COX-2 and MCP-1 expression.

CONCLUSION

Our findings suggest that papain can inhibit MPA formation-mediated expression of inflammatory mediators in activated monocytes by upregulating miRNA-146a transcription.

Turning Hot into Cold: Immune Microenvironment Reshaping for Atherosclerosis Attenuation Based on pH-Responsive shSiglec-1 Delivery System

Current atherosclerosis treatment is based on a combination of cholesterol-lowering medication and low-fat diets; however, the clinical effect is unsatisfactory. It has been shown that the level of immune cell infiltration and pro-inflammatory factors in the atherosclerotic immune microenvironment (AIM) play important roles in the development and progression of atherosclerosis. Therefore, we hypothesized that reshaping "hot AIM" into "cold AIM" could attenuate atherosclerosis. For this purpose, we designed a pH-responsive and charge-reversible nanosystem, referred to as Au-PEI/shSiglec-1/PEI-acetylsalicylic acid (ASPA NPs) to effectively deliver shSiglec-1, which blocked the interactions between macrophages with CD8⁺ T/NKT cells, thus inhibiting immune cell infiltration. Further, we demonstrated that acetylsalicylic acid (ASA), detached from the pH-responsive PEI-ASA polymer, and inhibited lipid accumulation in macrophage, thereby decreasing the lipid antigen presentation. Additionally, reduced macrophage-produced inflammatory factors by ASA and low CD8⁺ T/NKT cell infiltration levels synergistically inhibit Th17 cell differentiation, thus further dramatically attenuating inflammation in AIM by decreasing the IL-17A production. Eventually, ASPA NPs efficiently reshaped AIM by inhibiting immune cell infiltration, lipid antigen presentation, and pro-inflammation, which provided a feasible therapeutic strategy for atherosclerosis immunotherapy.

Papain Ameliorates the MPAs Formation-Mediated Activation of Monocytes by Inhibiting Cox-2 Expression via Regulating the MAPKs and PI3K/Akt Signal Pathway

Monocytes activation and subsequent inflammatory response mediated by monocyte-platelet aggregates (MPAs) formation play the key roles in the early pathogenesis of atherosclerosis (AS). Exploration of novel drugs to ameliorate MPAs formation-mediated monocytes activation would be helpful for the treatment of AS patients. Papain has definite pharmacological effects including antiplatelet, thrombolysis, and anti-inflammation. However, its effect on MPAs formation and the following monocytes activation remains vague. This study aimed to illustrate the underlying mechanisms of papain on MPAs formation-initiated monocytes activation in vitro. In this study, Papain, Cox-2 inhibitor (NS-398), and NF-κB agonist (TNF-α) were used as the treating agents, respectively. MPAs formation and activated monocytes were measured by flow cytometry (FCM). Cox-2 mRNA, MCP-1, and proteins of Cox-2 and NF-κB signal pathway were detected by qRT-PCR, ELISA, and western blotting, respectively. As we observed, papain exhibited the powerful inhibitory effects on thrombin-mediated MPAs formation and monocytes activation in a concentration-dependent manner as what Cox-2 inhibitor demonstrated. However, the inhibitory tendency was significantly reversed by TNF-α. We also discovered that both Cox-2 mRNA and protein expression as well as the release of MCP-1 of monocyte was inhibited by either papain or NS-398, but TNF-α stimulated Cox-2 expression and release of MCP-1. The results of western blotting assay indicated that thrombin-mediated proteins expression of MAPKs and PI3K/Akt signal pathway was inhibited by papain and NS-398. However, TNF-α notably abated the inhibitory effects of papain on the process of MPAs-initiated monocytes activation. Our findings suggest that papain can inhibit the MPAs formation-mediated activation of monocytes by inhibiting the MAPKs and PI3K/Akt signal pathway.

