Effect of Cheonggukjang supplementation upon hepatic acyl-CoA synthase, carnitine palmitoyltransferase I, acyl-CoA oxidase and uncoupling protein 2 mRNA levels in C57BL/6J mice fed with high fat diet

Fermented soybean foods and diabetes

The number of patients with type 2 diabetes mellitus is increasing, and its prevention and management are important. One of the factors contributing to the increased incidence of type 2 diabetes mellitus is the change in dietary habits, including a Westernized diet. Fermented foods are foods that are transformed by the action of microorganisms to produce beneficial effects in humans and have been consumed for thousands of years. The production and consumption of fermented soy foods, including natto, miso, douchi, cheonggukjang, doenjang, tempeh, and fermented soy milk, are widespread in Asian countries. This review focuses on fermented soybean foods and summarizes their effects on diabetes. Fermentation increases the content of ingredients originally contained in soybeans and adds new ingredients that are not present in the original soybeans. Recent studies have revealed that fermented soybean food modifies the gut microbiota-related metabolites by modifying dysbiosis. Furthermore, it has been reported that fermented soybean foods have antioxidant, anti-inflammatory, and anti-diabetic effects. In recent years, fermented foods, including fermented soybeans, have shown various beneficial effects. Therefore, it is necessary to continue focusing on the benefits and mechanisms of action of fermented foods.

Fermented Foods of Korea and Their Functionalities

Fermented foods are loved and enjoyed worldwide and are part of a tradition in several regions of the world. Koreans have traditionally had a healthy diet since people in this region have followed a fermented-foods diet for at least 5000 years. Fermented-product footprints are evolving beyond boundaries and taking the lead in the world of food. Fermented foods, such as jang (fermented soybean products), kimchi (fermented vegetables), jeotgal (fermented fish), and vinegar (liquor with grain and fruit fermentation), are prominent fermented foods in the Korean culture. These four major fermented foods have been passed down through the generations and define Korean cuisine. However, scientific advancements in the fermentation process have increased productivity rates and facilitated global exports. Recently, Korean kimchi and jang have garnered significant attention due to their nutritional and health-beneficial properties. The health benefits of various Korean fermented foods have been consistently supported by both preclinical and clinical research. Korean fermented foods effectively reduce the risk of cardiovascular and chronic metabolic diseases, such as immune regulation, memory improvement, obesity, diabetes, and high blood pressure. Additionally, kimchi is known to prevent and improve multiple metabolic diseases, including irritable bowel syndrome (IBS), and improve beneficial intestinal bacteria. These functional health benefits may reflect the synergistic effect between raw materials and various physiologically active substances produced during fermentation. Thus, fermented foods all over the world not only enrich our dining table with taste, aroma, and nutrition, but also the microorganisms involved in fermentation and metabolites of various fermentations have a profound effect on human health. This article describes the production and physiological functions of Korean fermented foods, which are anticipated to play a significant role in the wellness of the world’s population in the coming decades.

Anti-Obesity Effects of Traditional and Commercial Kochujang in Overweight and Obese Adults: A Randomized Controlled Trial

Kochujang shows anti-obesity effects in cell and animal models. Kochujang is traditionally prepared via slow fermentation or commercially using Aspergillus oryzae. We analyze the anti-obesity effects of two types of Kochujang in overweight and obese adults. The analyses included the following groups: traditional Kochujang containing either a high-dose (HTK; n = 19), or a low-dose of beneficial microbes (LTK; n = 18), and commercial Kochujang (CK; n = 17). Waist circumference decreased significantly in the HTK and CK groups. Total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels decreased in the HTK and LTK groups. Visceral fat is significantly reduced in the HTK group. The population of beneficial microorganisms in stool samples increased in all groups. Consumption of Kochujang reduces visceral fat content and improves the lipid profile, which can be enhanced by enrichment with beneficial microbes. These results suggest that Kochujang has the potential for application in obesity prevention.

