Acacetin from Traditionally Used Saussurea involucrata Kar. et Kir. Suppressed Adipogenesis in 3T3-L1 Adipocytes and Attenuated Lipid Accumulation in Obese Mice

Mechanism of acacetin regulating hepatic stellate cell apoptosis based on network pharmacology and experimental verification

Background

Hepatic fibrosis is caused by various liver diseases and eventually develops into liver cancer. There is no specific drug approved for the treatment of hepatic fibrosis in the world. Acacetin (AC), a natural flavonoid, is widely present in nature in various plants, such as black locust, Damiana, Silver birch. It has been reported that acacetin can inhibit the proliferation of cancer cells and induce apoptosis.

Purpose

In this study, we investigated the effect of acacetin on hepatic stellate cell apoptosis, thereby improving hepatic fibrosis, and combined experimental validation and molecular docking to reveal the underlying mechanism.

Result

First, we discovered that acacetin inhibited hepatic stellate cell proliferation as well as the expression of fibrosis-related proteins α-smooth muscle actin (α-SMA) and collagen type I 1 gene (COL1A1) in LX2 cells. Acacetin was then found to promote apoptosis of hepatic stellate cells through the caspase cascade pathway. Network pharmacology screening showed that TP53, CASP3, CASP8, BCL2, PARP1, and BAX were the most important targets related to apoptosis in the PPI network. GO and KEGG analyses of these six important targets were performed, and the top 10 enriched biological processes and related signaling pathways were revealed. Further network pharmacology analysis proved that apoptosis was involved in the biological process of acacetin's action against hepatic stellate cells. Finally, molecular docking revealed that acacetin binds to the active sites of six apoptotic targets. In vitro experiments further confirmed that acacetin could promote the apoptosis of LX2 cells by inducing the activation of P53, thereby improving hepatic fibrosis.

Conclusion

acacetin induces P53 activation and promotes apoptosis of hepatic stellate cells thereby ameliorating hepatic fibrosis.

Acacetin protects against sepsis-induced acute lung injury by facilitating M2 macrophage polarization via TRAF6/NF-κB/COX2 axis

Acute lung injury (ALI) is the leading cause of death in patients with sepsis syndrome and without effective protective or therapeutic treatments. Acacetin, a natural dietary flavonoid, reportedly exerts several biological effects, such as anti-tumor, anti-inflammatory, and anti-oxidative effects. However, acacetin's effect and underlying mechanism on sepsis-induced ALI remain unclear. Here, the mouse model was established to explore the impact of acacetin on sepsis-induced ALI. Acacetin significantly increased ALI murine survival and attenuated lung injury in histological examinations. Additionally, acacetin down-regulated myeloperoxidase activity, protein concentration, and number of neutrophils and macrophages in bronchoalveolar lavage fluid. Subsequently, inflammatory cytokines, including TNF-α, IL-1β, and IL-6, were examined. Results showed that acacetin dramatically suppressed the production of TNF-α, IL-1β, and IL-6. These above results indicated that acacetin attenuated sepsis-induced ALI by inhibiting the inflammatory response. Moreover, acacetin inhibited the expression of markers for M1-type (iNOS, CD86) macrophages and promoted the expression of markers for M2-type (CD206, Arg1) macrophages by western blot. In addition, acacetin down-regulated the expression TRAF6, NF-κB, and Cyclooxygenase-2 (COX2) by western blot. The high concentration of acacetin had a better effect than the low concentration. Besides, over-expression of TRAF6 up-regulated the expression of COX2, CD86, and iNOS, and the ratio of p-NF-κB to NF-κB increased the mRNA levels of TNF-α, IL-1β, and IL-6, down-regulated the expression of CD206 and Arg1. The effects of TRAF6 were the opposite of acacetin. And TRAF6 could offset the impact of acacetin. This study demonstrated that acacetin could prevent sepsis-induced ALI by facilitating M2 macrophage polarization via TRAF6/NF-κB/COX2 axis.

Hydroxylated polymethoxyflavones reduce the activity of pancreatic lipase, inhibit adipogenesis and enhance lipolysis in 3T3-L1 mouse embryonic fibroblast cells

Hydroxylated polymethoxyflavones (HPMFs) have been shown to possess various anti-disease effects, including against obesity. This study investigates the anti-obesity effects of HPMFs in further detail, aiming to gain understanding of their mechanism of action in this context. The current study demonstrates that two HPMFs; 3'-hydroxy-5,7,4',5'-tetramethoxyflavone (3'OH-TetMF) and 4'-hydroxy-5,7,3',5'-tetramethoxyflavone (4'OH-TetMF) possess anti-obesity effects. They both significantly reduced pancreatic lipase activity in a competitive manner as demonstrated by molecular docking and kinetic studies. In cell studies, it was revealed that both of the HPMFs suppress differentiation of 3T3-L1 mouse embryonic fibroblast cells during the early stages of adipogenesis. They also reduced expression of key adipogenic and lipogenic marker genes, namely peroxisome proliferator-activated receptor-gamma (PPAR-γ), CCAAT/enhancer-binding protein α and β (C/EBP α and β), adipocyte binding protein 2 (aP2), fatty acid synthase (FASN), and sterol regulatory element-binding protein 1 (SREBF 1). They also enhanced the expression of cell cycle genes, i.e., cyclin D1 (CCND1) and C-Myc, and reduced cyclin A2 expression. When further investigated, it was also observed that these HPMFs accelerate lipid breakdown (lipolysis) and enhance lipolytic gene expression. Moreover, they also reduced the secretion of proteins (adipokines), including pro-inflammatory cytokines, from mature adipocytes. Taken together, this study concludes that these HPMFs have anti-obesity effects, which are worthy of further investigation.

