Artemisinic acid is a regulator of adipocyte differentiation and C/EBP δ expression

Artemisinin counteracts Edwardsiella tarda-induced liver inflammation and metabolic changes in juvenile fat greenling Hexagrammos otakii

Emerging evidence suggests that artemisinin (ART) can modulate pathogen-induced immune responses and metabolic dysregulation. However, whether this modulation is associated with metabolic pathways related to oxidative stress and inflammation remains unclear. The aim of this study was to investigate the antioxidant and anti-inflammatory effects on the ART-fed juvenile fat greenling Hexagrammos otakii and the associated metabolic pathways in response to ART administration using an integrated biochemical and metabolomic approach. Biochemical analysis and histological examination showed that ART significantly increased body weight gain and improved tissue structure. ART effectively attenuated reactive oxygen species (ROS), malondialdehyde (MDA) and inflammatory responses (NFκB, TNF-α, IL-6, and MCP-1) in the Edwardsiella tarda-induced H. otakii model. Liver metabolomics analysis revealed that twenty-nine metabolites were up-regulated and twenty-one metabolites were down-regulated after ART administration compared to those in pathogen-induced fish. Pathway analysis indicated that ART alleviated the E. tarda-induced inflammation and oxidative stress through two major pathways, namely lipid metabolism and amino acid metabolism. Taken together, ART showed great potential as a natural feed additive against pathogen-induced oxidative stress and inflammation.

Reduction of NADPH oxidase 4 in adipocytes contributes to the anti-obesity effect of dihydroartemisinin

Artemisinin derivatives have been found to have anti-obesity effects recently, but the mechanism is still controversial. Herein, long-term DHA treatment in obese mice significantly reduced the body weight and improved glucose metabolism. However, short-term DHA treatment did not affect glucose metabolism in obese mice, suggesting that the improved glucose metabolism in mice with DHA treatment could be secondary to body weight reduction. Consistent with previous reports, we observed that DHA inhibited the differentiation of adipocytes. Mechanistically, DHA significantly reduced the expression of NADPH oxidase 4 (NOX4) in white adipose tissue (WAT) of mice and differentiated adipocytes, and using NOX4 siRNA or the NOX4 inhibitor GKT137831 significantly attenuated adipocyte differentiation. Over-expression of NOX4 partially reversed the inhibition effect of DHA on adipogenic differentiation of preadipocytes. In addition, targeted proteomics analysis showed that DHA improved the abnormality of metabolic pathways. In conclusion, DHA significantly reduced fat mass and improved glucose metabolism in obese mice, possibly by inhibiting NOX4 expression to suppress adipocyte differentiation and lipid accumulation in adipocytes.

Therapeutic potential of artemisinin and its derivatives in managing kidney diseases

Artemisinin, an antimalarial traditional Chinese herb, is isolated from Artemisia annua. L, and has shown fewer side effects. Several pieces of evidence have demonstrated that artemisinin and its derivatives exhibited therapeutic effects on diseases like malaria, cancer, immune disorders, and inflammatory diseases. Additionally, the antimalarial drugs demonstrated antioxidant and anti-inflammatory activities, regulating the immune system and autophagy and modulating glycolipid metabolism properties, suggesting an alternative for managing kidney disease. This review assessed the pharmacological activities of artemisinin. It summarized the critical outcomes and probable mechanism of artemisinins in treating kidney diseases, including inflammatory, oxidative stress, autophagy, mitochondrial homeostasis, endoplasmic reticulum stress, glycolipid metabolism, insulin resistance, diabetic nephropathy, lupus nephritis, membranous nephropathy, IgA nephropathy, and acute kidney injury, suggesting the therapeutic potential of artemisinin and its derivatives in managing kidney diseases, especially the podocyte-associated kidney diseases.

Ethanol Extract of Artemisia Annua Prevents LPS-Induced Inflammation and Blood-Milk Barrier Disruption in Bovine Mammary Epithelial Cells

This experiment evaluated the pre-protective effect of AAE on inflammatory injury and tight junction disturbance in bMECs induced by LPS. The bMECs were treated with AAE (3, 6, 12 μg/mL) for 3 h and then incubated with 10 μg/mL lipopolysaccharide (LPS) for 12 h. Our results showed that LPS significantly increased the mRNA and protein expression of CD36, induced the phosphorylation of IκBα and p65 and elevated the levels of TNF-α, IL-1β and IL-6 mRNA, which further resulted in ultrastructural damage, disrupted the expression of tight junction proteins (occludin, zonula occludens (ZO-1) and claudin-1) and decreased the viability of bMECs (p < 0.05). More importantly, AAE pretreatment attenuated the expression of CD36, suppressed the activity of the NF-κB signaling pathway and down-regulated the levels of inflammatory factors in LPS-stimulated bMECs (p < 0.05). Therefore, AAE can effectively protect bMECs against inflammatory injury and tight junction dysfunction, which has important research value for the prevention of bovine mastitis.

