Interactions of Dietary Fats and Proteins on Fatty Acid Composition of Immune Cells and LTB 4 Production by Peritoneal Exudate Cells of Rats

Distinct effects of dietary flax compared to fish oil, soy protein compared to casein, and sex on the renal oxylipin profile in models of polycystic kidney disease

Oxylipins are bioactive lipids derived from polyunsaturated fatty acids (PUFA) that are important regulators of kidney function and health. Targeted lipidomic analyses of renal oxylipins from four studies of rodent models of renal disease were performed to investigate the differential effects of dietary flax compared to fish oil, soy protein compared to casein, and sex. Across all studies, dietary fish oil was more effective than flax oil in reducing n-6 PUFA derived oxylipins and elevating eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) derived oxylipins, whereas dietary flax oil resulted in higher α-linolenic acid (ALA) oxylipins. Dietary soy protein compared to casein resulted in higher linoleic acid (LA) derived oxylipins. Kidneys from females had higher levels of arachidonic acid (AA) oxylipins, but similar or lower levels of oxylipins from other PUFA. Modulation of the oxylipin profile by diet and sex may help elucidate their effects on renal physiology and health.

Phospholipid Fatty Acid Composition and Diamine Oxidase Activity of Intestinal Mucosa From Rats Treated With Irinotecan Hydrochloride (CPT-11) under Vegetable Oil–Enriched Diets: Comparison Between Perilla Oil and Corn Oil

BACKGROUND

Irinotecan hydrochloride (CPT-11), a topoisomerase I inhibitor highly effective for various cancers, has its dosage limited by diffuse mucosal damage with increased prostaglandin (PG) E(2). However, an analysis of intestinal phospholipid fatty acid composition after CPT-11 treatment has not been reported. This study aimed to evaluate intestinal phospholipid fatty acid composition in relation to intestinal mucosal integrity and plasma and mucosal PGE(2) levels after CPT-11 treatment. The effect of dietary vegetable oil supplementation, perilla oil vs corn oil, was also evaluated.

METHODS

Intestinal phospholipid fatty acid composition, PGE(2) level, mucosal diamine oxidase (DAO) activity, diarrhea, and blood tests were evaluated in rats injected with CPT-11 under a conventional diet. The same parameters were compared among 3 different dietary vegetable oil supplementations: perilla oil, corn oil, and a 1:3, respectively, mixture with a semisynthetic diet during 14 days.

RESULTS

CPT-11 treatment caused severe diarrhea, and intestinal mucosal fatty acid composition changed with increased PGE(2) level and decreased DAO activity. Decreases in eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and EPA/arachidonic acid (AA) ratio in colonic mucosa were observed. Perilla oil increased omega-3 polyunsaturated fatty acids, alpha-linolenic acid, EPA, and EPA/AA ratio and decreased plasma PGE(2). But the amounts used were not enough to attenuate intestinal damage from CPT-11 treatment.

CONCLUSIONS

CPT-11 induced changes of intestinal mucosal fatty acid composition with increased PGE(2) level and decreased intestinal integrity; perilla oil shows the possibility of being able to attenuate those changes.

Plasma n-6 Fatty Acid Levels Are Associated With CD4 Cell Counts, Hospitalization, and Mortality in HIV-Infected Patients

BACKGROUND

Fatty acids, including n-6 series, modulate immune function, but their effect on CD4 cell counts, death, or hospitalization in HIV-infected patients on antiretroviral therapy is unknown.

METHODS

In a randomized trial for effects of multivitamins in HIV-infected patients in Uganda, we used gas chromatography to measure plasma n-6 fatty acids at baseline; determined CD4 counts at baseline, 3, 6, 12, and 18 months; and recorded hospitalization or death events. The associations of fatty acids with CD4 counts and events were analyzed using repeated-measures analysis of variance and Cox regression, respectively.

RESULTS

Among 297 patients with fatty acids measurements, 16 patients died and 69 were hospitalized within 18 months. Except for linoleic acid, n-6 fatty acids levels were positively associated with CD4 counts at baseline but not during follow-up. In models that included all 5 major n-6 fatty acids, age; sex; body mass index; anemia status; use of antiretroviral therapy, multivitamin supplements, and alcohol; and the risk of death or hospitalization decreased significantly with an increase in linoleic acid and gamma-linolenic acid levels, whereas associations for dihomo-gamma-linolenic acid, arachidonic acid, and aolrenic acid were null. The hazard ratios (95% confidence intervals) per 1 SD increase in linoleic acid and gamma-linolenic acid were 0.73 (0.56-0.94) and 0.51 (0.36-0.72), respectively. Gamma-linolenic acid remained significant (hazard ratio = 0.51; 95% confidence interval: 0.35 to 0.68) after further adjustment for other plasma fatty acids.

CONCLUSIONS

Lower levels of gamma-linolenic acid are associated with lower CD4 counts and an increased risk of death or hospitalization. These results suggest a potential for using n-6 fatty acids to improve outcomes from antiretroviral therapy.