Acacetin attenuates the pancreatic and hepatorenal dysfunction in type 2 diabetic rats induced by high-fat diet combined with streptozotocin

Acacetin is a natural flavonoid compound with multiple therapeutic potential in oxidative stress, inflammation, cancers, cardiovascular disease and infections. The present study aimed to detect the effect of acacetin on pancreatic and hepatorenal dysfunction in type 2 diabetic rats. The diabetic rats were induced by high-fat diet (HFD) followed by intraperitoneal injection of streptozotocin (STZ) at a dose of 45 mg/kg. Different doses of acacetin were orally administrated once a day for 8 weeks after the diabetic model was successfully established. The experimental results revealed that acacetin and acarbose displayed obvious attenuation in the levels of fasting blood glucose (FBG) and lipids compared to the untreated diabetic rats. In addition, the physiological function of liver and kidney was impaired in the persistent environment of hyperglycemia, while acacetin improved the damage of liver and kidney. Furthermore, hematoxylin-eosin (H&E) staining indicated that acacetin alleviated the pathological alterations of the pancreas, liver and kidney tissues. Besides, the increased levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-8 and malondialdehyde (MDA) were recused by acacetin treatment, while the reduction of superoxide dismutase (SOD) levels were suppressed by acacetin treatment. In conclusion, the experimental results demonstrated that acacetin improved the lipids and glucose levels, and hepatorenal antioxidant capacity, as well as ameliorated hepatorenal dysfunction in type 2 diabetic rats, and the potential mechanism might be associated with its antioxidant and anti-inflammatory activities.

Scytosiphon lomentaria Extract Ameliorates Obesity and Modulates Gut Microbiota in High-Fat-Diet-Fed Mice

Scytosiphon lomentaria (SL) is a brown seaweed with antioxidant and anti-inflammatory properties; however, its effects on obesity are unknown. In this research, we investigated the anti-obesity properties and underlying mechanisms of the SL extract in vitro and in vivo. In 3T3-L1 preadipocytes, SL extract inhibited lipid accumulation, decreased the expression of Acc1, C/ebpa, Pparg mRNA and p-ACC1, and increased the expression of Ucp1 mRNA, UCP1 and p-AMPK. In animal experiments, mice were fed a chow diet, a high-fat diet (HF; 60% of calories as fat), and high-fat diet with SL extract (150 and 300 mg/kg body weight) for eight weeks (n = 10/group). SL extract reduced HF-induced weight gain, epididymal fat weight, fat cell size, LDL-C, leptin, fasting glucose, and glucose tolerance. In addition, SL extract had comparable effects on mRNA expression in WAT and liver to those observed in vitro, thereby inhibiting p-ACC1/ACC1 and increasing p-AMPK/AMPK and UCP1 expression. Furthermore, SL extract decreased HF-induced Firmicutes/Bacteroidetes ratio and reversed HF-reduced Bacteroides spp., Bacteroides vulgatus, and Faecalibacterium prausnitzii. These findings suggest that SL extract can aid in weight loss in mice fed a high-fat diet by altering adipogenic and thermogenic pathways, as well as gut microbiota composition.

Anti-Inflammatory Mechanisms of Dietary Flavones: Tapping into Nature to Control Chronic Inflammation in Obesity and Cancer

Flavones are natural phytochemicals broadly distributed in our diet. Their anti-inflammatory properties provide unique opportunities to control the innate immune system and inflammation. Here, we review the role of flavones in chronic inflammation with an emphasis on their impact on the molecular mechanisms underlying inflammatory diseases including obesity and cancer. Flavones can influence the innate immune cell repertoire restoring the immune landscape. Flavones impinge on NF-κB, STAT, COX-2, or NLRP3 inflammasome pathways reestablishing immune homeostasis. Devoid of adverse side effects, flavones could present alternative opportunities for the treatment and prevention of chronic inflammation that contributes to obesity and cancer.

