Oenanthe javanica Ethanolic Extract Alleviates Inflammation and Modifies Gut Microbiota in Mice with DSS-Induced Colitis.

Oenanthe javanica, commonly known as water dropwort, has long been used to treat acute and chronic hepatitis, abdominal pain, alcohol hangovers, and inflammation in various traditional medicine systems in Asia. However, whether O. javanica has beneficial effects on colitis-induced intestinal damage remains elusive. This study tested the hypothesis that O. javanica has anti-inflammatory and antioxidant activities in mice with dextran sulfate sodium (DSS)-induced colitis. First, treatment of O. javanica ethanol extract (OJE) inhibited the production of inflammatory cytokines in lipopolysaccharide-affected macrophages. Second, in mice with DSS-induced colitis, OJE administration reduced pathological damage to the colon while alleviating weight gain and decreasing colon length, including inflammation and mucosal necrosis. In addition, OJE significantly (p < 0.01) restricted the activation of nuclear factor-κB (NF-κB) and the secretion of pro-inflammatory mediators and increased the expression of Nrf2-phase 2 antioxidant enzymes. The results of 16S rRNA gene sequencing workflows for taxonomic assignment analysis confirmed that the diversity (richness and evenness) of fecal microbiota was markedly elevated in the OJE group. OJE administration reduced the abundance of Proteobacteria including Escherichia and increased the abundance of the genus Muribaculum. These results suggested that OJE exerts beneficial effects on inflammation and gut microbial composition in a mouse model of colitis.

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).

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.

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.

Nardostachys jatamansi extract protects against cytokine-induced beta-cell damage and streptozotocin-induced diabetes.

AIM: To investigate the anti-diabetogenic mechanism of Nardostachys jatamansi extract (NJE). METHODS: Mice were injected with streptozotocin via a tail vein to induce diabetes. Rat insulinoma RINm5F cells and isolated rat islets were treated with interleukin-1beta and interferon-gamma to induce cytotoxicity. RESULTS: Treatment of mice with streptozotocin resulted in hyperglycemia and hypoinsulinemia, which was confirmed by immunohistochemical staining of the islets. The diabetogenic effects of streptozotocin were completely abolished when mice were pretreated with NJE. Inhibition of streptozotocin-induced hyperglycemia by NJE was mediated by suppression of nuclear factor (NF)-kappaB activation. In addition, NJE protected against cytokine-mediated cytotoxicity. Incubation of RINm5F cells and islets with NJE resulted in a significant reduction in cytokine-induced NF-kappaB activation and downstream events, inducible nitric oxide synthase expression and nitric oxide production. The protective effect of NJE was further demonstrated by the normal insulin secretion of cytokine-treated islets in response to glucose. CONCLUSION: NJE provided resistance to pancreatic beta-cell damage from cytokine or streptozotocin treatment. The beta-cell protective effect of NJE is mediated by suppressing NF-kappaB activation.