Dietary linoleic acid, immune inhibition and disease

Artemisia plants, arachidonic and other polyunsaturated fatty acids

Arachidonic acid (AA or ARA) is an extremely important fatty acid involved in cell regulation. It is a polyunsaturated fatty acid (20:4n6) covalently bound in esterified form in membrane phospholipids of most body cells. Following irritation or injury, arachidonic acid is released and oxygenated by enzyme systems leading to the formation of an important group of inflammatory mediators, to the prostaglandins (PGE₂) by the cyclooxygenase enzyme. This paper describes the positive health effects of arachidonic acid on malaria and other tropical diseases.

Modulatory Effect of Linoleic Acid During Brucella abortus 544 Infection in Murine Macrophage RAW264.7 Cells and Murine Model BALB/c Mice

In this study, we investigated the effects of linoleic acid (LA) treatment on Brucella abortus infection in professional phagocyte RAW264.7 cells, particularly during the pathogens invasion and intracellular growth in these cells, as well as in murine model BALB/c mice focusing on bacterial splenic proliferation and immunoregulatory activities. LA inhibited the growth of Brucella in a doseand time-dependent manner. The ability of the pathogen to enter the phagocytes was inhibited as was its survival within these cells. This was accompanied by increased nitrite accumulation in these cells at 24 h post-infection. The concentration of LA used in the present study did not affect the total body weight or liver function of the mice. During Brucella infection, the total splenic weight of these animals was not changed; rather, resistance to bacterial proliferation was enhanced in the spleen. Furthermore, mice treated with LA displayed elevated levels of IL-12 and IFN-γ but reduced levels of IL-10 during infection. The findings in this study showed the regulatory role of LA against B. abortus infection suggesting its potential use in designing intervention strategy for brucellosis.

Lipid emulsions in parenteral nutrition: current applications and future developments

INTRODUCTION

A parenteral lipid emulsion (LE), used as a key source of energy, essential fatty acids (FAs), and fat-soluble vitamins, is an integral part of a parenteral nutrition (PN) regimen. The conventional LEs, such as soybean oil (SO)-based emulsions, have caused concerns about the potential adverse effects involving oxidative stress, inflammation, and immune response probably because of undesirable FA composition.

AREAS COVERED

Recently, alternative LEs, optimizing the FA composition with partial substitution of SO with medium-chain triglyceride (MCT), olive oil (OO), and fish oil (FO), have been developed and applied in clinical practice. This review summarizes the characteristics and beneficial clinical effects of alternative parenteral LEs in critically ill, pediatric, and long-term PN patients.

EXPERT OPINION

More clinical data from sufficiently high-powered studies are required to characterize the integral biological properties of alternative LEs for further selection to fit individual needs and disease characteristics. Simultaneously, potential lipid sources with desirable FA compositions and biological properties should be selected to develop new therapeutic LEs. As supplements to current parenteral lipids, the new LEs with different therapeutic effects are expected to fit specified subpopulations of patients with different diseases. Great efforts should be devoted to the development of parenteral LEs.

Long-term effect of early protein malnutrition on growth curve, hematological parameters and macrophage function of rats

To evaluate the long-term effect of mild-early maternal protein malnutrition on weight gain, hematological parameters and macrophage function in rats at adult age, we compared rats whose dams were fed diets containing either 9.5% (low protein-LPD) or 23% protein (normal-NPD) for the first 12 d of lactation. At 80 d of age, the functions of spreading, phagocytosis and killing Candida albicans were determined in resident peritoneal macrophages, whereas leukocytes and red blood cells were counted in peripheral blood. The number of resident peritoneal macrophages from LPD was the same as from NPD, but the ability of spreading and phagocytosing opsonised yeast was impaired. Besides, they were not able to block the germ tube formation or kill C. albicans to the same extent as in the control group. The low protein diet produced a significant reduction in the pups' growth and in hematological parameters although no difference was found in leukocyte counts. Taken together the data suggest that protein malnutrition during early lactation induces permanent alterations in macrophage function, body composition and hematological status, which are not restored completely even after a normal protein diet is supplied.

