Prenylated Coumaric Acids from Artemisia scoparia Beneficially Modulate Adipogenesis.

Two new diprenylated coumaric acid isomers (1a and 1b) and two known congeners, capillartemisin A (2) and B (3), were isolated from Artemisia scoparia as bioactive markers using bioactivity-guided HPLC fractionation. Their structures were determined by spectroscopic means, including 1D and 2D NMR methods and LC-MS, with their purity assessed by 1D 1H pure shift qNMR spectroscopic analysis. The bioactivity of compounds was evaluated by enhanced accumulation of lipids, as measured using Oil Red O staining, and by increased expression of several adipocyte marker genes, including adiponectin in 3T3-L1 adipocytes relative to untreated negative controls. Compared to the plant's 80% EtOH extract, these purified compounds showed significant but still weaker inhibition of TNFα-induced lipolysis in 3T3-L1 adipocytes. This suggests that additional bioactive substances are responsible for the multiple metabolically favorable effects on adipocytes observed with Artemisia scoparia extract.

Safety and pharmacokinetics of naringenin: A randomized, controlled, single-ascending-dose clinical trial.

AIMS: To evaluate the safety and pharmacokinetics of naringenin in healthy adults consuming whole-orange (Citrus sinensis) extract. METHODS AND METHODS: In a single-ascending-dose randomized crossover trial, 18 adults ingested doses of 150 mg (NAR150), 300 mg (NAR300), 600 mg (NAR600) and 900 mg (NAR900) naringenin or placebo. Each dose or placebo was followed by a wash-out period of at least 1 week. Blood safety markers were evaluated pre-dose and 24 hours post-dose. Adverse events (AEs) were recorded. Serum naringenin concentrations were measured before and over 24 hours following ingestion of placebo, NAR150 and NAR600. Four- and 24-hour serum measurements were obtained after placebo, NAR300 and NAR900 ingestion. Data were analysed using a mixed-effects linear model. RESULTS: There were no relevant AEs or changes in blood safety markers following ingestion of any of the naringenin doses. The pharmacokinetic variables were: maximal concentration: 15.76 ± 7.88 µM (NAR150) and 48.45 ± 7.88 µM (NAR600); time to peak: 3.17 ± 0.74 hours (NAR150) and 2.41 ± 0.74 hours (NAR600); area under the 24-hour concentration-time curve: 67.61 ± 24.36 µM × h (NAR150) and 199.05 ± 24.36 µM × h (NAR600); and apparent oral clearance: 10.21 ± 2.34 L/h (NAR150) and 13.70 ± 2.34 L/h (NAR600). Naringenin half-life was 3.0 hours (NAR150) and 2.65 hours (NAR600). After NAR300 ingestion, serum concentrations were 10.67 ± 5.74 µM (4 hours) and 0.35 ± 0.30 µM (24 hours). After NAR900 ingestion, serum concentrations were 43.11 ± 5.26 µM (4 hours) and 0.24 ± 0.30 µM (24 hours). CONCLUSIONS: Ingestion of 150 to 900 mg doses of naringenin is safe in healthy adults, and serum concentrations are proportional to the dose administered. Since naringenin (8 µM) is effective in primary human adipocytes, ingestion of 300 mg naringenin twice/d will likely elicit a physiological effect.

The DESIGNER Approach Helps Decipher the Hypoglycemic Bioactive Principles of Artemisia dracunculus (Russian Tarragon).