Effects of Bacillus Subtilis-Fermented White Sword Bean Extract on Adipogenesis and Lipolysis of 3T3-L1 Adipocytes

To investigate the adipogenesis and lipolysis effects of the Bacillus subtilis-fermented white sword bean extract (FWSBE) on 3T3-L1 adipocytes, we treated 3T3-L1 preadipocytes before and after differentiation with FWSBE and measured triglyceride, free glycerol, mRNA, and protein levels. First, FWSBE reduced the cell viability of 3T3-L1 pre-adipocytes under 1000 µg/mL conditions. Triglyceride accumulation in 3T3-L1 pre-adipocytes was suppressed, and free glycerol content in mature 3T3-L1 adipocytes was increased in the FWSBE treatment groups, indicating that FWSBE has anti-obesity effects. Further, FWSBE suppressed adipogenesis in 3T3-L1 pre-adipocytes by lowering the protein levels of C/EBPα, PPARγ, and FAS and increasing the level of pACC and pAMPK. Additionally, FWSBE promoted lipolysis in mature 3T3-L1 adipocytes by increasing the transcription levels of Ppara, Acox, and Lcad and the protein levels of pHSL and ATGL. Thus, we suggest that FWSBE can be a potential dietary supplement because of its anti-obesity properties.

Current Perspectives on the Physiological Activities of Fermented Soybean-Derived Cheonggukjang

Cheonggukjang (CGJ, fermented soybean paste), a traditional Korean fermented dish, has recently emerged as a functional food that improves blood circulation and intestinal regulation. Considering that excessive consumption of refined salt is associated with increased incidence of gastric cancer, high blood pressure, and stroke in Koreans, consuming CGJ may be desirable, as it can be made without salt, unlike other pastes. Soybeans in CGJ are fermented by Bacillus strains (B. subtilis or B. licheniformis), Lactobacillus spp., Leuconostoc spp., and Enterococcus faecium, which weaken the activity of putrefactive bacteria in the intestines, act as antibacterial agents against pathogens, and facilitate the excretion of harmful substances. Studies on CGJ have either focused on improving product quality or evaluating the bioactive substances contained in CGJ. The fermentation process of CGJ results in the production of enzymes and various physiologically active substances that are not found in raw soybeans, including dietary fiber, phospholipids, isoflavones (e.g., genistein and daidzein), phenolic acids, saponins, trypsin inhibitors, and phytic acids. These components prevent atherosclerosis, oxidative stress-mediated heart disease and inflammation, obesity, diabetes, senile dementia, cancer (e.g., breast and lung), and osteoporosis. They have also been shown to have thrombolytic, blood pressure-lowering, lipid-lowering, antimutagenic, immunostimulatory, anti-allergic, antibacterial, anti-atopic dermatitis, anti-androgenetic alopecia, and anti-asthmatic activities, as well as skin improvement properties. In this review, we examined the physiological activities of CGJ and confirmed its potential as a functional food.

In Vitro Antidiabetic and Antiobesity Activities of Traditional Kochujang and Doenjang and Their Components

In this study we investigated the antidiabetic and antiobesity effects of aqueous ethanol extracts of traditional kochujang and doenjang. The average α-glucosidase inhibitory activity and adipogenesis inhibitory activity for the kochujang samples were 29.6% and 20.8%, respectively, while those of the doenjang samples were 46.3% and 11.6%, respectively. Therefore, antidiabetic activity is high in doenjang and antiobesity activity is high in kochujang. Kochujang and doenjang components responsible for suppressing the functional effects were investigated by metabolomic analysis. For kochujang, p-coumaric acid, N6,N6,N6-trimethyllysine, threonine, and methionine positively correlated with inhibition of adipogenesis activity, whereas for doenjang, betaine and betaine aldehyde were thought to be responsible for the antidiabetic effects. As p-coumaric acid and betaine were the most probable candidates with functional effects, these two compounds were selected for further analysis. Inhibition of adipogenesis was shown to be 14.0±1.85% for betaine chloride and 38.3±3.27% for p-coumaric acid, suggesting that p-coumaric acid is more effective than betaine against obesity. However, betaine exhibited higher α-glucosidase inhibitory activity than p-coumaric acid. Our results suggest that both kochujang and doenjang can be used against diabetes and obesity. However, clinical trials are necessary to support these results.