Modulatory effect of α-linolenic acid-rich garden cress (Lepidium sativum L.) seed oil on inflammatory mediators in adult albino rats

Vegetable oils containing α-linolenic acid (ALA; 18 : 3n-3) have been shown to modulate the functions of immunocompetent cells. The aim of the present study was to understand the modulatory effect of ALA-rich garden cress (Lepidium sativum L.) seed oil (GCO) on lipid composition, spleen lymphocyte (SL) proliferation and inflammatory mediator production by peritoneal macrophages (PMΦ) in rats. Female Wistar rats were fed diets containing either GCO (2·5, 5·0 and 10 %, w/w) or sunflower oil (SFO, 10 % w/w) for 8 weeks. Ex vivo proliferation of SL was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. IL-2 and TNF-α in SL and PMΦ were analysed by ELISA. Inflammatory mediators such as NO, leukotriene B(4) (LTB(4)) and H(2)O(2) were measured in mitogen-activated PMΦ. GCO significantly increased the levels of ALA, EPA and DHA, but reduced linoleic acid and arachidonic acid in SL and PMΦ lipids. GCO (10 %) significantly decreased the concanavalin A (Con-A)- and phytohaemagglutinin-mediated proliferation of SL by 54 and 38 %, respectively, in comparison with SFO. A marginal decrease in IL-2 and TNF-α was observed in Con-A-stimulated SL and lipopolysaccharide-stimulated PMΦ. LTB(4) levels in Ca ionophore-stimulated PMΦ were reduced by 40 % in GCO-fed rats. NO release in response to various stimuli was significantly decreased in PMΦ of GCO-fed rats. The present study is the first report on the modulatory efficacy of GCO on immunomediators in rats. GCO modulated inflammatory mediators such as NO and LTB(4), and thus may play a role in alleviating inflammatory conditions favourably.

Anti type I allergic property of Japanese butterbur extract and its mast cell degranulation inhibitory ingredients

Pollenosis is a disease that affects 1 in 10 of the Japanese population. During the season of cedar pollen dispersal, many patients suffer from symptoms such as sniffling, sternutation, and itching of the eyes. Japanese butterbur is a popular vegetable and is one of the few domestic vegetables in Japan. The anti type I allergic effects of an aqueous ethanol extract from aerial parts of Japanese butterbur (JBE) were evaluated in rats and RBL-2H3 mast cells. In the passive cutaneous anaphylaxis reaction in rats, a single oral treatment of JBE (1000 mg/kg) was found to suppress the reaction. In IgE-sensitized RBL-2H3 cells, JBE (10-100 microg/mL) inhibited beta-hexosaminidase release, leukotriene C(4)/D(4)/E(4) synthesis, and TNF-alpha production. Moreover, a high concentration of JBE (1000 microg/mL) suppressed smooth muscle constriction induced by histamine (10 microM) and leukotriene D(4) (10 nM) in a guinea pig trachea strip. The search for components in JBE with an inhibitory activity on mast cell degranulation was guided by inhibition of beta-hexsosaminidase release. Two eremophilane-type sesquiterpenes, six polyphenolic compounds, and two triterpene glycosides were isolated. Of these compounds, fukinolic acid, a principal polyphenol constituent, showed potent inhibitory activity (IC(50) value = 2.1 microg/mL). Consequently, On the basis of its inhibition of mast cell activation and direct smooth muscle reaction induced by released mediators, JBE was found to suppress the type I allergic reaction.

Impact of high flaxseed diet on mitogen-induced proliferation, IL-2 production, cell subsets and fatty acid composition of spleen cells from pregnant and F1 generation Sprague-Dawley rats

Flaxseed (FS) being rich in alpha-linolenic acid may alter the immune parameters. Therefore, we assessed the impact of FS and defatted flaxseed meal (FLM) on fatty acid composition, cell subsets, proliferation and IL-2 production by splenic lymphocytes. Pregnant female Sprague-Dawley rats were fed diets containing 0% FS and FLM, 20 or 40% FS, 13 or 26% FLM during gestation or gestation, lactation and 8 week post-weaning period. FS and FLM resulted in up to 8.3 fold and 4.6 fold increase in splenic ALA among pregnant rats, 4.5 fold and 1.2 fold increase in splenic ALA among F(1) generation rats. Splenic linoleic acid (LA) and arachidonic acid (AA) were 18 and 40% lower in 40% FS fed pregnant rats, and AA was 15% lower in all the other groups. Among F(1) rats, splenic LA and AA were 16 and 48% lower in 40% FS group, and AA was 18% lower in 20% FS and 26% FLM groups. Concanavalin A and phytohemagglutinin mediated proliferation of spleen cells were 60 and 52% lower in 40% FS fed pregnant and F(1) generation rats, respectively. No significant changes were observed in the cell subsets or IL-2 production by splenic cells from different groups.