Traditional Korean diet high in one-carbon nutrients increases global DNA methylation: implication for epigenetic diet.

PURPOSE: DNA methylation is a major epigenetic phenomenon through which diet affects health and disease. This study aimed to determine the epigenetic influence of the traditional Korean diet (K-diet) on global DNA methylation via one-carbon metabolism. METHODS: A crossover study was conducted on 52 women. Two diets, a K-diet, high in plant foods and low in calories and animal fat, and a control diet, similar to the diet currently consumed in Korea, were provided to all subjects alternately for 4 weeks with a 4-week washout period. Clinical parameters were measured before and after each dietary intervention. Nutrient intake was calculated by using a computer-aided nutritional analysis program. One-carbon metabolites in the serum and global DNA methylation in peripheral mononuclear cells were determined using ultra-performance liquid chromatography-tandem mass spectrometry. RESULTS: The K-diet group consumed more folate (669.9 ± 6.7 µg vs. 502.7 ± 3.0, p < 0.001), B6, B12, serine, and choline, and less methionine (992.6 ± 63 vs. 1048.3 mg ± 34.1, p < 0.0001) than the control group did. In the K-diet group, the increment of plasma 5-methyltetrahydrofolate (0.08 µg/mL ± 0.11 vs 0.02 ± 0.10, p < 0.009) and decrement of L-homocysteine (- 70.7 ± 85.0 vs - 39.3 ± 69.4, p < 0.0168) were greater than those of the control group. Global DNA methylation was significantly increased in the K-diet group (6.70 ± 3.02% to 9.45 ± 3.69, p < 0.0001) but not in the control group. CONCLUSIONS: A K-diet high in one-carbon nutrients can enhance the global DNA methylation status, suggesting an epigenetic mechanism by which the K-diet conveys health effects. Trial registration Korean Clinical Trial Registry (trial number: KCT0005340, 24/08/2020, retrospectively registered).

Tenacibaculum tangerinum sp. nov., isolated from a tidal flat sediment.

An orange-coloured bacterium, designated as strain GRR-S3-23T, was isolated from a tidal flat sediment collected from Garorim Bay, Chuncheongbuk-do, Republic of Korea. Cells of GRR-S3-23T were aerobic, Gram-stain-negative, rod-shaped and motile. GRR-S3-23T grew at 18-40 °C (optimum, 30 °C), pH 7.0-9.0 (optimum, pH 7.0) and with 2-4 % NaCl (optimum, 2-3 % w/v). Results of 16S rRNA gene sequence analysis indicated that GRR-S3-23T was closely related to Tenacibaculum aiptasiae a4T (97.6 %), followed by Tenacibaculum aestuarii SMK-4T (97.5 %), Tenacibaculum mesophilum MBIC 1140T (97.4 %), Tenacibaculum singaporense TLL-A2T (97.3 %), Tenacibaculum crassostreae JO-1T (97.2 %),and Tenacibaculum sediminilitoris YKTF-3T (97.1 %). The average amino acid identity values between GRR-S3-23T and the related strains were 86.8-72.8 %, the average nucleotide identity values were 83.3-74.1 %, and the digital DNA-DNA hybridization values were 27.0-19.6 %. GRR-S3-23T possessed menaquinone-6 (MK-6) as major respiratory quinone and had summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c, 20.6 %) and iso-C15 : 1G (10.8 %) as major fatty acids (>10.0 %). The polar lipid profiles of GRR-S3-23T contained phosphatidylethanolamine, one unidentified aminolipid, one unidentified aminophospholipid, three unidentified lipids, one unidentified glycolipid and four unidentified phospholipids. The DNA G+C content of GRR-S3-23T was 33.7%. On the basis of the results of the polyphasic analysis involving phylogenetic, phylogenomic, physiological and chemotaxonomic analyses described in this study, GRR-S3-23T is considered to represent a novel species within the genus Tenacibaculum, for which the name Tenacibaculum tangerinum is proposed. The type strain is GRR-S3-23T (=KCTC 102029T=KACC 23271T=JCM 36353T).