Targeting mTOR Signaling by Dietary Polyphenols in Obesity Prevention

Dietary polyphenols can be utilized to treat obesity and chronic disorders linked to it. Dietary polyphenols can inhibit pre-adipocyte proliferation, adipocyte differentiation, and triglyceride accumulation; meanwhile, polyphenols can also stimulate lipolysis and fatty acid β-oxidation, but the molecular mechanisms of anti-obesity are still unclear. The mechanistic target of rapamycin (mTOR) is a protein kinase that regulates cell growth, survival, metabolism, and immunity. mTOR signaling is also thought to play a key role in the development of metabolic diseases such as obesity. Recent studies showed that dietary polyphenols could target mTOR to reduce obesity. In this review, we systematically summarized the research progress of polyphenols in preventing obesity through the mTOR signaling pathway. Mechanistically, polyphenols can target multiple signaling pathways and gut microbiota to regulate the mTOR signaling pathway to exert anti-obesity effects. The main mechanisms include: modulating lipid metabolism, adipogenesis, inflammation, etc. Dietary polyphenols exerting an anti-obesity effect by targeting mTOR signaling will broaden our understanding of the anti-obesity mechanisms of polyphenols and provide valuable insights for researchers in this novel field.

Potential common mechanism of four Chinese patent medicines recommended by diagnosis and treatment protocol for COVID-19 in medical observation period

The global epidemic has been controlled to some extent, while sporadic outbreaks still occur in some places. It is essential to summarize the successful experience and promote the development of new drugs. This study aimed to explore the common mechanism of action of the four Chinese patent medicine (CPMs) recommended in the Medical Observation Period COVID-19 Diagnostic and Treatment Protocol and to accelerate the new drug development process. Firstly, the active ingredients and targets of the four CPMs were obtained by the Chinese medicine composition database (TCMSP, TCMID) and related literature, and the common action targets of the four TCMs were sorted out. Secondly, the targets of COVID-19 were obtained through the gene-disease database (GeneCards, NCBI). Then the Venn diagram was used to intersect the common drug targets with the disease targets. And GO and KEGG pathway functional enrichment analysis was performed on the intersected targets with the help of the R package. Finally, the results were further validated by molecular docking and molecular dynamics analysis. As a result, a total of 101 common active ingredients and 21 key active ingredients of four CPMs were obtained, including quercetin, luteolin, acacetin, kaempferol, baicalein, naringenin, artemisinin, aloe-emodin, which might be medicinal substances for the treatment of COVID-19. TNF, IL6, IL1B, CXCL8, CCL2, IL2, IL4, ICAM1, IFNG, and IL10 has been predicted as key targets. 397 GO biological functions and 166 KEGG signaling pathways were obtained. The former was mainly enriched in regulating apoptosis, inflammatory response, and T cell activation. The latter, with 92 entries related to COVID-19, was mainly enriched to signaling pathways such as Coronavirus disease-COVID-19, Cytokine-cytokine receptor interaction, IL-17 signaling pathway, and Toll-like receptor signaling pathway. Molecular docking results showed that 19/21 of key active ingredients exhibited strong binding activity to recognized COVID-19-related targets (3CL of SARS-CoV-2, ACE2, and S protein), even better than one of these four antiviral drugs. Among them, shinflavanone had better affinity to 3CL, ACE2, and S protein of SARS-CoV-2 than these four antiviral drugs. In summary, the four CPMs may play a role in the treatment of COVID-19 by binding flavonoids such as quercetin, luteolin, and acacetin to target proteins such as ACE2, 3CLpro, and S protein and acting on TNF, IL6, IL1B, CXCL8, and other targets to participate in broad-spectrum antiviral, immunomodulatory and inflammatory responses.

Acacetin antagonized lipotoxicity in pancreatic β-cells via ameliorating oxidative stress and endoplasmic reticulum stress

PURPOSE

During the pathogenesis and progression of diabetes, lipotoxicity is a major threat to the function and survival of pancreatic β-cells. To battle against the lipotoxicity induced cellular damages, the present study investigated the beneficial effects of acacetin, a natural antioxidant, on free fatty acid (FFA) stressed RINm5F cells and the potential mechanism involved.

MATERIALS AND METHODS

RINm5F cells with or without 1 h pretreatment of acacetin were treated with 0.35 mM sodium palmitate for 24 h. Cell viability, intracellular reactive oxygen species (ROS) level, antioxidant capacity, cellular apoptosis, and endoplasmic reticulum (ER) stress biomarker expression were investigated.

RESULTS

Our experiments demonstrated that acacetin treatment significantly scavenged the intracellular ROS, upregulated the endogenous antioxidant enzymes, and diminished the sub-G₁ DNA fraction in the cells exposed to FFA, suggesting its efficacy against oxidative stress. Meanwhile, acacetin treatment significantly mitigated the overload of intracellular Ca²⁺ and reduced the pro-apoptotic protein expression in the FFA stimulated cells, and thereby attenuated the ER stress-mediated cell apoptosis. Furthermore, siRNA interference results confirmed that the suppressing of C/EBP-homologous protein (CHOP) was critical to improve FFA-induced reduction in cell viability and ameliorated the ER stress caused by FFA stimulation.

CONCLUSIONS

Acacetin may antagonize lipotoxicity in pancreatic cells by attenuating the oxidative stress and ER stress.

