Fish Oil Fatty Acids and Experimental Arthritis

Omega-3 fatty acids and meloxicam supplementation and the incidence and histopathological changes associated with femoral head syndrome in broilers

Femoral head separation (FHS) is one of the problems commonly found in fast growing-type broilers that resulted in joint inflammation leading to lameness and poor animal welfare. This study aimed to examine the alimentary effects of omega-3 fatty acids (DHA) and meloxicam on the incidence of FHS in relation with changes in pathological features and serum concentrations of TNFα and IL1β in broilers. A total number of 1152 male day-old Cobb 500 broilers were divided into four groups. The chicks in T1 (Control) received the basal diet. Chicks in T2 to T4 were given burden of a modified speed bump, in which the chicks in T2 received the basal diet, and the chicks in T3 and T4 received 2% All-G-Rich (16% DHA) in the basal diet and meloxicam in drinking water (0.5 mg/kg BW) during Days 22–43 of age, respectively. It was demonstrated that the incidence of FHS in T4 was the smallest (P < 0.05) among groups although the incidence of FHS was not increased by modified speed bump itself. Although BW (and average daily gain) in T3 was the smallest, but the incidence of FHS was not decreased. An osteochondrosis cleft during histopathological examination could be detected even in the normal gross lesions. Serum concentrations in TNFα and IL1β were not different among groups. In conclusion, meloxicam as an anti-inflammatory drug was useful to alleviate the gross pathological changes of FHS whereas DHA was not effective at the used dosage. Studies on histopathological changes at the beginning of FHS lesion are necessary.

Dietary trans-10,cis-12 CLA reduces murine collagen-induced arthritis in a dose-dependent manner

Dietary trans-10,cis-12 (t10c12) conjugated linoleic acid (CLA) has been shown to reduce inflammation in a murine collagen-induced arthritis (CA) model. To understand the anti-inflammatory potential of t10c12-CLA in the diet, the minimum dose of pure dietary t10c12-CLA capable of reducing CA was investigated. Because plasma inflammatory cytokines often do not reflect the progression of late-stage arthritis, inflamed tissue cytokine concentrations were also investigated in relation to increasing dietary t10c12-CLA amounts. Mice were randomly assigned to the following dietary treatments upon the establishment of arthritis: corn oil (CO) or 0.125%, 0.25%, 0.375%, or 0.5% t10c12-CLA (wt:wt) for 84 d. Sham mice (no arthritis) were fed CO and served as controls. Arthritic paw score, based on subjective assessment of arthritic severity, and paw thickness decreased linearly overall [16-65% (P < 0.001) and 0.5-12% (P < 0.001), respectively] as dietary t10c12-CLA increased (P < 0.001, R(2) < 0.81). Increasing dietary t10c12-CLA was associated with a decrease in plasma interleukin (IL)-1β at days 21 and 42 compared with CO-fed arthritic mice, such that mice fed ≥0.25% t10c12-CLA had IL-1β concentrations that were similar to sham mice. Plasma cytokines returned to sham mice concentrations by day 63 regardless of treatment; however, an arthritis-induced elevation in paw IL-1β decreased linearly as dietary t10c12-CLA concentrations increased at day 84 (P = 0.007, R(2) = 0.92). Similarly, increasing dietary t10c12-CLA linearly decreased paw tumor necrosis factor (TNF)-α (P = 0.05, R(2) = 0.70). In conclusion, ≥0.125% t10c12-CLA dose-dependently reduced inflammation in a murine CA model.