Natural products and analogs as preventive agents for metabolic syndrome via peroxisome proliferator-activated receptors: An overview

Natural products and synthetic analogs have drawn much attention as potential therapeutical drugs to treat metabolic syndrome. We reviewed the underlying mechanisms of 32 natural products and analogs with potential pharmacological effects in vitro, and especially in rodent models and/or patients, that usually act on the PPAR pathway, along with other molecular targets. Recent outstanding total syntheses or semisyntheses of these lead compounds are stated. In general, they can activate the transcriptional activity of PPARα, PPARγ, PPARα/γ, PPARβ/δ, PPARα/δ, PPARγ/δ and panPPAR as weak, partial agonists or selective PPARγ modulators (SPPARγM), which may be useful for managing obesity, type 2 diabetes (T2D), dyslipidemia and non-fatty liver disease (NAFLD). Terpenoids is the largest group of compounds that act as potential modulators on PPARs and are comprised from small lipophilic cannabinoids to lipophilic pentacyclic triterpenes and polar saponins. Shikimates-phenylpropanoids include polar heterocyclic flavonoids and phenolic compounds containing at least one C3-C6 unit and usually a double bond on the propyl chain. Quercetin (19), resveratrol (24) and curcumin (27), stand out from this group for exhibiting beneficial effects on patients. Alkaloids, the minor group of potential modulators on PPARs, include berberine (30), which has been widely explored in preclinical and clinical studies for its potential beneficial effects on T2D and dyslipidemia. However, large-scale clinical trials may be warranted for the promising compounds.

Biotransformation of artemisinic acid to bioactive derivatives by endophytic Penicillium oxalicum B4 from Artemisia annua L

As a biosynthetic precursor of the antimalarial drug artemisinin, artemisinic acid (AA) is abundant in Artemisia annua L. with a content of 8-10-fold higher than artemisinin, but less effective. In this study, the biotransformation of AA was carried out with an endophytic fungus Penicillium oxalicum B4 to extend its utility. After 10-day-culture of the endophyte with AA at 2 mg/mL, eight biotransformation metabolites were isolated from the culture broth, including five undescribed metabolites, namely 3α,14-dihydroxyartemisinic acid, 14-hydroxy-3-oxo-artemisinic acid, 15-hydroxy-3-oxo-artemisinic acid, 12, 15-artemisindioic acid and 1,2,3,6-tetradehydro-12, 15-artemisindioic acid. The fungal enzymes possess the selective capacity to hydroxylate, carbonylate and ketonize the allyl group of AA. The major biotransformation metabolite was the hydroxylated product 3-α-hydroxyartemisinic acid (33.3%) in the cultures of early stage (day 1-6), whereas most of the other biotransformation products were synthesized in the later stage (day 8-10). Compared with AA, some metabolites (3α,14-dihydroxyartemisinic acid, 15-hydroxy-3-oxo-artemisinic acid and 1,2,3,6-tetradehydro-12, 15-artemisindioic acid) possessed stronger cytotoxic activity to the human colon carcinoma cell line (LS174T) and promyelocytic leukemia cell line (HL-60). The metabolites 12, 15-artemisindioic acid and 3-α-hydroxyartemisinic acid exhibited significant inhibitory activity to the lipopolysaccharide-induced nitrite production of RAW 264.7 cells at 10.00 μM and 2.50 μM, respectively. The results demonstrated the potential of fungal endophytes on biotransforming AA to its bioactive derivatives.

Anti-Obesity Effects of Artemisia annua Extract in Zucker Fatty Rats and High-Fat Diet Sprague Dawley Rats through Upregulation of Uncoupling Protein 1

Background

Obesity is a widespread disease and is caused mainly by excessive adipocyte differentiation and fat accumulation. Peroxisome proliferation-activated receptor γ (PPARγ) and CCAAT/enhancer-binding proteins (C/EBP) are major components for regulating adipocyte differentiation. Uncoupling protein 1 (UCP1) is a transmembrane protein that can convert white fat to brown adipose tissue. Artemisia annua L. has long been used in East Asia as an herbal drug for anti-oxidant, anti-bacterial, and anti-obesity purposes.