Complementing classical drug discovery, phytochemicals act on multiple pharmacological targets, especially in botanical extracts, where they form complex bioactive mixtures. The reductionist approach used in bioactivity-guided fractionation to identify single bioactive phytochemicals is inadequate for capturing the full therapeutic potential of the (bio)chemical interactions present in such complex mixtures. This study used a DESIGNER (Deplete and Enrich Select Ingredients to Generate Normalized Extract Resources) approach to selectively remove the known bioactives, 4'-O-methyldavidigenin (1; 4,2'-dihydroxy-4'-methoxydihydrochalcone, syn. DMC-1) and its isomer 4-O-methyldavidigenin (2; syn. DMC-2), from the mixture of phytochemicals in an ethanol extract from Artemisia dracunculus to determine to what degree the more abundant 2 accounts for the established antidiabetic effect of the A. dracunculus extract. Using an otherwise chemically intact "knock-out extract" depleted in 2 and its regioisomer, 1, in vitro and in vivo outcomes confirmed that 2 (and likely 1) acts as major bioactive(s) that enhance(s) insulin signaling in skeletal muscle, but also revealed that 2 does not account for the breadth of detectable biological activity of the extract. This is the first report of generating, at a sufficiently large preparative scale, a "knock-out extract" used as a pharmacological tool for in vitro and in vivo studies to dissect the biological impact of a designated bioactive in a complex phytochemical mixture.

An ethanolic extract of Artemisia scoparia inhibits lipolysis in vivo and has antilipolytic effects on murine adipocytes in vitro.

An ethanolic extract of Artemisia scoparia (SCO) has metabolically favorable effects on adipocyte development and function in vitro and in vivo. In diet-induced obese mice, SCO supplementation significantly reduced fasting glucose and insulin levels. Given the importance of adipocyte lipolysis in metabolic health, we hypothesized that SCO modulates lipolysis in vitro and in vivo. Free fatty acids and glycerol were measured in the sera of mice fed a high-fat diet with or without SCO supplementation. In cultured 3T3-L1 adipocytes, the effects of SCO on lipolysis were assessed by measuring glycerol and free fatty acid release. Microarray analysis, qPCR, and immunoblotting were used to assess gene expression and protein abundance. We found that SCO supplementation of a high-fat diet in mice substantially reduces circulating glycerol and free fatty acid levels, and we observed a cell-autonomous effect of SCO to significantly attenuate tumor necrosis factor-α (TNFα)-induced lipolysis in cultured adipocytes. Although several prolipolytic and antilipolytic genes were identified by microarray analysis of subcutaneous and visceral adipose tissue from SCO-fed mice, regulation of these genes did not consistently correlate with SCO's ability to reduce lipolytic metabolites in sera or cell culture media. However, in the presence of TNFα in cultured adipocytes, SCO induced antilipolytic changes in phosphorylation of hormone-sensitive lipase and perilipin. Together, these data suggest that the antilipolytic effects of SCO on adipose tissue play a role in the ability of this botanical extract to improve whole body metabolic parameters and support its use as a dietary supplement to promote metabolic resiliency.

St. John's Wort inhibits insulin signaling in murine and human adipocytes.

Adipocytes are insulin-sensitive cells that play a major role in energy homeostasis. Obesity is the primary disease of fat cells and a major risk factor for the development of Type 2 diabetes, cardiovascular disease, and metabolic syndrome. The use of botanicals in the treatment of metabolic diseases is an emerging area of research. In previous studies, we screened over 425 botanical extracts for their ability to modulate adipogenesis and insulin sensitivity. We identified St. John's Wort (SJW) extracts as inhibitors of adipogenesis of 3T3-L1 cells and demonstrated that these extracts also inhibited insulin-sensitive glucose uptake in mature fat cells. In these follow-up studies we have further characterized the effects of SJW on insulin action in both murine and human fat cells. We have shown that SJW also attenuates insulin-sensitive glucose uptake in human adipocytes. Moreover, SJW inhibits IRS-1 tyrosine phosphorylation in both murine and human fat cells. Botanical extracts are complex mixtures. Many bioactive compounds have been identified in SJW, including hypericin (HI) and hyperforin (HF). We have examined the ability of HI and HF, purified from SJW, to modulate adipocyte development and insulin action in mature adipocytes. Our novel studies indicate that the profound effects of SJW on adipogenesis, IRS-1 activation, and insulin-stimulated glucose uptake are not mediated by HI and/or HF. Nonetheless, we propose that extracts of SJW may contribute to adipocyte related diseases by limiting differentiation of preadipocytes and significantly inducing insulin resistance in mature fat cells.

Moringa isothiocyanate-1 regulates Nrf2 and NF-κB pathway in response to LPS-driven sepsis and inflammation.

