Lycium chinense Miller fruit extract lowers liver enzyme levels in subjects with mild hepatic dysfunction: a randomized, double-blind, placebo-controlled clinical trial.

PURPOSE: In our previous study, we showed that Lycium chinense Miller fruit extract (LFE) exerted hepatoprotective effects in mice. In the current study, we examined the effect of LFE on liver enzyme levels in subjects with mild hepatic dysfunction. METHODS: A total of 90 subjects, aged 19 to 70 years old, with abnormal alanine aminotransferase (ALT) levels, were randomly placed into either an LFE (n = 45) treatment group or a placebo group (n = 45). During the 12-week clinical trial, subjects in each group received either LFE or placebo capsules, and were instructed to take four tablets per day (1760 mg/day). The primary outcome of the study was the changes of ALT and γ-glutamyltransferase (GGT) levels in each subject. The safety of LFE supplementation was assessed and adverse events were recorded. RESULTS: LFE supplementation for 12 weeks resulted in a significant reduction of ALT (P = 0.0498) and GGT (P = 0.0368) levels in comparison to the placebo. No clinically significant changes were observed in any safety parameters. CONCLUSION: These results suggest that LFE can be applied to subjects with mild hepatic dysfunction with no possible side effects. TRIAL REGISTRATION: This study was registered at the Clinical Research Information Service (CRIS) as no. KCT0003985.

Limonium tetragonum Promotes Running Endurance in Mice through Mitochondrial Biogenesis and Oxidative Fiber Formation.

The purpose of this study was to examine whether Limonium tetragonum, cultivated in a smart-farming system with LED lamps, could increase exercise capacity in mice. C57BL/6 male mice were orally administered vehicle or Limonium tetragonum water extract (LTE), either 30 or 100 mg/kg, and were subjected to moderate intensity treadmill exercise for 4 weeks. Running distance markedly increased in the LTE group (100 mg/kg) by 80 ± 4% compared to the vehicle group, which was accompanied by a higher proportion of oxidative fibers (6 ± 6% vs. 10 ± 4%). Mitochondrial DNA content and gene expressions related to mitochondrial biogenesis were significantly increased in LTE-supplemented gastrocnemius muscles. At the molecular level, the expression of PGC-1α, a master regulator of fast-to-slow fiber-type transition, was increased downstream of the PKA/CREB signaling pathway. LTE induction of the PKA/CREB signaling pathway was also observed in C2C12 cells, which was effectively suppressed by PKA inhibitors H89 and Rp-cAMP. Altogether, these findings indicate that LTE treatment enhanced endurance exercise capacity via an improvement in mitochondrial biosynthesis and the increases in the formation of oxidative slow-twitch fibers. Future study is warranted to validate the exercise-enhancing effect of LTE in the human.

Supplementation with Vitis vinifera Jingzaojing Leaf and Shoot Extract Improves Exercise Endurance in Mice.

Switching myofibers from the fast-glycolytic type to the slow-oxidative type is associated with an alleviation of the symptoms associated with various cardiometabolic diseases. This study investigates the effect of Vitis vinifera Jingzaojing leaf and shoot extract (JLSE), which is rich in phenolic compounds, on the regulation of skeletal muscle fiber-type switching, as well as the associated underlying mechanism. Male C57BL/6N mice were supplemented orally with vehicle or JLSE (300 mg/kg) and subjected to treadmill exercise training. After four weeks, mice in the JLSE-supplemented group showed significantly improved exercise endurance and mitochondrial oxidative capacity. JLSE supplementation increased the expression of sirtuin 6 and decreased Sox6 expression, thereby elevating the number of mitochondria and encouraging fast-to-slow myofiber switching. The results of our experiments suggest that JLSE supplementation reprograms myofiber composition to favor the slow oxidative type, ultimately enhancing exercise endurance.

Therapeutic Effect of Acer tegmentosum Maxim Twig Extract in Bile Duct Ligation-Induced Acute Cholestasis in Mice.