Methods

We investigated the effects of water extracts of A. annua (WEAA) in C3H10T1/2, a mesenchymal stem cell line, by measuring the level of intracellular fat accumulation and the expression of genes associated with adipocyte differentiation. We also evaluated anti-obesity effects of WEAA in Zucker rats, a genetic model for the study of obesity, and in Sprague Dawley rats with high-fat diet (HFD)-induced obesity.

Results

In this study, WEAA reduced the expression levels of PPARγ and C/EBPα in C3H10T1/2 cells, as well as the expression of enzymes that regulate fatty acid metabolism. In the Zucker fatty rat model and the HFD-induced obesity rat model, WEAA significantly decreased adipogenic differentiation and white fat accumulation between the scapulae, in contrast to the brown fat that remained unchanged between the groups. A. annua suppressed the expression of the adipocyte differentiation-promoting genes, while increasing the expression of UCP1.

Conclusion

These results indicated that WEAA could reduce adipocyte differentiation and fat accumulation in in vitro and in vivo model systems, resulting in suppression of obesity and the occurrence of fatty liver due to a HFD.

The potential of Artemisia species for use as broad-spectrum agents in the management of metabolic syndrome: a review

Although the prevalence of metabolic syndrome (MetS), a cluster of cardiometabolic risk factors that predispose to the development of type 2 diabetes mellitus and cardiovascular diseases, is increasing globally, there is no broad-spectrum agent for its holistic treatment. Natural plant-derived products with a wide spectrum of biological activities are currently being explored as alternatives in the management of diseases. Artemisia species are a heterozygous group of plants of the Compositae family that possess several health benefits. Here we highlight their antidiabetic, anti-obesity, anti-hyperlipidaemic, hepatoprotective and cardioprotective properties among others. These activities have been linked to the presence of phytochemicals that act on several molecular targets to exert their effects and the species of Artemisia are considered to be relatively safe. Artemisia species offer significant anti-MetS activity and thus are strong therapeutic candidates for the effective management of MetS.

The Potential Roles of Artemisinin and Its Derivatives in the Treatment of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a chronic disease that has become a global public health problem. Studies on T2DM prevention and treatment mostly focus on discovering therapeutic drugs. Artemisinin and its derivatives were originally used as antimalarial treatments. In recent years, the roles of artemisinins in T2DM have attracted much attention. Artemisinin treatments not only attenuate insulin resistance and restore islet ß-cell function in T2DM but also have potential therapeutic effects on diabetic complications, including diabetic kidney disease, cognitive impairment, diabetic retinopathy, and diabetic cardiovascular disease. Many in vitro and in vivo experiments have confirmed the therapeutic utility of artemisinin and its derivatives on T2DM, but no article has systematically demonstrated the specific role artemisinin plays in the treatment of T2DM. This review summarizes the potential therapeutic effects and mechanism of artemisinin and its derivatives in T2DM and associated complications, providing a reference for subsequent related research.

Water Extract of Artemisia annua L. Exhibits Hepatoprotective Effects Through Improvement of Lipid Accumulation and Oxidative Stress-Induced Cytotoxicity

Nonalcoholic fatty liver disease (NAFLD) is a metabolic liver disease with a complex underlying mechanism that has not been completely understood. Thus, effective and safe drugs for this disease are not yet available. Artemisia annua L. is a medicinal plant with potent antimicrobial and antioxidant activities. In this study, we prepared a water extract of A. annua (WEAA) and examined its potential for NAFLD treatment. First, we pretreated HepG2 cells (human hepatocarcinoma cell line) with WEAA and then treated the cells with oleic acid or tert-butylhydroperoxide to examine the effect of WEAA on the lipid accumulation and the cytotoxicity, respectively. WEAA not only inhibited lipid accumulation within HepG2 cells but also protected cells from oxidative stress-mediated damage through the activation of antioxidant enzymes (such as activation of superoxide dismutase and production of glutathione) and its own scavenging activity. Next, to confirm protective effect of the WEAA in in vivo, mice were intragastrically administered with WEAA, extract of Silybum marianum or water once a day, and simultaneously provided with high-fat diet to induce fatty liver and hepatic steatosis. Oral administration of WEAA ameliorated weight gain and hepatic lipid accumulation in high-fat diet-fed mice. Moreover, the plasma levels of triglyceride, aspartate aminotransferase, and alanine aminotransferase were reduced in the WEAA-treated group. Our findings indicated that WEAA may be a potential intervention for preventing or treating hepatic lipid accumulation and liver damage.

