Infant sleep interventions with sleep measurements using actigraphy: A systematic review.

AIM: This review investigated the outcomes and methodological quality of infant sleep intervention studies utilizing actigraphy. BACKGROUND: Parents need appropriate support for infant sleep from nurses. There are few methodological reports of actigraphy in infant sleep intervention studies that objectively measure infant sleep in a natural setting. DESIGN: This was a systematic review study. DATA SOURCES: Ovid MEDLINE, Embase, Cochrane, CINAHL and PsycINFO were searched from database establishment to 30 December 2021. REVIEW METHODS: This systematic review utilized the Cochrane Collaboration review guidelines. RESULTS: Eleven sleep intervention studies were reviewed. Three used extinction-based behavioural interventions, and eight included parental education programs. The infant sleep interventions positively affected the sleep outcomes of both infants and parents. Fairly consistent effects were found on infants' number of awakenings and sleep onset latency. However, parental psychosocial outcomes were inconsistent. All studies reported device placement, the algorithm for analysis, the use of a sleep diary and number of days/nights, but external movements affecting infants' sleep records were insufficiently reported. Only two studies had a low risk of bias. CONCLUSIONS: The infant sleep interventions had positive effects on both infants and their parents. Comprehensive methodological considerations are required for more standardized assessments using actigraphy for infant sleep evaluation.

Exploring the potential use of the metaverse in nurse education through a mock trial.

BACKGROUND: The metaverse has been attracting attention as a space for the application of education, where integrating the real and virtual worlds offers immersive 3D experiences. Consequently, its potential for higher education, including nursing, is being explored as a dynamic alternative to traditional education. OBJECTIVES: This study explores the applicability of metaverse in nurse education. It was conducted to implement a mock court on the metaverse platform and explore the learning experiences of nursing students through mock trials. DESIGN: Qualitative study. SETTINGS: A virtual mock court in VRChat (a virtual reality space). PARTICIPANTS: Fourteen participants were divided into three groups. METHODS: An orientation was conducted to explain the virtual space before the mock trial. On the day of the mock trial, a health survey of study participants was conducted in advance. After the mock trial, questionnaires and reflective diaries were written. RESULTS: The experiences of nursing students were organized into eleven sub-themes and three themes: "core features of the metaverse platform," "participation in a mock trial in the VRChat virtual space," and "metaverse-based learning using a mock trial." CONCLUSIONS: Nursing students participated and immersed themselves in learning while accepting the characteristics of the metaverse platform, which differs from face-to-face classes or existing educational methods. The metaverse enables reflective learning based on experiential learning and strengthens awareness of diverse viewpoints.

Effectiveness of a Strength-Based Intervention into Nursing Education in South Korea.

Purpose: This study aimed to examine the effectiveness of strength-based interventions integrated into the nursing education. Materials and Methods: The participants were 259 baccalaureate nursing students in South Korea. Over 15 weeks, strength-based intervention was integrated into the regular nursing curriculum. Stress, resilience, and well-being of the participants were measured before and after the intervention. The data were analyzed using a linear mixed model via the SPSS statistics 21.0. program. Results: There was a negative weak association between stress and well-being and between stress and resilience (r = -0.164, p = 0.009 and r = -0.138, p = 0.029, respectively) and a positive moderate association between well-being and resilience (r = 0.561, p<0.001). After adjusting the covariates, the interaction of group*time for stress and resilience were significant after the intervention, reflecting a higher status of stress and improved resilience. (p= 0.046 and 0.030 respectively). Conclusion: Integrating strength-based interventions into the nursing curriculum was effective in improving the mental health of Korean nursing students. Future research is needed to identify various ways of applying positive psychology to the nursing education.

Nursing students' self-directed learning experiences in web-based virtual simulation: A qualitative study.