This study aims to document the dual mode of pharmacological action of moringa isothiocyanate-1 (MIC-1) derived from seeds of Moringa oleifera Lam. Oral administration of chemically stable MIC-1 (80 mg/kg) significantly reduced the expression of inflammatory markers (Tnf-α, Ifn-α, IL-1ß, IL-6) in the liver, kidney, spleen, and colon and decreased spleen weight in the lipopolysaccharide (LPS)-induced sepsis / acute inflammation model in mice. Transcriptomic analysis of the effect of MIC-1 on the liver and in the LPS-induced RAW264.7 murine macrophage showed that MIC-1 decreases inflammation via inflammation, immunity, and oxidative stress pathways. These results are supported by the immunocytochemical observations that MIC-1 increased the nuclear accumulation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) transcription factor and decreased the nuclear accumulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) in the LPS-induced macrophages. Transcriptional activation of antioxidant genes by MIC-1 translated into a reduction of reactive oxygen species (ROS) in the cytoplasm, decrease of mitochondrial superoxide content, and restoration of the mitochondrial membrane potential in the LPS-induced macrophages. Our data indicate that MIC-1 affects inflammation and oxidative stress, two key processes involved in the etiology of many chronic diseases. These effects involve upstream regulation of two key transcriptional factors regulating responses to these processes at a gene expression level.

Designing a Clinical Study With Dietary Supplements: It's All in the Details.

A successful randomized clinical trial of the effect of dietary supplements on a chosen endpoint begins with developing supporting data in preclinical studies while paying attention to easily overlooked details when planning the related clinical trial. In this perspective, we draw on our experience studying the effect of an ethanolic extract from Artemisia dracunculus L. (termed PMI-5011) on glucose homeostasis as a potential therapeutic option in providing resilience to metabolic syndrome (MetS). Decisions on experimental design related to issues ranging from choice of mouse model to dosing levels and route of administration in the preclinical studies will be discussed in terms of translation to the eventual human studies. The more complex considerations in planning the clinical studies present different challenges as these studies progress from testing the safety of the dietary supplement to assessing the effect of the dietary supplement on a predetermined clinical outcome. From the vantage point of hindsight, we will outline potential pitfalls when translating preclinical studies to clinical studies and point out details to address when designing clinical studies of dietary supplements.

High-fat diet-induced neuropathy of prediabetes and obesity: effect of PMI-5011, an ethanolic extract of Artemisia dracunculus L.

Artemisia species are a rich source of herbal remedies with antioxidant and anti-inflammatory properties. We evaluated PMI-5011, an ethanolic extract of Artemisia dracunculus L., on neuropathy in high-fat diet-fed mice, a model of prediabetes and obesity developing oxidative stress and proinflammatory changes in peripheral nervous system. C57Bl6/J mice fed high-fat diet for 16 weeks developed obesity, moderate nonfasting hyperglycemia, nerve conduction deficit, thermal and mechanical hypoalgesia, and tactile allodynia. They displayed 12/15-lipoxygenase overexpression, 12(S)-hydroxyeicosatetraenoic acid accumulation, and nitrosative stress in peripheral nerve and spinal cord. PMI-5011 (500 mg kg(-1) d(-1), 7 weeks) normalized glycemia, alleviated nerve conduction slowing and sensory neuropathy, and reduced 12/15-lipoxygenase upregulation and nitrated protein expression in peripheral nervous system. PMI-5011, a safe and nontoxic botanical extract, may find use in treatment of neuropathic changes at the earliest stage of disease.

Regulation of insulin action by an extract of Artemisia dracunculus L. in primary human skeletal muscle culture: a proteomics approach.