Acacetin Protects against Non-Alcoholic Fatty Liver Disease by Regulating Lipid Accumulation and Inflammation in Mice

We previously demonstrated that acacetin reduces adipogenesis in adipocytes, and decreases lipid accumulation in visceral adipocyte tissue. Here we investigated whether acacetin regulated the mechanisms of lipogenesis and inflammation in non-alcoholic fatty liver disease (NAFLD) in obese mice. Male C57BL/6 mice were fed a high-fat diet (HFD), and then administered acacetin by intraperitoneal injection. Acacetin reduced body weight and liver weight in obese mice. Acacetin-treated obese mice exhibited decreased lipid accumulation, increased glycogen accumulation, and improved hepatocyte steatosis. Acacetin regulated triglycerides and total cholesterol in the liver and serum. Acacetin decreased low-density lipoprotein and leptin concentrations, but increased high-density lipoprotein and adiponectin levels in obese mice. Acacetin effectively weakened the gene expressions of transcription factors related to lipogenesis, and promoted the expressions of genes related to lipolysis and fatty acid β-oxidation in liver. Acacetin also reduced expressions of inflammation-related cytokines in the serum and liver. Oleic acid induced lipid accumulation in murine FL83B hepatocytes, and the effects of acacetin treatment indicated that acacetin may regulate lipid metabolism through the AMPK pathway. Acacetin may protect against hepatic steatosis by modulating inflammation and AMPK expression.

Protective Roles of Apigenin Against Cardiometabolic Diseases: A Systematic Review

Apigenin is a flavonoid with antioxidant, anti-inflammatory, and anti-apoptotic activity. In this study, the potential effects of apigenin on cardiometabolic diseases were investigated in vivo and in vitro. Potential signaling networks in different cell types induced by apigenin were identified, suggesting that the molecular mechanisms of apigenin in cardiometabolic diseases vary with cell types. Additionally, the mechanisms of apigenin-induced biological response in different cardiometabolic diseases were analyzed, including obesity, diabetes, hypertension and cardiovascular diseases. This review provides novel insights into the potential role of apigenin in cardiometabolic diseases.

The liver metabolic features of Mogroside V compared to Siraitia grosvenorii fruit extract in allergic pneumonia mice

BACKGROUND

For a long time, Siraitia grosvenorii fruit extract (SGFE) and its dominant compounds, mogroside V(MV) were both reported to have therapeutic effects on allergic pneumonia, while previous studies only stay on phenotype and mechanism of the two active ingredients, hardly have any studies compared the two ingredients on the effect of liver metabolic, and revealed the relationship between mechanism and liver metabolism.

OBJECTIVE

Here we elucidated and compared the curative mechanisms of SGFE and MV on allergic pneumonia through liver metabolomics.

METHODS

We established allergic pneumonia mice using ovalbumin, then treated the mice with SGFE, MV and positive drug of Suhuang Zhike Jiaonang. The effects of the drugs were evaluated by detecting inflammatory cytokines, pathological examination and liver oxidative stress biomarkers. We explored the metabolic features between SGFE and MV through liver metabolomics consequently.

RESULTS

At phenotype, we confirmed that MV and SGFE both inhibited the expression of inflammatory cytokines including interleukins-5 (IL-5), IL-13, IL-17 and OVA-induced immunoglobulin E, which can also relieve inflammatory cells infiltration and mesenchymal thickening in lung tissue compared with positive drug. In addition, both of them can alleviate oxidative stress damage in liver, while MV showed a superior effect than SGFE. In metabolomic analysis, the two ingredients were found to ameliorate inflammatory and oxidative reaction mainly in controlling pathways of Riboflavin metabolism and Glutathione metabolism. While SGFE were found to control other metabolic pathways such as Phenylalanine metabolism, Sphingolipid metabolism, Glycerollipid metabolism, Glycine, serine and threonine metabolism and Arginine and proline metabolism.

CONCLUSION

From the results we can infer that the minor ingredients except MV in SGFE contribute poor function to the treatment of allergic pneumonia and MV may be the main functional constituent that relieve allergic pneumonia in SGFE. This study will be beneficial to figuring out a systematic theory of Siraitia grosvenorii active ingredients and proposing a guidance for pharmacology development.

