Seok Hyun Nam

Influence of Oryzanol and Ferulic Acid on the Lipid Metabolism and Antioxidative Status in High Fat-Fed Mice

The comparative effects of oryzanol and ferulic acid on the lipid metabolism and antioxidative status of high fat-fed mice were investigated. The mice were given a diet containing 17% fat (HF), supplemented with oryzanol (HF-O) or ferulic acid for 7 weeks. The control mice (NC) were fed with normal diet. The HF mice exhibited increased body weight gain, plasma and hepatic total cholesterol and triglyceride concentrations, and lipid peroxidation rate, and reduced high-density lipoprotein cholesterol level. In general, they also showed lower hepatic antioxidant and higher lipid-regulating enzymes activities relative to that of NC group. Addition of oryzanol or ferulic acid in the diet counteracted these high fat-induced hyperlipidemia and oxidative stress via increased faecal lipid excretion and regulation of antioxidant and lipogenic enzymes activities. This study illustrates that oryzanol and ferulic acid have relatively similar hypolipidemic actions and could be effective in lowering the risk of high fat diet-induced obesity.

Composition and mechanism of antitumor effects of Hericium erinaceus mushroom extracts in tumor-bearing mice.

We investigated antitumor effects of the following four extracts of freeze-dried Hericium erinaceus mushrooms in Balb/c mice intracutaneously transplanted on the backs with CT-26 colon cancer cells: HWE, hot water extraction by boiling in water for 3 h; MWE, microwaving in 50% ethanol/water at 60 W for 3 min; and ACE and AKE, boiling in 1% HCl or 3% NaOH for 2 h. HWE and MWE with a higher content of β-glucans, determined by an assay kit, than ACE and MKE were active in all bioassays. Gas chromatography/mass spectrometry analyses showed the presence of 40, 27, 16, and 13 compounds, respectively, in the four extracts. Daily intraperitoneal (ip) injections of HWE and MWE for 2 weeks significantly reduced tumor weights by 38 and 41%. Tumor regressions were associated with changes in the following cancer biomarkers as compared to phosphate buffer (PBS)-treated control mice: 2.7- and 2.4-fold increases in cytolytic activity of splenic natural killer (NK) cells; restored nitric oxide production and phagocytosis in peritoneal macrophages to 95-98% of normal levels; ∼2-fold increase in released pro-inflammatory cytokines tumor necrosis factor-α, interleukin-1β, and interleukin-6 from macrophages; and ∼56 and ∼60% reductions in the number of blood vessels inside the tumor. The pro-angiogenic factors vascular endothelial growth factor (VEGF), cyclooxygenase 2 (COX-2), and 5-lipoxygenase (5-LOX) were also significantly reduced in mRNA and protein expression by tumor genes. Enzyme-linked immunosorbent assay of tumor cells confirmed reduced expression of COX-2 and 5-LOX (32 and 31%). Reduced COX-2 and 5-LOX expression down-regulated VEGF expression, resulting in inhibition of neo-angiogenesis inside the tumors. The results indicate that induction of NK activity, activation of macrophages, and inhibition of angiogenesis all contribute to the mechanism of reduction of tumor size.

Dietary rice bran component γ-oryzanol inhibits tumor growth in tumor-bearing mice.

SCOPE We investigated the effects of rice bran and components on tumor growth in mice. METHODS AND RESULTS Mice fed standard diets supplemented with rice bran, γ-oryzanol, Ricetrienol®, ferulic acid, or phytic acid for 2 weeks were inoculated with CT-26 colon cancer cells and fed the same diet for two additional weeks. Tumor mass was significantly lower in the γ-oryzanol and less so in the phytic acid group. Tumor inhibition was associated with the following biomarkers: increases in cytolytic activity of splenic natural killer (NK) cells; partial restoration of nitric oxide production and phagocytosis in peritoneal macrophages increases in released the pro-inflammatory cytokines tumor necrosis factor-α, IL-1β, and IL-6 from macrophages; and reductions in the number of blood vessels inside the tumor. Pro-angiogenic biomarkers vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), and 5-lipoxygenase-5 (5-LOX) were also significantly reduced in mRNA and protein expression by tumor genes. ELISA of tumor cells confirmed reduced expression of COX-2 and 5-LOX up to 30%. Reduced COX-2 and 5-LOX expression downregulated VEGF and inhibited neoangiogenesis inside the tumors. CONCLUSION Induction of NK activity, activation of macrophages, and inhibition of angiogenesis seem to contribute to the inhibitory mechanism of tumor regression by γ-oryzanol.