Impaired endothelial function and increased carotid intima-media thickness in association with elevated von Willebrand antigen level in primary antiphospholipid syndrome

Primary antiphospholipid syndrome (APS) is characterized by venous or arterial thrombotic events and/or recurrent abortions, fetal death, preeclasmpsia, eclampsia in the presence of anticardiolipin antibodies or lupus anticoagulant, in the absence of accompanying diseases. Antiphospholipid antibodies can activate endothelial cells, and were recently implicated in atherosclerosis. To assess potential endothelial impairment and early signs of atherosclerosis, flow-mediated (endothelium-dependent) and nitrate-mediated (endothelium independent) vasodilation, as well as von Willebrand factor antigen level and carotid artery intima-media thickness (IMT) were measured in patients with primary antiphospholipid syndrome and in healthy controls. Flow-mediated vasodilation in patients with primary APS was significantly lower than that of controls (3.43 ± 2.86% versus 7.96 ± 3.57%; P < 0.0001). We also found significantly higher von Willebrand antigen levels in patients with primary APS than in the control group (157.91 ± 52.45% versus 125.87 ± 32.8%; P = 0.012). Moreover, carotid artery IMT was significantly larger in the primary APS group compared to controls (0.714 ± 0.2 mm versus 0.58 ± 0.085 mm; P = 0.0037). Our results reflect ongoing endothelial damage and accelerated atherosclerosis in patients with primary APS, and suggest that vasoprotective therapy may be beneficial in the treatment of these patients. Lupus (2007) 16, 497—503.

Factor V Leiden and Prothrombin G20210A Mutations and the Risk of Atherothrombotic Events in Systemic Lupus Erythematosus

Because genetic predisposition to atherothrombosis in systemic lupus erythematosus (SLE) remains to be determined, the most common genetic prothrombotic factors, prothrombin G20210A and factor V Leiden mutations, were studied. Seventy-four SLE patients with vascular ischemia (SLE cases) were studied and stratified into myocardial infarction and/or cerebrovascular accident subgroup (MI/CVA), and coronary heart disease subgroup without overt arterial thrombotic events (CHD). Seventy-one SLE patients without atherothrombosis were investigated as SLE controls. Factor V Leiden was detected in six cases (five in MI/CVA, one in CHD group) and three controls (OR 2.00, 95%CI 0.48-8.32). Two cases (both CHD patients) had prothrombin G20210A mutation vs. three controls (OR 0.63, 95%CI 0.1-3.88). Anticardiolipin antibodies (aCL) were increased in cases vs. controls (39/74 vs. 27/71); however, this was not statistically significant (OR 1.82, 95%CI 0.94-3.52). Neither univariate nor multivariate analysis indicated that investigated mutations are risk factors for atherothrombosis in SLE cases, MI/CVA, or CHD subgroups. Overall, disease activity was the strongest risk factor for atherothrombosis (p=0.0014) in SLE cases. Combination of disease activity+gender was the best predictor of atherothrombotic process (p=0.00045) in this cohort. In MI/CVA subgroup, disease activity was the only predictor (p=0.0058). In CHD patients, the best predictive value was conferred by combination of hypertension+gender+disease activity (p=0.00077). No other investigated risk factor (including aCL) conferred an increased risk individually or potentiated the other risk factors. The results deny the role of investigated mutations in atherothrombosis in SLE, but they underscore the importance of disease activity (i.e., ongoing inflammation) in pathogenesis of atherosclerosis and arterial thrombosis.

Cardiovascular involvement in autoimmune diseases

Autoimmune diseases (AD) represent a broad spectrum of chronic conditions that may afflict specific target organs or multiple systems with a significant burden on quality of life. These conditions have common mechanisms including genetic and epigenetics factors, gender disparity, environmental triggers, pathophysiological abnormalities, and certain subphenotypes. Atherosclerosis (AT) was once considered to be a degenerative disease that was an inevitable consequence of aging. However, research in the last three decades has shown that AT is not degenerative or inevitable. It is an autoimmune-inflammatory disease associated with infectious and inflammatory factors characterized by lipoprotein metabolism alteration that leads to immune system activation with the consequent proliferation of smooth muscle cells, narrowing arteries, and atheroma formation. Both humoral and cellular immune mechanisms have been proposed to participate in the onset and progression of AT. Several risk factors, known as classic risk factors, have been described. Interestingly, the excessive cardiovascular events observed in patients with ADs are not fully explained by these factors. Several novel risk factors contribute to the development of premature vascular damage. In this review, we discuss our current understanding of how traditional and nontraditional risk factors contribute to pathogenesis of CVD in AD.

