Experimental studies defining omega-3 fatty acid antiinflammatory mechanisms and abrogation of tumor-related syndromes

Nutrition Modulation of Cachexia/Proteolysis

Cachexia represents progressive wasting of muscle and adipose tissue and is associated with increased morbidity and mortality. Although anorexia usually accompanies cachexia, cachexia rarely responds to increased food intake alone. Our knowledge of the underlying mechanisms responsible for cachexia remains incomplete. However, most states of cachexia are associated with underlying inflammatory processes and/or cancer. These processes activate protein degradation and lipolytic pathways, resulting in tissue loss. In this article, we briefly review the pathophysiology of cachexia and discuss the role of specific nutrient supplements for the treatment of cachexia. The branched chain amino acid leucine, the leucine metabolite beta-hydroxy-beta-methylbutyrate, arginine, glutamine, omega-3 long chain fatty acids, conjugated linoleic acid, and polyphenols have demonstrated some efficacy in animal and/or human studies. Optimal treatment for cachexia is likely aimed at maximizing muscle and adipose synthesis while minimizing degradation.

Omega-3 Polyunsaturated Fatty Acids: The Way Forward in Times of Mixed Evidence

Almost forty years ago, it was first hypothesized that an increased dietary intake of omega-3 polyunsaturated fatty acids (PUFA) from fish fat could exert protective effects against several pathologies. Decades of intense preclinical investigation have supported this hypothesis in a variety of model systems. Several clinical cardiovascular studies demonstrated the beneficial health effects of omega-3 PUFA, leading medical institutions worldwide to publish recommendations for their increased intake. However, particularly in recent years, contradictory results have been obtained in human studies focusing on cardiovascular disease and the clinical evidence in other diseases, particularly chronic inflammatory and neoplastic diseases, was never established to a degree that led to clear approval of treatment with omega-3 PUFA. Recent data not in line with the previous findings have sparked a debate on the health efficacy of omega-3 PUFA and the usefulness of increasing their intake for the prevention of a number of pathologies. In this review, we aim to examine the controversies on the possible use of these fatty acids as preventive/curative tools against the development of cardiovascular, metabolic, and inflammatory diseases, as well as several kinds of cancer.

A multimodal, interdisciplinary programme for the management of cachexia and fatigue

Fatigue and cachexia are common symptoms of advanced disease that have a significant impact on quality of life for palliative care clients. Management of cachexia and fatigue is often overlooked, but growing understanding of the multidimensional nature of fatigue and muscle wasting has led to interest in a model of care based on multimodal therapy that has been successfully implemented in specialized multidisciplinary hospital-based clinics in the oncology/palliative care setting. This article reports on an innovative incorporation of features of this model into a client-centred, interdisciplinary programme that aims to manage the effects of cachexia and fatigue and to improve quality of life for palliative care clients in their home setting. This Cachexia and Fatigue Management Programme (CFMP) involves the use of an anti-inflammatory agent, high protein intake, and an individually tailored resistance exercise regimen to counteract muscle wasting and fatigue. The article provides an overview of the role of multimodal therapies in the management of cachexia and fatigue before moving on to discuss the development of the CFMP, its features, and potential benefits for palliative care clients, caregivers, and health services.

Lipoprotein-associated phospholipase A2 mass is significantly reduced in dyslipidemic patients treated with lifestyle modification and combination lipid-modifying drug therapy

Lipoprotein-associated phospholipase A2 (Lp-PLA(2)) mass is a novel inflammatory biomarker. In human blood, Lp-PLA(2) is predominately associated with low-density lipoprotein (LDL). This study examines the ability of lifestyle modification (diet and exercise) and combination lipid therapy to reduce Lp-PLA(2) levels while also determining the relationship between changes in LDL cholesterol and Lp-PLA(2). Thirty dyslipidemic patients who received lifestyle intervention and combination lipid therapy for an average of 6 months were included in these analyses (mean age, 60.9 years); 40% had stable angiographically established coronary artery disease, 40% had the metabolic syndrome, and 70% were men. Drug therapy included omega-3 fish oil, extended-release niacin, colesevelam hydrochloride, and a fixed combination of 10-mg ezetimibe and 40-mg simvastatin. The study revealed a 33% reduction in mean Lp-PLA(2) values (baseline 224.9+/-47.5 vs posttreatment 149.5+/-35.5 ng/mL; P<.001). Significant changes in mean LDL cholesterol from baseline (127.9+/-49.3 vs posttreatment 65.2+/-32.1 mg/dL; P<.001) were also observed. However, regression analysis revealed only a weak positive relationship between changes in LDL cholesterol and Lp-PLA(2) mass (R(2)=0.29; P<.01). Thus, Lp-PLA(2) mass is significantly reduced with lifestyle and combination lipid therapy. Changes in Lp-PLA(2) were only partially explained by the changes observed for LDL cholesterol.