Individual isomers of conjugated linoleic acid reduce inflammation associated with established collagen-induced arthritis in DBA/1 mice

Previously, dietary conjugated linoleic acid [(CLA), an equal mixture of cis-9, trans-11 (c9t11) and trans-10, cis-12 (t10c12) CLA isomers], was found to reduce inflammation in the murine collagen antibody-induced arthritis model, but less so in the murine collagen-induced arthritis (CIA) model, an arthritic model dependent upon acquired immunity. Because CLA is known to alter the acquired immune response, it was hypothesized that feeding CLA after the establishment of arthritis would reduce paw swelling in the CIA model. In this study, upon the establishment of arthritic symptoms, mice were randomized to the following dietary treatments: corn oil (CO) control (n = 6), 0.5% c9t11-CLA (n = 8), 0.5% t10c12-CLA (n = 6), or 1% combined CLA (1:1 c9t11:t10c12-CLA, n = 6). Paws were scored for severity of arthritis and measured for changes in thickness during an 84-d study period. Dietary c9t11- and combined-CLA similarly decreased the arthritic score (29%, P = 0.036, P = 0.049, respectively, when normalized to initial score) and paw thickness (0.11 mm, P = 0.027, P = 0.035, respectively) compared with CO. Dietary t10c12-CLA reduced the arthritic score (41%, P = 0.007 when normalized) and paw thickness (0.12 mm, P = 0.013) relative to CO. Reduced interleukin-1beta on d 7 and 21 for all CLA treatments (n = 3) relative to CO suggested that antiinflammatory effects of CLA isomers might work by common mechanisms of known pathways involved in chronic inflammation. In conclusion, dietary CLA reduced inflammation associated with CIA, and both c9t11-CLA and t10c12-CLA exhibited antiinflammatory effects.

Fatty acids as modulators of the immune response

Research describing fatty acids as modulators of inflammation and immune responses abounds. Many of these studies have focused on one particular group of fatty acids, omega-3. The data from animal studies have shown that these fatty acids can have powerful anti-inflammatory and immunomodulatory activities in a wide array of diseases (e.g., autoimmunity, arthritis, and infection). However, the evidence from human trials is more equivocal. In this review, a historical framework for understanding how and why fatty acids may affect the immune system is provided. Second, highlights of two recent landmark reports from the Agency for Healthcare Research and Quality are presented. These reports critically evaluate the evidence from human clinical trials of omega-3 fatty acids and rheumatoid arthritis, asthma, and a few other immune-mediated diseases. Third, the data from human clinical trials investigating the impact of various bioactive fatty acids on ex vivo and in vivo immune response are reviewed. Limitations in experimental design and immune assays commonly used are discussed. The discordance between expectation and evidence in this field has been a disappointment. Recommendations for improving both animal-based and human studies are provided.

Dietary fish oil inhibits antigen-specific murine Th1 cell development by suppression of clonal expansion

To determine the mechanisms by which dietary fish oil (FO) affects antigen-stimulated Th1 cell development, DO11.10 Rag 2(-/-) T cell receptor transgenic mice were fed a control diet (5% corn oil (CO) or a FO diet (1% CO + 4% FO, (n-3) PUFA) for 2 wk. CD4(+) T cells were cultured under neutral or Th1 polarizing conditions. FO feeding suppressed (P < 0.05) ovalbumin peptide-induced proliferation of nonpolarized CD4(+) T cells. Differentiation in vitro to Th1 cells was not affected by dietary FO, as evidenced by similar percentages of KJ1-26(+), IFN-gamma(+), IL-4(-) Th1 cells in cultures from CO-fed (99%) and FO-fed (97%) mice. However, the absolute number of viable Th1 cells in polarized cultures from FO-fed mice was less than half that observed in CO-fed mice (P < 0.05), indicating that FO inhibits in vitro Th1 clonal expansion. The reduced number of Th1 cells in FO cultures was not a result of increased apoptosis, because similar percentages of apoptotic Th1 cells were observed in cultures from FO- and CO-fed mice. IL-2-induced cell proliferation was significantly decreased in polarized Th1 cells from the FO group; however, the suppressed proliferation was not linked to reduced CD25 surface expression on antigen-stimulated CD4(+) T cells. Adoptively transferred CFSE-labeled DO11.10 CD4(+) cells into immunized mice (Th1 polarizing agents) showed that dietary FO reduced (P < 0.05) the number of cell divisions in vivo. These studies suggest that the attenuated inflammatory response which accompanies FO feeding may be explained, at least in part, by suppression of Th1 clonal expansion.