Anti-SARS-CoV-2 Potential of Artemisinins In Vitro

The discovery of novel drug candidates with anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) potential is critical for the control of the global COVID-19 pandemic. Artemisinin, an old antimalarial drug derived from Chinese herbs, has saved millions of lives. Artemisinins are a cluster of artemisinin-related drugs developed for the treatment of malaria and have been reported to have multiple pharmacological activities, including anticancer, antiviral, and immune modulation. Considering the reported broad-spectrum antiviral potential of artemisinins, researchers are interested in whether they could be used to combat COVID-19. We systematically evaluated the anti-SARS-CoV-2 activities of nine artemisinin-related compounds in vitro and carried out a time-of-drug-addition assay to explore their antiviral mode of action. Finally, a pharmacokinetic prediction model was established to predict the therapeutic potential of selected compounds against COVID-19. Arteannuin B showed the highest anti-SARS-CoV-2 potential with an EC50 of 10.28 ± 1.12 μM. Artesunate and dihydroartemisinin showed similar EC50 values of 12.98 ± 5.30 μM and 13.31 ± 1.24 μM, respectively, which could be clinically achieved in plasma after intravenous administration. Interestingly, although an EC50 of 23.17 ± 3.22 μM was not prominent among the tested compounds, lumefantrine showed therapeutic promise due to high plasma and lung drug concentrations after multiple dosing. Further mode of action analysis revealed that arteannuin B and lumefantrine acted at the post-entry step of SARS-CoV-2 infection. This research highlights the anti-SARS-CoV-2 potential of artemisinins and provides leading candidates for anti-SARS-CoV-2 drug research and development.

Artemisia annua, a Traditional Plant Brought to Light

Traditional remedies have been used for thousand years for the prevention and treatment of infectious diseases, particularly in developing countries. Of growing interest, the plant Artemisia annua, known for its malarial properties, has been studied for its numerous biological activities including metabolic, anti-tumor, anti-microbial and immunomodulatory properties. Artemisia annua is very rich in secondary metabolites such as monoterpenes, sesquiterpenes and phenolic compounds, of which the biological properties have been extensively studied. The purpose of this review is to gather and describe the data concerning the main chemical components produced by Artemisia annua and to describe the state of the art about the biological activities reported for this plant and its compounds beyond malaria.

Artemether Regulates Metaflammation to Improve Glycolipid Metabolism in db/db Mice

BACKGROUND

Artemether, a commonly used artemisinin derivative, has been shown to possess potential antidiabetic activities. However, only limited information is available on the mechanisms of artemether in type 2 diabetes. Therefore, in this study, we examined some of the possible mechanisms of artemether (ATM) upon glycolipid metabolism in the db/db mouse model of diabetes.

MATERIALS AND METHODS

Male C57BL/KsJ-db/db and C57BL/KsJ-db/+ mice at 4 weeks of age were divided into four groups (N=6/group): (1) NC (normal control - db/+ mice, 1% methylcellulose, intragastric administration), (2) DM (diabetic model - db/db mice, 1% methylcellulose, intragastric administration), (3) ATM 100 (DM + 100 mg/kg of artemether) and (4) ATM 200 (DM + 200 mg/kg of artemether). A number of assays related to diabetes were then performed following a 4-week period of these treatments.

RESULTS

Artemether at both doses significantly reduced rates of weight gain and fasting blood glucose levels, improved islet function and insulin resistance and reduced serum lipid levels to varying degrees in db/db mice. Artemether exerted a positive effect on islet vacuolar degeneration and hepatic steatosis, and increased expressions of AMP-activated protein kinase, glucose transporter 4 and Insulin receptor β protein in the liver of these db/db mice. With the use of liver protein chip detection, we found that artemether significantly improved the immune microenvironment, down-regulated the expression of inflammatory factors and activated the cytokine-mediated signaling pathway through cytokine-cytokine receptor interactions.

CONCLUSION

Artemether may regulate glycolipid metabolism in db/db mice by improving the immune microenvironment. The results of this study provide important new information that can serve as the foundation for future research into the use of artemether as a means to improve glycolipid metabolism.