An ethanolic extract of Artemisia dracunculus L. (PMI 5011) has been observed to decrease glucose and insulin levels in animal models and enhance cellular signaling in cultured cells. To determine the mechanism of action of PMI-5011, we have measured changes in protein expression in human primary skeletal muscle culture (HSMC) from subjects with Type 2 diabetes. After obtaining skeletal muscle biopsies, HSMCs were initiated, grown to confluence, and exposed to 10 microg/mL PMI 5011 overnight. Two-dimensional difference in-gel electrophoresis was used to separate proteins, and liquid chromatography mass spectrometry was used to identify differentially regulated proteins. Additionally, real-time polymerase chain reaction (PCR) was used to confirm candidate proteins identified. These data demonstrate that a well characterized botanical extract of Artemisia dracunculus L. significantly modulates proteins involved in regulating inflammatory pathways, particularly the NFkappaB complex system.

Mechanisms of Artemisia scoparia's Anti-Inflammatory Activity in Cultured Adipocytes, Macrophages, and Pancreatic ß-Cells.

OBJECTIVE: An ethanolic extract of Artemisia scoparia (SCO) improves adipose tissue function and reduces negative metabolic consequences of high-fat feeding. A. scoparia has a long history of medicinal use across Asia and has anti-inflammatory effects in various cell types and disease models. The objective of the current study was to investigate SCO's effects on inflammation in cells relevant to metabolic health. METHODS: Inflammatory responses were assayed in cultured adipocytes, macrophages, and insulinoma cells by quantitative polymerase chain reaction, immunoblotting, and NF-κB reporter assays. RESULTS: In tumor necrosis factor α-treated adipocytes, SCO mitigated ERK and NF-κB signaling as well as transcriptional responses but had no effect on fatty acid-binding protein 4 secretion. SCO also reduced levels of deleted in breast cancer 1 protein in adipocytes and inhibited inflammatory gene expression in stimulated macrophages. Finally, in pancreatic ß-cells, SCO decreased NF-κB-responsive promoter activity induced by IL-1ß treatment. CONCLUSIONS: SCO's ability to promote adipocyte development and function is thought to mediate its insulin-sensitizing actions in vivo. Our findings that SCO inhibits inflammatory responses through at least two distinct signaling pathways (ERK and NF-κB) in three cell types known to contribute to metabolic disease reveal that SCO may act more broadly than previously thought to improve metabolic health.

Adaptive Fat Oxidation Is Coupled with Increased Lipid Storage in Adipose Tissue of Female Mice Fed High Dietary Fat and Sucrose.

Western diets high in fat and sucrose are associated with metabolic syndrome (MetS). Although the prevalence of MetS in women is comparable to that in men, metabolic adaptations in females to Western diet have not been reported in preclinical studies. This study investigates the effects of Western diet on risk factors for MetS in female mice. Based on our earlier studies in male mice, we hypothesized that dietary supplementation with extracts of Artemisia dracunculus L. (PMI5011) and Momordica charantia (bitter melon) could affect MetS risk factors in females. Eight-week-old female mice were fed a 10% kcal fat, 17% kcal sucrose diet (LFD); high-fat, high-sucrose diet (HFS; 45% kcal fat, 30% kcal sucrose); or HFS diet with PMI5011 or bitter melon for three months. Body weight and adiposity in all HFS groups were greater than the LFD. Total cholesterol level was elevated with the HFS diets along with LDL cholesterol, but triglycerides and free fatty acids were unchanged from the LFD. Over the three month period, female mice responded to the HFS diet by adaptive increases in fat oxidation energy in muscle and liver. This was coupled with increased fat storage in white and brown adipose tissue depots. These responses were enhanced with botanical supplementation and confer protection from ectopic lipid accumulation associated with MetS in female mice fed an HFS diet.

Fenugreek Counters the Effects of High Fat Diet on Gut Microbiota in Mice: Links to Metabolic Benefit.