Multiparametric assessment of vascular function and atherosclerosis in patients with autoimmune gastritis: a comparative study

BACKGROUND/AIMS

Patients with autoimmune gastritis might have accelerated atherosclerosis due to autoimmunity and chronic inflammation. Endothelial dysfunction often precedes manifest atherosclerosis. The aim of the present study was to evaluate the risk factors of early atherosclerosis by using several different techniques.

METHODS

A total of 99 patients with autoimmune gastritis were compared to 42 healthy age sex-matched subjects. Patients with a known risk factor for atherosclerosis were excluded. Intima-media thickness of the common carotid artery, pulse wave velocity and flow-mediated dilation of brachial artery were measured. Clinical data and laboratory parameters (serum gastrin, antiparietal cell antibody, anti-Hp IgG, serum vitamin B(12) and lipid profile) were also determined.

RESULTS

Intima-media thickness (mm) of the carotid artery was significantly higher in autoimmune gastritis (0.062 ± 0.031 vs. 0.042 ± 0.007, P < 0.001) than in healthy individuals. Flow-mediated dilation was significantly lower in patients with autoimmune gastritis compared to control group (13.91 ± 6.68% vs. 20.37 ± 7.80%, P = 0.021) and there was a significant increase in pulse wave velocity (m/s) in autoimmune gastritis patients compared to controls (9.25 ± 3.42 vs. 6.40 ± 0.91, P = 0.001). Antiparietal cell antibody positivity (P = 0.05), low vitamin B(12) level (P = 0.05), and age (P = 0.002) were the predictors of high pulse wave velocity (>14 m/s).

CONCLUSION

Patients with autoimmune gastritis may have an increased risk for the development of early atherosclerosis. As early preventive treatment for accelerated atherosclerosis is available, it is important to detect those patients with autoimmune gastritis who would benefit from such treatment.

Pentraxins, anti-pentraxin antibodies, and atherosclerosis

Atherosclerosis is a disease of the vascular wall, which predominantly affects large and medium-sized arteries. It represents a leading cause of morbidity and mortality in the Western world. In the last few decades, it has been clearly shown that immune system plays a relevant role in atherogenesis. The effectors of both innate and adaptive immunity, including immune cells, cell or soluble receptors, cytokines, chemokines, complement components or coagulation systems, and autoantibodies are able to modulate atherosclerosis. Among proteins belonging to innate immunity, the highly conserved pentraxin family, which encompass C-reactive protein (CRP), serum amyloid P (SAP), and the long pentraxin 3 (PTX3) seems to be directly involved in the induction and progression of atherosclerosis. By immunohistochemical staining, pentraxins were found within the atherosclerotic plaques where they could play a key role interacting with atherogenic-modified lipoproteins, favoring the formation of foam cells, and exerting a proinflammatory action. Pentraxin serum levels have been shown to be associated with clinical and subclinical atherosclerosis in general population. Antibodies against pentraxins have been demonstrated in patients with autoimmune diseases, but their role in atherogenesis is still controversial.

The autoimmune origin of atherosclerosis

Atherosclerosis is a chronic inflammatory disease. Many studies and observations suggest that it could be caused by an immune reaction against autoantigens at the endothelial level, the most relevant of which are oxidized LDL and heat shock proteins (HSP) 60/65. Endothelial dysfunction plays a fundamental role. The first antigen is related to the increased leakage and oxidation of LDL; the second to cellular reaction to stress. Experimental and clinical observations confirm the pathogenetic role of these antigens. Both innate and adaptive immunity and impaired regulatory mechanisms of the autoimmune reaction are involved. Different triggering factors are examined: infectious agents, smoking, air pollution, diabetes and hypercholesterolemia. Analogies and differences between systemic atherosclerosis and transplant-related coronary atherosclerosis help to understand their respective nature. Immune mechanisms might be responsible for the passage from stable plaque to unstable and rupture-prone plaque. Finally, prospects of treatment and prevention are linked to the induction of tolerance to responsible antigens, activation of immune regulatory response and the use of immunomodulatory drugs.