The combination of Artemisia princeps Pamp, Leonurus japonicas Houtt, and Gardenia jasminoides Ellis fruit attenuates the exacerbation of energy, lipid, and glucose by increasing hepatic PGC-1α expression in estrogen-deficient rats.

BACKGROUND: Artemisia princeps Pamp (APP), Leonurus japonicas Houtt (LJH), and Gardenia jasminoides Ellis fruit (GJE) have been traditionally used in East Asia to treat women's diseases related to reproductive system. They may attenuate the deterioration of energy, lipid, glucose and bone metabolism by estrogen deficiency. The present study explored the combination of APP, LJH, and GJE to overcome the symptoms of estrogen deficiency and the mechanism was explored. METHODS: Ovariectomized (OVX) rats were divided into five groups and fed high-fat diets supplemented with 2 % dextrin (control), 2 % APP, 2 % APP + LJH (15:5), APP + LJH + GJE (10:5:5) or 17ß-estradiol (30 µg/kg bw/day) for 8 weeks. After 8 weeks of their consumption, energy, lipid, glucose and bone metabolisms were investigated and hepatic insulin signaling and fatty acid metabolism were determined. RESULTS: APP + LJH + GJE, but not APP itself, improved energy metabolism and attenuated a decrease in energy expenditure by the same amount as estrogen. Moreover, APP + LJH + GJE reduced visceral fat and intramuscular fat and increased lean body mass measured by DEXA by as much as the positive-control. APP itself suppressed increased LDL cholesterol and triglyceride levels in OVX rats and APP + LJH + GJE alleviated dyslipidemia in OVX rats. Overnight-fasted serum insulin levels and HOMA-IR were reduced in the descending order of APP, APP + LJH, APP + LJH + GJE, positive-control in OVX rats. APP and APP + LJH elevated insulin secretion in the 1st part of OGTT to decrease serum glucose levels while APP + LJH + GJE reduced serum glucose levels without increasing serum insulin levels during OGTT. APP + LJH + GJE decreased insulin resistance during ITT in OVX rats more than the positive-control. The APP + LJH + GJE group exhibited increased hepatic peroxisomal proliferator-activated receptor-γ coactivator-1α expression, which increased the number of genes involved in fatty acid oxidation and decreased fatty acid synthesis. Hepatic insulin signaling (pAkt and pGSK-1ß) was also potentiated to reduce phosphoenolpyruvate carboxykinase proteins. CONCLUSION: The combination of APP + LJH + GJE attenuated various menopausal symptoms in OVX rats. Thus, it may have potential as a therapeutic agent for the treatment of postmenopausal symptoms.

Fermenting soybeans with Bacillus licheniformis potentiates their capacity to improve cognitive function and glucose homeostaisis in diabetic rats with experimental Alzheimer's type dementia.

PURPOSE: Brain insulin resistance is related to both diabetes and Alzheimer's disease. We investigated whether both chungkookjangs, soybeans fermented in a traditional method (TFC) and with Bacillus lichenifomis (SFC), can protect against cognitive dysfunction and glucose dysregulation in rats with Alzheimer's disease and type 2 diabetes. METHODS: Partial pancreatectomy (Px) and ICV ß-amyloid (25-35) infusion into the CA1 region were fed either control diet (AD-CON), 10% cooked soybeans (CSB), 10% TFC, or 10% SFC in a high fat diet for 8 weeks. Px rats infused ß-amyloid (35-25) as a normal-control group (Non-AD-CON). RESULTS: SFC increased isoflavonoid aglycones, DDMP soyasaponin ßg, E soyasaponin Be and lysoposphatidylcholines in comparison to CSB. SFC markedly decreased its accumulation in ß-amyloid deposition in AD rats and improved hippocampal insulin signaling (pAkt → pGSK → pTau) that exacerbated in AD-CON rats. AD rats markedly impaired cognitive function than Non-AD-CON rats as measured by a water maze and passive avoidance tests while the disturbance was prevented in an ascending order of CON < CSB and TFC < SFC. In comparison to Non-AD rats, AD-CON rats lowered whole body glucose infusion rates and increased hepatic glucose output at hyperinsulinemic state during euglycemic hyperinsulinemic clamp which SFC normalized in AD rats. Interestingly, insulin secretion, especially at the second phase during hyperglycemic clamp, was higher in AD-CON rats, compared to Non-AD rats while CSB, TFC, SFC lowered it in AD-rats. However, SFC restored ß-cell mass in AD rats that reduced ß-cell mass by increased ß-cell apoptosis. CONCLUSIONS: ß-Amyloid accumulation in the hippocampus exacerbated insulin resistance and decreased ß-cell mass and SFC prevented their exacerbation in AD diabetic rats.