Fenugreek (Trigonella foenum-graecum) is an annual herbaceous plant and a staple of traditional health remedies for metabolic conditions including high cholesterol and diabetes. While the mechanisms of the beneficial actions of fenugreek remain unknown, a role for intestinal microbiota in metabolic homeostasis is likely. To determine if fenugreek utilizes intestinal bacteria to offset the adverse effects of high fat diets, C57BL/6J mice were fed control/low fat (CD) or high fat (HFD) diets each supplemented with or without 2% (w/w) fenugreek for 16 weeks. The effects of fenugreek and HFD on gut microbiota were comprehensively mapped and then statistically assessed in relation to effects on metrics of body weight, hyperlipidemia, and glucose tolerance. 16S metagenomic analyses revealed robust and significant effects of fenugreek on gut microbiota, with alterations in both alpha and beta diversity as well as taxonomic redistribution under both CD and HFD conditions. As previously reported, fenugreek attenuated HFD-induced hyperlipidemia and stabilized glucose tolerance without affecting body weight. Finally, fenugreek specifically reversed the dysbiotic effects of HFD on numerous taxa in a manner tightly correlated with overall metabolic function. Collectively, these data reinforce the essential link between gut microbiota and metabolic syndrome and suggest that the preservation of healthy populations of gut microbiota participates in the beneficial properties of fenugreek in the context of modern Western-style diets.

St. John's Wort inhibits adipocyte differentiation and induces insulin resistance in adipocytes.

Adipocytes are insulin sensitive cells that play a major role in energy homeostasis. Obesity is the primary disease of fat cells and a major risk factor for the development of Type II diabetes, cardiovascular disease, and metabolic syndrome. Obesity and its related disorders result in dysregulation of the mechanisms that control adipocyte gene expression and function. To identify potential novel therapeutic modulators of adipocytes, we screened 425 botanical extracts for their ability to modulate adipogenesis and insulin sensitivity. We observed that less than 2% of the extracts had substantial effects on adipocyte differentiation of 3T3-L1 cells. Two of the botanical extracts that inhibited adipogenesis were extracts from St. John's Wort (SJW). Our studies revealed that leaf and flower, but not root, extracts isolated from SJW inhibited adipogenesis as judged by examining PPARgamma and adiponectin levels. We also examined the effects of these SJW extracts on insulin sensitivity in mature 3T3-L1 adipocytes. Both leaf and flower extracts isolated from SJW substantially inhibited insulin sensitive glucose uptake. The specificity of the observed effects was demonstrated by showing that treatment with SJW flower extract resulted in a time and dose dependent inhibition of insulin stimulated glucose uptake. SJW is commonly used in the treatment of depression. However, our studies have revealed that SJW may have a negative impact on adipocyte related diseases by limiting differentiation of preadipocytes and significantly inducing insulin resistance in mature fat cells.

Distinct Fractions of an Artemisia scoparia Extract Contain Compounds With Novel Adipogenic Bioactivity.

Adipocytes are important players in metabolic health and disease, and disruption of adipocyte development or function contributes to metabolic dysregulation. Hence, adipocytes are significant targets for therapeutic intervention in obesity and metabolic syndrome. Plants have long been sources for bioactive compounds and drugs. In previous studies, we screened botanical extracts for effects on adipogenesis in vitro and discovered that an ethanolic extract of Artemisia scoparia (SCO) could promote adipocyte differentiation. To follow up on these studies, we have used various separation methods to identify the compound(s) responsible for SCO's adipogenic properties. Fractions and subfractions of SCO were tested for effects on lipid accumulation and adipogenic gene expression in differentiating 3T3-L1 adipocytes. Fractions were also analyzed by Ultra Performance Liquid Chromatography- Mass Spectrometry (UPLC-MS), and resulting peaks were putatively identified through high resolution, high mass accuracy mass spectrometry, literature data, and available natural products databases. The inactive fractions contained mostly quercetin derivatives and chlorogenates, including chlorogenic acid and 3,5-dicaffeoylquinic acid, which had no effects on adipogenesis when tested individually, thus ruling them out as pro-adipogenic bioactives in SCO. Based on these studies we have putatively identified the principal constituents in SCO fractions and subfractions that promoted adipocyte development and fat cell gene expression as prenylated coumaric acids, coumarin monoterpene ethers, 6-demethoxycapillarisin and two polymethoxyflavones.

Evaluation of botanicals for improving human health.