OxLDL/beta2GPI-anti-oxLDL/beta2GPI complex and atherosclerosis in SLE patients

It has been demonstrated that atherosclerosis (ATS) is enhanced in autoimmune rheumatic diseases, such as systemic lupus erythematosus (SLE). The reason for this accelerated process is still debatable and, although traditional risk factors are more prevalent in SLE patients than in general population, they do not seem to fully explain the enhanced risk. ATS has the characteristics of an autoimmune chronic disease, involving both the innate and the adaptive immunity. Moreover, it satisfies the four criteria defining an autoimmune disease, proposed by Witebsky and Rose. It has been shown that some autoantibodies, including anti-oxLDL, anti-beta(2)GPI, anti-HSP60/65, and more recently anti-oxLDL/beta(2)GPI, play a key role in the pathogenesis of ATS. However the role of these autoantibodies in accelerated ATS in SLE patients is still controversial. In fact, some of them seem to be proatherogenic and other protective; moreover, it has been demonstrated that induced oral tolerance has a protective role against ATS. We have recently observed that the levels of oxLDL/beta(2)GPI antigenic complexes and their antibodies were higher in patients with SLE than in healthy subjects, but we did not find a clear association between oxLDL/beta(2)GPI complexes and IgG or IgM anti-oxLDL/beta(2)GPI autoantibodies and subclinical ATS in SLE patients. Many other studies are required to explain the role of autoantibodies in the pathogenesis of ATS in SLE patients, because the characteristics of SLE seem to mask their effects for atherogenesis.

Free Hemoglobin: A Dangerous Signal for the Immune System in Patients with Carotid Atherosclerosis?

Atherosclerosis is a chronic inflammatory multifactorial disease in which immune responses are key pathogenetic factors. T cell-mediated immunity contributes to the initiation and progression of atherosclerotic disease, but the nature of antigens responsible for immune cell activation is still not completely elucidated. Convincing evidence supports a determinant role of autoimmune responses to self-structures in shaping the progression of the disease. Autoimmune responses may be directed against altered self-structures, such as oxidized low-density lipoproteins (LDL). Oxidative stress, increasingly reported in patients with atherosclerosis, is the major event causing protein structural modification, thus inducing the appearance of neo/cryptic epitopes on the molecule. Intraplaque hemorrhage, a common event in advanced lesions, causes the deposition of large amounts of hemoglobin (Hb). The pro-oxidative intraplaque microenvironment may induce structural changes in extra-erythrocytic free Hb, thus generating novel/cryptic autoantigenic epitopes. We demonstrated that an oxidized Hb preparation enriched in hemichromes expands IFN-gamma-secreting T lymphocytes in patients with advanced carotid atherosclerosis and enhances the phenotypical and functional maturation of human monocyte-derived dendritic cells induced by lipopolysaccharide (LPS). Overall, our findings suggest that oxidized forms of Hb could act as a dangerous signal for the immune system, thus contributing to the inflammatory process that takes place within the atherosclerotic plaque.

Application of a static fluorescence-based cytometer: the CellScan in clinical immunology

The CellScan system is a laser scanning cytometer which enables repetitive fluorescence intensity (FI) and polarization (FP) measurements in living cells, as a means of monitoring lymphocyte activation. By monitoring FP changes in peripheral blood lymphocytes (PBL) following exposure to antigenic stimuli, the CellScan may have a role in the diagnosis of autoimmune diseases. Monitoring changes in FI and FP in PBLs from patients with atherosclerosis following exposure to various stimuli, has illustrated the role of the immune system in the atherosclerotic process. The CellScan has also been evaluated as a diagnostic tool for drug-induced allergy, based on FP reduction in PBLs following incubation with the suspected drugs. FI and FP changes in cancer cells have been found to correlate with the cytotoxic effect of different anti-neoplastic drugs, illustrating the potential role of the CellScan system in clinical oncology. In conclusion, the CellScan is a promising new tool with a variety of applications in cell biology, immunology, cancer research and clinical pharmacology.