Euphorbiasteroid, a component of Euphorbia lathyris L., inhibits adipogenesis of 3T3-L1 cells via activation of AMP-activated protein kinase.

The purpose of this study is to investigate the effects of euphorbiasteroid, a component of Euphorbia lathyris L., on adipogenesis of 3T3-L1 pre-adipocytes and its underlying mechanisms. Euphorbiasteroid decreased differentiation of 3T3-L1 cells via reduction of intracellular triglyceride (TG) accumulation at concentrations of 25 and 50 µM. In addition, euphorbiasteroid altered the key regulator proteins of adipogenesis in the early stage of adipocyte differentiation by increasing the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase. Subsequently, levels of adipogenic proteins, including fatty acid synthase, peroxisome proliferator-activated receptor-γ and CCAAT/enhancer-binding protein α, were decreased by euphorbiasteroid treatment at the late stage of adipocyte differentiation. The anti-adipogenic effect of euphorbiasteroid may be derived from inhibition of early stage of adipocyte differentiation. Taken together, euphorbiasteroid inhibits adipogenesis of 3T3-L1 cells through activation of the AMPK pathway. Therefore, euphorbiasteroid and its source plant, E. lathyris L., could possibly be one of the fascinating anti-obesity agent.

Dietary supplementation with rice bran fermented with Lentinus edodes increases interferon-γ activity without causing adverse effects: a randomized, double-blind, placebo-controlled, parallel-group study.

BACKGROUND: The purpose of this study was to investigate the hypothesis that dietary supplementation with rice bran fermented with Lentinus edodes (rice bran exo-biopolymer, RBEP), a substance known to contain arabinoxylan, enhances natural killer (NK) cell activity and modulates cytokine production in healthy adults. METHODS: This study was designed in a randomized, double-blind, placebo-controlled, and parallel-group format. Eighty healthy participants with white blood cell counts of 4,000-8,000 cells/µL were randomly assigned to take six capsules per day of either 3 g RBEP or 3 g placebo for 8 weeks. Three participants in the placebo group were excluded after initiation of the protocol; no severe adverse effects from RBEP supplementation were reported. NK cell activity of peripheral blood mononuclear cells was measured using nonradioactive cytotoxicity assay kits and serum cytokine concentrations included interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-4, IL-10, and IL-12 were measured by Bio-Plex cytokine assay kit. This study was registered with the Clinical Research Information Service (KCT0000536). RESULTS: Supplementation of RBEP significantly increased IFN-γ production compared with the placebo group (P = 0.012). However, RBEP supplementation did not affect either NK cell activity or cytokine levels, including IL-2, IL-4, IL-10, IL-12, and TNF-α, compared with the placebo group. CONCLUSIONS: The data obtained in this study indicate that RBEP supplementation increases IFN-γ secretion without causing significant adverse effects, and thus may be beneficial to healthy individuals. This new rice bran-derived product may therefore be potentially useful to include in the formulation of solid and liquid foods designed for treatment and prevention of pathological states associated with defective immune responses.

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.

Capsaicin stimulates glucose uptake in C2C12 muscle cells via the reactive oxygen species (ROS)/AMPK/p38 MAPK pathway.