Effects of various antimicrobial agents on multi-directional differentiation potential of bone marrow-derived mesenchymal stem cells

Antimicrobial drugs of several classes play an important role in the treatment of bone and joint infections. In addition to fighting pathogenic microorganisms, the effects of drugs on local tissues and cells are also related to the course and prognosis of bone and joint infections. The multi-directional differentiation potential of bone marrow-derived mesenchymal stem cells (MSCs) is essential for tissue repair after local injury, which is directly related to the recovery of bone, cartilage, and medullary adipose tissue. Our previous studies and the literature indicate that certain antimicrobial agents can regulate the differentiation potential of bone marrow-derived MSCs. Here, in order to systematically analyze the effects of various antimicrobial drugs on local tissue regeneration, we comprehensively review the studies on the effects of these drugs on MSC differentiation, and classify them according to the three differentiation directions (osteogenesis, chondrogenesis, and adipogenesis). Our review demonstrates the specific effects of different antimicrobial agents on bone marrow-derived MSCs and the range of concentrations at which they work, and provides a basis for drug selection at different sites of infection.

Bicyclic eremophilane-type petasite sesquiterpenes potentiate peroxisome proliferator-activated receptor γ activator-mediated inhibition of dendritic cells

Dendritic cell (DC) activation induces expression of co-stimulatory surface molecules, as well as migration into secondary lymphoid organs, where they activate naïve T-cells. A family of plant derivatives, eremophilane-type petasite sesquiterpenes, can regulate the immune system through DC targeting due to their anti-inflammatory effects. Peroxisome proliferator–activated receptor gamma (PPARγ) is involved in inhibition of inflammatory responses and induction of DCs to acquire a mucosal phenotype. Since mucosal DCs are central in innate immune responses, we hypothesized that eremophilane-type petasite sesquiterpenes exerted their anti-inflammatory effects by inhibiting DC maturation and activation through PPARγ. This study assessed the bicyclic eremophilane-type petasite sesquiterpene compounds Fukinone and 10βH-8α,12-Epidioxyeremophil-7(11)-en-8β-ol (ZYFDC21 and ZYFDC22) in the maturation and activation of mouse DC. We measured surface expression of co-stimulatory molecules by flow cytometry and cell-free supernatant cytokine production upon lipopolysaccharide stimulation by enzyme-linked immunosorbent assays (ELISAs) in the presence or absence of PPARγ agonists. DCs were generated from C57BL/6 mice bone marrow cells and harvested. Cells were exposed to bicyclic eremophilane-type petasite sesquiterpenes ZYFDC21 or ZYFDC22 in the presence or absence of synthetic PPARγ agonists (GW1929 and TGZ) or the natural PPARγ ligand 15d-PGJ₂, followed by overnight activation with LPS. We observed differences in the upregulation of surface expression of CD86, along with TNF, IL-6, and IL-12p70 released by DCs stimulated with LPS, when using combinations of bicyclic eremophilane-type petasite sesquiterpenes ZYFDC21 or ZYFDC22, and PPARγ agonists, in particular the PPARγ ligand 15d-PGJ₂. Our results indicate that bicyclic eremophilane-type petasite sesquiterpenes ZYFDC21 or ZYFDC22 inhibit maturation and activation of DC, and this activity is augmented upon PPARγ activation.

Chinese Medicine in the Battle Against Obesity and Metabolic Diseases

Obesity is a multi-factor chronic disease caused by the mixed influence of genetics, environments and an imbalance of energy intake and expenditure. Due to lifestyle changes, modern society sees a rapid increase in obesity occurrence along with an aggravated risk of metabolic syndromes in the general population, including diabetes, hepatic steatosis, cardiovascular diseases and certain types of cancer. Although obesity has become a serious worldwide public health hazard, effective and safe drugs treating obesity are still missing. Traditional Chinese medicine (TCM) has been implicated in practical use in China for thousands of years and has accumulated substantial front line experience in treating various diseases. Compared to western medicine that features defined composition and clear molecular mechanisms, TCM is consisted with complex ingredients from plants and animals and prescribed based on overall symptoms and collective experience. Because of their fundamental differences, TCM and western medicine were once considered irreconcilable. However, nowadays, sophisticated isolation technologies and deepened molecular understanding of the active ingredients of TCM are gradually bridging the gap between the two, enabling the identification of active TCM components for drug development under the western-style paradigms. Thus, studies on TCM open a new therapeutic avenue and show great potential in the combat against obesity, though challenges exist. In this review, we highlight six key candidate substances derived from TCM, including artemisinin, curcumin, celastrol, capsaicin, berberine and ginsenosides, to review their recent discoveries in the metabolic field, with special focus on their therapeutic efficacy and molecular mechanisms in treating obesity and metabolic diseases. In addition, we discuss the translational challenges and perspectives in implementing modern Chinese medicine into the western pharmaceutical industry.