Cholestatic liver disease, or cholestasis, is a condition characterized by liver inflammation and fibrosis following a bile duct obstruction and an intrahepatic accumulation of bile acids. Inhibiting inflammation is a promising therapeutic strategy for cholestatic liver diseases. Acer tegmentosum Maxim extract (ATE) is best known for its anti-inflammatory and antioxidative properties. In this study, we investigated the effects of ATE on liver injury and fibrosis in mice with bile duct ligation (BDL)-induced cholestasis through analysis of gene expression, cytokines, and histological examination. Oral administration of ATE (20 or 50 mg/kg) for 14 days significantly attenuated hepatocellular necrosis compared to vehicle-treated BDL mice, which was accompanied by the reduced level of serum bile acids and bilirubin. We determined that ATE treatment reduced liver inflammation, oxidative stress, and fibrosis. These beneficial effects of ATE were concurrent with the decreased expression of genes involved in the NF-κB pathway, suggesting that the anti-inflammatory effect of ATE could be a possible mechanism against cholestasis-associated liver injury. Our findings substantiate ATE's role as an alternative therapeutic agent for cholestasis-induced liver injury and fibrosis.

Angelica keiskei Root Extract Attenuates Bile Duct Ligation-Induced Liver Injury in Mice.

Although multiple studies have shown that Angelica keiskei of the Umbelliferae family has potent anti-inflammatory and antioxidative activities and that it reduces the serum bile acids in humans, whether A. keiskei has protective effects against cholestasis-induced liver injury remains unexplored until now. This study tests the hypothesis that Angelica keiskei root extract (AKE) alleviates liver injury, inflammation, and fibrosis in mouse models of acute cholestasis induced by bile duct ligation (BDL). Oral administration of AKE (200 or 500 mg/kg) attenuated hepatocellular necrosis and significantly reduced serum levels of bile acids and bilirubin in BDL mice. The critical enzyme of bile acid synthesis, CYP7A1, was repressed by AKE, suggesting that reduced bile acid production may contribute to liver protection. Moreover, we determined through gene expression and cytokine analysis and histological examination that AKE treatment decreased liver inflammation, oxidative stress, and fibrosis. AKE also suppressed the NF-κB pathway, suggesting this as a possible mediator of its anti-inflammatory effect. Our findings substantiate that AKE may be promising for treating cholestatic liver diseases in the future.

A randomized, double-blind, placebo-controlled crossover clinical trial to evaluate the anti-diabetic effects of Allium hookeri extract in the subjects with prediabetes.

BACKGROUND: Allium hookeri is widely consumed as a vegetable and herbal medicine in Asia. A. hookeri has been reported anti-inflammatory, anti-obesity, osteoblastic, anti-oxidant, and anti-diabetic effects in animal studies. We investigated the anti-diabetic effects of A. hookeri aqueous extract (AHE) in the Korean subjects. METHODS: Prediabetic subjects (100 ≤ fasting plasma glucose (FPG) < 126 mg/dL) who met the inclusion criteria were recruited for this study. The enrolled subjects (n = 30) were randomly divided into either an AHE (n = 15, 486 mg/day) or placebo (n = 15) group. Outcomes were measurements of FPG, glycemic response to an oral glucose tolerance test (OGTT), insulin, C-peptide, hemoglobin A1c (HbA1c), total cholesterol, triglyceride, HDL-cholesterol, and LDL-cholesterol. The t-test was used to assess differences between the groups. A p-value < 0.05 was considered statistically significant. RESULTS: Eight weeks after AHE supplementation, HbA1c level was significantly decreased in the AHE group compared with the placebo group. No clinically significant changes in any safety parameter were observed. CONCLUSION: The findings suggest that AHE can be effective in reducing HbA1c, indicating it as an adjunctive tool for improving glycemic control. TRIAL REGISTRATION: The study protocol was retrospectively registered at www.clinicaltrials.gov ( NCT03330366 , October 30, 2017).

A Randomized, Double-Blind, Placebo-Controlled Clinical Trial Assessing the Effects of Angelica Gigas Nakai Extract on Blood Triglycerides.