Plantago asiatica L. Seed Extract Improves Lipid Accumulation and Hyperglycemia in High-Fat Diet-Induced Obese Mice

Obesity and its common association with type 2 diabetes, dyslipidemia, and cardiovascular diseases are worldwide epidemics. Currently, to prevent or treat obesity and associated metabolic disorders, herbal dietary supplements or medicines have attracted more and more attention owing to their relative effectiveness with fewer significant side effects. We investigate the therapeutic effects and underlying mechanisms of Plantago asiatica L. seed extract (PSE) on obesity and associated metabolic disorders in high-fat (HF) diet-induced mice. Our results displayed that PSE did not modify food intake or body weight but decreased abdominal white adipose tissue ratio, white/brown adipocyte size, serum total cholesterol, triglyceride (TG), low density lipoprotein cholesterol, free fatty acid, and hepatic TG concentrations when compared with the HF group. The levels of fasting blood glucose and glucose tolerance were improved in the PSE group when compared with the HF group. Furthermore, PSE upregulated mRNA expressions of peroxisome proliferator activated receptors (PPARs) and target genes related to fatty acid metabolism and energy expenditure in liver and adipose tissue of obese mice when compared with the HF group. PSE treatment effectively improved lipid and glucose metabolism in HF diet-induced obese mice. These effects might be attributed to the upregulation of PPAR signaling.

Cheonggukjang, a soybean paste fermented with B. licheniformis-67 prevents weight gain and improves glycemic control in high fat diet induced obese mice

In this study, we investigated the anti-obesity effects of soybean paste—Cheonggukjang, fermented with poly gamma glutamic acid producing Bacillus licheniformis-67 in diet induced obese C57BL/6J mice. Forty male C57BL/6J mice aged 4 weeks were divided into four dietary groups; normal diet control, high fat diet control, high fat diet containing 30% of unfermented soybean and high fat diet containing 30% Cheonggukjang fermented with Bacillus licheniformis-67. After 13 weeks of dietary intervention the mice were sacrificed; serum and tissue samples were examined. Serum and hepatic lipid profile, blood glucose, insulin, leptin level were lower (<0.05) along with the body weight and epididymal fat pad weight in the 30% Cheonggukjang supplemented group compared with the high fat diet control group. The expression level of lipid anabolic gene was significantly decreased; whereas the expression level of lipid catabolic genes were significantly increased in the 30% Cheonggukjang supplemented group compared to the high fat diet control group. Collectively, these results suggested that intake of Cheonggukjang fermented with Bacillus licheniformis-67 significantly prevents obesity related parameters.

Effect of ursolic acid and Rosiglitazone combination on hepatic lipid accumulation in high fat diet-fed C57BL/6J mice

This study investigated the combined effect of ursolic acid (UA) and Rosiglitazone (RSG) on lipid regulatory genes in high fat diet (HFD)-fed mice. Male C57BL/6J mice were fed either normal diet or HFD for 10 weeks, after which animals in each dietary group were divided into following six groups, (normal diet, normal diet plus UA and RSG, HFD alone, HFD plus UA, HFD plus RSG, and HFD plus UA and RSG), for the next 5 weeks. UA (5mg/kg BW) and RSG (4mg/kg BW) were administered as suspensions directly into the stomach using a gastric tube. At the end of the study (106th day), their liver was analyzed for lipid content. RT-PCR and western blotting methods were used to analyze lipid regulatory genes. HFD-fed mice showed increased activities of hepatic marker enzymes (aspartate aminotransferase and alanine aminotransferase) in plasma and an increased concentration of total cholesterol, triglyceride and free fatty acid in liver. These results were confirmed by upregulated mRNA expression of lipogenic genes such as sterol-regulatory-element-binding protein-1c, fatty acid synthase and acetyl-CoA carboxylase and downregulated mRNA expression of fatty acid oxidative genes such as carnitine palmitoyltransferase-1, acetyl-CoA carboxylase and peroxisome proliferator activated receptor-α in HFD-fed mice. Combined treatment (UA/RSG) significantly reduced the hepatic marker enzyme activities and decreased the lipid accumulation in liver. Furthermore, combination treatment (UA/RSG) down-regulated lipogenic genes and upregulated fatty acid oxidative genes in HFD-fed mice. This study suggests that UA in combination with RSG reduced lipid accumulation in liver.