Capsaicin has been reported to regulate blood glucose levels and to ameliorate insulin resistance in obese mice. This study demonstrates that capsaicin increases glucose uptake directly by activating AMP-activated protein kinase (AMPK) in C2C12 muscle cells, which manifested as an attenuation of glucose uptake when compound C, an AMPK inhibitor, was co-administered with capsaicin. However, the insulin signaling molecules insulin receptor substrate-1 (IRS-1) and Akt were not affected by capsaicin. Additional results showed that p38 mitogen-activated protein kinase (MAPK) is also involved in capsaicin-induced glucose transport downstream of AMPK because capsaicin increased p38 MAPK phosphorylation significantly and its specific inhibitor SB203580 inhibited capsaicin-mediated glucose uptake. Treatment with an AMPK inhibitor reduced p38 MAPK phosphorylation, but the p38 MAPK inhibitor had no effect on AMPK. Capsaicin stimulated ROS generation in C2C12 muscle cells, and when ROS were captured using the nonspecific antioxidant NAC, the increase in both capsaicin-induced AMPK phosphorylation and capsaicin-induced glucose uptake was attenuated, suggesting that ROS function as an upstream activator of AMPK. Taken together, these results suggest that capsaicin, independent of insulin, increases glucose uptake via ROS generation and consequent AMPK and p38 MAPK activations.

Yuzu extract prevents cognitive decline and impaired glucose homeostasis in ß-amyloid-infused rats.

Our preliminary study revealed that dementia induced by ß-amyloid accumulation impairs peripheral glucose homeostasis (unpublished). We therefore evaluated whether long-term oral consumption of yuzu (Citrus junos Tanaka) extract improves cognitive dysfunction and glucose homeostasis in ß-amyloid-induced rats. Male rats received hippocampal CA1 infusions of ß-amyloid (25-35) [plaque forming ß-amyloid; Alzheimer disease (AD)] or ß-amyloid (35-25) [non-plaque forming ß-amyloid; C (non-Alzheimer disease control)] at a rate of 3.6 nmol/d for 14 d. AD rats were divided into 2 dietary groups that received either 3% lyophilized 70% ethanol extracts of yuzu (AD-Y) or 3% dextrin (AD-C) in high-fat diets (43% energy as fat). The AD-C group exhibited greater hippocampal ß-amyloid deposition, which was not detected in the C group, and attenuated hippocampal insulin signaling. Yuzu treatment prevented ß-amyloid accumulation, increased tau phosphorylation, and attenuated hippocampal insulin signaling observed in AD-C rats. Consistent with ß-amyloid accumulation, the AD-C rats experienced cognitive dysfunction, which was prevented by yuzu. AD-C rats gained less weight than did C rats due to decreased feed consumption, and yuzu treatment prevented the decrease in feed consumption. Serum glucose concentrations were higher in AD-C than in C rats at 40-120 min after glucose loading during an oral-glucose-tolerance test, but not at 0-40 min. Serum insulin concentrations were highly elevated in AD-C rats but not enough to lower serum glucose to normal concentrations, indicating that rats in the AD-C group had insulin resistance and a borderline diabetic state. Although AD-C rats were profoundly insulin resistant, AD-Y rats exhibited normal first and second phases of glucose tolerance and insulin sensitivity and secretion. In conclusion, yuzu treatment prevented the cognitive dysfunction and impaired energy and glucose homeostasis induced by ß-amyloid infusion.

Maslinic acid inhibits the metastatic capacity of DU145 human prostate cancer cells: possible mediation via hypoxia-inducible factor-1α signalling.