Defects in regulation of local immune responses resulting in atherosclerosis

Atherosclerosis is nowadays generally accepted as an inflammatory disease but the mechanism of its origin and development have not yet been fully clarified. The present review focuses on the role of the local immune system as one of the key players in the pathogenesis of the complex process. Its part represented by vascular-associated lymphoid tissue (VALT) within the arterial wall participates directly in the vascular wall's homeostatis. Its inordinate activation during ontogenic development of an individual, this formerly defensive and physiologic mechanism transform into a pathological process resulting in an impairing inflammation. Hsp60, CRP and oxidized or otherwise modified LDL are serious candidates for triggering these pathological changes. The principal role is played by anti-Hsp60 antibodies and by shear stress originating on the surface of endothelium due to blood flow. The experimental and clinical data supporting this immunological hypothesis of atherosclerosis are discussed.

[Accelerated atherosclerosis in rheumatic systemic diseases as an example of systemic lupus erythematosus--what is the consequence?]

Large increases in mortality related to premature atherosclerosis with coronary artery disease and stroke have been reported during the last few years in patients with systemic lupus erythematosus (SLE). Studies found relative risks of 5 to 7 for myocardial infarction in SLE patients. The traditional risk factors fail to fully account for accelerated atherosclerosis in SLE and APS, in addition prolonged glucocorticoid therapy and long duration of SLE seem to be of importance. The disease SLE per se is an independent risk factor. The current pathogenic hypothesis for atherosclerosis involves an inflammatory response, autoantibodies, immune complexes (containing antibodies to phospholipids, to oxidized LDLs, and to endothelial cells), CD40/CD40 ligand interactions, and bacterial or viral infections responsible for an immune response. The determination of classic and new risk factors, together with specific autoantibody titers and the use of Doppler carotid ultrasound, are useful methods to detect early atherosclerosis. Therapeutic strategies, including early risk factor intervention and effective control of inflammation, are essential to reduce morbidity and mortality and should be incorporated into the management of connective tissue disease with the goal of protecting patients against atherosclerosis.

Arterial stiffness in type 1 diabetes mellitus is aggravated by autoimmune thyroid disease

OBJECTIVE

The aim of our study was to measure arterial stiffness in patients with Type 1 diabetes mellitus, its contributing factors and its relation to macrovascular arterial changes.

MATERIALS AND METHODS

Thirty-one female Type 1 diabetic patients were studied; 11 had concomitant autoimmune thyroid disease although euthyroid during the study period. Stiffness was studied using applanation tonometry and pulse wave analysis for evaluation of systolic arterial pressure augmentation secondary to arterial stiffening and early wave reflection. Results were compared to 24 healthy individuals. In all patients, endothelium-related flow-mediated dilation (FMD) of the brachial artery and intima-media thickness (IMT) of the carotid artery were measured.

RESULTS

Augmentation pressure (AP) and augmentation index (AI) were higher in Type 1 diabetic patients suggesting stiffer arteries compared to controls (AP: 5.8 +/- 3.6 vs 2.8 +/- 2.2 mmHg, p < 0.001; and AI:18.3 +/- 9 vs 11.1 +/- 8.8%, p = 0.004). The subgroup of diabetic patients with autoimmune thyroid disease presented stiffer arteries than those without (AP: 6.5 +/- 2.9 vs 5.5 +/- 3.9 mmHg, p < 0.05; and AI: 21.3 +/- 5.4 vs 16.7 +/- 10.3%, p < 0.05), though the two groups did not differ statistically by means of age, disease duration, hemoglobin A1c (HbA1c), lipid levels, FMD and IMT. In multiple regression analysis, variables independently associated to AI in the diabetes group were: age (p = 0.028), IMT of the carotid artery bifurcation (p = 0.045), disease duration (p = 0.031) and autoimmune thyroid disease (p = 0.015). No correlation was observed between AI and metabolic control, blood pressure, microalbuminuria, presence of retinopathy and endothelial function (FMD).