Acacetin ameliorates cardiac hypertrophy by activating Sirt1/AMPK/PGC-1α pathway

Cardiac hypertrophy is a major risk factor for developing heart failure. This study investigates the effects of the natural flavone acacetin on myocardial hypertrophy in cellular level and whole animals. In cardiomyocytes from neonatal rat with hypertrophy induced by angiotensin II (Ang II), acacetin at 0.3, 1, and 3 μM reduced the increased myocyte surface area, brain natriuretic peptide (BNP), and ROS production by upregulating anti-oxidative molecules (i.e. Nrf2, SOD1, SOD2, HO-1), anti-apoptotic protein Bcl-2, and downregulating the pro-apoptotic protein Bax and the inflammatory cytokine IL-6 in a concentration-dependent manner. In addition, acacetin rescued Ang II-induced impairment of PGC-1α, PPARα and pAMPK. These beneficial effects of acacetin were mediated by activation of Sirt1, which was confirmed in cardiac hypertrophy induced by abdominal aorta constriction (AAC) in SD rats. Acacetin prodrug (10 mg/kg, s.c., b.i.d.) treatment reduced the elevated artery blood pressure, improved the increased heart size and thickness of left ventricular wall and the ventricular fibrosis associated with inhibiting myocardial fibrosis and BNP, and reversed the impaired protective signal molecules including PGC-1α, Nrf2, PPARα, pAMPK and Sirt1 of left ventricular tissue. Our results demonstrate the novel pharmacological effect that acacetin ameliorates cardiac hypertrophy via Sirt1-mediated activation of AMPK/PGC-1α signal molecules followed by reducing oxidation, inflammation and apoptosis.

Agastache rugosa Extract and Its Bioactive Compound Tilianin Suppress Adipogenesis and Lipogenesis on 3T3-L1 Cells

Agastache rugosa, or Korean mint, is an herb used as a spice, food additive and traditional medicinal ingredient. It has desirable effects, such as its antibacterial, antifungal and antioxidant properties. A. rugosa contains many phenolic compounds studied for their various health benefits, with the primary components being tilianin. A. rugosa extract (ARE), which was extracted with ethanol and freeze-dried, contained 21.14 ± 0.15 mg/g of tilianin with a total polyphenol content of 38.11 ± 0.88 mg/g. Next, the antiadipogenic effect of A. rugosa and tilianin was clarified using 3T3-L1 cells, which differentiate into adipocytes and develop lipid droplets. 3T3-L1 cells were treated with ARE or tilianin and lipid accumulation (%) was calculated through oil red O staining. Tilianin elicited dose-dependent decrease in lipid accumulation (% of positive control) (30 μM 92.10 ± 1.19%; 50 μM 69.25 ± 1.78%; 70 μM 54.86 ± 1.76%; non-differentiation 18.10 ± 0.32%), assessed by oil-red-O staining, whereas ARE treatments caused consistent diminution in lipid accumulation regardless of dose (100 μM 86.90 ± 4.97%; 200 μM 87.25 ± 4.34%; 400 μM 88.54 ± 2.27%; non-differentiation 17.96 ± 1.30%), indicating that both compounds have anti-obesity effects on adipocytes. Treatment with ARE lowered the mRNA (PPARγ; C/EBPα; FABP4; SREBP1; ACC; FAS) and protein (PPARγ; C/EBPα; SREBP1) levels of adipogenesis and lipogenesis-related factors. Tilianin showed a greater effect on the mRNA levels compared with ARE. Thus, tilianin and ARE may have anti-adipogenic and anti-lipogenic effects on 3T3-L1 cells and be possible candidates of obesity-related supplements.

Cardiac senescence is alleviated by the natural flavone acacetin via enhancing mitophagy

Cardiac senescence is associated with cardiomyopathy which is a degenerative disease in the aging process of the elderly. The present study investigates using multiple experimental approaches whether the natural flavone acacetin could attenuate myocardial senescence in C57/BL6 mice and H9C2 rat cardiac cells induced by D-galactose. We found that the impaired heart function in D-galactose-induced accelerated aging mice was improved by oral acacetin treatment in a dose-dependent manner. Acacetin significantly countered the increased serum advanced glycation end products, the myocardial telomere length shortening, the increased cellular senescence marker proteins p21 and p53, and the reduced mitophagy signaling proteins PINK1/Parkin and Sirt6 expression in aging mice. In H9C2 rat cardiac cells, acacetin alleviated cell senescence induced by D-galactose in a concentration-dependent manner. Acacetin decreased p21 and p53 expression, up-regulated PINK1/Parkin, LC3II/LC3I ratio, pLKB1, pAMPK and Sirt6, and reversed the depolarized mitochondrial membrane potential in aging cardiac cells. Mitophagy inhibition with 3-methyladenine or silencing Sirt6 abolished the protective effects of acacetin against cardiac senescence. Further analysis revealed that acacetin effect on Sirt6 was mediated by Sirt1 activation and increase of NAD+/NADH ratio. These results demonstrate that acacetin significantly inhibits in vivo and in vitro cardiac senescence induced by D-galactose via Sirt1-mediated activation of Sirt6/AMPK signaling pathway, thereby enhancing mitophagy and preserving mitochondrial function, which suggests that acacetin may be a drug candidate for treating cardiovascular disorders related to aging.

Acacetin ameliorates insulin resistance in obesity mice through regulating Treg/Th17 balance via MiR-23b-3p/NEU1 Axis

BACKGROUND

The role of miR-23b-3p in insulin resistance (IR) remained poorly understood.