Maslinic acid is found in various natural sources, most notably in pomace olive oil, and exerts pro-apoptotic activities in various cancer cells in vitro. In the present study, DU145 human prostate cancer cells were cultured with 0-25 µm-maslinic acid to examine the effects of maslinic acid on the metastatic capacity of prostate cancer cells. Maslinic acid significantly (P <0.05) inhibited the basal and epidermal growth factor (EGF)-induced migration (27-64 %), invasion (23-60 %) and adhesion (8-40 %) of DU145 cells. Maslinic acid significantly (P <0·05) down-regulated both basal and EGF-stimulated secretion of matrix metalloproteinase (MMP)-9 (25-67 %), MMP-2 (50-86 %), urokinase-type plasminogen activator (uPA, about 100 %), vascular endothelial growth factor (VEGF, 98-100 %) and tissue inhibitors of metalloproteinases (TIMP)-1, as well as expression of uPA receptor (uPAR), intercellular adhesion molecules (22-33 %), vascular cell adhesion molecules (23-46 %) and E-cadherin, whereas it increased TIMP-2 secretion. Maslinic acid dramatically reduced the levels of hypoxia-inducible factor-1α (HIF-1α) protein and mRNA; the reduction was accompanied by reduced stability, nuclear levels and transcriptional activity of HIF-1α. The levels of phospho-Akt and phospho-extracellular signal-related kinase (ERK) were reduced in cells treated with maslinic acid, and the phosphoinositide 3-kinase inhibitor LY294002 and the mitogen-activated protein kinase kinase inhibitor PD98059 reduced HIF-1α levels and VEGF secretion. The results show that maslinic acid markedly inhibited the migration, invasion and adhesion of DU145 prostate cancer cells. Suppressing HIF-1α activation by inhibiting Akt and ERK activation may be part of the mechanism by which maslinic acid inhibited uPAR, E-cadherin, VEGF and MMP expression in DU145 cells.

The effectiveness of fermented turmeric powder in subjects with elevated alanine transaminase levels: a randomised controlled study.

BACKGROUND: Previous animal studies have shown that Curcuma longa (turmeric) improves liver function. Turmeric may thus be a promising ingredient in functional foods aimed at improving liver function. The purpose of the study is to investigate the hepatoprotective effect of fermented turmeric powder (FTP) on liver function in subjects with elevated alanine transaminase (ALT) levels. METHODS: A randomised, double-blind, placebo-controlled trial was conducted between November 2010 and April 2012 at the clinical trial center for functional foods of the Chonbuk National University Hospital. The trial included 60 subjects, 20 years old and above, who were diagnosed mild to moderate elevated ALT levels between 40 IU/L and 200 IU/L. Sixty subjects were randomised to receive FTP 3.0 g per day or placebo 3.0 g per day for 12 weeks. The treatment group received two capsules of FTP three times a day after meals, for 12 weeks. The primary efficacy endpoint was change in the ALT levels in the two groups. The secondary efficacy endpoints included its effect on aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), total bilirubin (TB), and lipid profiles. Safety was assessed throughout the study using ongoing laboratory tests. Adverse events (AEs) were also recorded. RESULTS: Sixty subjects were randomised in the study (30 into the FTP group, 30 into the placebo group), and among them, twelve subjects were excluded from the analysis for protocol violation, adverse events or consent withdrawal. The two groups did not differ in baseline characteristics. After 12 weeks of treatment, 48 subjects were evaluated. Of the 48 subjects, 26 randomly received FTP capsules and 22 received placebo. The FTP group showed a significant reduction in ALT levels after 12 weeks of treatment compared with the placebo group (p = 0.019). There was also observed that the serum AST levels were significantly reduce in the FTP group than placebo group (p = 0.02). The GGT levels showed a tendency to decrease, while the serum alkaline phosphatase (ALP), TB, and lipids levels were not modified. There were no reported severe AEs during this study, or abnormalities observed on blood glucose, total protein, albumin, blood urea nitrogen (BUN), and creatinine levels. CONCLUSION: The data of this trial indicate that FTP is effective and safe, generally well-tolerated without severe AEs, in the treatment of subjects with elevated ALT levels over a 12 weeks period. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01634256

Standardized chungkookjang, short-term fermented soybeans with Bacillus lichemiformis, improves glucose homeostasis as much as traditionally made chungkookjang in diabetic rats.

