Viola mandshurica ethanolic extract prevents high-fat-diet-induced obesity in mice by activating AMP-activated protein kinase

Lipid lowering and anti-ageing effects of edible flowers of Viola x wittrockiana Gams in a Caenorhabditis elegans obese model

Life expectancy has increased considerably in the last decades, clearing the way for preventive medicine. The ingestion of healthy foods or ingredients to improve health is gaining attention and edible flowers entail a promising source of bioactive compounds. The aim of this work was to study the anti-ageing and anti-obesity properties of an extract obtained from an edible flower Viola x wittrockiana though in vitro and in vivo methodologies with Caenorhabditis elegans as a model. The capacity to inhibit the enzymes α-glucosidase and lipase as well as to prevent advance glycation end-product (AGE) formation was tested in vitro. Caenorhabditis elegans was used as an obesity in vivo model to assess the effects of the extract on fat accumulation, development, progeny and health span. Viola flowers showed lower IC50 values in the α-glucosidase assay than the reference drug acarbose and exerted a higher inhibition of AGE formation than the reference substance aminoguanidine; the extract also showed pancreatic lipase inhibiting properties. Moreover, the extract lowered fat storage of C. elegans in a dose-dependent manner, up to 90.37% at the highest tested dose, and improved health span biomarkers such as lipofuscin accumulation and progeny availability. Our results demonstrate, for the first time, the anti-obesogenic and anti-ageing activity of Viola x wittrockiana flowers and their potential use as functional foods and nutraceuticals.

A comprehensive review of phytochemistry, pharmacology and quality control of plants from the genus Viola

OBJECTIVES

The genus Viola belongs to the family Violaceae, and the plants from this genus are essential folk herb medicine extensively used in many areas. The plants from the genus Viola are used to treat various diseases and exert a significant role in protecting people's health. This review summarized the genus Viola plants' phytochemistry, pharmacology, and quality control methods.

KEY FINDINGS

The information on chemical constituents and pharmacological effects of the genus Viola was obtained by searching the Web of Science, Pubmed, CNKI, and other databases. A total of 208 valuable articles were selected and analyzed in this review. The main chemical components of plants from the genus Viola consist of flavonoids, coumarins, alkaloids, lignans, sesquiterpenes, cyclotides, etc. The active chemical components of medicinal plants from this genus exert antibacterial, antiviral, antioxidant, anti-inflammatory, anti-tumor, neuroprotective, hepatoprotective activities, and so on. The quality control of these plants is not sufficient and needs further research.

SUMMARY

The chemical constituents, pharmacological effects, and quality control of plants from the genus Viola were systematically summarized in this paper, and this review provides a literature basis for the further research of plants from this genus.

Improvement effects of esculetin on the formation and development of atherosclerosis

Atherosclerosis is one of the potential causes of death in patients with cardiovascular disease. With the discovery of new anti atherosclerotic drugs becoming the pursuit of the pharmaceutical industry, natural products have attracted more and more attention because of their unique efficacy in the treatment of atherosclerosis. More and more studies have shown that esculetin, a coumarin mainly found in cortex fraxini, can improve atherosclerosis by participating in cellular antioxidant responses and reducing inflammation related pathogenesis. This paper summarizes the researches of esculetin on anti-atherosclerosis in the past two decades. Esculetin plays an anti atherosclerotic role through reducing blood triglyceride level, preventing the proliferation of vascular smooth muscle cells (VSMC) and the production of matrix metallopeptidase 9 (MMP-9), inhibiting the oxidation of low density lipoprotein (LDL) and the secretion of adhesion factors and chemokines, and increasing the outflow level of high density lipoprotein cholesterol (HDL-C). Esculetin is safe and reliable, easy to be absorbed by the body and can be synthesized in a variety of ways. Although there are still few clinical studies on anti-atherosclerosis, in vivo experiments have proved that esculetin has high bioavailability. From the current research, the anti-atherosclerotic effect of esculetin is positive and encouraging. However, much work remains to be done to clarify the molecular mechanism of esculetin in the treatment of atherosclerosis.

