Effects of dietary oxidized frying oil on immune responses of spleen cells in rats

Schemes for enhanced antioxidant stability in frying meat: a review of frying process using single oil and blended oils

Deep-fried meat products are widely popular. However, harmful compounds produced by various chemical reactions during frying have been shown to be detrimental to human health. It is of great necessity to raise practical suggestions for improving the oxidation problem of frying oils and frying conditions in some aspects. Vegetable oils are not as thermally stable as saturated fats, and blended oils have higher thermal stability than single oil. In this review, we discussed the oxidation problems frying oils and meats are subject to during frying, starting from the oil oxidation mechanism, the effects of different oils and fats on the quality of different fried meats under different conditions were concluded to alleviate the oxidation problem, to highlight the necessity of applying blended oils for frying, and effective antioxidants added to frying oils are also introduced, that would provide more convenient and practical options for obtaining higher quality of fried meat products and offer better understanding of the potential of blended frying oils for frying meat products.

Effects of heat treatment of soy protein isolate on the growth performance and immune function of broiler chickens

This study was conducted to evaluate the effects of oxidative modification of soy protein isolate (SPI) after exposure to heat on the growth performance and immune function of broilers. The SPI was heated in an oven at 100°C for 1, 4, and 8 h, respectively, and resultant oxidative status was evaluated. A total of 320 one-day-old Arbor Acres chickens were randomly divided into 4 treatment groups with 8 replicates of 10 birds, and fed diets supplemented with the native SPI or 1 of the 3 heat-treated SPI for 21 d. The results showed that heat exposure of SPI for 4 and 8 h caused an increase in protein carbonyl (P < 0.05), and a simultaneous decrease in sulfhydryl and free amine groups (P < 0.05) compared with native SPI. The BW of broilers fed diets supplemented with SPI heated for 8 h were significantly lower than that of broilers fed diets supplemented with native SPI (P < 0.05). Compared with native SPI, heat-treated SPI (heated for 8 h) diminished liver weight at 14 d (P = 0.01), spleen (P < 0.01) and bursa (P < 0.05) weights at 21 d; and the content of IgG in serum and duodenal mucosa of broilers (at 14 d) was decreased when diets supplemented with heat-treated SPI (heated for 8 h; P < 0.01). No significant differences were observed in the mucosa secretory IgA contents of broilers among the treatment groups (P > 0.05). Compared with native SPI, a significant increases were observed in the content of adrenocorticotropic hormone and cortisol in serum of broilers fed the heat-treated SPI (heated for 8 h) at 21 d (P < 0.05); and the myeloperoxidase activities in serum (at 14 d) and mucosa of broilers were increased when diets supplemented with heat-treated SPI (heated for 8 h; P < 0.05). The present study suggests that protein oxidation of SPI is induced by heating, and oxidized protein may negatively affect the immune function of broilers.

The immunosuppressive effects of 10mg/kg cyclophosphamide in Wistar rats

The purpose of this study is to identify the immunosuppressive effects of cyclophosphamide (a known immunosuppressant) in male Wistar rats which were administered orally for 30 days repeatedly, and to find a proper dose of cyclophosphamide at which the immunosuppressive effects is identified. The dose of cyclophosphamide is 2, 5, 10mg/kg bw, respectively. The results showed that 10mg/kg cyclophosphamide treatment induced decreases in body weight, body weight gain, relative weight of spleen and thymus, antibody plaque-forming cells, delayed-type hypersensitivity reaction, natural killer cell activity, lipopolysaccharide-induced B-cell proliferation, and Concanavalin A-induced T-cell proliferation. The histopathology observation on spleen and thymus revealed as decreased cellularity. But, no significant clinical symptoms of toxicities and stress were observed and no rats died. These results indicated that the immunosuppressive effects of 10mg/kg cyclophosphamide dosed for 30 days orally were identified in male Wistar rats. Based on the results, it is considered that the dose of 10mg/kg of cyclophosphamide orally for 30 days in male Wistar rats could be used as the dose of positive control group for chemicals immunotoxicity assessment tests. This study also proved that the testing procedures and the experimental techniques established in our laboratory for immunotoxicity tests in male Wistar rats are reliable and feasible.