Anti-obesity effects of traditional and standardized meju in high-fat diet-induced obese C57BL/6J mice

The aim of the study was to evaluate the anti-obesity effects of two types of meju in diet induced obese C57BL/6J mice. Animals were randomly divided into 4 dietary group (n = 10); normal diet, high fat diet with 30% soybean, high fat diet with 30% traditional meju, high fat diet with 30% standardized meju. After 16 weeks, after animals were sacrificed. It was observed that the high fat diet with 30% traditional meju and high fat diet with 30% standardized meju significantly reduced body weight gain, epididymal fat weight, serum triglyceride along with serum insulin and leptin levels compared to the high fat diet with 30% soybean. And also, the expression levels of hepatic lipid anabolic genes were significantly decreased in the high fat diet with 30% traditional meju and high fat diet with 30% standardized meju compared to the high fat diet with 30% soybean. In conclusion, the assessment of all the obesity markers strongly advocate the anti-obesity effect of traditional as well as standardized meju in diet induce obesity conditions.

Genistein sensitizes hepatic insulin signaling and modulates lipid regulatory genes through p70 ribosomal S6 kinase-1 inhibition in high-fat-high-fructose diet-fed mice

CONTEXT

Genistein reduces high-calorie diet-induced insulin resistance and fat accumulation in animals, but the mechanism is unresolved.

OBJECTIVE

This study explores whether action of genistein is associated with p70 ribosomal S6 kinase-1 (S6K1) inhibition.

MATERIALS AND METHODS

Adult male mice were fed either normal diet or high-fat-high-fructose diet (HFFD) for 15 days, after which animals in each dietary group were divided into two groups and administered either genistein (1 mg kg(-1) day(-1), p.o.) in 0.5 ml of 30% dimethylsulfoxide (DMSO) or 30% DMSO (0.5 ml) for the next 45 days. At the end of the study, their liver was analyzed for lipid content. Semi-quantitative RT-PCR and western blotting methods were used to analyze lipid regulatory genes and insulin signaling proteins, respectively.

RESULTS

Genistein significantly (p < 0.05) lowered HFFD-induced body and liver weight gain and plasma and hepatic lipid levels. Histology showed a 2.5-fold increase of lipid in HFFD compared to control. Genistein treatment to HFFD-fed animals significantly decreased lipid accumulation (by 40%) compared to HFFD. Insulin-stimulated tyrosine phosphorylation of insulin receptor-β and insulin receptor substrates-1 (IRS-1), IRS-1 associated phospatidylinositol-3kinase (PI3K) and Akt Ser(473) phosphorylation were improved while IRS-1 serine phosphorylation was significantly (p < 0.05) decreased by genistein in HFFD. Significant (p < 0.05) increase in adenosine monophosphate-activated protein kinase (AMPK) Thr(172) phosphorylation and decrease in S6K1 Thr(389) phosphorylation were observed in HFFD-plus genistein compared to HFFD. Genistein downregulated lipogenic genes and upregulated fatty acid oxidative genes in HFFD-fed mice.

CONCLUSION

Genistein improves insulin signaling and attenuates fat accumulation in liver through S6K1 inhibition.