Effects of Dipsacus asperoides and Phlomis umbrosa Extracts in a Rat Model of Osteoarthritis

The implementation of the Nagoya Protocol highlighted the importance of identifying alternative herbal products that are as effective as traditional medicine. Dipsacus asperoides and Phlomis umbrosa, two species used in the Korean medicine ‘Sok-dan’, are used for the treatment of bone- and arthritis-related diseases, and they are often mixed or misused. To identify herbal resources with similar efficacy, we compared the effects of D. asperoides extract (DAE) and P. umbrosa extract (PUE) on osteoarthritis (OA) in a monosodium iodoacetate (MIA)-induced OA rat model. Weight-bearing distribution, serum cytokines, histopathological features, and the expression of matrix metalloproteinases (MMPs) of knee joint tissues were examined in the OA rats treated with DAE and PUE (200 mg/kg) for 21 days. DAE and PUE restored weight-bearing distribution, inhibited the production of serum cytokines, and alleviated the histopathological features of the OA knee tissue. DAE or PUE treatment decreased OA-induced overexpression of MMP-2, MMP-9, and MMP-13 in the knee joint tissue. This study demonstrated the efficacy of both DAE and PUE in an MIA-induced OA model, providing a basis for the clinical use of these products in traditional Korean medicine.

Artemisia scoparia and Metabolic Health: Untapped Potential of an Ancient Remedy for Modern Use

Botanicals have a long history of medicinal use for a multitude of ailments, and many modern pharmaceuticals were originally isolated from plants or derived from phytochemicals. Among these, artemisinin, first isolated from Artemisia annua, is the foundation for standard anti-malarial therapies. Plants of the genus Artemisia are among the most common herbal remedies across Asia and Central Europe. The species Artemisia scoparia (SCOPA) is widely used in traditional folk medicine for various liver diseases and inflammatory conditions, as well as for infections, fever, pain, cancer, and diabetes. Modern in vivo and in vitro studies have now investigated SCOPA's effects on these pathologies and its ability to mitigate hepatotoxicity, oxidative stress, obesity, diabetes, and other disease states. This review focuses on the effects of SCOPA that are particularly relevant to metabolic health. Indeed, in recent years, an ethanolic extract of SCOPA has been shown to enhance differentiation of cultured adipocytes and to share some properties of thiazolidinediones (TZDs), a class of insulin-sensitizing agonists of the adipogenic transcription factor PPARγ. In a mouse model of diet-induced obesity, SCOPA diet supplementation lowered fasting insulin and glucose levels, while inducing metabolically favorable changes in adipose tissue and liver. These observations are consistent with many lines of evidence from various tissues and cell types known to contribute to metabolic homeostasis, including immune cells, hepatocytes, and pancreatic beta-cells. Compounds belonging to several classes of phytochemicals have been implicated in these effects, and we provide an overview of these bioactives. The ongoing global epidemics of obesity and metabolic disease clearly require novel therapeutic approaches. While the mechanisms involved in SCOPA's effects on metabolic, anti-inflammatory, and oxidative stress pathways are not fully characterized, current data support further investigation of this plant and its bioactives as potential therapeutic agents in obesity-related metabolic dysfunction and many other conditions.

Herbal Combination of Phyllostachys pubescens and Scutellaria baicalensis Inhibits Adipogenesis and Promotes Browning via AMPK Activation in 3T3-L1 Adipocytes