As the traditional homemade chungkookjang is replaced by standardized chungkookjang fermented by inoculating Bacillus spp., it is desirable to maintain the anti-diabetic efficacy of the most potent traditional varieties. Preliminary in vitro research suggested that anti-diabetic efficacy can be achieved by using B. lichemiformis as a starter and fermenting for 48 h. Experimental type 2 diabetic male rats induced by partial pancreatectomy and high fat diets were administered either control diet, 10% cooked soybeans, 10% traditional chungkookjang with potent anti-diabetic efficacy, or standardized chungkookjang fermented with B. lichemiformis for 48 h. Rats were fed their respective diets for 8 weeks after surgery. Cooked soybeans as well as both chungkookjangs partially restored fasting serum glucose concentrations, but only the chungkoojangs increased fasting insulin levels. That trend was also seen in the glucose-stimulated insulin secretion during hyperglycemic clamp and was explained by the greater ß-cell mass and BrdU incorporation indicating increased proliferation of ß-cells. The euglycemic hyperinsulinemic clamp indicated that all soy products improved insulin sensitivity. Phosphorylation of Akt and AMPK in the liver increased in an ascending order of the control, cooked soybeans, traditional chungkookjang and standardized chungkookjang while PEPCK expression was lowered in a descending order of the control, cooked soybeans, traditional chungkookjang and standardized chungkookjang. These results indicate that standardized chungkookjang is most effective for improving hepatic insulin signaling. In conclusion, chungkookjang fermented with B. lichemiformis retains the anti-diabetic properties of the most efficacious traditional chungkookjang and it may be even more effective for improving insulin function than traditionally prepared chungkookjang.

Liquid chromatography-mass spectrometry-based metabolomic analysis of livers from aged rats.

We used UPLC-Q-TOF MS to analyze hepatic metabolites of rats aged 6, 12, 18, and 24 months; the MS data were processed by partial least-squares discriminant analysis (PLS-DA) to investigate the discrimination among sample groups. Rats were significantly separated with increasing age, except those aged between 6 and 12 months. We identified only 25 of 120 metabolites contributing to the separation: lipid metabolites (glycerol-3-phosphate, linolenic acid, lysophosphatidylcholines [lysoPCs]), energy metabolism intermediates (betaine, carnitine, acylcarnitines, creatine, pantothenic acid), nucleic acid metabolites (inosine, xanthosine, uracil, hypoxanthine, xanthine), and tyrosine. Aging accumulated energy metabolism intermediates, hypoxanthine, xanthine, and 2 major lysoPCs (C18:0 and C22:6). The NAD level and NAD/NADH ratio decreased with age. It was indicated that aging might decrease energy production through ß-oxidation because of a decrease in NAD despite the accumulation of lipid energy metabolism intermediates. In addition to energy dysregulation, hypoxanthine and xanthine, which are elevated with age, might accumulate reactive oxygen species in the liver. These results strongly support two aging theories: those of energy dysregulation and free radicals. Additionally, we propose a metabolic pathway related to aging based on these hepatic metabolites. These metabolites and the proposed aging pathway could be used to understand aging and related diseases better, and increase the predictability of aging risk.

Design of a highly potent inhibitory peptide acting as a competitive inhibitor of HMG-CoA reductase.

This study presents a design of a highly potent and competitive inhibitory peptide for 3-hydroxy-3-methylglutaryl CoA reductase (HMGR). HMGR is the major regulatory enzyme of cholesterol biosynthesis and the target enzyme of many investigations aimed at lowering the rate of cholesterol biosynthesis. In previous studies, the two hypocholesterolemic peptides (LPYP and IAVPGEVA) were isolated and identified from soy protein. Based on these peptide sequences, a number of peptides were designed previously by using the correlation between the conformational flexibility and bioactivity. The design method that was applied in previous studies was slightly modified for the purpose of the current research and 12 new peptides were designed and synthesized. Among all peptides, SFGYVAE showed the highest ability to inhibit HMGR. A kinetic analysis revealed that this peptide is a competitive inhibitor of HMG-CoA with an equilibrium constant of inhibitor binding (K (i)) of 12 ± 0.4 nM. This is an overall 14,500-fold increase in inhibitory activity compared to the first isolated LPYP peptide from soybeans. Conformational data support a conformation of the designed peptides close to the bioactive conformation of the previously synthesized active peptides.

Platyconic acid, a saponin from Platycodi radix, improves glucose homeostasis by enhancing insulin sensitivity in vitro and in vivo.