Dietary oxidized oil influences the levels of type 2 T-helper cell-related antibody and inflammatory mediators in mice

The aim of this present study was to investigate the effect of amount and degree of oxidation of dietary oil on type 2 T-helper cell (TH)-related immune responses. Four groups of BALB/c mice were fed either 50 g soyabean oil/kg (50-S), 50 g oxidized oil/kg (50-O), 150 g soyabean oil/kg (150-S) or 150 g oxidized oil/kg (150-O). After 14 weeks consuming the experimental diets, the mice were immunized with ovalbumin (OVA) plus Al and antigen-specific immunoglobulin (Ig)E, IgG1 and IgG2a, inflammatory mediators such as prostaglandin (PG) E2 and leukotriene (LT)B4 were determined. Higher hepatic microsomal cytochrome P450 was noted in mice fed 150 g oxidized oil/kg compared with those of other groups. OVA-specific IgG1 and IgE were higher in mice fed 150 g oxidized oil/kg compared with those of the other groups. The data suggested the interleukin (IL)-4: interferon (IFN)-γ ratio was higher in mice fed 50 g dietary oxidized oil/kg compared with that of the 50-S group. The IL-5:IFN-γ ratios were higher in the 150-S and 150-O groups than in the 50-S and 50-O groups. PGE2 and LTB4 produced by macrophages stimulated by lipopolysaccharide were highest in mice in the 150 g oxidized oil/kg group. The data suggested that an increased intake of oxidized oil might exert an unfavourable effect on the TH2 response involved in allergic disease.

The effects of vitamin E supplementation on autoimmune-prone New Zealand black x New Zealand white F1 mice fed an oxidised oil diet

The purpose of the present study was to investigate the effect of vitamin E supplementation on autoimmune disease in New Zealand blackxNew Zealand white F1 (NZB/W F1) female mice fed an oxidised oil diet. First, 5-month-old mice were fed an AIN-76 diet containing either 150 g fresh soyabean oil/kg (15S), 50 g fresh soyabean oil/kg + 100 g oxidised frying oil/kg (5S10F) or 5S10F supplemented with all-rac-alpha-tocopheryl acetate at 275 mg/kg diet level (5S10F5E) or 550 mg/kg (5S10F10E), respectively, in experiment 1. The results showed that mice fed the 5S10F10E diet had a lower anti-double-stranded DNA IgG antibody level and a longer lifespan than those fed the 15S and 5S10F diets. Therefore, the 5S10F and 5S10F10E treatments were repeated in experiment 2 for further analysis. The results showed that vitamin E supplementation in the oxidised oil significantly decreased thiobarbituric acid-reactive substance values in the kidney and spleen of NZB/W F1 mice. Interferon-gamma and IL-6 production by mitogen-stimulated splenocytes decreased in mice fed the 5S10F10E diet, whereas the secretion of IL-2 and IL-10 was not affected. The percentage of T-cells was significantly higher and that of MHC class II-bearing cells was lower in the spleens of the 5S10F10E group. The 5S10F10E group had a significantly higher linoleic acid (18 : 2n-6) composition than the 5S10F diet group. Therefore, vitamin E supplementation in oxidised oil might decrease oxidative stress, anti-double-stranded DNA IgG antibody, regulate cytokines and lymphocyte subsets, and subsequently alleviate the severity of autoimmune disease such as systemic lupus erythematosus under oxidative stress.

Dietary factors associated with physician-diagnosed asthma and allergic rhinitis in teenagers: analyses of the first Nutrition and Health Survey in Taiwan

The occurrence of asthma and allergy are related to lifestyle factors, and dietary pattern may be one of the contributing factors. To examine the possible association between dietary intake and the prevalence of asthma and allergic rhinitis in teenagers. In a population-based cross-sectional survey, the relationship was sought between food frequency and physician-diagnosed asthma and allergic rhinitis in 1166 adolescents aged 13-17. The prevalence was 4.0% for asthma and 12.4% for rhinitis. Living in an urbanized area was a significant predictor of asthma and rhinitis. In univariate analysis, higher frequencies of oily fish, butcher's meat, liver and deep-fried foods were associated with asthma. Relevant food frequency variables were dichotomized at the 75th percentile for multivariate logistic regression analysis, which included adjustment for two levels of urbanization. Asthma was associated with intakes of liver (OR = 2.32, 95%CI 1.11-4.80), deep-fried foods (OR = 2.13, 95%CI 1.06-4.30) and butcher's meat (OR 1.84, 95%CI 0.89-3.80). In a similar analysis, allergic rhinitis was associated with liver (OR = 1.67, 95%CI 1.06-2.63). No protective effect was demonstrated for any of the food items examined. Protein-rich and fat-rich foods of animal origin were associated with a higher prevalence of asthma in teenagers.