BACKGROUND: Since the start of the COVID-19 pandemic, virtual reality simulation, including web-based simulation, has increased in nursing education. This study explored nursing students' self-directed problem-solving in web-based virtual simulation experiences. METHOD: Convenience sampling yielded 16 Korean senior nursing students who had experienced clinical practice in the last semester. Data were collected from August 2020 to January 2021 through in-depth Zoom video interviews and organized using NVivo version 12.0. Thematic analysis was applied to analyze the data. RESULTS: The following four themes were identified from nursing students' learning experiences during the web-based virtual simulations: "self-awareness of a lack of nursing competency in virtual reality," "applying new learning strategies learned from failure," "voluntary learning behavior," and "cognitive shift toward a holistic understanding." Web-based virtual simulations activated various cognitive and metacognitive factors of self-directed learning, and the system's prompt feedback and students' reflections facilitated learning effects. Nursing students corrected their cognitive errors while learning from their failures and mistakes and gained a holistic view of nursing practice. CONCLUSION: In this study, web-based self-directed learning activated the metacognition of nursing students in a virtuous cycle. The virtual environment with no actual harm to the patient has become a space for learners to experience a sense of confidence, achievement, and satisfaction. Web-based virtual simulation can be an effective teaching method to improve nursing students' self-directed learning abilities and nursing competency.

Korean naked waxy barley (saechalssal) extract reduces blood glucose in diabetic mice by modulating the PI3K-Akt-GSK3ß pathway.

Saechalssal barley is Korea's representative naked waxy barley. This study investigated the anti-diabetic effect of the extract derived from saechalssal and its mechanism. The prethanol extract of saechalssal (SPE) showed greater α-glucosidase inhibitory activity in vitro and a more significant lowering of the postprandial blood glucose levels in normal mice compared to its water extract (SWE). When mice with type 2 diabetes (T2DM) induced by a high-fat diet and streptozotocin were fed SPE (200 mg/kg/day) for six weeks, the fasting blood glucose and serum free fatty acid levels were significantly lower than those of the control group. SPE significantly elevated the hepatic glycogen accumulation with increasing glycogen synthesis-related gene (GYS2 and UGP2) levels compared to the control group. SPE stimulated the expression of the hepatic glycolysis-related genes (GK, PFK1, and PK) and suppressed the gluconeogenesis-related genes (G6Pase, FBP1, and PEPCK). SPE up-regulated the phosphorylation of phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt), whereas it down-regulated the phosphorylation of glycogen synthase kinase 3 beta (GSK3ß) compared to the control. The major flavonoids of SPE were naringin, prunin, and catechin, while its phenolic acids were ferulic acid and vanillic acid. These phytochemical compounds may contribute to the anti-hyperglycemic effects of SPE in diabetes. Overall, these results suggest that SPE has potential anti-diabetic activity through the regulating the PI3K/Akt/GSK3ß pathway.

A qualitative study of the sleep ecology of infants under 2 years old and their mothers in South Korea.

OBJECTIVES/DESIGN: Infancy is a crucial period for establishing an individual's sleep pattern, and it is a common period during which infants and mothers experience sleep problems. The aim of this qualitative study was to explore the sleep ecology of infants under 2 years of age and their mothers. SETTING/PARTICIPANTS: The study participants were 20 mothers with infants aged 3-19 months living in South Korea. METHODS: Data were collected through in-depth interviews and analyzed using the thematic analysis. RESULTS: Five themes related to the sleep of infants and their mothers emerged from the data: (1) changes in sleep patterns, (2) room-sharing, (3) environmental factors affecting sleep, (4) efforts to improve sleep quality, and (5) infant sleep and the mother's health. The sleep patterns of infants and their mothers were mutually interrelated, and were strongly affected by various environmental factors, including infants' biological maturity (a microsystem) as well as cultural factors (a macrosystem). Culture had an especially profound effect on sleep patterns of infants, similar to the effects of microsystem-level factors. CONCLUSIONS: To improve the sleep quality of infants and mothers, an ecological approach considering the biological characteristics and cultural contexts of infants is required based on an understanding of sleep as a phenomenon that evolves in a relationship of mutual influence between infants and mothers.

Effects of school-based "We Fit" weight control programme in adolescents.