BACKGROUND: Previous research demonstrated that the crude saponins of Platycodi radix improve glucose metabolism by enhancing insulin sensitivity in type 2 diabetic animals; however, which individual saponins are the most potent insulin sensitizers is unknown. OBJECTIVES: This study investigated which saponin(s) have anti-diabetic action in vitro and in vivo. METHODS: The insulin-stimulated glucose uptake and PPAR-γ agonistic actions of six saponins from Platycodi radix were investigated in 3T3-L1 adipocytes, and glucose-stimulated insulin secretion was determined in Min6 cells. Four individual saponins (20 mg/kg body weight) were orally administered to low-dose streptozotocin-injected diabetic mice fed a high-fat diet for 8 weeks to evaluate glucose tolerance by oral glucose tolerance testing (OGTT), insulin sensitivity by insulin tolerance testing, and insulin signaling in the liver and adipose tissues. RESULTS: Platyconic acid (PA) most effectively increased insulin-stimulated glucose uptake in 3T3-L1 adipocytes, possibly in part by working as a peroxisome proliferator-activated receptors (PPAR)-γ activator; however, none of the saponins improved glucose-stimulated insulin secretion in insulinoma cells. PA-treated diabetic mice exhibited the lowest peak serum glucose levels and highest serum insulin levels during the first part of OGTT. PA also improved insulin sensitivity: PA increased glycogen accumulation and decreased triacylglycerol storage in liver, which was associated with enhanced hepatic insulin signaling, while PA potentiated the expression of adiponectin and PPAR-γ in adipose tissue, and improved insulin signaling and increased GLUT4 translocation into the membranes. CONCLUSIONS: PA improves glucose homeostasis in type 2 diabetic mice, partly by enhancing hepatic and adipocyte insulin sensitivity, possibly by activating PPAR-γ.

Long-Term Consumption of Platycodi Radix Ameliorates Obesity and Insulin Resistance via the Activation of AMPK Pathways.

This study was designed to evaluate the effects and mechanism of Platycodi radix, having white balloon flower (Platycodon grandiflorum for. albiflorum (Honda) H. Hara) on obesity and insulin resistance. The extracts of Platycodi radix with white balloon flower were tested in cultured cells and administered into mice on a high-fat diet. The Platycodi radix activated the AMPK/ACC phosphorylation in C2C12 myotubes and also suppressed adipocyte differentiation in 3T3-L1 cells. In experimental animal, it suppressed the weight gain of obese mice and ameliorated obesity-induced insulin resistance. It also reduced the elevated circulating mediators, including triglyceride (TG), T-CHO, leptin, resistin, and monocyte chemotactic protein (MCP)-1 in obesity. As shown in C2C12 myotubes, the administration of Platycodi radix extracts also recovered the AMPK/ACC phosphorylation in the muscle of obese mice. These results suggest that Platycodi radix with white balloon flower ameliorates obesity and insulin resistance in obese mice via the activation of AMPK/ACC pathways and reductions of adipocyte differentiation.

Preventive effect of Korean red ginseng for acute respiratory illness: a randomized and double-blind clinical trial.

Korean Red Ginseng (KRG) is a functional food and has been well known for keeping good health due to its anti-fatigue and immunomodulating activities. However, there is no data on Korean red ginseng for its preventive activity against acute respiratory illness (ARI). The study was conducted in a randomized, double-blinded, placebo-controlled trial in healthy volunteers (Clinical Trial Number: NCT01478009). Our primary efficacy end point was the number of ARI reported and secondary efficacy end point was severity of symptoms, number of symptoms, and duration of ARI. A total of 100 volunteers were enrolled in the study. Fewer subjects in the KRG group reported contracting at least 1 ARI than in the placebo group (12 [24.5%] vs 22 [44.9%], P = 0.034), the difference was statistically significant between the two groups. The symptom duration of the subjects who experienced the ARI, was similar between the two groups (KRG vs placebo; 5.2 ± 2.3 vs 6.3 ± 5.0, P = 0.475). The symptom scores were low tendency in KRG group (KRG vs placebo; 9.5 ± 4.5 vs 17.6 ± 23.1, P = 0.241). The study suggests that KRG may be effective in protecting subjects from contracting ARI, and may have the tendency to decrease the duration and scores of ARI symptoms.