Antidiabetic and Antiobesity Effects of Artemether in db/db Mice

This study is designed to investigate the effect of artemether on type 2 diabetic db/db mice. The experiments consisted of three groups: normal control (NC, db/+, 1% methylcellulose, intragastric administration), diabetic control (DM, db/db, 1% methylcellulose, intragastric administration), and artemether treated (artemether, db/db, 200 mg/kg of artemether, intragastric administration). The treatment lasted for two weeks. The food intake, body weight, and fasting blood glucose of mice were measured every three days. At the start and end of the experiment, the intraperitoneal glucose tolerance test (IPGTT) and insulin tolerance test (IPITT) were performed. We determined the serum insulin and glucagon levels by ELISA kits and calculated insulin resistance index (HOME-IR). HE staining was used to observe the morphologies of pancreas and liver in mice. The damage of pancreatic beta cells was evaluated by TUNEL staining and immunofluorescence. We found the following: (1) compared with the DM group, the food intake and weight increase rate of artemether group significantly reduced (P < 0.05); (2) compared with pretreatment, artemether significantly reduced the fasting blood glucose levels, and the areas under the curves (AUCs) of IPGTT were decreased significantly, increasing the tolerance to glucose of db/db mice. (P < 0.05); (3) artemether improved hyperinsulinemia and decreased the AUCs of IPITT and HOME-IR, increasing the insulin sensitivity of db/db mice. (4) Artemether significantly ameliorated islet vacuolar degeneration and hepatic steatosis in db/db mice. (5) Artemether reduced the apoptosis of pancreatic beta cells and increased insulin secretion in db/db mice compared with DM group (P < 0.05). Our results indicated that artemether significantly improved glucose homeostasis and insulin resistance and had the potential activity to prevent obesity, reduced the severity of fatty liver, and protected pancreatic beta cells, promising to treat type 2 diabetes.

Constitutive activation of p46JNK2 is indispensable for C/EBPδ induction in the initial stage of adipogenic differentiation

Adipogenic differentiation plays a vital role in energy homeostasis and endocrine system. Several transcription factors, including peroxisome proliferator-activated receptor gamma 2 and CCAAT-enhancer-binding protein (C/EBP) α, β, and δ, are important for the process, whereas the stage-specific intracellular signal transduction regulating the onset of adipogenesis remains enigmatic. Here, we explored the functional role of c-jun N-terminal kinases (JNKs) in adipogenic differentiation using in vitro differentiation models of 3T3-L1 cells and primary adipo-progenitor cells. JNK inactivation with either a pharmacological inhibitor or JNK2-specific siRNA suppressed adipogenic differentiation, characterized by decreased lipid droplet appearance and the down-regulation of Adiponectin, fatty acid protein 4 (Fabp4), Pparg2, and C/ebpa expressions. Conversely, increased adipogenesis was observed by the inducible overexpression of p46JNK2 (JNK2-1), whereas it was not observed by that of p54JNK2 (JNK2-2), indicating a distinct role of p46JNK2. The essential role of JNK appears restricted to the early stage of adipogenic differentiation, as JNK inhibition in the later stages did not influence adipogenesis. Indeed, JNK phosphorylation was significantly induced at the onset of adipogenic differentiation. As for the transcription factors involved in early adipogenesis, JNK inactivation significantly inhibited the induction of C/ebpd, but not C/ebpb, during the initial stage of adipogenic differentiation. JNK activation increased C/ebpd mRNA and protein expression through the induction and phosphorylation of activating transcription factor 2 (ATF2) that binds to a responsive element within the C/ebpd gene promoter region. Taken together, these data indicate that constitutive JNK activity is specifically required for the initial stage differentiation events of adipocytes.