Angelica gigas Nakai, Korean dang-gui, has long been widely used in traditional treatment methods. There have been a number of studies of the health effects of A. gigas and related compounds, but studies addressing effects on blood triglycerides (TG) are lacking. To investigate the effects of A. gigas Nakai extract (AGNE) on TG in Korean subjects, we carried out a 12-week, randomized, double-blind, placebo-controlled clinical trial. Subjects who met the inclusion criterion (130 mg/dL ≤ fasting blood TG ≤ 200 mg/dL) were recruited for this study. One hundred subjects were assigned to the AGNE group (n = 50) or the placebo group (n = 50), who were given 1 g/day of AGNE (as a gigas Nakai extract 200 mg/d) in capsules and the control group for 12 weeks. Outcomes were efficacy TG, lipid profiles, atherogenic index, and safety parameters were assessed initially for a baseline measurement and after 12 weeks. After 12 weeks of supplementation, TG and very low-density lipoprotein cholesterol (VLDL-C) concentration and TG/HDL-C ratio in the AGNE group were significantly reduced compared to the placebo group (p < 05). No significant changes in any safety parameter were observed. These results suggest that the ingestion of AGNE may improve TG and be useful to manage or prevent hypertriglyceridemia.

Gypenoside UL4-Rich Gynostemma pentaphyllum Extract Exerts a Hepatoprotective Effect on Diet-Induced Nonalcoholic Fatty Liver Disease.

Nonalcoholic steatohepatitis (NASH) arises from nonalcoholic fatty liver disease (NAFLD) as a consequence of oxidative stress. Gynostemma pentaphyllum extract (GPE) is proven to be beneficial for patients suffering from NAFLD. However, the precise mechanism by which GPE confers these benefits remains largely unknown. The purpose of this study was to investigate the underlying mechanism and to determine whether supplementation with the newly discovered GPE gypenoside UL4 mitigates NASH progression. Male c57BL/6 mice were fed a normal chow diet, a methionine choline-deficient (MCD) diet, or an MCD diet supplemented with various doses of UL4-rich GPE for eight weeks. GPE supplementation suppressed oxidative stress induced by the MCD diet by increasing levels of sirtuin 6 and phase 2 anti-oxidant enzymes in mouse liver and HepG2 cells. Additionally, GPE supplementation prevented diet-induced hepatic fat accumulation, hepatocellular injury, inflammation, and fibrosis in mice fed the MCD diet. These results indicate the possible therapeutic potential of dietary supplementation of UL4-rich GPE in preventing the development of fatty liver and its progression to NASH.

Epigallocatechin-3-Gallate-Rich Green Tea Extract Ameliorates Fatty Liver and Weight Gain in Mice Fed a High Fat Diet by Activating the Sirtuin 1 and AMP Activating Protein Kinase Pathway.

The prevalence of metabolic diseases has risen globally in parallel with the obesity epidemic over the past few decades. Green tea has been reported to have metabolically beneficial effects on obesity; however, the mechanism by which green tea regulates lipid metabolism is not clearly understood. Male c57BL/6 mice were fed a normal chow diet, a high-fat diet (HFD), or an HFD supplemented with various doses of epigallocatechin gallate-rich green tea extract (GTE) for 12 weeks. GTE supplementation reduced body weight gain, prevented hepatic fat accumulation, decreased hypertriglyceridemia, and improved hyperglycemia and insulin resistance in HFD-fed mice. The underlying mechanisms of these beneficial effects of GTE might involve the upregulation of sirtuin 1 and AMP activated protein kinase (AMPK) and the downregulation of enzymes related to de novo lipogenesis. Consistent with the in vivo findings, GTE increased the expression and activity of sirtuin 1, enhanced the binding of sirtuin 1 to liver kinase B1 (LKB1) and subsequent deacetylation of LKB1, and reduced triglyceride accumulation in HepG2 cells. These results suggest the possible therapeutic potential of dietary epigallocatechin gallate-rich GTE supplementation for preventing the development and progression of hepatic steatosis and obesity.