Botanical preparations have been used medicinally for thousands of years. Many commercially available botanical products are being marketed in the United States with little or no publicly available scientific validation of efficacy or consistency. For botanicals to be reliable for research purposes and consumer products, they must be standardized with sufficient quality controls to ensure consistent composition, safety, and potency. This includes uniform cultivation of source plants with controls to monitor for contamination from other species, pesticides, and environmental toxins. The active components of botanicals must be identified by activity-guided fractionation with the use of in vitro assays that require little test material followed by validation in vivo. Concentrations of active compounds within the botanicals can then be accurately measured to ensure the delivery of a dependable dose in the final product. The use of bioenhancing agents may be considered for compounds with poor bioavailability. Standardization of botanical therapeutics can only be achieved when the active compounds are identified and biological activity is confirmed, thus ensuring a consistent product.

Botanicals and the metabolic syndrome.

Metabolic syndrome describes the human condition characterized by the presence of coexisting traditional risk factors for cardiovascular disease, such as hypertension, dyslipidemia, glucose intolerance, and obesity, in addition to nontraditional cardiovascular disease risk factors, such as inflammatory processes and abnormalities of the blood coagulation system. Although the specific etiology for metabolic syndrome is not known, insulin resistance--a clinical state in which a normal or elevated insulin concentration reflects an impaired biological response--is present and is considered a key pathophysiologic abnormality. As such, metabolic syndrome can be considered to be a prediabetic state and contributes greatly to increased morbidity and mortality in humans. Given the public health significance of metabolic syndrome, successful strategies are direly needed to intervene in its development. As such, nutritional supplementation with botanicals that effectively address pathogenic mechanisms, combined with the acceptance and widespread use of botanical supplements by the general public, represents an attractive, novel, and potentially effective approach to the problem. Thus, the overall goal of our botanical research center is to comprehensively evaluate botanicals in addressing the pathophysiologic mechanisms that lead to the development of insulin resistance and metabolic syndrome. Currently, each of the 3 research projects evaluates a specific botanical [Russian tarragon (Artemisia dracunculus L), shilianhua (Sinocrassula indica), and grape (Vitus vinifera) anthocyanins] and assesses the effect on pathogenic mechanisms leading to the development of insulin resistance. With the completion of our research, we anticipate a better understanding of the cellular mechanisms by which insulin resistance develops and the role of botanicals in modulating the progression to metabolic syndrome.

Botanicals as epigenetic modulators for mechanisms contributing to development of metabolic syndrome.

Epigenetics refers to heritable changes in gene expression that are not attributable to changes in DNA sequence and impacts many areas of applied and basic biology including developmental biology, gene therapy, somatic cell nuclear transfer, somatic cell reprogramming, and stem cell biology. Epigenetic changes are known to contribute to aging in addition to multiple disease states. Epigenetic changes can be influenced by environmental factors that in turn can be inherited by daughter cells during cell division and can also be inherited through the germ line. Thus, it is intriguing to consider that epigenetics, in general, may play a role in human conditions that are strongly influenced by changes in the environment and lifestyle. In particular, metabolic syndrome, a condition increasing in prevalence around the world, is one such condition for which epigenetics is postulated to contribute. Epigenetic defects (epimutations) are thought to be more easily reversible (when compared with genetic defects) and, as such, have inspired efforts to identify novel compounds that correct epimutations or prevent progression to the disease state. These efforts have resulted in the development of a rapidly growing new field being referred to as epigenetic therapy. To date, 2 classes of drugs have received the most attention, that is, DNA methyltransferase inhibitors and histone deacetylase inhibitors; but recent data suggest that botanical sources may be a rich source of agents that can potentially modulate the epigenome and related pathways and potentially be useful in attenuating the progression of many factors related to development of metabolic syndrome. This review will provide an overview of the field of epigenetics, epigenetic therapy, and the molecules currently receiving the most interest with respect to treatment, and review data on botanical compounds that show promise in this regard.

A natural history of botanical therapeutics.

