Byoung Seok Moon

Metabolomic Profiles of Aspergillus oryzae and Bacillus amyloliquefaciens During Rice Koji Fermentation

Rice koji, used early in the manufacturing process for many fermented foods, produces diverse metabolites and enzymes during fermentation. Using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS), ultrahigh-performance liquid chromatography linear trap quadrupole ion trap tandem mass spectrometry (UHPLC-LTQ-IT-MS/MS), and multivariate analysis we generated the metabolite profiles of rice koji produced by fermentation with Aspergillus oryzae (RK_AO) or Bacillus amyloliquefaciens (RK_BA) for different durations. Two principal components of the metabolomic data distinguished the rice koji samples according to their fermenter species and fermentation time. Several enzymes secreted by the fermenter species, including α-amylase, protease, and β-glucosidase, were assayed to identify differences in expression levels. This approach revealed that carbohydrate metabolism, serine-derived amino acids, and fatty acids were associated with rice koji fermentation by A. oryzae, whereas aromatic and branched chain amino acids, flavonoids, and lysophospholipids were more typical in rice koji fermentation by B. amyloliquefaciens. Antioxidant activity was significantly higher for RK_BA than for RK_AO, as were the abundances of flavonoids, including tricin, tricin glycosides, apigenin glycosides, and chrysoeriol glycosides. In summary, we have used MS-based metabolomics and enzyme activity assays to evaluate the effects of using different microbial species and fermentation times on the nutritional profile of rice koji.

Metabolomics reveal that amino acids are the main contributors to antioxidant activity in wheat and rice gochujangs (Korean fermented red pepper paste)

Metabolite profiling of gochujangs (Korean fermented red pepper paste) produced from different kinds of raw materials (WG, wheat gochujang; RG, rice gochujang) was performed using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) and ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-Q-TOF-MS). Using principal component analysis (PCA), gochujang samples were differentiated based on the differences in starchy source and secondary materials used in their production. The content of amino acids and sugars was higher in WG, whereas the content of flavonoids, soyasaponins, and γ-aminobutyric acid (GABA) was higher in RG. The content of flavonoids and soyasaponins was related to the higher soybean koji content of RG. The level of antioxidant activity in WG was higher than that in RG and showed a strong positive correlation with amino acid content and a negative correlation with flavonoid content. Although the Trolox equivalent antioxidant capacity of flavonoids was only 10-fold higher than that of amino acids in an antioxidant activity assay, the total amino acid content was as much as several hundred fold higher than total flavonoid content in gochujang. This result suggests that the amino acids could be a main contributor to the antioxidant capacity in gochujang.

The Beneficial Effects of Combined Grape Pomace and Omija Fruit Extracts on Hyperglycemia, Adiposity and Hepatic Steatosis in db/db Mice: A Comparison with Major Index Compounds

This study investigated the effects of combined grape pomace and omija fruit extracts (GO) on diabetes-related metabolic changes in type 2 diabetic db/db mice. The effects of GO were compared with those of a resveratrol and schizandrin mixture (RS), which is a mixture of major components of GO. Mice were fed a normal diet with RS (0.005% resveratrol and 0.02% schizandrin in diet, w/w) or GO (0.3% grape pomace ethanol extract and 0.05% omija fruit ethanol extract in diet, w/w) for seven weeks. RS and GO not only lowered the levels of blood and plasma glucose, HbA1c, insulin and homeostasis model assessment of insulin resistance (HOMA-IR) with a simultaneous decrease in hepatic gluconeogenic enzymes activities and adiposity, but also improved preservation of the pancreatic β-cells. Plasma leptin and resistin levels were lower while the plasma adiponectin level was higher in the RS and GO groups than in the control group. Especially, GO increased hepatic glucokinase activity and gene expression and improved hepatic steatosis by elevating fatty acid oxidation compared to RS. These findings suggest that GO ameliorates hyperglycemia, adiposity and hepatic steatosis in type 2 diabetic mice.

Time-resolved comparative metabolomes for Koji fermentation with brown-, white-, and giant embryo-rice

A time-resolved non-targeted metabolomic study towards evaluating the effects of three rice substrate types viz., white rice (WR), giant embryo rice (GER), and brown rice (BR), on Koji fermentation was performed. Notwithstanding the relatively higher proportions of metabolites in unfermented BR (BR 0>WR 0, GER 0), the relative levels of metabolic repertoire in BR Koji were marginally enhanced during 36h fermentation except those for phenolic acids, fatty acids, and vitamins. The WR Koji showed higher levels of lysophospholipids (LysoPCs) and protease-released amino acids (WR 36>GER 36>BR 36). The higher β-glucosidase activity in GER Koji effected the increased levels of sugars and flavonoid aglycons complementing its higher antioxidant activity (GER Koji>BR Koji∼WR Koji). The present study holistically underpins the dynamic metabolomes and enzymatic states during rice Koji fermentation with varying substrate types. The present study finds applications in optimization of commercial Koji production.