Angelica gigas Ameliorates Hyperglycemia and Hepatic Steatosis in C57BL/KsJ-db/db Mice via Activation of AMP-Activated Protein Kinase Signaling Pathway.

The prevention and management of type 2 diabetes mellitus has become a major global public health challenge. Decursin, an active compound of Angelica gigas Nakai roots, was recently reported to have a glucose-lowering activity. However, the antidiabetic effect of Angelica gigas Nakai extract (AGNE) has not yet been investigated. We evaluated the effects of AGNE on glucose homeostasis in type 2 diabetic mice and investigated the underlying mechanism by which AGNE acts. Male C57BL/KsJ-db/db mice were treated with either AGNE (10 mg/kg, 20 mg/kg, and 40 mg/kg) or metformin (100 mg/kg) for 8 weeks. AGNE supplementation (20 and 40 mg/kg) significantly decreased fasting glucose and insulin levels, decreased the areas under the curve of glucose in oral glucose tolerance and insulin tolerance tests, and improved homeostatic model assessment-insulin resistant (HOMA-IR) scores. AGNE also ameliorated hepatic steatosis, hyperlipidemia, and hypercholesterolemia. Mechanistic studies suggested that the glucose-lowering effect of AGNE was mediated by the activation of AMP activated protein kinase, Akt, and glycogen synthase kinase-3[Formula: see text]. AGNE can potentially improve hyperglycemia and hepatic steatosis in patients with type 2 diabetes.

Randomized, double-blind, placebo-controlled trial of Ficus carica paste for the management of functional constipation.

BACKGROUND AND OBJECTIVES: Constipation affects up to 20% of the world's population. The aim of this study was to investigate whether supplementation with Ficus carica paste could be used to treat constipation in Korean subjects with functional constipation. METHODS AND STUDY DESIGN: We conducted a randomized, double-blind, placebo-controlled trial. Subjects with functional constipation were orally supplemented with either F. carica paste (n=40) or placebo (n=40) for 8 weeks. We measured the efficacy and safety of F. carica paste. Primary outcomes (colon transit time) and secondary outcomes (questionnaire related to defecation) were compared before and after the 8-week intervention period. RESULTS: F. carica paste supplementation was associated with a significant reduction in colon transit time and a significant improvement in stool type and abdominal discomfort compared with the placebo. Blood parameters and clinical findings for organ toxicity remained within normal ranges. CONCLUSION: These results suggest that F. carica paste may have beneficial effects in subjects suffering from constipation.

Enhanced M2 macrophage polarization in high n-3 polyunsaturated fatty acid transgenic mice fed a high-fat diet.

SCOPE: Diet-induced obesity and consequent insulin resistance are caused, in part, by macrophage polarization and accumulation in peripheral tissues. Here, we examined the effects of endogenously synthesized n-3 PUFAs on macrophage chemotaxis and polarization. METHODS AND RESULTS: Fat-1 mice and wild-type (WT) littermates were fed a 60% calorie high-fat diet (HFD) for 10 weeks. Bone marrow macrophages (BMMs) from fat-1 and WT mice were used in in vitro chemotaxis assays and macrophage polarization studies. WT mice fed a HFD exhibited glucose intolerance, insulin resistance, and lipid accumulation and macrophage infiltration in liver and adipose tissue. However, these metabolic and inflammatory phenotypes were not observed in HFD-fed fat-1 mice. In flow cytometric analysis, M1 macrophage infiltration into adipose tissue was markedly attenuated in fat-1 mice. Consistently, results from in vitro experiments indicated that n-3 PUFAs prevented adipocyte conditioned medium-mediated macrophage chemotaxis, stimulated M2 polarization, and suppressed M1 polarization. The inhibition of macrophage migration by n-3 PUFAs was associated with suppression of multiple kinases, such as IκB kinase, AKT, and focal adhesion kinase. CONCLUSION: Our results indicate that n-3 PUFAs play a crucial role in macrophage polarization and chemotaxis, and thus regulate the development of HFD-induced tissue inflammation and metabolic derangements.

n-3 Polyunsaturated fatty acids protect against pancreatic ß-cell damage due to ER stress and prevent diabetes development.

