Effects of various fiber additions on lipid digestion during in vitro digestion of beef patties.

The purpose of this study was to examine the effect of various fiber additions on lipid digestion during the in vitro digestion of beef patties. The control patties were prepared with 90.5% lean meat and 9.5% tallow. Treatments consisted of 90% lean meat with 9.5% tallow and either 0.5% cellulose, 0.5% chitosan, or 0.5% pectin. The beef patties were then passed through an in vitro digestion model that simulated the composition of the mouth, stomach, and small intestine juices. The change in structure and properties of the lipid droplets was monitored by laser scanning confocal fluorescence microscopy. In general, there was a decrease in lipid droplet diameter as the droplets moved from mouth to stomach to small intestine. The amount of free fatty acid dramatically increased after in vitro digestion in all beef patties. The amount of free fatty acid was, however, lower in beef patties containing chitosan and pectin than other beef patties after in vitro digestion. Beef patties containing various fibers had lower thiobarbituric acid-reactive substances (TBARS) values than samples with no fibers. Among the samples to which fibers were added, chitosan and pectin had lower TBARS than beef patties with cellulose. The cholesterol content decreased after in vitro digestion in all beef patties but was not different among the beef patties before and after in vitro digestion. These results enhance our understanding of the physicochemical and structural changes that occur to ground beef within the gastrointestinal tract.

Comparative effect of seeds of Rhynchosia volubilis and soybean on MG-63 human osteoblastic cell proliferation and estrogenicity.

The seeds of Rhynchosia volubilis (SRV) (Leguminosae) and soybean have been used in oriental folk medicine to prevent postmenopausal osteoporosis. Their beneficial effects are caused by a high content of isoflavone, which function as partial agonists or antagonists of estrogen. To compare the estrogenic effects of SRV and soybean on the MG-63 osteoblastic cell proliferation, 70% methanol extracts of SRV or soybean were treated on MG-63 cells. Although biphasic over a concentration range of 0.001 mg/ml-0.1 mg/ml, both SRV and soybean extracts increased MG-63 cell proliferation. However SRV was more effective at increasing the cell proliferation that paralleled with the greater estrogenic effects as determined by estrogen receptor alpha (ERalpha) expression, an estrogenic response element (ERE)-luciferase activity and the selective expression of insulin-like growth factor-I (IGF-I). SRV-induced IGF-I expression resulted from increases in the mRNA levels. Despite the increased expression of ERbeta, ERE activity and IGF-I expression by soybean were lower than those by SRV. Furthermore, the comparable estrogenic effects between SRV and the combined treatment of genistein and daidzein standards at 0.5 x 10(-8) M, which is a concentration of these two isoflavones similar to that of SRV at 0.001 mg/ml, demonstrate that the greater estrogenicity of SRV for MG-63 cell proliferation is mediated by the synergism of low levels of isoflavones for the selective expression of IGF-I.

Dietary (n-6) and (n-3) fatty acids and energy restriction modulate mesenteric lymph node lymphocyte function in autoimmune-prone (NZB x NZW)F1 mice.

We previously showed that dietary fish oil (FO) and energy restriction (R) have beneficial anti-inflammatory properties in the peripheral blood and spleens of (NZB x NZW)F1 (B/W) lupus-prone mice. Furthermore, unsaturated fatty acids also were shown in the past to influence mesenteric lymph node (MLN) lymphocyte function in healthy young rats. The MLN play a pivotal role in mediating food allergy. To date, the effect of R on intestinal immunity is not well understood; therefore we determined the effect of diet on MLN lymphocyte function. Mice were given either free access to a 5 g/100 g corn oil (CO) or fish oil (FO) diet or the same corn oil (CR) or fish oil (FR) diets restricted to 60% of the intake of the control group. At the age of 4 (young) and 8 (old) mo, MLN lymphocytes were isolated and B- (CD19(+)) and T-lymphocyte subsets (CD4(+) and CD8(+)) were determined by flow cytometry. Additional MLN lymphocytes were placed in culture with or without concanavalin A and culture supernatants collected after 72 h for cytokine and immunoglobulin (Ig) quantitation by ELISA. Aging significantly (P < 0.05) decreased both CD4(+) and CD8(+) T-lymphocytes. Spontaneous and activation-induced interleukin-4 (IL-4), IL-10, and interferon-gamma secretion were greater while IL-2 was lower in CO-fed old mice compared to CO-fed young mice. In contrast, CR or FO alone partially blunted the age-dependent alterations in T-lymphocyte ratios including cytokine and Ig secretion, whereas the FR diet significantly (P < 0.005) normalized the accelerated aging effects on these immune variables. We show for the first time that FR is a far more potent anti-inflammatory therapy than either CR or FO alone in modulating MLN lymphocyte function.

