Dietary omega-3 and omega-9 fatty acids uniquely enhance allograft survival in cyclosporine-treated and donor-specific transfusion-treated rats

Combating Ischemia-Reperfusion Injury with Micronutrients and Natural Compounds during Solid Organ Transplantation: Data of Clinical Trials and Lessons of Preclinical Findings

Although extended donor criteria grafts bear a higher risk of complications such as graft dysfunction, the exceeding demand requires to extent the pool of potential donors. The risk of complications is highly associated with ischemia-reperfusion injury, a condition characterized by high loads of oxidative stress exceeding antioxidative defense mechanisms. The antioxidative properties, along with other beneficial effects like anti-inflammatory, antiapoptotic or antiarrhythmic effects of several micronutrients and natural compounds, have recently emerged increasing research interest resulting in various preclinical and clinical studies. Preclinical studies reported about ameliorated oxidative stress and inflammatory status, resulting in improved graft survival. Although the majority of clinical studies confirmed these results, reporting about improved recovery and superior organ function, others failed to do so. Yet, only a limited number of micronutrients and natural compounds have been investigated in a (large) clinical trial. Despite some ambiguous clinical results and modest clinical data availability, the vast majority of convincing animal and in vitro data, along with low cost and easy availability, encourage the conductance of future clinical trials. These should implement insights gained from animal data.

Effect of immunosuppressive therapy on the serum fatty acids of phospholipids fraction in patients after heart transplantation

BACKGROUND

The effects of tacrolimus (Tac) and cyclosporine (CsA) on lipid profile is well known; however, little is known about the changes in fatty acids (FA) of phosholipids fraction (PL) in heart transplant patients after treatment with these immunosuppressants. This study aimed to investigate the effect of Tac and CsA on serum FA of PL in heart transplant patients.

METHODS

The study included 23 patients after heart transplantation on Tac (n = 14; group II) or CsA (n = 9; group I). Eleven healthy persons served as a control group. Serum FA of PL were extracted, separated on Sep-Pak NH2, methylated, and measured with the use of gas chromatography. Chemstation software was used to analyze the data.

RESULTS

No differences between the studied groups and control were noted for saturated FA, monounsaturated FA, polyunsaturated FA (PUFA), total FA, and PUFA n-6. The mean value of PUFA n-3 was significantly higher in the CsA group compared with the Tac group (P < .015) and control (P < .002) as well as in the Tac group compared with control (P < .001). For individual FA, higher mean concentration, compared with control, was found for C24, C20:2, C20:4, and C22:6 (P < .001 in all cases) and lower for C18:2cis (P < .001 in both groups) and for C18:3 in the Tac group. The mean values of PUFA n-6 to PUFA n-3 ratios were lower than in control (both P < .001).

CONCLUSIONS

Different pattern of FA of PL may indicate the different FA metabolism in heart transplant patients treated by different immunosuppressants. This should be taken into account when FA supplementation in these patients is considered.

Immunonutrition in kidney and liver transplant recipients

The immunonutrients arginine and omega-3 fatty acids decrease adverse outcomes after solid organ transplant in humans and experimental animals. Kidney transplant recipients who received daily supplements with arginine (9 g) and canola oil (30 mL) had significantly lower frequencies of complications between 30 days to 3 years than transplant recipients who did not receive supplements. In another study in kidney transplant recipients, arginine combined with either canola oil or fish oil was safe, effective, and provided good protection against rejection in patients who had steroid-free immunosuppression. In the 27 patients (50%) who had omega-3 index (percent omega-3 component of all fatty acids in red blood cell membranes) > 6 there was no acute rejection by 1 year after transplant; in 27 patients who had omega-3 index < 6, there were 5 patients (19%) who had acute rejection (P ≤ .01). No studies are available in liver transplant patients that have provided adequate doses or duration of immunonutrients. A prospective, randomized, double-blind clinical trial using immunonutrients is proposed for patients having primary liver transplant. In summary, immunonutrition in kidney transplant recipients with high doses of oral arginine and omega-3 fatty acids is effective, safe, and inexpensive, and may decrease the frequency of complications such as rejection, infection, new onset diabetes and cardiovascular disease. Further study with similar protocols in liver transplant recipients is justified.

Cardiovascular effects of marine omega-3 fatty acids

Much evidence shows that the marine omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid have beneficial effects in various cardiac disorders, and their use is recommended in guidelines for management of patients after myocardial infarction. However, questions have been raised about their usefulness alongside optimum medical therapies with agents proven to reduce risk of cardiac events in high-risk patients. Additionally, there is some evidence for a possible pro-arrhythmic effect in subsets of cardiac patients. Some uncertainly exists about the optimum dose needed to obtain beneficial effects and the relative merit of dietary intake of omega-3 polyunsaturated fatty acids versus supplements. We review evidence for the effects of omega-3 polyunsaturated fatty acids on various cardiac disorders and the risk factors for cardiac disease. We also assess areas of uncertainty needing further research.