Obesity-related metabolomic analysis of human subjects in black soybean peptide intervention study by ultraperformance liquid chromatography and quadrupole-time-of-flight mass spectrometry

The present study aimed to identify key metabolites related to weight reduction in humans by studying the metabolic profiles of sera obtained from 34 participants who underwent dietary intervention with black soybean peptides (BSP) for 12 weeks. This research is a sequel to our previous work in which the effects of BSP on BMI and blood composition of lipid were investigated. Sera of the study were subjected to ultra performance liquid chromatography and quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS), and the data were analyzed using partial least-squares discriminate analysis (PLS-DA) score plots. Body mass index and percent body fat of the test group were reduced. Levels of betaine, benzoic acid, pyroglutamic acid, pipecolic acid, N-phenylacetamide, uric acid, l-aspartyl-l-phenylalanine, and lysophosphatidyl cholines (lysoPCs) (C18:1, C18:2, C20:1, and C20:4) showed significant increases. Levels of l-proline, valine, l-leucine/isoleucine, hypoxanthine, glutamine, l-methionine, phenylpyruvic acid, several carnitine derivatives, and lysoPCs (C14:0, PC16:0, C15:0, C16:0, C17:1, C18:0, and C22:0) were significantly decreased. In particular, lysoPC 16:0 with a VIP value of 12.02 is esteemed to be the most important metabolite for evaluating the differences between the 2 serum samples. Our result confirmed weight-lowering effects of BSP, accompanied by favorable changes in metabolites in the subjects' blood. Therefore, this research enables us to better understand obesity and increases the predictability of the obesity-related risk by studying metabolites present in the blood.

Effect of fermented soybean product (Cheonggukjang) intake on metabolic parameters in mice fed a high-fat diet

As a nontargeted metabolomics approach, we investigated changes in the plasma metabolite levels in a mouse model of obesity induced by a high-fat diet and fermented soybean product diet. We analyzed the plasma samples by using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). In the present study, the animals were divided into four groups according to the diet type; normal fat diet control group (ND), high-fat diet control group (HD), high-fat diet plus 30% cooked soybean power (HD + S), and high-fat diet plus 30% 72-h fermented Cheonggukjang powder (HD + CGJ). To examine the changes in plasma metabolite levels because of high-fat diet feeding, total cholesterol and triglyceride levels were measured. Total cholesterol and triglyceride levels were lower in the HD + S and HD + CGJ groups than in the ND group. According to partial least-squares discriminant analysis (PLS-DA), major metabolites contributing to the discrimination between each group were assigned as lipid metabolites in plasma, e.g., lyso-phosphatidylcholines and phosphatidylcholines. Therefore, diets containing soy-based food products, which are rich sources of isoflavonoids, might be helpful for controlling the lipid metabolism under high-fat diet conditions.

Kochujang, fermented soybean-based red pepper paste, decreases visceral fat and improves blood lipid profiles in overweight adults

Health benefits of Kochujang (KCJ) and its bioactive compounds have been reported in several in vitro and animal studies.

OBJECTIVE

The aim of this study was to investigate the efficacy of KCJ supplementation on body composition and blood lipid profiles in overweight adults.

METHODS

Sixty overweight men and women with BMI ≥23 kg/m2 and waist-hip-ratio (WHR) ≥0.90 for men and ≥0.85 for women were randomly assigned to a KCJ supplement (n=30, 32 g/day) or placebo (n=30, 32 g/day) group for a 12-week, double-blind, placebo controlled study. We measured anthropometric parameters, serum lipid profiles, abdominal fat distribution by computerized tomography and calculated the atherosclerosis indices in 53 subjects (n=26 in KCJ group, n=27 in placebo group) who completed the study.

RESULTS

After 12 weeks, the KCJ group showed a significant reduction in visceral fat (cm2) (p<0.05), although body weight (kg) and WHR did not change. Serum concentration of triglycerides and ApoB were decreased when compared to those of the placebo group.

CONCLUSION

KCJ supplementation (32 g/day) for 12 weeks in overweight adults showed anti-atherosclerotic and anti-obesogenic effects.

TRIAL REGISTRATION

Clinical trials.gov Identifier: NCT01532375.