Protective Effects of Black Rice Bran against Chemically-Induced Inflammation of Mouse Skin

We investigated the inhibitory effects of black rice (cv. LK1-3-6-12-1-1) bran against 12-O-tetradecanolylphorbol-13-acetate (TPA)-induced skin edema and 2,4-dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis (ACD) in inflammatory mouse models. We also determined the effects of the bran extract on the following biomarkers: pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), eicosanoids leukotriene B4 (LTB4), and prostaglandin E2 (PGE2). Topical application of TPA to ears of CD-1 mice induced inflammation accompanied with substantial increase in TNF-α, IL-1β, IL-6, LTB4, and PGE2 levels and an elevation in intercellular adhesion molecule-1 (ICAM-1) gene expressions in ear skin tissues. Intraperitoneal injection of black rice bran extract prior to TPA application in mice significantly suppressed TPA-induced inflammation (edema) and induced a marked decrease in the production of TNF-α, IL-1β, IL-6, and LTB4. Feeding mice a standard diet with added 10% black rice bran also significantly suppressed DNFB-induced allergic contact dermatitis on the skin of the mice. By contrast, a nonpigmented brown rice bran extract did not inhibit the TPA-induced edema and failed to significantly suppress production of pro-inflammatory biomarkers (mediators). These in vivo findings further demonstrate the potential value of black rice bran as an anti-inflammatory and antiallergic food ingredient and possibly also as a therapeutic agent for the treatment and prevention of diseases associated with chronic inflammation.

Cholesterol-Lowering and Antioxidant Status-Improving Efficacy of Germinated Giant Embryonic Rice (Oryza sativa L.) in High Cholesterol-Fed Rats

Background/Aims: The purpose of the current study is to investigate the influence of germinated giant embryonic rice consumption on the lipid metabolism and antioxidant system in rats fed a high-cholesterol diet. Methods: Four groups of rats were given a diet containing 1 g cholesterol/kg for 5 weeks. The control group only received a high-cholesterol diet, while the other 3 experimental groups received each of the diets made of germinated giant embryonic rice, giant embryonic rice, or conventional brown rice (hereafter referred to as GGE-D, GE-D, and BR-D, respectively). Plasma and hepatic lipid profiles were measured, and the antioxidant status of liver was examined. Results: The plasma HDL-cholesterol concentration was significantly higher in rats fed GGE-D compared with the source material (GE-D) or BR-D, while there were no differences in the plasma total cholesterol and triglyceride concentrations between the groups. Consequently, the atherogenic indices of the GGE-D and GE-D groups were significantly lower than for the other groups. The plasma and hepatic thiobarbituric acid-reactive substance levels were higher in rats in the order of those fed BR-D > GE-D > GGE-D. While superoxide dismutase and catalase were significantly activated in rats fed both GGE-D and GE-D, glutathione peroxidase was significantly and most effectively activated in those fed GGE-D. Conclusions: The current results indicate that consumption of germinated giant embryonic rice is effective in lowering atherosclerosis cardiovascular disease risk.

Hericium erinaceus (Lion’s Mane) Mushroom Extracts Inhibit Metastasis of Cancer Cells to the Lung in CT-26 Colon Cancer-Tansplanted Mice