SCOPE: In this study, we focus on the effects of n-3 polyunsaturated fatty acids (PUFAs) on tunicamycin-, streptozotocin-, or high fat diet (HFD)-induced ß-cell damage and dysfunction. MATERIALS AND METHODS: Pretreatment with n-3 PUFAs protected RINm5F cells and mouse islets against tunicamycin-induced ß-cell damage through suppression of ER stress and apoptosis induction. This protective effect of n-3 PUFAs on ß-cells was further demonstrated by the normalization of insulin secretion in response to glucose in tunicamycin-treated islets. In multiple low-dose streptozotocin-induced diabetes models, fat-1 mice, which endogenously synthesize n-3 PUFAs from n-6 PUFAs, were fully resistant to the development of diabetes, with normal islet morphology, high insulin immunoreactivity, and decreased apoptotic cells. In HFD-induced diabetes models, fat-1 mice also exhibited improved glucose tolerance and functional ß-cell mass. In both diabetes models, we observed an attenuation of ER stress in fat-1 mice. Interestingly, n-3 PUFAs attenuated the nuclear translocation of lipogenic transcription factors sterol regulatory element-binding protein-1 (SREBP-1) and C/EBPß, induced by tunicamycin or HFD, suggesting that n-3 PUFAs suppress ER stress via modulation of SREBP-1 and C/EBPß. CONCLUSION: Together, these results suggest that n-3 PUFAs block ER stress, thus protecting ß cells against diabetogenic insult; therefore, dietary supplementation of n-3 PUFAs has therapeutic potential for the preservation of functional ß-cell mass.

Hypoglycemic effects of aqueous persimmon leaf extract in a murine model of diabetes.

Previously, powdered persimmon leaves have been reported to have glucose- and lipid-lowering effects in diabetic (db/db) mice. As persimmon leaf is commonly consumed as tea, an aqueous extract of persimmon leaves (PLE) was prepared and its anti-diabetic efficacy was investigated. In the present study, PLE was tested for its inhibitory activity on α-glucosidase in vitro. An oral maltose tolerance test was performed in diabetic mice. Next, the acute effect of PLE was examined in streptozotocin-induced diabetic mice. Last, the long-term effect of PLE supplementation was assessed in db/db after eight weeks. An oral glucose tolerance test, biochemical parameters, as well as histological analyses of liver and pancreas were evaluated at the end of the study. PLE inhibited α-glucosidase activity and increased antioxidant capacity. Streptozotocin-induced diabetic mice pre-treated with PLE displayed hypoglycemic activity. Daily oral supplementation with PLE for eight weeks reduced body weight gain without affecting food intake, enhanced the glucose tolerance during the oral glucose tolerance test (OGTT), improved blood lipid parameters, suppressed fat accumulation in the liver and maintained islet structure in db/db mice. Further mechanistic study showed that PLE protected pancreatic islets from glucotoxicity. In conclusion, the results of the present study indicated that PLE exhibits considerable anti-diabetic effects through α-glucosidase inhibition and through the maintenance of functional ß-cells. These results provided a rationale for the use of persimmon leaf tea for the maintenance of normal blood glucose levels in diabetic patients.

Endogenous conversion of n-6 to n-3 polyunsaturated fatty acids attenuates K/BxN serum-transfer arthritis in fat-1 mice.