Plants have been used as a source of medicine throughout history and continue to serve as the basis for many pharmaceuticals used today. Although the modern pharmaceutical industry was born from botanical medicine, synthetic approaches to drug discovery have become standard. However, this modern approach has led to a decline in new drug development in recent years and a growing market for botanical therapeutics that are currently available as dietary supplements, drugs, or botanical drugs. Most botanical therapeutics are derived from medicinal plants that have been cultivated for increased yields of bioactive components. The phytochemical composition of many plants has changed over time, with domestication of agricultural crops resulting in the enhanced content of some bioactive compounds and diminished content of others. Plants continue to serve as a valuable source of therapeutic compounds because of their vast biosynthetic capacity. A primary advantage of botanicals is their complex composition consisting of collections of related compounds having multiple activities that interact for a greater total activity.

Bioactives of Artemisia dracunculus L enhance cellular insulin signaling in primary human skeletal muscle culture.

An alcoholic extract of Artemisia dracunculus L (PMI 5011) has been shown to decrease glucose and improve insulin levels in animal models, suggesting an ability to enhance insulin sensitivity. We sought to assess the cellular mechanism by which this botanical affects carbohydrate metabolism in primary human skeletal muscle culture. We measured basal and insulin-stimulated glucose uptake, glycogen accumulation, phosphoinositide 3 (PI-3) kinase activity, and Akt phosphorylation in primary skeletal muscle culture from subjects with type 2 diabetes mellitus incubated with or without various concentrations of PMI 5011. We also analyzed the abundance of insulin receptor signaling proteins, for example, IRS-1, IRS-2, and PI-3 kinase. Glucose uptake was significantly increased in the presence of increasing concentrations of PMI 5011. In addition, glycogen accumulation, observed to be decreased with increasing free fatty acid levels, was partially restored with PMI 5011. PMI 5011 treatment did not appear to significantly affect protein abundance for IRS-1, IRS-2, PI-3 kinase, Akt, insulin receptor, or Glut-4. However, PMI 5011 significantly decreased levels of a specific protein tyrosine phosphatase, that is, PTP1B. Time course studies confirmed that protein abundance of PTP1B decreases in the presence of PMI 5011. The cellular mechanism of action to explain the effects by which an alcoholic extract of A dracunculus L improves carbohydrate metabolism on a clinical level may be secondary to enhancing insulin receptor signaling and modulating levels of a specific protein tyrosine phosphatase, that is, PTP1B.

Quercetin transiently increases energy expenditure but persistently decreases circulating markers of inflammation in C57BL/6J mice fed a high-fat diet.

Quercetin, a polyphenolic compound and a major bioflavonoid in the human diet, has anti-inflammatory properties and has been postulated to enhance energy expenditure (EE). We sought to determine whether quercetin alters body weight, body composition, EE, and circulating markers of inflammation. At 6 weeks (W) of age, 2 cohorts of C57BL/6J mice (N = 80) were placed on one of 2 diets for 3W or 8W: (1) high fat (HF) (45% kcal fat) or (2) high fat + quercetin (HF + Q) (45% kcal fat + 0.8% quercetin). Quercetin concentrations in the diet and plasma were evaluated using mass spectrometry. Body weight, composition (nuclear magnetic resonance), and food consumption were measured weekly. Energy expenditure was measured by indirect calorimetry at 3 and 8W, and inflammatory markers were measured in plasma obtained at 8W. The presence of quercetin in the HF diet did not alter food consumption over time in the HF + Q group and did not differ from the HF group at any time point. However, circulating plasma quercetin concentrations declined between 3 and 8W. At 3W, EE was higher during both day and night phases (P < .0001) in the HF + Q group compared with the HF group; but this difference was not detected at 8W and did not translate into significant differences between the HF + Q and HF groups with respect to body weight or body composition. During the night phase, concentrations of the inflammatory markers (interferon-gamma, interleukin-1alpha, and interleukin-4) were significantly lower when compared with HF treatment group (P < .05). Dietary supplementation with quercetin produces transient (3W) increases in EE that are not detected after 8W on the diet. A corresponding decrease in circulating quercetin between 3 and 8W suggests that metabolic adaptation may have diminished the impact of quercetin's early effect on EE and diminished its overall effect on nutrient partitioning and adiposity. However, quercetin at the levels provided was effective in reducing circulating markers of inflammation observed in animals on an HF diet at 8W.