This study investigated the antimetastatic activity of four Hericium erinaceus edible mushroom extracts using CT-26 murine colon carcinoma cells as an indicator of inhibition of cell migration to the lung. Hot water (HWE) and microwaved 50% ethanol (MWE) extracts of H. erinaceus strongly elicited cancer cell death through apoptosis and inhibited metastasis of cancer cells to the lungs by 66% and 69%, respectively. HWE and MWE reduced the expression of matrix metalloproteinases MMP-2 and MMP-9 in cells and their activities in culture media. Urokinase-type plasminogen activator (u-PA), another extracellular matrix (ECM)-degrading proteinase, also showed decreased protein expression. In CT-26 cells, HWE and MWE down-regulated extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) phosphorylations. The reduced phosphorylations seem to cause reduction of activity of the MMPs, thereby blocking migration and invasion of cells. Dietary administration of HWE and MWE reduced the formation of tumor nodules in the lung by about 50% and 55%, respectively, and prevented increases in lung weight caused by cancer cell metastasis. These results demonstrate the effectiveness of HWE and MWE as beneficial antimetastatic agents, targeting their upstream signaling molecules for mediating the expression of the ECM-degrading proteinases. Acidic and alkaline extracts were not bioactive. Bioactivity seems to be related to composition. H. erinaceus edible mushrooms have the potential to serve as a health-promoting functional food.

Hericium erinaceus Mushroom Extracts Protect Infected Mice against Salmonella Typhimurium-Induced Liver Damage and Mortality by Stimulation of Innate Immune Cells

The present study investigated the antibacterial effect of four extracts from the fruitbody of the edible medicinal mushroom Hericium erinaceus (hot water extract, HWE; microwave/50% ethanol extract, MWE; acid extract, ACE; and alkaline extract, AKE) against murine salmonellosis. The extracts had no effect on Salmonella ser. Typhimurium growth in culture. Nor were the extracts toxic to murine macrophage cells, RAW 264.7. HWE and MWE stimulated uptake of the bacteria into the macrophage cells as indicated by increased colony-forming unit (CFU) counts of the contents of the lysed macrophages infected with Salmonella Typhimurium for 30 and 60 min. Two hours postinfection, the bacterial counts increased in the macrophages, but 4 and 8 h postinfection the HWE- and MWE-treated cells showed greater activity against the bacteria than the control. HWE- and MWE-treated noninfected macrophages had altered morphology and elevated inducible nitric oxide (NO) synthase (iNOS) mRNA expression. In the presence of S. Typhimurium, iNOS mRNA expression was further increased, accompanied by an increase in NO production. Histology assays of the livers of mice infected with a sublethal dose (1 × 10(4) CFU) of S. Typhimurium showed that HWE and MWE, administered by daily intraperitoneal injection, protected against necrosis of the liver, a biomarker of in vivo salmonellosis. The lifespans of mice similarly infected with a lethal dose of S. Typhimurium (1 × 10(5) CFU) were significantly extended by HWE and MWE. β-Glucan, known to stimulate the immune system, was previously found to be present in high amounts in the active extracts. These results suggest that the mushroom extract activities against bacterial infection in mice occur through the activation of innate immune cells.

Composition of Liquid Rice Hull Smoke and Anti-Inflammatory Effects in Mice

A new liquid rice hull smoke extract with a smoky aroma and sugar-like odor prepared by pyrolysis of rice hulls followed by liquefaction of the resulting smoke contained 161 compounds characterized by GC/MS. Antioxidative, antiallergic, and anti-inflammatory activities of the extract were assessed in vitro and in vivo. At pH 5, the extract inhibited 1-diphenyl-2-picrylhydrazyl (DPPH) free radicals and suppressed nitric oxide (NO) and β-hexosaminidase releases from lipopolysaccharide (LPS)-induced RAW264.7 mouse macrophage leukemia cells and ionophore A23187-stimulated RBL-2H3 rat basophilic cells without significant cytotoxicity. 12-O-Tetradecanolylphorbol-13-acetate (TPA) was applied to the ears of CD-1 mice to induce inflammation (edema), which was accompanied by increases in a series of biomarkers. Topical application of 1% of the extract as well as feeding mice a standard diet with 1% extract for two weeks significantly reduced the expression of biomarkers associated with the TPA-induced inflammation. These include tumor necrosis factor-α (TNF-α), IL-1β, interleukin-1β (IL-1β), interleukin-6 (IL-6), leukotriene B(4) (LTB(4)), prostaglandin E(2) (PGE(2)), myeloperoxidase (MPO). These in vitro and in vivo findings demonstrate the potential value of rice hull smoke extract derived from a major agricultural byproduct to serve as a new biomaterial for the improvement of food quality and safety and the environment.