To investigate the anti-obesity effects and underlying mechanism of BS21, a combination of Phyllostachys pubescens leaves and Scutellaria baicalensis roots was used to investigate the effects of BS21 on adipogenesis, lipogenesis, and browning in 3T3-L1 adipocytes. The expression of adipocyte-specific genes was observed via Western blot, and the BS21 chemical profile was analyzed using ultra-performance liquid chromatography (UPLC). BS21 treatment inhibited adipocyte differentiation and reduced the expression of the adipogenic proteins peroxisome proliferator-activated receptor γ (PPAR-γ), CCAAT/enhancer-binding protein (C/EBP-α), and adipocyte protein 2 (aP2), as well as the lipogenic proteins sterol regulatory element-binding protein 1c (SREBP-1c) and fatty-acid synthase (FAS). BS21 enhanced protein levels of the beta-oxidation genes carnitine palmitoyltransferase (CPT1) and phospho-acetyl-coA carboxylase (p-ACC). BS21 also induced protein expressions of the browning marker genes PR domain containing 16 (PRDM16), peroxisome proliferator-activated receptor gamma co-activator 1-alpha (PGC1α), and uncoupling protein (UCP) 1, and it induced the expression of the thermogenic gene UCP2. Furthermore, BS21 increased adenosine monophosphate-activated protein kinase (AMPK) activation. UPLC analysis showed that BS21 contains active constituents such as chlorogenic acid, orientin, isoorientin, baicalin, wogonoside, baicalein, tricin, wogonin, and chrysin. Our findings demonstrate that BS21 plays a modulatory role in adipocytes by reducing adipogenesis and lipogenesis, increasing fat oxidation, and inducing browning.

Aqueous and ethanolic extracts of welsh onion, Allium fistulosum, attenuate high-fat diet-induced obesity

Background

Allium fistulosum (Welsh onion) is a traditional medicinal plant used for the treatment of colds, influenza, abdominal pain, headache, and heart disease. This study evaluated the effects of A. fistulosum ethanolic extract (AFE) and aqueous extract (AFW) on body weight and other obesity-related parameters.

Methods

Male 8-week-old C57BL/6 J mice were fed either a standard chow diet (normal control) or a high-fat diet (HFD) either alone (HFD-control) or in combination with G. cambogia extract containing hydroxycitric acid (HCA, an herbal weight-loss supplement), conjugated linoleic acid (CLA, a weight-loss supplement), orlistat (a clinically available anti-obesity drug), AFW, or AFE (n = 6 mice per group) for 6 weeks. At the end of 6 weeks, several body weight and obesity-related parameters were examined, including: liver and adipose weight, adipocyte size, serum lipid profiles, liver expression of adenosine monophosphate-activated protein kinase (AMPK), and adipose tissue expression of uncoupling protein 2 (UCP2).

Results

High-performance liquid chromatography showed that both AFE and AFW contain ferulic acid and quercetin. Oral administration of AFW and AFE to HFD-fed mice decreased body weight as well as liver and adipose tissue weight and adipocyte size. Serum lipid profiles and adiponectin levels were improved in HFD-fed mice treated with AFE but not AFW. However, both AFW and AFE significantly attenuated HFD-induced changes in serum leptin and insulin-like growth factor 1 levels, liver expression of AMPK, and adipose tissue expression of UCP2.

Conclusions

The findings from this study suggest that A. fistulosum extracts have potential as functional food materials for weight control in obesity.

Effects of Mollugo pentaphylla extract on monosodium urate crystal-induced gouty arthritis in mice

Background

Gout is an inflammatory condition induced by the deposition of monosodium urate (MSU) crystals in joints and soft tissues, and it can lead to acute or chronic arthritis. MSU are pro-inflammatory stimuli that can initiate, amplify and sustain an intense inflammatory response. In this study, we evaluated the anti-inflammatory effect of an extract of Mollugo pentaphylla (MPE) on MSU-induced gouty arthritis in a mouse model.

Method

An MSU crystal suspension (4 mg/50 μL) was injected intradermally into the right paw. The mice were orally administered MPE (150 mg/kg or 300 mg/kg) or the positive control drug colchicine (1 mg/kg) 1 h before the MSU crystals were injected and then once daily for 3 days. The effects of MPE included inflammatory paw edema and pain upon weight-bearing activity, and we evaluated the inflammatory cytokine expression and paw tissue inflammation-related gene expression.