Complementary and Alternative Pain Therapy in the Emergency Department

One primary reason patients go to emergency departments is for pain relief. Understanding the physiologic dynamics of pain, pharmacologic methods for treatment of pain, as well CAM therapies used in treatment of pain is important to all providers in emergency care. Asking patients about self-care and treatments used outside of the emergency department is an important part of the patient history. Complementary and alternative therapies are very popular for painful conditions despite the lack of strong research supporting some of their use. Even though evidenced-based studies that are double blinded and show a high degree of interrater observer reliability do not exist, patients will likely continue to seek out CAM therapies as a means of self-treatment and a way to maintain additional life control. Regardless of absolute validity of a therapy for some patients, it is the bottom line: "it seems to help my pain." Pain management distills down to a very simple endpoint, patient relief, and comfort. Sham or science, if the patient feels better, feels comforted, feels less stressed, and more functional in life and their practices pose no health risk, then supporting their CAM therapy creates a true wholistic partnership in their health care.CAM should be relatively inexpensive and extremely safe. Such is not always the case, as some patients have discovered with the use of botanicals. It becomes an imperative that all providers be aware of CAM therapies and informed about potential interactions and side effects when helping patients manage pain and explore adding CAM strategies for pain relief. The use of regulated breathing, meditation, guided imagery, or a massage for a pain sufferer are simple but potentially beneficial inexpensive aids to care that can be easily employed in the emergency department. Some CAM therapies covered here, while not easily practiced in the emergency department, exist as possibilities for exploration of patients after they leave, and may offer an improved sense of well-being and empowerment in the face of suffering and despair. The foundations of good nutrition, exercise, stress reduction, and reengagement in life can contribute much to restoring the quality of life to a pain patient. Adding nondrug therapies of physical therapy, cognitive-behavioral therapy, TENS, hypnosis, biofeedback, psychoanalysis, and others can complete the conventional picture. Adding in simple mind/body therapies, touch therapies, acupuncture, or others may be appropriate in select cases, and depending on the circumstances, may effect and enhance a conventional pain management program. Armed with an understanding of pain dynamics and treatments, practitioners can better meet patient needs, avoid serious side effects, and improve care when addressing pain management in the emergency department.

Dietary fish oil suppresses experimental immunoglobulin a nephropathy in mice

Dietary fish oil (FO) supplementation reportedly retards the progression of renal disease in patients with immunoglobulin (Ig)A nephropathy (IgAN), the most common glomerulonephritis worldwide. Using an experimental mouse model in which early immunopathological hallmarks of IgAN are induced by the mycotoxin vomitoxin (VT), the ameliorative effects of FO ingestion on this disease were evaluated in two studies. In Study 1, the capacity of VT to induce IgAN was evaluated in mice fed for 12 wk AIN-76A diets containing 50 g/kg corn oil (CO), 50 g/kg CO plus 9 mg/kg tert butylhydroquinone (TBHQ), or 5 g/kg CO plus 45 g/kg menhaden FO that contained 200 mg/kg TBHQ. Serum IgA, serum IgA immune complexes and kidney mesangial IgA deposition were greater in mice fed VT + CO compared with the CO control group, whereas all three variables were significantly attenuated in mice fed VT + FO. Although TBHQ also had attenuating effects, these were significantly less than those for the VT + FO group. In Study 2, the effects of feeding modified AIN 93G diets containing either 70 g/kg CO or 10 g/kg CO plus 60 g/kg FO for 20 wk on VT-induced IgAN were compared. Again, consumption of FO attenuated all three immunopathological variables. In addition, spleen cell cultures from the VT + FO group produced markedly less IgA than those cultures from mice fed VT + CO. Taken together, the results suggested that diets containing FO may impair early immunopathogenesis in VT-induced IgAN and that this was not totally dependent on the presence of the antioxidant TBHQ.