A Polysaccharide Isolated from the Liquid Culture of Lentinus edodes (Shiitake) Mushroom Mycelia Containing Black Rice Bran Protects Mice against a Salmonella Lipopolysaccharide-Induced Endotoxemia

Endotoxemia (sepsis, septic shock) is an inflammatory, virulent disease that results mainly from bacterial infection. The present study investigates the inhibitory effect of a bioprocessed polysaccharide (BPP) isolated from the edible Lentinus edodes liquid mycelial mushroom culture supplemented with black rice bran against murine endotoxemia induced by the Salmonella lipopolysaccharide and d-galactosamine (LPS/GalN). BPP was obtained after dialysis against water using a cellulose tube with a molecular weight cutoff of 10000. BPP eluted as a single peak on an HPLC chromatogram. Acid hydrolysis of BPP showed the presence of the following sugars: fucose, galactose, galactosamine, glucose, glucosamine, mannose, rhamnose, and xylose. Treatment of BPP with β-glucanase reduced its immunostimulating activity, suggesting that the polysaccharide has a β-glucan structure. Pretreatment of mice with BPP via oral or intraperitoneal (ip) administration for 2 weeks resulted in the suppression of LPS/GalN-induced catalase, superoxide dismutase (SOD), and transaminase (GOT/GPT) liver enzymes, amelioration of necrotic liver lesions, and reduction of tumor necrosis factor α (TNF-α) and nitrite serum levels as well as myeloperoxidase (MPO) activity, an index of necrotic injury. Immunostimulating macrophage activity was up to 5.4-fold greater than that observed with the culture without the rice bran. BPP also extended the lifespan of the toxemic mice. These positive results with inflammation biomarkers and lifespan studies suggest that the BPP can protect mice against LPS/GalN-induced liver, lung, and kidney injuries and inflammation by blocking oxidative stress and TNF-α production, thus increasing the survival of the toxic shock-induced mice. The polysaccharide has the potential to serve as a new functional food.

A Polysaccharide isolated from the liquid culture of Lentinus edodes (Shiitake) mushroom mycelia containing black rice bran protects mice against salmonellosis through upregulation of the Th1 immune reaction.

The present study investigated the antibacterial effect of a bioprocessed polysaccharide (BPP) isolated from Lentinus edodes liquid mycelial culture supplemented with black rice bran against murine salmonellosis. BPP was not bactericidal in vitro, it did, however, stimulate uptake of the bacteria into RAW 264.7 murine macrophage cells, as indicated by increased colony-forming unit (CFU) counts of the contents of the lysed macrophages incubated with Salmonella Typhimurium for 30 and 60 min. Two hours postinfection, the bacterial counts drastically increased in the macrophages, but 4 and 8 h postinfection BPP extract-treated cells showed lower bacterial counts than the vehicle (saline phosphate pH 7.4 buffer, PBS)-treated control. BPP elicited altered morphology and markedly elevated inducible nitric oxide (NO) synthase (iNOS) mRNA and protein expression in the infected macrophage cells. BPP also activated leukocytes in S. Typhimurium-infected mice, as determined by spleen lymphocyte proliferation and IFN-γ levels in mice sera. ELISA analysis on cytokine production by Th1 and Th2 immune cells from splenocytes of infected mice showed significant increases in the levels of the following Th1 cytokines: IL-1β, IL-2, IL-6, and IL-12. Histology assays of the livers of mice infected with a sublethal dose (1 × 10(4) CFU) of S. Typhimurium showed that BPP, administered daily through an intraperitoneal (ip) or oral route, protected against necrosis of the liver, a biomarker of in vivo salmonellosis. The lifespan of mice similarly infected with a lethal dose of S. Typhimurium (1 × 10(5) CFU) was significantly extended by ip injection or oral administration of the BPP without side effects. These results suggest that the activity of BPP against bacterial infection in mice occurs mainly through the activation of macrophage-mediated immune response resulting from augmented Th1 immunity. The significance of the results for microbial food safety and human health and further research needs are discussed.