Vitamin E and C supplementation prevents decrease of eicosapentaenoic acid in mononuclear cells in chronic hepatitis C patients during combination therapy of interferon alpha-2b and ribavirin

OBJECTIVE

We investigated the effects of vitamin E and C supplementation on the fatty acid composition of mononuclear cells and on the clinical observations in patients who had chronic hepatitis C and received interferon-alpha-2b (IFN-alpha-2b) and ribavirin combination therapy.

METHODS

Patients were randomly allocated to receive daily 500 mg of vitamin E and 750 mg of vitamin C (vitamin group, n = 14) or no supplement (non-vitamin group, n = 16) in addition to IFN-alpha-2b and ribavirin therapy. The fatty acid composition of mononuclear cell phospholipids was analyzed before and at 2, 4, and 8 wk after treatment.

RESULTS

After vitamin supplementation, plasma and red blood cell alpha-tocopherol and plasma ascorbic acid levels increased in the vitamin group. Serum levels of alanine aminotransferase decreased significantly after 2 wk of treatment in both groups. At the start of treatment, a lower level of eicosapentaenoic acid (EPA) and a higher level of the molar ratio of arachidonic acid to EPA in mononuclear cells were observed in the present patients compared with healthy volunteers, and a significant correlation between the molar ratio and serum alanine aminotransferase level was found. The EPA level of mononuclear cells was maintained in the vitamin group during treatment, whereas a significant decrease was observed in the non-vitamin group at 4 and 8 wk after treatment.

CONCLUSIONS

Antioxidant vitamin supplementation during IFN-alpha-2b and ribavirin therapy prevented a decrease in EPA of mononuclear cell phospholipids. If a further decrease in the ratio of arachidonic acid to EPA can be achieved by using oral EPA supplementation, the efficacy of IFN-alpha-2b and ribavirin therapy may be improved.

Nutrition rehabilitation of undernourished children utilizing Spiruline and Misola

BACKGROUND

Malnutrition constitutes a public health problem throughout the world and particularly in developing countries.

AIMS

The objective of the study is to assess the impact of an elementary integrator composed of Spiruline (Spirulina platensis) and Misola (millet, soja, peanut) produced at the Centre Medical St Camille (CMSC) of Ouagadougou, Burkina Faso, on the nutritional status of undernourished children.

MATERIALS AND METHODS

550 undernourished children of less than 5 years old were enrolled in this study, 455 showed severe marasma, 57 marasma of medium severity and 38 kwashiorkor plus marasma. We divided the children randomly into four groups: 170 were given Misola (731 +/- 7 kcal/day), 170 were given Spiruline plus traditional meals (748 +/- 6 kcal/day), 170 were given Spiruline plus Misola (767 +/- 5 kcal/day). Forty children received only traditional meals (722 +/- 8 kcal/day) and functioned as the control group. The duration of this study was eight weeks.

RESULTS AND DISCUSSION

Anthropometrics and haematological parameters allowed us to appreciate both the nutritional and biological evolution of these children. The rehabilitation with Spiruline plus Misola (this association gave an energy intake of 767 +/- 5 kcal/day with a protein assumption of 33.3 +/- 1.2 g a day), both greater than Misola or Spiruline alone, seems to correct weight loss more quickly.

CONCLUSION

Our results indicate that Misola, Spiruline plus traditional meals or Spiruline plus Misola are all a good food supplement for undernourished children, but the rehabilitation by Spiruline plus Misola seems synergically favour the nutrition rehabilitation better than the simple addition of protein and energy intake.

Nutrition rehabilitation of HIV-infected and HIV-negative undernourished children utilizing spirulina

The objective of this study was to assess the impact of an alimentary integrator composed of spirulina (Spirulina platensis; SP), produced at the Centre Médical St Camille of Ouagadougou, Burkina Faso, on the nutritional status of undernourished HIV-infected and HIV-negative children. We compared two groups of children: 84 were HIV-infected and 86 were HIV-negative. The duration of the study was 8 weeks. Anthropometric and haematological parameters allowed us to appreciate both the nutritional and biological effect of SP supplement to traditional meals. Rehabilitation with SP shows on average a weight gain of 15 and 25 g/day in HIV-infected and HIV-negative children, respectively. The level of anaemia decreased during the study in all children, but recuperation was less efficient among HIV-infected children. In fact 81.8% of HIV-negative undernourished children recuperated as opposed to 63.6% of HIV-infected children (Z: 1.70 (95% CI -0.366, -0.002, p = 0.088)). Our results confirm that SP is a good food supplement for undernourished children. In particular, rehabilitation with SP also seems to correct anaemia and weight loss in HIV-infected children, and even more quickly in HIV-negative undernourished children.