Results

MPE suppressed inflammatory paw edema and pain in the MSU-induced mice. MPE showed anti-inflammatory activity by inhibiting the production of TNF-α, interleukin (IL)-1β, NLRP3 inflammasome and NF-κB.

Conclusion

These results suggest that MPE has potent anti-inflammatory activities and may be useful as a therapeutic agent against gouty arthritis.

Anti-obesity activity, acute toxicity, and chemical constituents of aqueous and ethanol Viola mandshurica extracts

Background

Viola mandshurica has traditionally been used as an expectorant, diuretic, and anti-inflammatory drug. The present study was designed to test the hypothesis that low doses of two different V. mandshurica extracts have anti-obesity effects.

Methods

We evaluated the effects of ethanol extract (VME) and aqueous extract (VMA) from V. mandshurica on high-fat diet (HFD)-induced obese mice as well as the acute oral toxicities and chemical compositions of both extracts.

Results

Oral administration of VME or VMA (50, 100, or 200 mg/kg) decreased body weight gain, liver and adipose tissue mass, adipocyte size, and serum lipid levels. Both extracts increased adiponectin serum concentrations and mRNA expression in epididymal adipose tissue. VME and VMA also reversed the HFD-induced mRNA expression of lipogenic genes such as CCAAT/enhancer binding protein (C/EBP)α, C/EBPβ, sterol regulatory element-binding protein 1c, and leptin in adipose tissue, whereas they increased mRNA expression of uncoupling protein 2 and adenosine monophosphate-activated protein kinase (AMPK). VME and VMA increased the phosphorylation of AMPK and acetyl-coA carboxylase with a concomitant decrease in fat accumulation in the liver. High performance liquid chromatography analysis revealed that both VME and VMA contained esculetin (0.566% for VME, 0.231% for VMA) and schaftoside (0.147% for VME, 0.126% for VMA). In a 2-week acute toxicity study, administration of a single oral dose of VME or VMA (5000 mg/kg) caused no signs of toxicity or mortality.

Conclusions

These results suggest that both VM extracts exert anti-obesity effects in HFD-induced obese mice by suppressing lipogenesis and activating AMPK in the liver and adipose tissue. Our findings suggest that VM extracts could be a safe and effective treatment for obesity.

Effects of Viola mandshurica on Atherosclerosis and Hepatic Steatosis in ApoE−∕− via the AMPK Pathway

Atherosclerosis was previously thought to be a disease that primarily involves lipid accumulation in the arterial wall. In this report, we investigated the effect of Viola mandshurica W. Becker (V. mandshurica) water extract on atherosclerosis in apolipoprotein E deficient (ApoE[Formula: see text]) mice. The administration of V. mandshurica to high-fat diet-fed mice reduced body weight, liver weight, and serum levels of lipids (total cholesterol, low-density lipoprotein-cholesterol, triglycerides), glucose, alanine transaminase, and aspartate transaminase. Histopathologic analyses of the aorta and liver revealed that V. mandshurica attenuated atherosclerotic lesions and reduced lipid accumulation, inflammatory responses and fatty acid synthesis. V. mandshurica also increased phosphorylation of adenosine monophosphate-activated protein kinase (AMPK), thereby reducing acetyl-CoA carboxylase (ACC) in liver tissue and inhibiting sterol regulatory element-binding protein 1c (SREBP-1c). V. mandshurica reduced protein expression levels of adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin) as well as ACC, fatty acid synthase, and SREBP-1c. In addition, quantitative analysis of V. mandshurica by high-performance liquid chromatography revealed the presence of esculetin and scopoletin. Esculetin and scopoletin reduced adhesion molecules in human aortic smooth muscle cells. Our results indicate that the anti-atherosclerotic effects of V. mandshurica may be associated with activation of the AMPK pathway. Therefore, AMPK-dependent phosphorylation of SREBP-1c by V. mandshurica may be an effective therapeutic strategy for combatting atherosclerosis and hepatic steatosis.