Application of flow injection--chemiluminescence to the study of radical scavenging activity in plants.

Chemiluminescence (CL) was observed during the oxidation of luminol (2 mg/L). mediated by 0.06% hydrogen peroxide (H(2)O(2)) and cytochrome c (10 mg/L). CL intensity was decreased by the presence of radical scavengers and the reduction was linearly proportional to the concentration and ability of scavengers; butylated hydroxytoluene (BHT), caffeic acid and gallic acid. The order of effectiveness as radical scavengers was gallic acid > caffeic acid > BHT, which shows that the number of hydroxyl groups (OH) in the B-ring of flavonoids plays a key role in a good radical scavenging activity. Of eight catechins obtained from green tea extracts, (-)-catechin was the least effective and (-)-epigallocatechin gallate (EGCg) showed the strongest activity. This result indicates that the stereoscopic structure between the C-3 group and the B ring of flavonoids as well as substituents at the C-3 position make a contribution to radical scavenging activity. Of the tested Chinese herbal ingredients, five species of ingredients represented more than 90% of the radical scavenging activity.

The antioxidative effect of ganhuangenin against lipid peroxidation.

The antioxidative effect of ganhuangenin (GHG), isolated from Scutellaria baicalensis Georgi, was examined by measuring its ability to suppress the formation of phospatidylcholine hydroperoxide (PCOOH). The results show that a pretreatment with GHG effectively suppressed PCOOH formation, which was initiated by the peroxyl-generating oxidant, AAPH (2,2'-azobis-2-aminopropane hydrochloride). The protective action of GHG against the formation of the PCOOH was observed in liver, lung, and kidney. When compared with other known antioxidants, we found the antioxidative potency of GHG to be greater than that of alpha-tocopherol. Our data strongly indicate that GHG is a powerful antioxidant against lipid peroxidation and is, therefore, responsible for this prophylactic effect.

Dietary fibers modulate indices of intestinal immune function in rats.

To explore the immunological roles of dietary fiber, male 4-wk-old Sprague-Dawley rats were fed for 2 wk cellulose (water-insoluble), konjak mannan (water-soluble), pectin (water-soluble) or chitosan (acid-soluble) at 5 g/100 g diet. Serum IgE concentrations in rats fed konjak mannan, pectin and chitosan were significantly lower than in those fed cellulose (mean +/- SEM: 5.0 +/- 1.1, 3.6 +/- 1.3, 3.0 +/- 1.2 and 9.6 +/- 1.9 microg/L, respectively). Rats fed pectin had significantly higher serum IgA and IgG concentrations (358 +/- 38 and 424 +/- 36 mg/L for IgA and IgG, respectively) than those fed cellulose (240 +/- 31 and 337 +/- 25 mg/L) or chitosan (176 +/- 22 and 379 +/- 23 mg/L), while the IgM concentration did not differ among the groups. Concentrations of IgA, IgG and IgM in mesenteric lymph node (MLN) lymphocytes generally were greater, while IgE concentration was lower, in rats fed pectin and chitosan than in those fed cellulose. The proportion of CD4+ T-cells in MLN lymphocytes was also dietary fiber-dependent, and the CD4+/CD8+ ratio was significantly higher in the pectin fed group than in all other groups. Under certain experimental conditions, MLN lymphocytes from rats fed pectin had markedly greater interferon-gamma concentration than cells from other groups, while the effect on tumor necrosis factor-alpha concentration was less marked. Thus, dietary fiber may have an immunoregulatory effect on the intestinal immune system of rats.

Effects of gamma-linolenic acid and its positional isomer pinolenic acid on immune parameters of brown-Norway rats.

Male Brown-Norway rats given purified diets containing safflower oil (SFO, linoleic acid, 18:2 n-6), evening primrose oil (EPO, gamma-linolenic acid, 6,9,12- 18:3 n-6) or Korean pine seed oil (PSO, 5,9,12- 18:3) at the 10% level were immunized twice with intraperitoneal ovalbumin, on days 14 and 35 of the feeding diets, and killed one day after the second booster. The relative population of CD4+ T-lymphocytes in the spleen was significantly lower in rats fed SFO than in those fed EPO or PSO, while that of CD8+ subsets remained unchanged. There was a significant increase in the splenic production of IgG and IgE in the PSO group compared to the SFO group, while EPO significantly increased IgE. The periodical response patterns of the serum levels of IgG and IgE varied depending on the source of dietary fats, and the initial rise of total immunoglobulins tended to be higher in the EPO group. The release by peritoneal exudate cells of histamine was comparable among three groups irrespective of saturation by calcium ionophore A23187, while PSO significantly increased leukotriene B4 production. These observations not only indicate specific roles of gamma-linolenic acid but also diverse influences of different octadecatrienoic acids in various immune measurements.