METHODS

After acacetin injection, obesity-induced IR model was constructed with or without miR-23b-3p upregulation and Neuraminidase 1 (NEU1) overexpression in mice. Body weight, serum metabolite and fat percent of the mice were measured. Tests on oral glucose and insulin tolerance were performed, and inflammatory cytokines C-reactive protein (CRP), Interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein 1 (MCP1) levels were quantified with enzyme-linked immunosorbent assay (ELISA). The binding sites between miR-23b-3p and NEU1 were predicted by TargetScan, and verified using dual-luciferase reporter assay. Relative expressions were detected with quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Proportion of Treg and Th17 cells in total CD4+ T cells was detected with flow cytometry.

RESULTS

MiR-23b-3p offset the effects of acacetin on body weight, fat percent, inflammatory cytokines levels and expressions of markers of regulatory T cells (Treg cells) and T helper 17 cells (Th17 cells), NEU1 and miR-23b-3p. NEU1 was a target of miR-23b-3p, and overexpressed NEU1 reversed the effects of upregulated miR-23b-3p on reducing Treg cells but increased body weight, fat percent and inflammatory cytokines levels, percentage of Th17 cells, and upregulated NEU1 expression.

CONCLUSION

Upregulation of miR-23b-3p offset the effects of acacetin on obesity-induced IR through regulating Treg/Th17 cell balance via targeting NEU1.The present findings provide a possible prevention strategy for obesity-induced IR.

Acacetin Ameliorates Experimental Colitis in Mice via Inhibiting Macrophage Inflammatory Response and Regulating the Composition of Gut Microbiota

Acacetin, a natural dietary flavonoid abundantly found in acacia honey and citrus fruits, reportedly exerts several biological effects, such as anti-tumor, anti-inflammatory, and anti-oxidative effects. However, the effects of acacetin on intestinal inflammation remain unclear. We sought to investigate whether acacetin ameliorates inflammatory bowel disease (IBD) in mice with dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). Our results suggest that acacetin alleviates the clinical symptoms of DSS-induced colitis, as determined by body weight loss, diarrhea, colon shortening, inflammatory infiltration, and histological injury. Further studies showed that acacetin remarkably inhibited both the macrophage inflammatory response in vitro and levels of inflammatory mediators in mice with colitis. In addition, some features of the gut microbiota were disordered in mice with DSS-induced colitis, as evidenced by a significant reduction in microbiota diversity and a marked shift in bacterial profiles. However, acacetin treatment improved this imbalance and restored gut microbiota to levels that were similar to those in normal mice. In conclusion, our work presents evidence that acacetin attenuates DSS-induced colitis in mice, at least in part, by inhibiting inflammation and regulating the intestinal microbiota.

Acacetin Protects Against High Glucose-Induced Endothelial Cells Injury by Preserving Mitochondrial Function via Activating Sirt1/Sirt3/AMPK Signals

The strategy of decreasing atherosclerotic cardiovascular disorder is imperative for reducing premature death and improving quality of life in patients with diabetes mellitus. The aim of this study was to investigate whether the natural flavone acacetin could protect against endothelial injury induced by high glucose and attenuate diabetes-accelerated atherosclerosis in streptozotocin-(STZ) induced diabetic ApoE^−/− mice model. It was found that in human umbilical vein endothelial cells (HUVECs) cultured with normal 5.5 mM or high 33 mM glucose, acacetin (0.3–3 μM) exerted strong cytoprotective effects by reversing high glucose-induced viability reduction and reducing apoptosis and excess production of intracellular reactive oxygen species (ROS) and malondialdehyde in a concentration-dependent manner. Acacetin countered high glucose-induced depolarization of mitochondrial membrane potential and reduction of ATP product and mitoBcl-2/mitoBax ratio. Silencing Sirt3 abolished the beneficial effects of acacetin. Further analysis revealed that these effects of acacetin rely on Sirt1 activation by increasing NAD⁺ followed by increasing Sirt3, pAMPK and PGC-1α. In STZ-diabetic mice, acacetin significantly upregulated the decreased signaling molecules (i.e. SOD, Bcl-2, PGC-1α, pAMPK, Sirt3 and Sirt1) in aorta tissue and attenuated atherosclerosis. These results indicate that vascular endothelial protection of acacetin by activating Sirt1/Sirt3/AMPK signals is likely involved in alleviating diabetes-accelerated atherosclerosis by preserving mitochondrial function, which suggests that acacetin may be a drug candidate for treating cardiovascular disorder in patients with diabetes.

The Inhibitory Effects of Juglanin on Adipogenesis in 3T3-L1 Adipocytes

Introduction

Deregulation of adipogenesis plays an important role in obesity and other metabolism disorders. PPAR, C/EBP and SREBP1c are key transcriptional factors involved in adipogenesis and lipogenesis. Juglanin is a natural compound belonging to flavonoids, and it has been reported that juglanin has a potent inhibitory effect on inflammation and certain type of cancers. However, the effects of juglanin in adipogenesis have not been reported before.

