Cardioprotective effects of omega 3 fatty acids from fish oil and it enhances autoimmunity in porcine cardiac myosin-induced myocarditis in the rat model

Fish Oil, Plasma n-3 PUFAs, and Risk of Macro- and Microvascular Complications Among Individuals With Type 2 Diabetes

OBJECTIVE

To evaluate associations of fish oil supplementation and plasma omega 3 polyunsaturated fatty acids (n-3 PUFAs) with risks of macrovascular and microvascular complications among people with type 2 diabetes and to further explore the potential mediating role of metabolism-related biomarkers.

RESEARCH DESIGN AND METHODS

This study included 20 338 participants with type 2 diabetes from the UK Biobank. Diabetic complications were identified through hospital inpatient records.

RESULTS

During 13.2 years of follow-up, 5396 people developed macrovascular complications, and 4868 people developed microvascular complications. After multivariable adjustment, hazard ratios (HRs) and 95% confidence intervals (CIs) for patients with fish oil were 0.90 (0.85, 0.97) for composite macrovascular complications, 0.91 (0.84, 0.98) for coronary heart disease (CHD), 0.72 (0.61, 0.83) for peripheral artery disease and 0.89 (0.83, 0.95) for composite microvascular complications, 0.87 (0.79, 0.95) for diabetic kidney disease, and 0.88 (0.80, 0.97) for diabetic retinopathy. In addition, higher n-3 PUFA levels, especially docosahexaenoic acid (DHA), were associated with lower risks of macrovascular and microvascular complications. Comparing extreme quartiles of plasma DHA, the HRs (95% CIs) were 0.68 (0.57, 0.81) for composite macrovascular complications, 0.63 (0.51, 0.77) for CHD, and 0.59 (0.38, 0.91) for diabetic neuropathy. Moreover, biomarkers including lipid profile and inflammatory markers collectively explained 54.4% and 63.1% of associations of plasma DHA with risks of composite macrovascular complications and CHD.

CONCLUSION

Habitual use of fish oil supplementation and higher plasma n-3 PUFA levels, especially DHA, were associated with lower risks of macrovascular and microvascular complications among individuals with type 2 diabetes, and the favorable associations were partially mediated through improving biomarkers of lipid profile and inflammation.

Association of Plasma Omega-3 Levels With Incident Heart Failure and Related Mortalities

OBJECTIVE

To investigate the association between plasma omega-3 levels and incident heart failure (HF) and to examine their relationship with total and cardiovascular (CV) mortality among patients with preexisting HF.

PATIENTS AND METHODS

The UK Biobank is an ongoing prospective cohort study of individuals recruited in the United Kingdom between April 1, 2007, and December 31. 2010. We used Cox proportional hazards models to predict incident HF in those without baseline HF and total and CV mortality in those with baseline HF, all as a function of baseline plasma omega-3 levels.

RESULTS

In participants without HF at baseline (n=271,794), a generally linear inverse association was observed between omega-3 levels and incident HF during a median follow-up of 13.7 years. The risk was 21% lower in the highest quintile of omega-3 compared with the lowest quintile (hazard ratio, 0.79; 95% CI, 0.74 to 0.84; P<.001) in multivariable models. In parallel models in participants with prevalent HF (n=1239), risk for all-cause and CV mortality were both reduced by approximately 50% comparing top to bottom omega-3 quintiles (hazard ratio, 0.53; 95% CI, 0.33 to 0.86; and hazard ratio, 0.50; 95% CI, 0.31 to 0.79, respectively; both P<.01).

CONCLUSION

Higher plasma levels of marine omega-3 fatty acids were associated with a lower incidence of HF. Furthermore, among patients with preexisting HF, higher omega-3 levels were associated with lower risks of all-cause mortality and CV mortality. These findings suggest that increasing plasma omega-3 levels, whether by diet or supplementation, could reduce both risk for development of HF and death in those with prevalent HF.

MicroRNAs in Myocarditis-Review of the Preclinical In Vivo Trials

Myocarditis is an inflammatory heart disease with viruses as the most common cause. Regardless of multiple studies that have recently been conducted, the diagnostic options still need to be improved. Although endomyocardial biopsy is known as a diagnostic gold standard, it is invasive and, thus, only sometimes performed. Novel techniques of cardiac magnetic resonance are not readily available. Therapy in viral infections is based mainly on symptomatic treatment, while steroids and intravenous immunoglobulins are used in autoimmune myocarditis. The effectiveness of neither of these methods has been explicitly proven to date. Therefore, novel diagnostic and therapeutic strategies are highly needed. MiRNAs are small, non-coding molecules that regulate fundamental cell functions, including differentiation, metabolism, and apoptosis. They present altered levels in different diseases, including myocarditis. Numerous studies investigating the role of miRNAs in myocarditis have already been conducted. In this review, we discussed only the original preclinical in vivo research. We eventually included 30 studies relevant to the discussed area. The altered miRNA levels have been observed, including upregulation and downregulation of different miRNAs in the mice models of myocarditis. Furthermore, the administration of mimics or inhibitors of particular miRNAs was shown to significantly influence inflammation, morphology, and function of the heart and overall survival. Finally, some studies presented prospective advantages in vaccine development.

AMP kinase activation by Omega-3 polyunsaturated fatty acid protects the retina against ischemic insult: An in vitro and in vivo study

PURPOSE

To investigate the possible beneficial effects of omega-3 polyunsaturated fatty acids (ω3-PUFAs) in ischemic retinal angiogenesis and whether AMP-activated protein kinase (AMPK) is involved.