Hepatic Metabolic, Inflammatory, and Stress-Related Gene Expression in Growing Mice Consuming a Low Dose of Trans-10, cis-12-Conjugated Linoleic Acid

Dietary trans-10, cis-12-conjugated linoleic acid (trans-10, cis-12-CLA) fed to obese and nonobese rodents reduces body fat but leads to greater liver mass due to steatosis. The molecular mechanisms accompanying such responses remain largely unknown. Our study investigated the effects of chronic low trans-10, cis-12-CLA supplementation on hepatic expression of 39 genes related to metabolism, inflammation, and stress in growing mice. Feeding a diet supplemented with 0.3% trans-10, cis-12-CLA (wt/wt basis) for 6 weeks increased liver mass and concentration of long-chain fatty acids (LCFAs) in liver, while adipose tissue mass decreased markedly. These changes were accompanied by greater expression of genes involved in LCFA uptake (Cd36), lipogenesis, and triacylglycerol synthesis (Acaca, Gpam, Scd, Pck1, Plin2). Expression of these genes was in line with upregulation of the lipogenic transcription factor Srebf1. Unlike previous studies where higher >0.50% of the diet) doses of trans-10, cis-12-CLA were fed, we found greater expression of genes associated with VLDL assembly/secretion (Mttp, Cideb), ketogenesis (Hmgcs2, Bdh1), and LCFA oxidation (Acox1, Pdk4) in response to trans-10, cis-12-CLA. Dietary CLA, however, did not affect inflammation- and stress-related genes. Results suggested that a chronic low dose of dietary CLA increases liver mass and lipid accumulation due to activation of lipogenesis and insufficient induction of LCFA oxidation and VLDL assembly/secretion.

Enhancement of the catalytic activity of a 27 kDa subtilisin-like enzyme from Bacillus amyloliquefaciens CH51 by in vitro mutagenesis

AprE51 from Bacillus amyloliquefaciens CH51 is a 27 kDa subtilisin-like protease with fibrinolytic activity. To enhance the catalytic activity of AprE51, two residues, Gly-169 and Ser-101, which, according to the three-dimensional structural model of subtilisin, are located in the P1 substrate-binding site and S3 subsite, respectively, were mutated by site-directed mutagenesis. Results of the mutational analysis showed that substitution of alanine for Gly-169 increased the fibrinolytic activity 1.4-fold. All four Ser-101 mutations, that is, replacements with arginine, leucine, lysine, and tryptophan, also increased the fibrinolytic activity up to 3.9-fold. The S101W mutant with a bulky side chain was more active than mutants with a positively charged or nonpolar small side chains. The fibrinolytic activity of the S101W mutant was further increased by error-prone polymerase chain reaction. The AprE51-6 mutant (S101W/G169A/V192A) had stronger fibrinolytic activity than the S101W mutant. Purified AprE51-6 had a 2.5-fold higher k(cat) and a 2.3-fold lower K(m), which resulted in a 6-fold increase in catalytic efficiency (k(cat)/K(m)) relative to that of wild-type AprE51. In addition, AprE51-6 showed a relatively broader pH range and increased thermostability as compared to AprE51.

Anti-obesity and antioxidative effects of purple sweet potato extract in 3T3-L1 adipocytes in vitro

The purpose of the current study was to determine the anti-obesity and anti-inflammatory effects of an extract of purple sweet potatoes (PSPs) on 3T3-L1 adipocytes. For this purpose, differentiated 3T3-L1 adipocytes were treated with a PSP extract at concentrations of 1,000, 2,000, and 3,000 μg/mL for 24 hours. Then, we measured the changes in the sizes of the adipocytes, the secretion of leptin, and the mRNA/protein expression of lipogenic, inflammatory, and lipolytic factors after the treatment with the PSP extract. The PSP extract diminished leptin secretion, indicating that growth of fat droplets was suppressed. The extract also suppressed the expression of mRNAs of lipogenic and inflammatory factors and promoted lipolytic action. The antioxidative activity of the PSP extract was also measured using three different in vitro methods: 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity, ferric reducing ability potential assay, and chelating activity of transition metal ions. Taken together, our study shows that PSP extract has antilipogenic, anti-inflammatory, and lipolytic effects on adipocytes and has radical scavenging and reducing activity.