Effects of polyunsaturated fatty acids on the proliferation of mitogen stimulated bovine peripheral blood mononuclear cells

The present study aimed at analysis of the effects of polyunsaturated fatty acid (PUFA), linoleic acid (LA, C18:2n - 6) and linolenic acid (LNA, C18:3n - 3) on bovine peripheral blood mononuclear cells (PBMC) in vitro. Both mitogen (ConA)-induced proliferative lymphocyte responsiveness during 4 days of culture and eicosanoid (prostaglandin E(2) (PGE(2)) and leukotriene B(4) (LTB(4))) production during 36 h were determined in relation to the absence or presence of various concentrations of LA and LNA (0, 1, 5, 25, 125 and 250 microM). Mitogen-driven proliferative responses of lymphocytes tended to be uninfluenced in the presence of lower concentrations of LA, whereas significant inhibition was observed at the higher concentrations of LA (125 and 250 microM). However, increasing amounts of LNA did not affect the proliferation. ConA stimulation induced a clear PGE(2) response, which significantly decreased in the presence of 250 microM of LA. In addition, increasing amounts of LNA, but not LA, led to a significant decrease in LTB(4) levels. However, The production of LTB(4) did not alter due to mitogenic stimulation. In conclusion, the present study shows that bovine mononuclear cells may functionally be influenced by the presence of PUFA in their environment. Further studies need to be conducted to clarify in vivo consequences of these findings in a situation of PUFA enriched rations in ruminants.

Self-protection Mechanism in d-Cycloserine-producing Streptomyces lavendulae

An antibiotic, D-cycloserine (DCS), inhibits the catalytic activities of alanine racemase (ALR) and d-alanyl-d-alanine ligase (DDL), which are necessary for the biosynthesis of the bacterial cell wall. In this study, we cloned both genes encoding ALR and DDL, designated alrS and ddlS, respectively, from DCS-producing Streptomyces lavendulae ATCC25233. Each gene product was purified to homogeneity and characterized. Escherichia coli, transformed with a pET vector carrying alrS or ddlS, displays higher resistance to DCS than the same host carrying the E. coli ALR- or DDL-encoded gene inserted into the pET vector. Although the S. lavendulae DDL was competitively inhibited by DCS, the K(i) value (920 microM) was obviously higher (40 approximately 100-fold) than those for E. coli DdlA (9 microM) or DdlB (27 microM). The high K(i) value of the S. lavendulae DDL suggests that the enzyme may be a self-resistance determinant in the DCS-producing microorganism. Kinetic studies for the S. lavendulae ALR suggest that the time-dependent inactivation rate of the enzyme by DCS is absolutely slower than that of the E. coli ALR. We conclude that ALR from DCS-producing S. lavendulae is also one of the self-resistance determinants.

Safe and efficacious prolonged use of an olive oil-based lipid emulsion (ClinOleic©) in chronic intestinal failure

BACKGROUND & AIMS

Injectable lipid emulsion is an important component of parenteral nutrition. ClinOleic is a lipid emulsion composed of olive oil (80%) and soybean oil (20%). This study evaluated the efficacy and safety of ClinOleic in adults already receiving parenteral nutrition, comparing it to their usual lipid (soybean-oil-based).

METHODS

Thirteen adults dependent on home parenteral nutrition were recruited from a single hospital. ClinOleic was administered for 6 months. Two-monthly assessments were made. In addition, clinical and adverse events were recorded for 6-month periods before, during and after the study.

RESULTS

Total numbers of important complications for the 6 months before, during and after the study were 13, 9 and 9, respectively. There were, respectively, 5, 3 and 2 line infections, and 2, 0 and 5 thrombotic episodes in the 3 periods. The numbers of unplanned admissions were, respectively, 8, 5 and 7, with in-patient days accounting for 3.4%, 1.5%, and 2.6% of feeding days, respectively. One patient died (pneumonia). One new case of cholecystolithiasis appeared.