METHODS

Human retinal microvascular endothelial cells (hRMECs) were exposed to dimethyloxalylglycine (DMOG), a hypoxia-inducible factor hydroxylase inhibitor, in the presence or absence of docosahexaenoic acid (DHA) and small interfering RNA (siRNA) for AMPKα for 24 h. Ischemic factors, endothelial mesenchymal transition marker, endothelial barrier integrity, cell migration, and tube formation were evaluated. Neonatal AMPKα₂^-/- and control wild-type (WT) mice were submitted to an oxygen-induced retinopathy (OIR) protocol; their nursing mother mice were either fed ω3-PUFAs or not. In the end, ischemic markers and endothelial cell proliferation were evaluated in neonatal mouse retinal tissue through immunohistochemical or immunofluorescent assays among all studied groups.

RESULTS

Cells exposed to DMOG displayed increased expressions of hypoxic and endothelial mesenchymal transition (vimentin) markers and barrier disarrangement of Zonula Occludens-1 compared to the control, accompanied by increased cellular migration and tube formation (p < 0.05). AMPK activity was significantly decreased. Supplementation with DHA restored the mentioned alterations compared to DMOG (p<0.05). In siRNA_AMPKα-treated cells, the beneficial effects observed with DHA were abolished. DHA upregulated G-protein receptor-120 (GPR120), which promptly increased intracellular levels of calcium (p ≤ 0.001), which consequently increased Calcium/calmodulin-dependent protein kinase kinase β expression (CaMKKβ) thus phosphorylating AMPK^Thr172. AMPKα₂^-/- and wild-type (WT) OIR mice exhibited similar retinal ischemic changes, and the oral supplementation with ω3-PUFA efficiently prevented the noticed ischemic alterations only in WT mice, suggesting that AMPKα₂ is pivotal in the protective effects of ω3-PUFA.

CONCLUSIONS

ω3-PUFAs protect the retina from the effects of ischemic conditions, and this effect occurs via the GPR120-CaMKKβ-AMPK axis. A better understanding of this mechanism might improve the control of pathological angiogenesis in retinal ischemic diseases.

Modulation of NRF-2 Pathway Contributes to the Therapeutic Effects of Boswellia serrata Gum Resin Extract in a Model of Experimental Autoimmune Myocarditis

Myocarditis is a clinically dangerous disease that can result in death. Oxidative stress as well as inflammatory and immune responses play important roles in the development of myocarditis. Presently, more research has been carried out on anti-inflammatory treatment using natural compounds. The aim was to evaluate the anti-inflammatory and antioxidant effect of Boswellia gum resin extract in an experimental autoimmune myocarditis (EAM) and the involvement of molecular pathways. Rats were immunized with porcine cardiac myosin to ascertain EAM. The EAM rats were treated orally with Boswellia extract or vehicle for 21 days. EAM caused macroscopic and microscopic alterations with necrosis, inflammatory cell infiltration, fibrosis of the heart tissues, as well as clinical biochemical changes, cytokines release, altered immune response, and oxidative stress. Oral treatment with Boswellia markedly reduced myocardial damage, decreased inflammatory infiltrate, fibrosis, biochemical markers, such as lactate dehydrogenase and the creatine kinase, and heart weight/body weight ratio. In addition, low nitric oxide and malondialdehyde levels together with the upregulation of antioxidant nuclear factor erythroid 2–related factor 2 NRF-2 pathway were observed in EAM rats treated with Boswellia. Thus, Boswellia could be considered as a new natural extract to combat heart pathologies, such as autoimmune myocarditis.

The function of omega-3 polyunsaturated fatty acids in response to cadmium exposure

Throughout history, pollution has become a part of our daily life with the improvement of life quality and the advancement of industry and heavy industry. In recent years, the adverse effects of heavy metals, such as cadmium (Cd), on human health have been widely discussed, particularly on the immune system. Here, this review summarizes the available evidence on how Cd exposure may affect health. By analyzing the general manifestations of inflammation caused by Cd exposure, we find that the role of omega-3 (n-3) polyunsaturated fatty acids (PUFAs) in vivo can counteract Cd-induced harm. Additionally, we elucidate the effects of n-3 PUFAs on the immune system, and analyze their prophylactic and therapeutic effects on Cd exposure. Overall, this review highlights the role of n-3 PUFAs in the pathological changes induced by Cd exposure. Although n-3 PUFAs remain to be verified whether they can be used as therapeutic agents, as rehabilitation therapy, supplementation with n-3 PUFAs is reliable and effective.

The Effects of Fish Oil on Cardiovascular Diseases: Systematical Evaluation and Recent Advance

Fish oil is rich in unsaturated fatty acids, i.e., eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), both of which are widely distributed in the body such as heart and brain. In vivo and in vitro experiments showed that unsaturated fatty acids may have effects of anti-inflammation, anti-oxidation, protecting vascular endothelial cells, thrombosis inhibition, modifying autonomic nerve function, improving left ventricular remodeling, and regulating blood lipid. Given the relevance to public health, there has been increasing interest in the research of potential cardioprotective effects of fish oil. Accumulated evidence showed that fish oil supplementation may reduce the risk of cardiovascular events, and, in specific, it may have potential benefits in improving the prognosis of patients with hypertension, coronary heart disease, cardiac arrhythmias, or heart failure; however, some studies yielded inconsistent results. In this article, we performed an updated systematical review in order to provide a contemporary understanding with regard to the effects of fish oil on cardiovascular diseases.