Effect of fermented soybean products intake on the overall immune safety and function in mice

Various functional activities have been reported for the fermented soybean products doenjang (DJ) and cheonggukjang (CGJ), although no systemic investigations of their immune functions have been conducted to date. We examined the effects of an experimental diet of DJ, CGJ, or a mixture of unfermented raw material for 4 weeks on overall immunity and immune safety in mice. No significant alterations were observed in peripheral or splenic immune cells among groups. Enhanced splenic natural killer cell activity was observed in the DJ and CGJ groups compared with the plain diet group. T helper type-1 (Th1)-mediated immune responses were enhanced in the DJ and CGJ groups with an upregulated production ratio of IFN-γ vs. IL-4 and IgG2a vs. IgG1 in stimulated splenic T and B cells, respectively. Resistance to Listeria monocytogenes infection was observed in the DJ and CGJ groups. Overall, the results of this study suggest that DJ and CGJ intake consolidates humoral and cellular immunity to Th1 responses.

Therapeutic effects of orally administered CJLP55 for atopic dermatitis via the regulation of immune response

Atopic dermatitis (AD) is an inflammatory skin condition accompanied by symptoms such as edema and hemorrhage. Kimchi is a traditional fermented Korean dish consisting of various probiotics. In this study, the therapeutic effect of Lactobacillus plantarum CJLP55 isolated from Kimchi was studied in AD-induced mice. Orally administered Lactobacillus strain, CJLP55, suppressed AD symptoms and high serum IgE levels. CJLP55 administration reduced the thickness of the epidermis, infiltration of mast cells and eosinophils into the skin lesion, enlargement of axillary lymph nodes, and increase in cell population in axillary lymph nodes. CJLP55 treatment decreased the production of type 2 cytokines, such as interleukin (IL)-4, IL-5, IL-10, IL-12, interferon (IFN)-γ, and IL-6,which were stimulated by house dust mite extracts, in the axillary lymph node cells. Orally administered CJLP55 exhibited a therapeutic effect on house dust mite-induced AD in NC/Nga mice after onset of the disease by altering immune cell activation. The Lactobacillus strain, CJLP55, isolated from Kimchi, suppressed AD. Our results suggest its possible use as a potential candidate for management of AD.

Dual effects of a mixture of grape pomace (Campbell Early) and Omija fruit ethanol extracts on lipid metabolism and the antioxidant defense system in diet-induced obese mice.

BACKGROUND/OBJECTIVES We investigated the effects of a combination of grape pomace (Vitis labrusca, Campbell Early) and Omija fruit (Schizandra chinensis, Baillon) ethanol extracts on lipid metabolism and antioxidant defense system in diet-induced obese mice. MATERIALS/METHODS Forty male C57BL/6J mice were divided into four groups and fed high-fat diet (control group, CON) or high-fat diet added 0.5% grape pomace extract (GPE), 0.05% Omija fruit extract (OFE) or 0.5% GPE plus 0.05% OFE (GPE+OFE) for 12 weeks. RESULTS In contrast to the GPE- or OFE-supplemented groups, the GPE+OFE group showed significantly lower body weight and white adipose tissue weights than the CON group. Moreover, GPE+OFE supplementation significantly decreased plasma total cholesterol and increased the plasma HDL-cholesterol/total-cholesterol ratio (HTR) compared to the control diet. The hepatic triglyceride level was significantly lower in the GPE+OFE and GPE groups by increasing β-oxidation and decreasing lipogenic enzyme compared to the CON group. Furthermore, GPE+OFE supplementation significantly increased antioxidant enzyme activities with a simultaneous decrease in liver H2O2 content compared to the control diet. CONCLUSIONS Together our results suggest that supplementation with the GPE+OFE mixture may be more effective in improving adiposity, lipid metabolism and oxidative stress in high-fat diet-fed mice than those with GPE and OFE alone.