Long-term n-3 polyunsaturated fatty acids administration ameliorates arteriosclerosis by modulating T-cell activity in a rat model of small intestine transplantation

BACKGROUND

Fish oil, rich in n-3 polyunsaturated fatty acids (n-3 PUFAs), has been found to reduce graft rejection and increase allografts survival. But these studies mainly focused on acute rejection. We imitated long-term fish oil administration to investigate the effects of n-3 PUFAs on graft arteriosclerosis, and T cells in a rat model of small intestine transplantation.

METHODS

From 2 weeks pre-transplantation to the 60th day post-transplantation, the Lewis rats were supplemented by gavage with phosphate buffer saline, corn oil and fish oil respectively. Total small intestine was heterotopically transplanted from F344 to Lewis rat. Graft arteriosclerosis was assessed by histological grading of intimal thickening. The expression of CD25 and CD154, IL-2 level, and NF-kappaB activation in T cells were analyzed by western blotting, ELISA, and electrophoretic mobility shift assay respectively.

RESULTS

Compared with corn oil, graft arteriosclerosis was ameliorated by fish oil significantly. The expression of CD25 and CD154, IL-2 level, and NF-kappaB activation were markedly reduced by fish oil.

CONCLUSIONS

Long-term n-3 PUFAs administration pre- and post-transplantation could inhibit T-cell activity by reducing CD154 expression and NF-kappaB activation, which might contribute to amelioration of graft arteriosclerosis.

Fish oil ameliorates the allograft arteriosclerosis of intestine on rats

Fish oil had been shown to have an immunomodulating effect and had favorable effect on the pathogenesis of atherosclerosis. The aim of this study was to estimate the effect of fish oil on the graft arteriosclerosis and graft immune response after rat allogenic small intestinal transplantation. Since two wk pretransplantation, the Lewis rats were supplemented by gavage with: (i) phosphate buffer saline, 0.6% volume of body weight (V/W), as control group; (ii) fish oil (0.6%, V/W); (iii) fish oil (0.3%, V/W). Total intestine from donor F344 was heterotopically transplanted into the Lewis recipient. The recipient rats were killed on the 60th day post-transplantation. The cytokine levels, the activity of NF-kappa B and the arteriosclerosis of grafts were analyzed. Intragastrical supplementation with 0.6% fish oil induced pronounced inhibition of the pro-inflammtory cytokine expression of interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha, and the increase of anti-inflammtory cytokine expression of IL-10 in graft. Suppression of the TNF-alpha and IL-6 expression by fish oil was attributed to its inhibitory effect on NF-kappaB activation. Intragastric 0.6% fish oil infusion ameliorated the development of graft arteriosclerosis. Fish oil was therefore considered to have an immunosuppressive effect on rat allogenic small intestinal transplant model based on the intra-graft IL-6, TNF-alpha and IL-10 levels. It might result in ameliorating the arteriosclerosis of the grafts.

Nutrition and Immune Function

The complexity of the immune system allows for a multitude of potential avenues for nutrient modulation, but this also increase the challenge of producing a predictable in vivo response. Because the immune response is a cascade of biologic events, development of nutritional support paradigms cannot and should not be made in a vacuum or with the expectation of a singular response. It is absolutely imperative that the clinician/nutritionist understand the differences in metabolIc and physiologic responses to disease states (ie, shock, trauma, organ-specific dysfunction) so as to maximize immunocompetence through specialized feeding practices. This level of understanding is invaluable, especially when considering the possible benefit of nutrient combinations for immunomodualtion.