AIM: This study examined the effects of a 12-week school-based "We Fit" weight control programme. DESIGN: A nonequivalent control group was used, with a non-synchronized pretest-posttest design. METHODS: In total, 109 Korean high school adolescents participated. The programme comprised exergaming, diet diary and counselling, health education, and social networking service-based group discussions. Anthropometric factors, physiological factors and physical activity (daily steps and sitting time) were measured in the intervention and the control groups before and after the intervention. Programme satisfaction was assessed post-intervention. Data were analysed using descriptive statistics; the chi-square, Mann-Whitney U and t tests; and generalized estimating equations. RESULTS: The intervention group showed a significantly decreased waist circumference, increased skeletal muscle mass, increased high-density lipoprotein cholesterol, decreased low-density lipoprotein cholesterol and reduced weekend sitting time. CONCLUSION: This study adds to the evidence for the applicability and effectiveness of healthy weight control programmes using exergames for adolescents in school settings.

An Adult Mouse Model of Dilated Cardiomyopathy Caused by Inducible Cardiac-Specific Bis Deletion.

BCL-2 interacting cell death suppressor (BIS) is a multifunctional protein that has been implicated in cancer and myopathy. Various mutations of the BIS gene have been identified as causative of cardiac dysfunction in some dilated cardiomyopathy (DCM) patients. This was recently verified in cardiac-specific knock-out (KO) mice. In this study, we developed tamoxifen-inducible cardiomyocyte-specific BIS-KO (Bis-iCKO) mice to assess the role of BIS in the adult heart using the Cre-loxP strategy. The disruption of the Bis gene led to impaired ventricular function and subsequent heart failure due to DCM, characterized by reduced left ventricular contractility and dilatation that were observed using serial echocardiography and histology. The development of DCM was confirmed by alterations in Z-disk integrity and increased expression of several mRNAs associated with heart failure and remodeling. Furthermore, aggregation of desmin was correlated with loss of small heat shock protein in the Bis-iCKO mice, indicating that BIS plays an essential role in the quality control of cardiac proteins, as has been suggested in constitutive cardiac-specific KO mice. Our cardiac-specific BIS-KO mice may be a useful model for developing therapeutic interventions for DCM, especially late-onset DCM, based on the distinct phenotypes and rapid progressions.

Association of Weight Control Behaviors with Body Mass Index in Korean Adolescents: A Quantile Regression Approach.

PURPOSE: Adolescents are interested in weight control but likely practice unhealthy weight control behaviors. This study aimed to examine weight control behaviors associated with body mass index (BMI) in Korean adolescents. DESIGN AND METHODS: In this descriptive cross-sectional study of 16- to 19-year-old adolescents (97 girls and 90 boys), analyses were conducted of physical activity, sedentary behaviors, dietary behaviors, and self-efficacy for physical activity and diet. Daily steps were measured using pedometers. Height and weight were self-reported. We conducted descriptive statistics and quantile regression analysis using STATA 14.0. RESULTS: About 10% were underweight, and 8.6% overweight and obese. Average weekday and weekend steps/day were <10,000. Only 4.3% reported performing moderate-to-vigorous physical activity (MVPA) daily. Less than half (42.5%) reported that they had three meals/day every day. Most (89.3%) had milk less than once/day. Quantile regression showed that, for the 5th BMI percentile group, (1) age (ß = 0.941) and milk consumption (ß = 2.148) were significantly positively associated with BMI, whereas (2) dietary self-efficacy (ß = -0.083) was significantly negatively associated with BMI. For the 95th percentile group, having three meals/day (ß = 2.558) was significantly positively associated with BMI, whereas MVPA (ß = -5.440) and muscle-strengthening exercise (ß = -3.392) were significantly negatively associated with BMI. CONCLUSIONS: Milk consumption was positively associated with BMI of underweight adolescents, whereas physical activities were negatively associated with BMI of overweight and obese adolescents. PRACTICE IMPLICATION: Weight control programs for adolescents may need to be tailored for differing BMI levels.

Anti-Obesity Property of Lichen Thamnolia vermicularis Extract in 3T3-L1 Cells and Diet-Induced Obese Mice.