Materials and Methods

3T3-L1 preadipocytes were incubated with differentiation induction medium in the presence or absence of 0.5, 2.5, or 5 µM juglanin for an 8-day differentiation period. The lipid droplets accumulated in the cytoplasm were monitored by Oil Red O staining on days 0, 2, 5, and 8. The regulatory effects of juglanin on adipogenesis-related genes and proteins were investigated by real-time polymerase chain reaction and Western blot analysis.

Results

Juglanin significantly decreased lipid accumulation in differentiated adipocytes. Our findings show that juglanin reduced the expression of C/EBPα, C/EBPβ, and SREBP-1c without affecting PPARα or PPARγ expression. Additionally, juglanin increased the activation of the SIRT1/AMPK signaling pathway through the phosphorylation of AMPKα. Finally, we performed an AMPK inhibitor experiment, which revealed that the inhibitory effects of juglanin on adipogenesis are mediated through AMPK.

Discussion

Juglanin can prevent adipogenesis by suppressing lipid accumulation and the differentiation of preadipocytes. The mechanism of juglanin regulating adipogenesis requires further investigation. Future clinical study in vivo could shed more light on its implication in modulating obesity and metabolic disorders.

Acacetin exerts antioxidant potential against atherosclerosis through Nrf2 pathway in apoE-/- Mice

Oxidative stress has a considerable influence on endothelial cell dysfunction and atherosclerosis. Acacetin, an anti-inflammatory and antiarrhythmic, is frequently used in the treatment of myocarditis, albeit its role in managing atherosclerosis is currently unclear. Thus, we evaluated the regulatory effects of acacetin in maintaining endothelial cell function and further investigated whether the flavonoid could attenuate atherosclerosis in apolipoprotein E deficiency (apoE^-/- ) mice. Different concentrations of acacetin were tested on EA.hy926 cells, either induced or non-induced by human oxidized low-density lipoprotein (oxLDL), to clarify its influence on cell viability, cellular reactive oxidative stress (ROS) level, apoptotic ratios and other regulatory effects. In vivo, apoE^-/- mice were fed either a Western diet or a chow diet. Acacetin pro-drug (15 mg/kg) was injected subcutaneously two times a day for 12 weeks. The effects of acacetin on the atherosclerotic process, plasma inflammatory factors and lipid metabolism were also investigated. Acacetin significantly increased EA.hy926 cell viability by reducing the ratios of apoptotic and necrotic cells at 3 μmol/L. Moreover, 3 μmol/L acacetin clearly decreased ROS levels and enhanced reductase protein expression through MsrA and Nrf2 pathway through phosphorylation of Nrf2 and degradation of Keap1. In vivo, acacetin treatment remarkably attenuated atherosclerosis by increasing reductase levels in circulation and aortic roots, decreasing plasma inflammatory factor levels as well as accelerating lipid metabolism in Western diet-fed apoE^-/- mice. Our findings demonstrate the anti-oxidative and anti-atherosclerotic effects of acacetin, in turn suggesting its potential therapeutic value in atherosclerotic-related cardiovascular diseases (CVD).

HM-chromanone inhibits adipogenesis by regulating adipogenic transcription factors and AMPK in 3T3-L1 adipocytes

Portulaca oleracea L. is used as a folk medicine in many countries because of its wide range of pharmacological effects. HM-chromanone, isolated from P. oleracea using bioassay-guided fractionation and HPLC, belongs to the homoisoflavonoid group and has been shown to exert several biological effects. In this study, we evaluated whether HM-chromanone inhibits adipogenesis by regulating adipogenic transcription factors in 3T3-L1 adipocytes. The results showed that HM-chromanone suppresses adipocyte differentiation and adipogenesis in a dose-dependent manner in 3T3-L1 adipocytes. The HM-chromanone-treated adipocytes exhibited lower triglyceride accumulation and leptin secretion, and higher glycerol and adiponectin secretion than the control adipocytes. Microscopic observation using oil red O staining revealed a dose-dependent reduction in the number of lipid droplets in the HM-chromanone-treated adipocytes compared to the control group. HM-chromanone significantly down-regulated the protein expression of major adipogenic transcription factors sterol regulatory element binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor γ (PPARγ), and CCAAT/enhancer binding protein α (C/EBPα) and markedly inhibited several key adipogenic enzymes including fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC). In addition, adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) were both more activated in the HM-chromanone-treated adipocytes than in the control adipocytes. HM-chromanone also promoted the phosphorylation of 5' Adenosine monophosphate-activated protein kinase (AMPK), which inhibits adipogenesis through the regulation of adipogenic transcription factors. These results suggest that HM-chromanone may be an effective anti-adipogenesis agent that functions via the suppression of adipogenic transcription factors and the activation of AMPK.