Neuronal maturation in the hippocampal dentate gyrus via chronic oral administration of Artemisa annua extract is independent of cyclooxygenase 2 signaling pathway in diet-induced obesity mouse model

Recently, we reported that Artemisia annua (AA) has anti-adipogenic properties in vitro and in vivo. Reduction of adipogenesis by AA treatment may dampen systemic inflammation and protect neurons from cytokine-induced damage. Therefore, the present study was undertaken to assess whether AA increases neuronal maturation by reducing inflammatory responses, such as those mediated by cyclooxygenase 2 (COX-2). Mice were fed normal chow or a high-fat diet with or without chronic daily oral administration of AA extract (0.2 g/10 mL/kg) for 4 weeks; then, changes in their hippocampal dentate gyri were measured via immunohistochemistry/immunofluorescence staining for bromodexoxyuridine, doublecortin, and neuronal nuclei, markers of neuronal maturation, and quantitative western blotting for COX-2 and Iba-1, in order to assess correlations between systemic inflammation (interleukin-6) and food type. Additionally, we tested the effect of AA in an Alzheimer's disease model of Caenorhabditis elegans and uncovered a potential benefit. The results show that chronic AA dosing significantly increases neuronal maturation, particularly in the high-fat diet group. This effect was seen in the absence of any changes in COX-2 levels in mice given the same type of food, pointing to the possibility of alternate anti-inflammatory pathways in the stimulation of neurogenesis and neuro-maturation in a background of obesity.

Annual Wormwood Leaf Inhibits the Adipogenesis of 3T3-L1 and Obesity in High-Fat Diet-Induced Obese Rats

Annual wormwood (AW) (Artemisia annua L.) has anti-malarial, anti-bacterial, anti-oxidant, anti-tumour, and anti-inflammatory activities. In the present study, we evaluated the effects of annual wormwood leaves (AWL) on adipocyte differentiation in 3T3-L1 cells and high-fat diet (HFD)-induced obese rats. 3T3-L1 adipocytes and HFD-induced obese rats were treated with AWL, and its effect on gene expression was analyzed using RT-PCR and Western blotting experiments. Treatment with AWL effectively prevented triglyceride accumulation during adipogenesis in a dose-dependent manner. Consistently, AWL suppressed the differentiation of 3T3-L1 preadipocytes into adipocytes through the downregulation of dexamethasone, 3-isobutyl-1- methylxanthine, and insulin (DMI)-induced serine/threonine kinase protein kinase B (PKB/Akt) activation and the expression of adipogenic genes, including the CCAAT/enhancer binding protein-α (C/EBPα) and peroximal proliferator-activated receptor-γ (PPARγ). Moreover, the expression of adipocyte fatty acid-binding protein 4 (aP2), which is a known PPARγ-target gene, was downregulated by AWL treatment. Oral administration of AWL extracts significantly decreased the body weight gain, adipose tissue mass, adipocyte cell size, serum triglyceride (TG), and total cholesterol (TC) levels in HFD-induced obese rats. These results provide novel insight into the molecular mechanisms underlying the anti-obesity effects of AWL that are mediated by the downregulation of the expression of major adipogenic transcription factors, C/EBPα and PPARγ and Akt signalling.

Anti-adipogenic effect of Artemisia annua in diet-induced-obesity mice model

Obesity has increased continuously in western countries during the last several decades and recently become a problem in developing countries. Currently, anti-obesity drugs originating from natural products are being investigated for their potential to overcome adverse effects associated with chemical drugs. Artemisinic acid, which was isolated from the well-known anti-malaria herb Artemisia annua (AA) L., was recently shown to possess anti-adipogenic effects in vitro. However, the anti-adipogenic effects of AA in animal models have not yet been investigated. Therefore, we conducted daily oral administration with AA water extract in a diet-induced obesity animal model and treated 3T3-L1 cells with AA to confirm the anti-adipogenic effects in the related protein expressions. We then evaluated the physiology, adipose tissue histology and mRNA expressions of many related genes. Inhibition of adipogenesis by the AA water extract was observed in vitro. In the animal model, weight gain was significantly lower in the AA treated group, but there were no changes in food intake volume or calories. Reductions in lipid droplet size and mRNA expression associated with adipogenesis were also observed in animal epididymal fat. This study is the first to report that AA has an anti-obese effects in vivo.