Effect of the Capsicoside G-rich Fraction from Pepper (Capsicum annuum L.) Seeds on High-fat Diet-induced Obesity in Mice

Obesity is one of the most common metabolic syndromes and is a major threat to human health worldwide. Given the size of this problem, there is growing interest in natural agents that may decrease obesity. In this study, we investigated the anti-obesity effect of a capsicoside G-rich fraction (CRF; 13.35% capsicoside G) isolated from pepper seeds in diet-induced obese mice. C57BL/6J mice were fed either a normal diet or a high-fat diet (HFD), with or without CRF (HFD + CRF; 10 and 100 mg/kg body weight). The body weight and food efficiency ratio of mice fed HFD + CRF were lower in comparison to that of mice fed only an HFD. Epididymal adipose tissue weight and adipocyte hypertrophy were significantly lower in HFD + CRF mice than in HFD mice. The fat deposition in the liver of mice fed HFD + CRF was lower compared to that of mice fed only an HFD. CRF significantly reversed the HFD-induced elevation of the expression of key adipocyte differentiation regulators, including peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein α, sterol regulatory element binding protein 1c, and their target genes. These results suggest that CRF could be used as dietary therapy for the prevention of obesity and obesity-related metabolic diseases. Copyright © 2016 John Wiley & Sons, Ltd.

Age-dependent effects of esculetin on mood-related behavior and cognition from stressed mice are associated with restoring brain antioxidant status

Dietary antioxidants might exert an important role in the aging process by relieving oxidative damage, a likely cause of age-associated brain dysfunctions. This study aims to investigate the influence of esculetin (6,7-dihydroxycoumarin), a naturally occurring antioxidant in the diet, on mood-related behaviors and cognitive function and its relation with age and brain oxidative damage. Behavioral tests were employed in 11-, 17- and 22-month-old male C57BL/6J mice upon an oral 35day-esculetin treatment (25mg/kg). Activity of antioxidant enzymes, GSH and GSSG levels, GSH/GSSG ratio, and mitochondrial function were analyzed in brain cortex at the end of treatment in order to assess the oxidative status related to mouse behavior. Esculetin treatment attenuated the increased immobility time and enhanced the diminished climbing time in the forced swim task elicited by acute restraint stress (ARS) in the 11- and 17-month-old mice versus their counterpart controls. Furthermore, ARS caused an impairment of contextual memory in the step-through passive avoidance both in mature adult and aged mice which was partially reversed by esculetin only in the 11-month-old mice. Esculetin was effective to prevent the ARS-induced oxidative stress mostly in mature adult mice by restoring antioxidant enzyme activities, augmenting the GSH/GSSG ratio and increasing cytochrome c oxidase (COX) activity in cortex. Modulation of the mood-related behavior and cognitive function upon esculetin treatment in a mouse model of ARS depends on age and is partly due to the enhancement of redox status and levels of COX activity in cortex.

Regulation of AMP-activated protein kinase by natural and synthetic activators

The AMP-activated protein kinase (AMPK) is a sensor of cellular energy status that is almost universally expressed in eukaryotic cells. While it appears to have evolved in single-celled eukaryotes to regulate energy balance in a cell-autonomous manner, during the evolution of multicellular animals its role has become adapted so that it also regulates energy balance at the whole body level, by responding to hormones that act primarily on the hypothalamus. AMPK monitors energy balance at the cellular level by sensing the ratios of AMP/ATP and ADP/ATP, and recent structural analyses of the AMPK heterotrimer that have provided insight into the complex mechanisms for these effects will be discussed. Given the central importance of energy balance in diseases that are major causes of morbidity or death in humans, such as type 2 diabetes, cancer and inflammatory disorders, there has been a major drive to develop pharmacological activators of AMPK. Many such activators have been described, and the various mechanisms by which these activate AMPK will be discussed. A particularly large class of AMPK activators are natural products of plants derived from traditional herbal medicines. While the mechanism by which most of these activate AMPK has not yet been addressed, I will argue that many of them may be defensive compounds produced by plants to deter infection by pathogens or grazing by insects or herbivores, and that many of them will turn out to be inhibitors of mitochondrial function.