CONCLUSIONS

Women with Type 1 diabetes have increased arterial stiffness, which indicates macroangiopathy. An independent correlation between these indices and carotid IMT was observed. Concomitant autoimmune thyroid disease seems to aggravate arterial compliance in these patients, a finding that merits further investigation.

Amplification of autoimmune disease by infection

Reports of infection with certain chronic persistent microbes (herpesviruses or Chlamydiae) in human autoimmune diseases are consistent with the hypothesis that these microbes are reactivated in the setting of immunodeficiency and often target the site of autoimmune inflammation. New experimental animal models demonstrate the principle. A herpesvirus or Chlamydia species can be used to infect mice with induced transient autoimmune diseases. This results in increased disease severity and even relapse. The evidence suggests that the organisms are specifically imported to the inflammatory sites and cause further tissue destruction, especially when the host is immunosuppressed. We review the evidence for the amplification of autoimmune inflammatory disease by microbial infection, which may be a general mechanism applicable to many human diseases. We suggest that patients with autoimmune disorders receiving immunosuppressing drugs should benefit from preventive antiviral therapy.

C-reactive protein and interleukin-6 in vascular disease: culprits or passive bystanders?

Recent advances in basic science have shown that atherosclerosis should be considered as a chronic inflammatory process, and that a pivotal role of inflammation is evident from initiation through progression and complication of atherosclerosis. In the past few years many studies have examined the potential for biochemical markers of inflammation to act as predictors of coronary heart disease (CHD) risk in a variety of clinical settings. Several large, prospective epidemiological studies have shown consistently that C-reactive protein (CRP) and interleukin-6 (IL-6) plasma levels are strong independent predictors of risk of future cardiovascular events, both in patients with a history of CHD and in apparently healthy subjects. These molecules could be useful to complement traditional risk factors, as well as to identify new categories of subjects prone to atherosclerosis development. An intriguing question is whether these inflammatory molecules simply represent sensitive markers of systemic inflammation or if they actively contribute to atherosclerotic lesion formation and instability. In this paper we will review the evidence concerning the cardiovascular prognostic value and the potential direct involvement of CRP and IL-6 in atherogenesis.

Supplementation of diets with the black rice pigment fraction attenuates atherosclerotic plaque formation in apolipoprotein e deficient mice

Apolipoprotein (apo)E-deficient mice were used to study the antiatherogenic effect of black rice pigment fraction (BRF) and the possible mechanisms by which it inhibits atherogenesis. The apoE-deficient mice (n = 45) were randomly divided into three groups and received AIN-93G diet (positive group), AIN-93G with 5 g of black rice pigment fraction/100 g (BRF group) and AIN-93G with 5 g of white rice outer layer fraction/100 g (WRF group) for 16 wk. C57BL/6J mice (n = 15) received AIN-93G and were used as a control group. Blood samples were collected for measurement of lipid concentration, antioxidized LDL antibody and nitric oxide concentration. Livers were extracted for determination of cholesterol concentrations, and aortas were used to determine cholesterol concentrations and inducible nitric oxide synthase protein and mRNA expression. Hearts were used to assess atherosclerotic plaque formation. The apoE-deficient mice fed the black rice pigment fraction diet had 48% (P < 0.01) less atherosclerotic lesion area compared with apoE-deficient mice fed only the AIN-93G diet and 46% (P < 0.01) less lesion area compared with mice fed the white rice outer layer fraction diet. This observation corresponded with significantly (P < 0.05) lower total serum cholesterol, lower liver and aorta cholesterol (P < 0.01) and higher HDL cholesterol (P < 0.05) concentrations and lower (P < 0.05) antioxidized LDL antibody titer in apoE-deficient mice fed the black rice pigment fraction diet compared with positive and WRF groups. Notwithstanding this, mice fed the black rice pigment fraction diet also had lower CD4(+) T lymphocyte expression (P < 0.05) and weaker inducible nitric oxide synthase expression (P < 0.05) compared with mice fed the AIN-93G diet and the white rice outer layer fraction diet, respectively. We concluded that the inhibition of atherosclerotic lesions of the black rice pigment fraction is attributed to the improvement in cholesterol accumulation and reduction in oxidative stress and inflammation.