It is suggested that n-3 polyunsaturated fatty acids (PUFAs) can be used in the preventive or therapeutic management of rheumatoid arthritis (RA); however, controversial results have been reported. Here, we examined the effects of a decrease in the n-6/n-3 PUFA ratio on RA using fat-1 transgenic mice. First, we tested whether fat-1 expression modulated signaling pathways in fibroblast-like synoviocytes (FLSs) stimulated with tumor necrosis factor α (TNF-α). TNF-α activated p38 mitogen-activated protein kinase and increased phosphorylation of the signal transducer and activator of transcription 3 in wild type (WT) FLSs but not in fat-1 FLSs. Arthritis was induced by injection of K/BxN serum. Based on clinical scores, ankle thickness and pathological severity, we showed that WT mice developed clinically overt arthritis, whereas fat-1 mice showed attenuated arthritis. Moreover, fat-1 mice exhibited down-regulated local and systemic levels of inflammatory cytokines. Lastly, bone marrow-derived macrophages (BMMs) of WT mice differentiated into tartrate-resistant acid phosphatase-positive multinucleated osteoclasts, whereas the osteoclastogenenic process was suppressed in BMMs of fat-1 mice. The endogenous conversion of n-6 to n-3 PUFAs via fat-1 plays a key role in attenuation of RA; therefore, dietary supplementation of n-3 PUFAs may have therapeutic potential for the management of RA.

Supplementation with Aspergillus oryzae-fermented kochujang lowers serum cholesterol in subjects with hyperlipidemia.

BACKGROUND & AIMS: Kochujang, a traditional fermented red pepper paste, is known for its hypocholesterolemic effect; however, these studies used non-commercial preparations of kochujang. In this study, we examined whether commercially-made kochujang in which Aspergillus oryzae (also known as koji) was used as a microorganism for fermentation has the same cholesterol-lowering effects. METHODS: Hyperlipidemic subjects (based upon criteria of 110 ∼ 190 mg/dL LDL cholesterol or 200 ∼ 260 mg/dL total cholesterol) who had not been diagnosed with any disease and met the inclusion criteria were recruited for this study. The 30 subjects were randomly divided into either the kochujang (n = 15) or placebo (n = 15) group. All subjects ingested either the kochujang pill (34.5 g/d) or a placebo three times daily during meals for 12 weeks. Outcomes included measurements of efficacy (total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglyceride) and safety (adverse events, laboratory tests, electrocardiogram, and vital signs). RESULTS: In the kochujang-supplemented group, subjects' total cholesterol level significantly decreased (from 215.5 ± 16.1 mg/dL to 194.5 ± 25.4 mg/dL, p = 0.001). LDL-C cholesterol levels were also decreased by kochujang supplementation (from 133.6 ± 14.8 mg/dL to 113.5 ± 23.1 mg/dL); however no significant difference was seen between groups (p = 0.074). There were no statistically significant differences in HDL-cholesterol and triglyceride levels between the supplemented and non-supplemented groups. None of the subjects complained of any adverse effects. CONCLUSIONS: These results indicate that A. oryzae-fermented kochujang elicits a significant hypocholesterolemic effect and might be useful for improving blood cholesterol levels in subjects at high risk for cardiovascular disease. CLINICAL TRIAL REGISTRATION: NCT01865370.

Reduction of blood lipid parameters by a 12-wk supplementation of aged black garlic: a randomized controlled trial.

OBJECTIVE: The cholesterol-lowering effects of garlic as part of a healthy diet remain controversial. The aim of this study was to investigate whether supplementation with aged black garlic (ABG) could improve blood lipid profiles in patients with mild hypercholesterolemia. METHODS: We conducted a double-blind, randomized placebo-controlled trial. Sixty participants were randomly assigned to receive either ABG or placebo twice daily (total 6 g/d) before consumption of a meal every morning and evening for 12 wk. During the study, two participants dropped out of the ABG group, and three participants dropped out of the placebo group. Thus, the effects of AGB on fasting blood levels of lipids were evaluated in 28 participants and compared with the placebo group (n = 27). RESULTS: Among lipid components, no significant differences in triglycerides, low-density lipoprotein cholesterol, total cholesterol, or free fatty acid levels were observed between the two groups. However, ABG increased high-density lipoprotein cholesterol levels compared with the placebo group at the end of the study. Moreover, a significant decrease in the levels of alipoprotein B and a significant increase in the ratio of low-density lipoprotein cholesterol/alipoprotein B were observed in the ABG group. No adverse effects were reported in any of the patients. CONCLUSION: ABG supplementation reduced atherogenic markers and thus may have a cardioprotective effect beyond the gold standard medication in patients with mild hypercholesterolemia.