Polyunsaturated fatty acids, inflammation, and immunity

The fatty acid composition of inflammatory and immune cells is sensitive to change according to the fatty acid composition of the diet. In particular, the proportion of different types of polyunsaturated fatty acids (PUFA) in these cells is readily changed, and this provides a link between dietary PUFA intake, inflammation, and immunity. The n-6 PUFA arachidonic acid (AA) is the precursor of prostaglandins, leukotrienes, and related compounds, which have important roles in inflammation and in the regulation of immunity. Fish oil contains the n-3 PUFA eicosapentaenoic acid (EPA). Feeding fish oil results in partial replacement of AA in cell membranes by EPA. This leads to decreased production of AA-derived mediators. In addition, EPA is a substrate for cyclooxygenase and lipoxygenase and gives rise to mediators that often have different biological actions or potencies than those formed from AA. Animal studies have shown that dietary fish oil results in altered lymphocyte function and in suppressed production of proinflammatory cytokines by macrophages. Supplementation of the diet of healthy human volunteers with fish oil-derived n-3 PUFA results in decreased monocyte and neutrophil chemotaxis and decreased production of proinflammatory cytokines. Fish oil feeding has been shown to ameliorate the symptoms of some animal models of autoimmune disease. Clinical studies have reported that fish oil supplementation has beneficial effects in rheumatoid arthritis, inflammatory bowel disease, and among some asthmatics, supporting the idea that the n-3 PUFA in fish oil are anti-inflammatory and immunomodulatory.

Omega-3 polyunsaturated fatty acids and skeletal health

This minireview on skeletal biology describes the actions of prostaglandins and cytokines involved in the local regulation of bone metabolism, it documents the role of lipids in bone biology, and it presents relationships between fatty acids and other factors that impact skeletal metabolism. The data presented herein show consistent and reproducible beneficial effects of omega-3 (n-3) fatty acids on bone metabolism and bone/joint diseases. Polyunsaturated fatty acids modulate eicosanoid biosynthesis in numerous tissues and cell types, alter signal transduction, and influence gene expression. These effects have not been explored in the skeletal system. Future research on n-3 fatty acids in bone biology should focus on the following two aspects. First, the further elucidation of how n-3 fatty acids alter biochemical and molecular processes involved in bone modeling and bone cell differentiation, and second, the evaluation of the potential pharmaceutical applications of these nutraceutical fatty acids in maintaining bone mineral status and controlling inflammatory bone/joint diseases.

Diets, dietary supplements, and nutritional therapies in rheumatic diseases

Rheumatoid arthritis and many other systemic rheumatic diseases remain illnesses of unknown cause for which current therapy is often inadequate. This leads patients to seek questionable remedies, prominent among which are dietary manipulations. Is there a role for dietary modifications in the routine therapy for patients with rheumatic diseases? This article discusses the relationships between diets, fasting, elemental nutrition, vitamins, minerals, and foods for rheumatic diseases. Known scientific-based evidence for the use, safety, and efficacy of diets and dietary-related practices subscribed by patients with rheumatic diseases are presented. Studies that link diet with arthritis offer the possibility of identifying new therapeutic approaches for selected patients and of developing new insights to disease pathogenesis. Dietary therapy for arthritis, however, is still being investigated.

Effect of six months of fish oil supplementation in stable rheumatoid arthritis. A double-blind, controlled study

Therapeutic effects of fish oil (10 g/day) in rheumatoid arthritis were investigated in a randomized, controlled, double-blind study. Forty-three patients completing the study were evaluated at 0, 3 and 6 months. The nutrient intake in the fish oil group and in the control group was essentially similar. In the fish oil group, the percentage of n-3 fatty acids in serum phosphatidylcholine increased by 9.6 (range 2.6-16.1). Patients in the fish oil group reported a significantly decreased consumption of NSAID at 3 and 6 months, and the status of global arthritic activity improved at 3 months in physician's assessment. Control patients reported an increased global arthritic activity at 6 months. No change was found in patient assessment of pain, duration of morning stiffness or functional capacity. Essentially no change occurred in biochemical markers of inflammation. We conclude that fish oil has small anti-inflammatory effects with at most a NSAID-saving potential. The value of prolonged supplementation remains to be evaluated.