The nutritional composition and anti-obesity effects of an herbal mixed extract containing Allium fistulosum and Viola mandshurica in high-fat-diet-induced obese mice

Background

In traditional oriental medicine, A. fistulosum and V. mandshurica are considered to be effective in promoting blood circulation. Therefore, in this study, we investigated whether a solution containing both A. fistulosum and V. mandshurica (AFE + VME) extracts has synergistic effects on the treatment of hyperlipidemia and obesity.

Methods

Anti-obesity effects of an herbal extract containing Allium fistulosum and Viola mandshurica (AFE + VME) were investigated in high-fat diet (HFD)-induced obese mice. AFE + VME was orally administrated to mice with the HFD at a dose of 200 mg/kg/day for 8 weeks. We observed the effects of mixed extract on body weight, fat mass, serum lipid levels, and mRNA expression levels of lipid metabolism-related genes in the adipose tissue of mice.

Results

The nutritional analysis revealed that this mixed extract is high in carbohydrate (72.2 g/100 g) and protein (11.5 g/100 g); low in fat (1.7 g/100 g); rich in vitamins E (4.8 mg/100 g), B₁ (14.8 mg/100 g), B₂ (1.0 mg/100 g), niacin (7.9 mg/100 g), and folic acid (1.57 mg/100 g); and rich in minerals such as calcium (600 mg/100 g), iron (106.1 mg/100 g), and zinc (5.8 mg/100 g). The oral administration of AFE + VME in obese mice reduced body weight, tissue weight, adipocyte size, and lipid accumulation in the liver compared with HFD control mice. AFE + VME also decreased serum triglyceride, total cholesterol, and leptin concentrations. Furthermore, AFE + VME markedly increased the mRNA expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), uncoupling protein-2 (UCP-2), and adiponectin and decreased leptin expression in the epididymal white adipose tissue. Our results suggest that the extract containing A. fistulosum and V. mandshurica improved lipid metabolism via the up-regulation of PPAR-γ, UCP-2, and adiponectin expression and the down-regulation of leptin in HFD-induced obese mice.

Conclusions

Therefore, the extract containing Allium fistulosum and Viola mandshurica may be a potentially effective therapy for obesity and its related metabolic disorders such as hyperlipidemia and insulin resistance.

High corn oil dietary intake improves health and longevity of aging mice

Corn oil has been recommended as a replacement for saturated fats because of its high levels of poly- and mono-unsaturated fatty acids. In the present study, we tested whether very high levels of corn oil (58.6% fat-derived calories, FDC) intake improve health and longevity of aging mice. Twelve month old male C57BL/6 mice were fed a normal diet (10% FDC of corn oil, N) or a high fat diet (58.6% FDC of corn oil, HF) for 13-15 months. Our results show that a HF diet significantly increased the longevity of the aged mice (at 25 months of age, 53.8% of mice died in the N group, whereas the mortality rate was only 23.2% in the HF group). High corn oil also reversed aging-increased blood lipids including triglyceride, total cholesterol and LDL. Similarly, high corn oil intake overturned aging-raised pro-inflammatory markers including IL-1β, IL-6, and monocyte chemotactic protein-1 (MCP-1) in the blood. In addition, corn oil intake reversed aging-damaged rotarod performance and liver function. Interestingly, the HF group was significantly heavier than the N group (53.6g/mouse vs. 41.3g/mouse); however, both HF and N groups had the same calorie intake (12.48 kcal/d/mouse vs. 12.24 kcal/d/mouse). Although, the HF group's food consumption was lower than that of the N group (2.4 g/d/mouse vs. 3.4 g/d/mouse). These results suggest that if total calorie consumption stays in the normal range, very high levels of corn oil intake improve health and longevity of aging mice.