CXCL3 positively regulates adipogenic differentiation

Chemokines are a family of cytokines inducing cell migration and inflammation. Recent reports have implicated the roles of chemokines in cell differentiation. However, little is known about the functional roles of chemokines in adipocytes. Here, we explored gene expression levels of chemokines and chemokine receptors during adipogenic differentiation. We have found that two chemokines, chemokine (C-X-C motif) ligand 3 (CXCL3) and CXCL13, as well as CXC chemokine receptor 2 (CXCR2), a CXCL3 receptor, are highly expressed in mature adipocytes. When 3T3-L1 cells and ST2 cells were induced to differentiate, both the number of lipid droplets and the expression levels of adipogenic markers were significantly promoted by the addition of CXCL3, but not CXCL13. Conversely, gene knockdown of either CXCL3 or CXCR2 by specific siRNA effectively inhibited the course of adipogenic differentiation. CXCL3 treatment of 3T3-L1 cells significantly induced the phosphorylation of ERK and c-jun N-terminal kinase (JNK). Furthermore, CXCL3-induced CCAAT-enhancer binding protein (C/EBP)β and δ expression was suppressed by both ERK and JNK-specific inhibitors. Furthermore, chromatin immunoprecipitation assay revealed functional binding of PPARγ2 within the cxcl3 promoter region. Taken together, these results have indicated that CXCL3 is a novel adipokine that facilitates adipogenesis in an autocrine and/or a paracrine manner through induction of c/ebpb and c/ebpd.

Apple ethanol extract promotes proliferation of human adult stem cells, which involves the regenerative potential of stem cells

Tissue regeneration using adult stem cells (ASCs) has significant potential as a novel treatment for many degenerative diseases. Previous studies have established that age negatively affects the proliferation status and differentiation potential of ASCs, suggesting a possible limitation in their potential therapeutic use. Therefore, we hypothesized that apple extract might exert beneficial effects on ASCs. The specific objectives were to investigate the proliferative effect of apple ethanol extract on human adipose tissue-derived mesenchymal stem cells (ADSCs) and human cord blood-derived mesenchymal stem cells (CB-MSCs), and identify the possible molecular mechanisms. Apple extract promoted proliferation of ADSCs and CB-MSCs as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Click-iT 5-ethynyl-2'-deoxyuridine flow cytometry assays. In addition, phosphorylation of p44/42 MAPK (ERK), mammalian target of rapamycin (mTOR), p70 S6 kinase (p70S6K), S6 ribosomal protein (S6RP), eukaryotic initiation factor (eIF) 4B and eIF4E was induced stepwise in ADSCs. Furthermore, apple extract significantly induced the production of vascular endothelial growth factor and interleukin-6 in both ADSCs and CB-MSCs. Similarly, apple extract-induced phosphorylation of the mTOR/p70S6K/S6RP/eIF4B/eIF4E pathway was blocked by pretreatment with PD98059, a specific ERK inhibitor. These results indicate that apple extract-induced proliferation of ADSCs under serum-free conditions is mediated by ERK-dependent cytokine production. Moreover, the beneficial effect of apple extract on proliferation of ASCs may overcome the limitation in therapeutic use of stem cells in tissue regeneration and maintenance of stem cell homeostasis.

Artemisinic acid inhibits melanogenesis through downregulation of C/EBP α-dependent expression of HMG-CoA reductase gene

Cholesterol is associated with the regulation of melanogenesis which is the major physiological defense against solar irradiation. The present study was designed to determine the effects of artemisinic acid on melanogenesis and its mechanisms of action in human epidermal melanocytes. In this study, we found that artemisinic acid inhibited melanin content. The mRNA levels of microphthalmia-associated transcription factor (MITF) and its downstream genes tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2 were reduced by artemisinic acid treatment. Additionally, the mRNA levels of melanogenesis-related genes (c-KIT, stem cell factor (SCF), and macrophage migration inhibitory factor (MIF)) were down-regulated by artemisinic acid. Furthermore, cAMP production and protein kinase A (PKA) activity were suppressed by artemisinic acid. Moreover, attempts to elucidate a possible mechanism underlying the artemisinic acid-mediated effects revealed that artemisinic acid regulated melanogenesis by inhibiting cholesterol synthesis through downregulation of the hydroxymethylglutaryl CoA (HMG CoA) reductase gene, which was mediated through reduced expression of the CCAAT/enhancer-binding protein (C/EBP) α gene. Taken together, these findings indicate that the inhibition of melanogenesis by artemisinic acid occurs through reduced expression of the HMG CoA reductase gene, which is mediated by C/EBP α inhibition and suggest that artemisinic acid may be useful as a hyperpigmentation inhibitor.