Dietary n-3 fatty acids attenuate cardiac allograft vasculopathy via activating peroxisome proliferator-activated receptor-gamma

Recent in vitro data suggested that n-3 fatty acids could inhibit the activation of PPAR gamma. This study was designed to test the hypothesis that fish oil ameliorates CAV development via activating PPAR gamma in an inbred rat model of heart transplantation. Animals were divided into four groups: isograft, control (CsA + vehicle), LFO-treated group (CsA + 0.3% v/w fish oil), and HFO-treated group (CsA + 0.6% v/w fish oil). CsA was administered at 1.5 mg/kg/day for two wk postoperatively. Recipients were treated with fish oil or vehicle daily for eight wk. The histopathological and immunohistochemical examination, activity of NF-kappaB and PPAR gamma, intragraft chemokine levels, and chemokine receptor expression were analyzed. Both LFO and HFO significantly decreased the CAV score, inhibited recruitment of T lymphocytes and macrophages, elevated the activity of PPAR gamma, inhibited the activity of NF-kappaB, reduced levels of intragraft MCP-1 and IP-10 as well as downregulated expression of chemokine receptors CCR2. CXCR3 expression was not affected. Our results demonstrated that fish oil might attenuate CAV development, possibly through activating PPAR gamma and subsequently inhibiting the NF-kappaB activation, the chemokines secretion, as well as the CCR2 expression.

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.

Dietary Phytosterols Reduce Cyclosporine-Induced Hypercholesterolemia in Apolipoprotein E-Knockout Mice

BACKGROUND

Cyclosporine-induced hypercholesterolemia is a major concern after solid organ transplantation. Reducing this side effect of cyclosporine by dietary agents may be safe, cost-effective, and attractive to both patients and health professionals.

METHODS

In this study, the interactions between dietary phytosterols (2% w/w) and cyclosporine (0.02% w/w) in regard to blood cyclosporine concentrations, lipoprotein profile, and histological and morphometrical features of atherosclerotic lesions were studied over 14 weeks in apolipoprotein E-knockout mice.

RESULTS

Cyclosporine alone increased plasma non-HDL cholesterol, and triglyceride concentrations and reduced HDL-cholesterol levels as compared to controls. However, these changes were not associated with further increases in atherogenesis as compared to controls. Unlike cyclosporine, phytosterols reduced non-HDL cholesterol and atherosclerosis, and increased HDL-cholesterol concentrations, as compared to the control group. The addition of dietary phytosterols to cyclosporine reduced the extent of cyclosporine-induced hypercholesterolemia, but not cyclosporine-induced hypertriglyceridemia. The extent of atherosclerosis in the combination therapy group was significantly lower than that in the control group or cyclosporine-treated group. Blood cyclosporine concentrations were comparable between the two groups of cyclosporine-treated and the combination therapy groups at the end of the study.

CONCLUSION

This study suggests that simultaneous consumption of dietary phytosterols and cyclosporine may attenuate posttransplant hypercholesterolemia associated with the immunosuppressive cyclosporine. Additional studies are required to understand the mechanisms by which dietary phytosterols reduce cyclosporine-induced hypercholesterolemia.

Omega-3 Fatty Acids in Health and Disease: Part 2—Health Effects of Omega-3 Fatty Acids in Autoimmune Diseases, Mental Health, and Gene Expression

Omega-3 fatty acids from marine and plant sources provide a wide range of benefits in several human health conditions. In vivo studies indicate that omega-3 fatty acids influence the course of several human diseases, including those that involve abnormal immune function, mental disorders, and genetic abnormalities in lipid metabolism. Omega-3 fatty acids are taken up by virtually all body cells and affect membrane composition, eicosanoid biosynthesis, cell signaling cascades, and gene expression. These fatty acids are especially important during human brain development; maternal deficiency of omega-3 fatty acids may lead to several neurological disorders. The review highlights recent findings on omega-3 fatty acids' influence on autoimmune diseases, mental health, and gene expression.

The Influence of Immunomodulatory Diets on Transplant Success and Complications

BACKGROUND

Animal studies have shown that dietary supplementation with arginine and lipids containing the omega-3 and omega-9 fatty acids prolong allograft survival in animals receiving a short course of low-dose cyclosporine. They also reduce cardiovascular complications and infections in humans.

METHODS

Adult renal transplant patients receiving standard immunosuppression were stratified according to gender, diabetic state, donor source (LD or CD), and first versus repeat transplant, and randomized to receive or not receive supplemental arginine and canola oil (containing both omega-3 and omega-9 fatty acids) twice daily. Patients were followed for a minimum of 3 years.