Thamnolia vermicularis (TV) is an edible lichen that is prevalent in the alpine zone of East Asia. This study evaluated the feasibility of using TV acetone extracts as a functional food based on experiments using cell line and obese mice. The cellular triglyceride levels and Oil red O staining of 3T3-L1 cells indicated that TV extracts (5 and 10 µg/mL) dose-dependently suppressed adipocyte differentiation and lipid accumulation compared with the control. The TV extract (0.4%, w/w) in a high-fat diet (HFD) was supplemented to C57BL/6N mice for 12 weeks, and TV extract supplement significantly reduced visceral fat mass and body weight compared with HFD feeding alone. The TV extract also induced significant decreases in serum and hepatic lipids, whereas it increased the serum high-density lipoproteins-cholesterol/total cholesterol ratio and fecal lipids levels. Moreover, the TV extract led to significantly lower homeostasis model assessment of insulin resistance in diet-induced obese mice. Taken together, these results suggest that the TV extract may have anti-obesity effects, including lipid-lowering, and it is a natural resource with the potential for use in obesity management.

Weight Control in Adolescents: Focus Groups With Korean Adolescents and Their Teachers.

PURPOSE: This qualitative descriptive study sought to identify perceptions about and status of weight control in adolescents from the perspective of adolescents and their teachers. METHODS: Focus groups were used with six separate groups, 20 adolescents divided into four groups and 14 teachers divided into two groups. The qualitative data were analyzed using a thematic analysis in NVivo 11.0. Consolidated criteria for reporting qualitative studies (COREQ) were followed. RESULTS: We extracted three themes and 12 sub-themes with 52 meaningful codes. Both adolescents and teachers stated that perceptions about weight control in adolescents were overly weighted toward management of one's appearance. The adolescents reported an increase in weight gained during adolescence, especially after entering high school, and they noted a lack of participation in physical activities and the presence of unhealthy dietary behaviors. However, adolescents perceived excessive weight gain during adolescence as natural, as long as they studied hard. Their teachers and parents were also permissive about weight gain resulted from study. The participants suggested that a weight control program for adolescents should be conducted in schools and should include every student in order to avoid discrimination. In addition, teacher involvement was emphasized to promote participation of adolescents in a school program. CONCLUSION: Our findings indicate that adolescents, especially those in a society emphasizing academics, need to practice healthy weight control behaviors. A school-based weight control program involving teachers and peers would be suitable and should be provided to all students regardless of weight classification.

Establishment of a novel human papillomavirus-negative and radiosensitive head and neck squamous cell carcinoma cell line.

BACKGROUND: The purpose of this study was to develop a CMCSCC-1 cell line for head and neck cancer research into new therapies for head and neck squamous cell carcinoma (HNSCC). METHODS: The CMCSCC-1 cell line was isolated from a primary oral tongue tumor specimen of a female patient. Tumor cells were evaluated for biomarkers expression by Western blots, reverse transcriptase-polymerase chain reaction (RT-PCR), fluorescence activated cell sorter, and immunostaining. Cell proliferation in response to radiation was measured by the WST-8 assay. RESULTS: The characterization analyses revealed a typical epithelial morphology; a doubling time of approximately 24 hours, high tumorigenicity in immunodeficient mice, and upregulated biomarkers. CMCSCC-1 cells were negative for human papillomavirus (HPV) infection, but more sensitive to radiation compared with those FaDu cell lines. CONCLUSION: CMCSCC-1, a novel oral tongue SCC cell line, was established. It will help in the elucidation of the molecular pathogenesis of HPV-negative radiosensitive tumors. © 2015 Wiley Periodicals, Inc. Head Neck 38: E542-E551, 2015.

Low doses of curcumin protect alcohol-induced liver damage by modulation of the alcohol metabolic pathway, CYP2E1 and AMPK.