A placebo-controlled trial of Korean red ginseng extract for preventing influenza-like illness in healthy adults.

BACKGROUND: Standardized Korean red ginseng extract has become the best-selling influenza-like illness (ILI) remedy in Korea, yet much controversy regarding the efficacy of the Korean red ginseng (KRG) in reducing ILI incidence remains. The aim of the study is to assess the efficacy of the KRG extract on the ILI incidence in healthy adults. METHODS/DESIGN: We will conduct a randomized, double-blind, placebo-controlled study at the onset of the influenza seasons. A total of 100 subjects 30-70 years of age will be recruited from the general populations. The subjects will be instructed to take 9 capsules per day of either the KRG extract or a placebo for a period of 3 months. The primary outcome measure is to assess the frequency of ILI onset in participated subjects. Secondary variable measures will be included severity and duration of ILI symptoms. The ILI symptoms will be scored by subjects using a 4-point scale. DISCUSSION: This study is a randomized placebo controlled trial to evaluate the efficacy of the KRG extract compared to placebo and will be provided valuable new information about the clinical and physiological effects of the KRG extract on reduction of ILI incidence including flu and upper respiratory tract infections. The study has been pragmatically designed to ensure that the study findings can be implemented into clinical practice if KRG extract can be shown to be an effective reduction strategy in ILI incidence. TRIAL REGISTRATION: NCT01478009.

Antiosteoporotic activity of Saururus chinensis extract in ovariectomized rats.

Recent studies suggest that phytoestrogens may exert a protective effect against osteoporosis. This study examined whether treatment with phytoestrogen extracts from Saururus chinensis (SC) exerted a preventive effect on estrogen-deficiency-induced osteoporosis. Six- to seven-month-old female Sprague-Dawley rats were randomly assigned into either a sham-operated group or one of three ovariectomy (OVX) subgroups: OVX treated with vehicle, OVX with alendronate, and OVX with SC extract (SC). Rats began receiving treatment 4 weeks before the OVX treatment and continued receiving treatment for an additional 10 weeks after OVX (for a combined total of 14 weeks). The results showed that the SC treatment prevented loss of femur bone mineral density after OVX, as determined by a significant decrease in the levels of serum bone turnover markers osteocalcin and alkaline phosphatase as well as urinary deoxypyridinoline. Micro-computed tomography analysis showed that the SC treatment significantly prevented decreases in bone volume/tissue volume, trabecular number and trabecular thickness, while also preventing an increase in trabecular separation. It was concluded that SC treatment could prevent OVX-induced loss of bone mass and deterioration in trabecular microarchitecture by suppressing bone turnover, thereby maintaining bone structural integrity. Further, no stimulation of proliferation of uterine tissue was noted. Therefore, it is suggested that treatment with S. chinensis extracts might be a potential alternative therapy for treating postmenopausal osteoporosis.

Decursin, an active compound isolated from Angelica gigas, inhibits fat accumulation, reduces adipocytokine secretion and improves glucose tolerance in mice fed a high-fat diet.

Decursin (De), an active component of Angelica gigas, is known to exert anticancer and neuroprotective effects. However, its antiobesity and antidiabetic potential has not yet been investigated. This study evaluated the antiobesity effect of decursin, particularly focusing on its ability to inhibit adipocyte differentiation in 3T3-L1 cells. Decursin treatment resulted in the inhibition of adipocyte differentiation and the expression of fatty acid synthase. The study further investigated these antiobesity effects using mice fed a normal diet (ND), a high-fat diet (HFD) and a HFD plus decursin 200 mg/kg diet (HFD + De) for 7 weeks. Mice administered HFD plus decursin showed a drastic decrease in weight gain, triglyceride content, total cholesterol content and fat size compared with those that received the HFD alone; this was observed despite similar quantities of total food intake. Furthermore, decursin improved glucose tolerance in mice fed a HFD. Finally, administration of decursin along with the HFD significantly reduced the secretion of HFD-induced adipocytokines such as leptin, resistin, IL-6 and MCP-1. These results suggest that decursin might be useful for the treatment of obesity and diabetes.