Effects of the Combined Extracts of Grape Pomace and Omija Fruit on Hyperglycemia and Adiposity in Type 2 Diabetic Mice

Grape products have been known to exert greater antioxidant and anti-obesity than anti-hyperglycemic effects in animals and humans. Omija is used as an ingredient in traditional medicine, and it is known to have an anti-hyperglycemic effect. We investigated whether the combined extracts of grape pomace and omija fruit (GE+OE) could reduce fat accumulation in adipose and hepatic tissues and provide beneficial effects against hyperglycemia and insulin resistance in type 2 diabetic mice. C57BL/KsJ-db/db mice were fed either a normal control diet or GE+OE (0.5% grape pomace extract and 0.05% omija fruit extract, w/w) for 7 weeks. GE+OE decreased plasma leptin and resistin levels while increasing adiponectin levels and reducing the total white adipose tissue weight. Furthermore, GE+OE lowered plasma free fatty acid (FFA), triglyceride, and total-cholesterol levels as well as hepatic FFA and cholesterol levels. Hepatic fatty acid synthase and glucose 6-phosphate dehydrogenase activities were decreased in the GE+OE group, whereas hepatic β-oxidation activity was increased. Furthermore, GE+OE supplementation not only reduced hyperglycemia and pancreatic β-cell failure but also lowered blood glycosylated hemoglobin and plasma insulin levels. The homeostasis model assessment of insulin resistance levels was also decreased and the decrease seems to be mediated by the lowered activities of hepatic glucose-6-phosphatase and phosphoenolpyruvate carboxykinases. The present data suggest that GE+OE may have the potential to reduce hyperglycemia, insulin resistance, and obesity in patients with type 2 diabetes.

Process specific differential metabolomes for industrial gochujang types (pepper paste) manufactured using white rice, brown rice, and wheat

The metabolic perplexes for gochujang (GCJ) fermentative bioprocess, a traditional Korean pepper paste, has largely remain equivocal for preparative conditions and raw material (RM) additives exacerbating its commercial standardization. Herein, we outlined a differential non-targeted metabolite profiling for three GCJ (white rice-WR; brown rice-BR; wheat-WT) under varying processing steps (P1 - fermentation; P2 - meju addition; P3 - ripening; and P4 - red pepper addition). We correlated the process specific metabolomes with corresponding physicochemical factors, enzymatic phenotypes, and bioactivities for GCJ-types. The P1 was characterized by a uniform increase in the levels of RM-derived lysoPCs. In contrast, P2 was observed with proportionally higher levels of meju-released isoflavones and soyasaponins in WR-GCJ, followed by BR and WT-GCJ. The P3 involved a cumulative increase in primary metabolites in all GCJ samples except lower organic acid contents in WT-GCJ. The pepper derived flavonoids and alkaloids were selectively increased while P4 in all GCJ-types.

Mixture of Ethanol Extract of Grape Pomade and Omija Fruit Prevents Hyperglycemia and Alleviates Oxidative Stress in Mice Fed an Obesogenic Diet

Background: A high-fat diet (HFD) is thought to be one of the main environmental factors for obesity in which oxidative stress is an important pathogenic mechanism of obesity-associated metabolic syndrome including diabetes. Polyphenol-rich food plants are known to improve obesity-related diseases. The aim of this study was to investigate the effects of grape pomace (GP) and GP plus omija fruit (GPOF) on hyperglycemia and oxidative stress in diet-induced obese (DIO) mice. Methods: Male C57BL/6J mice were fed an HFD with GP (0.5%, w/w) or GPOF (0.5% GP plus 0.05% omija fruit, w/w) for 12 weeks. One gram of GP contains 0.26 mg of total flavonoid and 0.475 mg of total polyphenol, while 1 g of GPOF contains 0.2635 mg of total flavonoid and 0.491 mg of total polyphenol. Results: GP and GPOF significantly lowered fasting blood glucose level and insulin/glucagon ratio compared to HFD but increased plasma glucagon level. Supplementation with GP or GPOF improved glucose tolerance and the expressions of pancreatic insulin and glucagon while preserving α- and β-cells. GPOF in particular seems to improve insulin sensitivity by reducing plasma insulin and homeostasis model assessment of insulin resistance levels. Erythrocyte glutathione peroxidase and glutathione reductase activities were significantly lower in the GPOF group than in the HFD group along with decreases in erythrocyte hydrogen peroxide and thiobarbituric acid-reactive substance levels. Conclusion: These results suggest that GPOF, which is rich in flavonoids, may be beneficial in preventing an increase in the risk factors for diabetes in obesity, including fasting hyperglycemia, glucose intolerance, and oxidative stress.