AIMS: This study investigated the hepatoprotective effects of low doses of curcumin against liver damage induced by chronic alcohol intake and a high-fat diet. We also examined several potential underlying mechanisms including action on alcohol metabolism, antioxidant activity, AMPK level and lipid metabolism. MAIN METHOD: Alcohol (25% v/v, 5 g/kg body weight) was orally administered once a day for 6 weeks to mice fed a high-fat diet with or without two different doses of curcumin (0.02% and 0.05%, wt/wt). KEY FINDINGS: Curcumin significantly decreased the plasma aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase and alkaline phosphatase activities (p<0.05) and prevented hepatic steatosis compared with the alcohol control group. Curcumin significantly reversed the alcohol-induced inhibition of the alcohol dehydrogenase, aldehyde dehydrogenase 2 and antioxidant enzyme activities as well as the activation of cytochrome P4502E1 and promotion of lipid peroxidation (p<0.05). Curcumin significantly increased the hepatic total AMPK protein level and concomitantly suppressed the fatty acid synthase and phosphatidate phosphohydrolase activities compared with the alcohol control group (p<0.05). Furthermore, curcumin significantly lowered the plasma leptin, free fatty acids and triglycerides levels and hepatic lipid levels (p<0.05). SIGNIFICANCE: These findings indicate that low doses of curcumin may protect against liver damage caused by chronic alcohol intake and a high-fat diet partly by modulating the alcohol metabolic enzyme activity, the antioxidant activity and the lipid metabolism. Therefore, curcumin may provide a promising natural therapeutic strategy against liver disease.

Effects of a multi-herbal extract on type 2 diabetes.

BACKGROUND: An aqueous extract of multi-hypoglycemic herbs of Panax ginseng C.A.Meyer, Pueraria lobata, Dioscorea batatas Decaisne, Rehmannia glutinosa, Amomum cadamomum Linné, Poncirus fructus and Evodia officinalis was investigated for its anti-diabetic effects in cell and animal models. METHODS: Activities of PPARγ agonist, anti-inflammation, AMPK activator and anti-ER stress were measured in cell models and in db/db mice (a genetic animal model for type 2 diabetes). RESULTS: While the extract stimulated PPARγ-dependent luciferase activity and activated AMPK in C2C12 cells, it inhibited TNF-α-stimulated IKKß/NFkB signaling and attenuated ER stress in HepG2 cells. The db/db mice treated with the extract showed reduced fasting blood glucose and HbA1c levels, improved postprandial glucose levels, enhanced insulin sensitivity and significantly decreased plasma free fatty acid, triglyceride and total cholesterol. CONCLUSION: The aqueous extract of these seven hypoglycemic herbs demonstrated many therapeutic effects for the treatment of type 2 diabetes in cell and animal models.

Chlorogenic acid exhibits anti-obesity property and improves lipid metabolism in high-fat diet-induced-obese mice.

This study investigated the efficacy of chlorogenic acid on altering body fat in high-fat diet (37% calories from fat) induced-obese mice compared to caffeic acid. Caffeic acid or chlorogenic acid was supplemented with high-fat diet at 0.02% (wt/wt) dose. Both caffeic acid and chlorogenic acid significantly lowered body weight, visceral fat mass and plasma leptin and insulin levels compared to the high-fat control group. They also lowered triglyceride (in plasma, liver and heart) and cholesterol (in plasma, adipose tissue and heart) concentrations. Triglyceride content in adipose tissue was significantly lowered, whereas the plasma adiponectin level was elevated by chlorogenic acid supplementation compared to the high-fat control group. Body weight was significantly correlated with plasma leptin (r=0.894, p<0.01) and insulin (r=0.496, p<0.01) levels, respectively. Caffeic acid and chlorogenic acid significantly inhibited fatty acid synthase, 3-hydroxy-3-methylglutaryl CoA reductase and acyl-CoA:cholesterol acyltransferase activities, while they increased fatty acid beta-oxidation activity and peroxisome proliferator-activated receptors alpha expression in the liver compared to the high-fat group. These results suggest that caffeic acid and chlorogenic acid improve body weight, lipid metabolism and obesity-related hormones levels in high-fat fed mice. Chlorogenic acid seemed to be more potent for body weight reduction and regulation of lipid metabolism than caffeic acid.

ER stress is implicated in mitochondrial dysfunction-induced apoptosis of pancreatic beta cells.