CONCLUSION

ClinOleic may be used as a safe alternative to standard soybean-oil-based lipid emulsions.

Why is psoriasis uncommon in Africans? The influence of dietary factors on the expression of psoriasis

Psoriasis is uncommonly seen in Africans, probably partly due to genetic factors. However, the dietary habits of Africans may provide another explanation, which is explored in this paper. Maize, the staple diet in most parts of Africa, is high in linoleic acid but low in other polyunstaturated fatty acids and riboflavin. Linoleic acid is a precursor of prostaglandin E2 (PGE2) and its high intake, especially in the absence of other polyunsaturated fatty acids (PUFAs) and riboflavin, results in high tissue production of PGE2. PGE2 is known to suppress cellular immunity, resulting in decreased expression of psoriasis.

The beneficial and detrimental effects of linoleic acid on autoimmune disorders

Type 1, or cellular, immune response is characterized by overproduction of IL-1, IL-2, IFN-gamma and TNF-alpha and is the underlying immune mechanism of some autoimmune disorders such as psoriasis, alopecia areata, rheumatoid arthritis, Crohn's disease, multiple sclerosis, insulin-dependent diabetes mellitus and experimental autoimmune uveitis. Type 2 immune response is seen in allergic and antibody-mediated autoimmune diseases and is characterized by IL-4, IL-6 and IL-10 overproduction. Linoleic acid is a precursor of prostaglandin E2 (PGE2) and its intake results in tissue production of PGE2, especially in the absence of other polyunsaturated fatty acids (PUFAS) which inhibit this conversion. PGE2 decreases the production of IL-1, IL-2, IFN-gamma and TNF-alpha and proliferation of TH1 cells and increases the production of IL-4, leading to suppression of the type 1 immune response. Taken together, linoleic acid, the major PUFA of maize oil, could have therapeutic efficacy against cellular autoimmune disorders. On the other hand, excessive intake of linoleic acid may aggravate type 2 autoimmune disorders.

Effect of a Dietary n-6 Polyunsaturated Fatty Acid Supplement on Distinct Immune Functions of Goats

The aim of this study was to investigate whether dietary n-6 polyunsaturated fatty acids (PUFA) alter immune functions as lymphocyte blastogenesis, expression of lymphocyte and monocyte markers, and cell adhesion molecules of the integrin family in goats. Dutch White castrated male goats received a diet either rich in olive oil (control group, n = 4) or rich in corn oil (test group, n = 4) over a period of 3 weeks. The animals in the test group had significantly higher linoleic acid (LA, 18:2n-6) levels in plasma on days 7, 14 and 21 of the diet than control animals. This was also true for washed erythrocyte membranes at day 21. A significant reduction in the percentage of alpha-4 integrin (CD49d) expressing lymphocytes was observed in goats fed LA rich corn oil at day 21. However, no changes were observed in either lymphocyte proliferative responses to ConA and PHA or the expression of other lymphocyte/monocyte markers. In conclusion, feeding corn oil rich in LA caused significant increases in the proportion of LA in the fatty acid composition of plasma and erythrocyte membranes and was accompanied by a significant decrease of the adhesion molecule alpha-4 integrin (CD49d) on lymphocytes but not on monocytes.

Dietary fat and salivary prostaglandin E2

A study of the relation between dietary fat intake and salivary prostaglandin E2 was undertaken in Transkei, South Africa. Samples of saliva were obtained from (1) Transkeians on a very low fat diet, (2) Transkeians on a low fat diet, (3) Transkeians on a medium fat diet, (4) British patients. Salivary PGE2 means for the groups were (1) 2357 pg/ml, (2) 2020 pg/ml, (3) 733 pg/ml, (4) 312.5 pg/ml. Differences between groups 1 and 3, 1 and 4, and 2 and 4 were significant. Rural Transkeians on a low-fat diet have an elevated level of PGE2 in saliva. As fat increases in the diet, PGE2 in saliva tends towards the level found in those who eat a western diet. An increase in the level of PGE2 production in the upper gastrointestinal tract and in the tissues of the body may be a factor in promoting cancer of the esophagus and diseases favored by Th1 immune dysfunction.