Postprandial glucose-lowering effects of fermented red ginseng in subjects with impaired fasting glucose or type 2 diabetes: a randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND: Red ginseng is prepared by steaming raw ginseng, a process believed to increase the pharmacological efficacy. Further bioconversion of red ginseng through fermentation is known to increase its intestinal absorption and bioactivity, and bioconversion diminishes the toxicity of red ginseng's metabolite. This study was conducted to investigate the effects of daily supplementation with fermented red ginseng (FRG) on glycemic status in subjects with impaired fasting glucose or type 2 diabetes. METHODS: This study was a four-week long, randomized, double-blind, placebo-controlled trial. Forty-two subjects with impaired fasting glucose or type 2 diabetes were randomly allocated to two groups assigned to consume either the placebo or fermented red ginseng (FRG) three times per day for four weeks. Fasting and postprandial glucose profiles during meal tolerance tests were assessed before and after the intervention. RESULTS: FRG supplementation led to a significant reduction in postprandial glucose levels and led to an increase in postprandial insulin levels compared to the placebo group. There was a consistently significant improvement in the glucose area under the curve (AUC) in the FRG group. However, fasting glucose, insulin, and lipid profiles were not different from the placebo group. CONCLUSION: Daily supplementation with FRG lowered postprandial glucose levels in subjects with impaired fasting glucose or type 2 diabetes. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01826409.

Effects of n-3 PUFA on the CD4⁺ type 2 helper T-cell-mediated immune responses in Fat-1 mice.

SCOPE: It has been suggested that n-3 PUFA can be used as a preventive or therapeutic strategy to control allergic asthma. But little is known about the exact mechanisms by which n-3 PUFA modulates it. Here, the effects of elevated n-3 PUFA on ovalbumin (OVA) induced airway inflammation were investigated using Fat-1 transgenic mice that can convert n-6 PUFA to n-3 PUFA endogenously. METHODS AND RESULTS: First, we tested whether Fat-1 expression modulates CD4⁺ T-cell activation, proliferation, and differentiation in vitro and found that the Fat-1 expression attenuated all of these CD4⁺ T-cell responses by suppression of T-cell receptor mediated signaling and cytokine-mediated phosphorylation of STATs. When the Fat-1 mice were sensitized and challenged with the OVA, they showed a significant decrease in the recruitment of inflammatory cells into airway, the production of Th2 cytokines, eotaxin, and mucin in the lung, and the concentration of OVA-specific IgE in the serum. Furthermore, the differentiation of CD4⁺ T cells into Th2 was also decreased in the spleen of Fat-1 mice. CONCLUSION: Our results showed that an elevated level of n-3 PUFA was effective in preventing allergic airway inflammation by modulating the activation and differentiation of CD4⁺ T cells in Fat-1 mice.

Overexpression of the small GTPase Arl4D suppresses adipogenesis.

Arl4D is a developmentally-regulated member of the ADP-ribosylation factor/ARF-like protein (ARF/Arl) family of Ras-related GTPases. Although Arl4 protein is reported to be expressed in adipose tissue, the function of Arl4D is unknown. To investigate the potential role of Arl4D in adipogenesis, we examined Arl4D expression during adipocyte differentiation and the effects of Arl4D overexpression on adipogenesis. Arl4D protein increased early in adipogenesis, with the highest expression at 4 h after adipogenesis initiation, followed by a decrease thereafter. Overexpression of Arl4D in 3T3-L1 cells potently inhibited their ability to differentiate and accumulate lipid, and reduced the expression of adipogenic genes. Furthermore, treatment with valproic acid, an Arl4D inducer, suppressed adipogenesis. These results suggest that rapid reduction of Arl4D is required for adipogenesis to proceed.