Mitochondrial dysfunction induces apoptosis of pancreatic ß-cells and leads to type 2 diabetes, but the mechanism involved in this process remains unclear. Chronic endoplasmic reticulum (ER) stress plays a role in the apoptosis of pancreatic ß-cells; therefore, in current study, we investigated the implication of ER stress in mitochondrial dysfunction-induced ß-cells apoptosis. Metabolic stress induced by antimycin or oligomycin was used to impair mitochondrial function in MIN6N8 cells, which are mouse pancreatic ß-cells. Impaired mitochondria dysfunction increased ER stress proteins such as p-eIF2α, GRP78 and GRP 94, as well as ER stress-associated apoptotic factor, CHOP, and activated JNK. AMP-activated protein kinase (AMPK) was also activated under mitochondria dysfunction by metabolic stress. However, the inhibition of AMPK by treatment with compound C, inhibitor of AMPK, and overexpression of mutant dominant negative AMPK (AMPKK45R) blocked the induction of ER stress, which was consist-ent with the decreased ß-cell apoptosis and increase of insulin content. Furthermore, mitochondrial dysfunction increased the expression of the inducible nitric oxide synthase (iNOS) gene and the production of nitric oxide (NO), but NO production was prevented by compound C and mutant dominant negative AMPK (AMPK-K45R). Moreover, treatment with 1400W, which is an inhibitor of iNOS, prevented ER stress and apoptosis induced by mitochondrial dysfunction. Treatment of MIN6N8 cells with lipid mixture, physiological conditions of impaired mitochondria function, activated AMPK, increased NO production and induced ER stress. Collectively, these data demonstrate that mitochondrial dysfunction activates AMPK, which induces ER stress via NO production, resulting in pancreatic ß-cells apoptosis.

cAMP-response element binding protein (CREB) positively regulates mouse adiponectin gene expression in 3T3-L1 adipocytes.

Adiponectin is expressed in adipose tissue by adipogenic transcription factors including PPARgamma, C/EBPalpha, and ADD1/SREBP1c. Because cAMP-response element binding protein (CREB) is also a central transcriptional activator of adipocyte differentiation, we evaluated CREB to determine if it stimulates adiponectin gene expression. To accomplish this, we evaluated the effects of activated CREB on the promoter activity of the mouse adiponectin gene, and identified the cAMP-response element (CRE) in the promoter. The constitutively active form of CREB increased the promoter activity of the mouse adiponectin gene. In addition, transfection studies using 5' serial deleted promoters revealed the presence of a putative CRE located between the -1250 and -1000bp region. Furthermore, an electrophoresis mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) analysis demonstrated that CREB bound to the region between -1022 and -995 in the adiponectin promoter. Insulin-like growth factor (IGF-1), which activate CREB, increased the adiponectin promoter activity. However, this stimulation was prevented by the dominant negative form of CREB (ACREB) and pretreatment with PD098059, indicating that IGF-1 stimulate adiponectin expression through CREB phosphorylation via the ERK pathway. Importantly, the transactivation of adiponectin expression by CREB was inhibited by ATF3. Coimmunoprecipitation and GST pull-down assay revealed that ATF3 bound to CREB and prevented CREB phosphorylation induced during differentiation of 3T3-L1 adipocytes. Collectively, these findings demonstrate that CREB is a positive regulator of mouse adiponectin gene expression in adipocytes, which play an important role in the regulation of adiponectin expression in response to growth factor.

Ursolic acid enhances the cellular immune system and pancreatic beta-cell function in streptozotocin-induced diabetic mice fed a high-fat diet.