RESULTS

Seventy-six patients were randomized to the supplement group (S) and 71 patients to the control group (C). Intent-to-treat analysis revealed that S patients had fewer post-30 day first rejection episodes (5.4%) when compared with the C group (23.7%) (P=0.01) and fewer post-30 day episodes of calcineurin inhibitor (CNI) drug toxicity (9.2% vs. 35.3%, P=0.003). S patients developed new onset diabetes mellitus (NODM) less frequently by 3 years (2.3% vs. 14.5%, P=0.04), had fewer cardiac events (5.0% vs. 17.1%, P=0.05), and fewer episodes of sepsis (6.5% vs. 18.7%, P=0.05).

CONCLUSIONS

Dietary supplementation with L-arginine and canola oil is a safe, inexpensive, and unique treatment, which is associated with decreased rejection rates and CNI toxicity after the first month in renal transplant patients. Due to reductions in NODM and cardiac events, long-term benefits for patient survival may be particularly important.

Nutritional pharmacology in surgical patients

The use of pharmaconutrition for supportive care of surgical patients is now well established, but the field is still in its infancy. Complex pharmaconutrient formulas containing arginine, glutamine, and n-3 fatty acids have been proven to shorten hospital stay, decrease the incidence of infection, and reduce hospital costs in selected groups of patients. The effects are greatest in those patients with severe trauma including burn injury, those undergoing major surgical procedures, especially when malnourished, and those who are critically ill ICU patients including patients with existing infection. The complex interaction of pharmaconutrients and other pharmacologic agents are just now beginning to be investigated.

Oral arginine improves blood pressure in renal transplant and hemodialysis patients

BACKGROUND

Hypertension in kidney transplant (KT) patients may result from attenuated whole-body nitric oxide (NO) content and abnormal NO-mediated vasodilation. Increasing NO bioavailability with L-arginine (ARG) could theoretically restore the NO-mediated vasodilatory response and lower blood pressure.

METHODS

In a prospective pilot study, 6 normotensive volunteers and 10 KT patients received oral supplements of ARG (9.0 g/d) for 9 days, then 18.0 g/d for 9 more days. Six hemodialysis (HD) and 4 peritoneal dialysis patients received the same dose for 14 days. Five KT patients received 30 mL/d of canola oil (CanO) in addition to ARG. Systolic (SBP) and diastolic (DBP) blood pressure, creatinine clearance (CCr), and serum creatinine (Cr) were measured at baseline, day 9, and day 18. In a subsequent study, 20 hypertensive KT patients with stable but abnormal renal function were randomized in a crossover study to start ARG-only or ARG+CanO supplements for two 2-month periods with an intervening month of no supplementation. SBP, DBP, CCr, and Cr were measured monthly for 7 months.

RESULTS

In the pilot study, ARG reduced the SBP in HD patients from 171.5 +/- 7.5 mmHg (baseline) to 142.8 +/- 8.3 mmHg (p = .028). In the crossover study, SBP was reduced from baseline (155.9 +/- 5.0 mmHg), after the first 2 months (143.2 +/- 3.2 mmHg; p = .03) and subsequent 2 months (143.3 +/- 2.5 mmHg; p = .014) of supplementation. DBP was also reduced after supplementation in both studies. CanO had no effect on blood pressure. Renal function did not change.

CONCLUSIONS

Oral preparations of ARG (+/-CanO) were well tolerated for up to 60 consecutive days and had favorable effects on SBP and DBP in hypertensive KT and HD patients.

Nutritional immunomodulation leads to enhanced allograft survival in combination with cyclosporine A and rapamycin, but not FK506

BACKGROUND

Recently, specific immunonutrients were found to increase experimental allograft survival when combined with cyclosporine A (CsA). This study compared the effect on rat cardiac allograft survival when nutritional immunomodulation was used with CsA, rapamycin (Rapa), or tacrolimus (FK506).

METHODS

Intra-abdominal ACI to Lewis cardiac allografts were performed and assessed daily by palpation. Study groups included untreated controls and those receiving CsA, Rapa, or FK506. Rats were fed ad libitum with Impact diet (fortified with fish oil, arginine, and RNA) or standard rat food. Further study groups were transplanted that received a donor-specific transfusion in addition to immunosuppression and diet.

RESULTS

Allograft survival was extended by combining Impact with CsA (45.3+/-19 days) and Rapa (165.3+/-52 days), but not FK506 (12.4+/-3.2 days). Mean graft survival in the Rapa/Impact group met criteria for functional tolerance. The addition of a donor-specific transfusion did not lead to graft survival advantages over similar groups not receiving a donor-specific transfusion.

CONCLUSIONS

The use of immunonutrients improves transplant outcome in animals treated with short courses of CsA and Rapa, but not FK506. These findings highlight the potential differences in the effects of nutritional immunomodulation with different immunosuppressive drugs in the treatment of transplant patients.