This study investigated the effects of ursolic acid on immunoregulation and pancreatic beta-cell function in type 1 diabetes fed a high-fat diet for 4 weeks. Male mice were divided into non-diabetic, diabetic control, and diabetic-ursolic acid (0.05%, w/w) groups, which were fed a high-fat (37% calories from fat). Diabetes was induced by injection of streptozotocin (200 mg/kg B.W., i.p.). Ursolic acid significantly improved blood glucose levels, glucose intolerance, and insulin sensitivity compared to the diabetic group. The plasma insulin and C-peptide concentrations were significantly higher in the diabetic-ursolic acid group than in the diabetic group. Ursolic acid significantly elevated the insulin levels with preservation of insulin staining of beta-cells in the pancreas. In splenocytes, concanavalin (Con) A-induced T-cell proliferation was significantly higher in the diabetic-ursolic acid group compared to the diabetic group, but liposaccharide (LPS)-induced B-cell proliferation did not differ between groups. Ursolic acid enhanced IL-2 and IFN-gamma production in response to Con A stimulation, whereas it inhibited TNF-alpha production in response to LPS stimulation. In this study, neither streptozotocin nor ursolic acid had effects on lymphocyte subsets. These results indicate that ursolic acid exhibits potential anti-diabetic and immunomodulatory properties by increasing insulin levels with preservation of pancreatic beta-cells and modulating blood glucose levels, T-cell proliferation and cytokines production by lymphocytes in type 1 diabetic mice fed a high-fat diet.

Potential hypoglycemic effect of an ethanol extract of Gynostemma pentaphyllum in C57BL/KsJ-db/db mice.

This study was conducted to evaluate the antihyperglycemic effect of an extract of Gynostemma pentaphyllum Makino, containing standardized concentrations of gypenosides, in C57BL/KSJ-db/db mice. For 5 weeks, animals were provided a standard AIN-76 diet (normal control) with rosiglitazone (0.005%, wt/wt) or two different doses of G. pentaphyllum ethanol extract (GPE) of the plant leaves (0.0025% and 0.01%, wt/wt). After the experimental period, the blood glucose levels of the high-dose GPE- and rosiglitazone-supplemented groups were significantly lower than that of the control group. The plasma insulin concentrations of the GPE-supplemented mice were significantly elevated compared to the control group. The GPE and rosiglitazone treatments profoundly affected the intraperitoneal insulin tolerance test compared to the control group, but not the intraperitoneal glucose tolerance test. In the evaluation of effects on hepatic glucose metabolism, the ratios of glucokinase/glucose-6-phosphatase activities in the high-dose GPE- and rosiglitazone-supplemented groups were prominently higher than that of the control group. The histology of the pancreatic islets revealed that the insulin-positive beta-cell numbers were higher in the high-dose GPE- and rosiglitazone-supplemented groups than in the control group. These results suggest that the supplementation of high-dose GPE (0.01%) in the diet lowers the blood glucose level by altering the hepatic glucose metabolic enzyme activities.

Effect of curcumin supplementation on blood glucose, plasma insulin, and glucose homeostasis related enzyme activities in diabetic db/db mice.

We investigated the effect of curcumin on insulin resistance and glucose homeostasis in male C57BL/KsJ-db/db mice and their age-matched lean non-diabetic db/+ mice. Both db/+ and db/db mice were fed with or without curcumin (0.02%, wt/wt) for 6 wks. Curcumin significantly lowered blood glucose and HbA 1c levels, and it suppressed body weight loss in db/db mice. Curcumin improved homeostasis model assessment of insulin resistance and glucose tolerance, and elevated the plasma insulin level in db/db mice. Hepatic glucokinase activity was significantly higher in the curcumin-supplemented db/db group than in the db/db group, whereas glucose-6-phosphatase and phosphoenolpyruvate carboxykinase activities were significantly lower. In db/db mice, curcumin significantly lowered the hepatic activities of fatty acid synthase, beta-oxidation, 3-hydroxy-3-methylglutaryl coenzyme reductase, and acyl-CoA: cholesterol acyltransferase. Curcumin significantly lowered plasma free fatty acid, cholesterol, and triglyceride concentrations and increased the hepatic glycogen and skeletal muscle lipoprotein lipase in db/db mice. Curcumin normalized erythrocyte and hepatic antioxidant enzyme activities (superoxide dismutase, catalase, gluthathione peroxidase) in db/db mice that resulted in a significant reduction in lipid peroxidation. However, curcumin showed no effect on the blood glucose, plasma insulin, and glucose regulating enzyme activities in db/+ mice. These results suggest that curcumin seemed to be a potential glucose-lowering agent and antioxidant in type 2 diabetic db/db mice, but had no affect in non-diabetic db/+ mice.