Acacetin Suppresses IL-1β-Induced Expression of Matrix Metalloproteinases in Chondrocytes and Protects against Osteoarthritis in a Mouse Model by Inhibiting NF-κB Signaling Pathways

Osteoarthritis (OA) is a very common chronic joint dysfunction, and there is currently a poor understanding of its etiology and pathogenesis. Therefore, there are no active disease-modifying drugs currently available for clinical treatment. Several natural compounds have been shown to play a role in inhibiting OA progression. The present study is aimed at investigating the curative effects of acacetin, a natural flavonoid compound, against OA. Our results demonstrated that MMP-1, MMP-3, and MMP-13 were highly expressed in OA specimens. Acacetin inhibited the interleukin-1β- (IL-1β-) induced expression of MMP-1, MMP-3, and MMP-13in chondrocytes by blocking nuclear factor-κB (NF-κB) signaling pathways. Furthermore, we found that acacetin suppressed OA progression and inhibited the expression of MMP-1, MMP-3, and MMP-13 in ACLT-induced OA mice. Taken together, our study revealed that acacetin may serve as a potential drug for treating OA.

Acacetin, a flavone with diverse therapeutic potential in cancer, inflammation, infections and other metabolic disorders

BACKGROUND

Acacetin is a di-hydroxy and mono-methoxy flavone present in various plants, including black locust, Damiana, Silver birch. Literature information revealed that acacetin exhibits an array of pharmacological potential including chemopreventive and cytotoxic properties in cancer cell lines, prevents ischemia/reperfusion/myocardial infarction-induced cardiac injury, lipopolysaccharide (LPS), 1-methyl-4-phenyl pyridinium ion (MPP+) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP)-induced neuroinflammation, LPS and sepsis-induced lung injury, rheumatoid and collagen-induced arthritis, inhibit the microbial growth, obesity, viral-mediated infections as well as hepatic protection.

PURPOSE

This review highlights the therapeutic potential of acacetin, with updated and comprehensive information on the biological sources, chemistry, and pharmacological properties along with the possible mechanism of action, safety aspects, and future research opportunities.

STUDY DESIGN

The information was retrieved from various search engines, including Pubmed, SciFinder, Science direct, Inxight:drugs, Google scholar, and Meta cyc.

RESULT

The first section of this review focuses on the detailed biological source of acacetin, chromatographic techniques used for isolation, chemical characteristics, the method for the synthesis of acacetin, and the available natural and synthetic derivatives. Subsequently, the pharmacological activities, including anti-cancer, anti-inflammatory, anti-viral, anti-microbial, anti-obesity, have been discussed. The pharmacokinetics data and toxicity profile of acacetin are also discussed.

CONCLUSION

Acacetin is a potent molecule reported for its strong anti-inflammatory and anti-cancer activity, however further scientific evidence is essential to validate its potency in disease models associated with inflammation and cancer. There is limited information available for toxicity profiling of acacetin; therefore, further studies would aid in establishing this natural flavone as a potent candidate for research studies at clinical setup.

Flavones as a Privileged Scaffold in Drug Discovery: Current Developments

BACKGROUND

Flavones are one of the main subclasses of flavonoids with diverse pharmacological properties. They have been reported to possess antimalarial, antimicrobial, anti-tuberculosis, anti-allergic, antioxidant, anti-inflammatory activities, among others.

OBJECTIVE

The present review summarizes the recent information on the pharmacological properties of naturally occurring and synthetic flavones.

METHODS

Scientific publications referring to natural and synthetic flavones in relation to their biological activities were hand-searched in databases such as SciFinder, PubMed (National Library of Medicine), Science Direct, Wiley, ACS, SciELO, Springer, among others.

RESULTS

As per the literature, seventy-five natural flavones were predicted as active compounds with reference to their IC50 (<20 µg/mL) in in vitro studies. Also, synthetic flavones were found active against several diseases.

CONCLUSION

As per the literature, flavones are important sources for the potential treatment of multifactorial diseases. However, efforts toward the development of flavone-based therapeutic agents are still needed. The appearance of new catalysts and chemical transformations is expected to provide avenues for the synthesis of unexplored flavones, leading to the discovery of flavones with new properties and biological activities.

Acacetin enhances glucose uptake through insulin-independent GLUT4 translocation in L6 myotubes

BACKGROUND

Lowering blood glucose levels by increasing glucose uptake in insulin target tissues, such as skeletal muscle and adipose tissue, is one strategy to discover and develop antidiabetic drugs from natural products used as traditional medicines.

PURPOSE

Our goal was to reveal the mechanism and activity of acacetin (5,7-dihydroxy-4'-methoxyflavone), one of the major compounds in Agastache rugose, in stimulating glucose uptake in muscle cells.

METHODS

To determine whether acacetin promotes GLUT4-dependent glucose uptake in cultured L6 skeletal muscle cells, we performed a [¹⁴C] 2-deoxy-_D-glucose (2-DG) uptake assay after treating differentiated L6-GLUT4myc cells with acacetin.

RESULTS

Acacetin dose-dependently increased 2-DG uptake by enhancing GLUT4 translocation to the plasma membrane. Our results revealed that acacetin activated the CaMKII-AMPK pathway by increasing intracellular calcium concentrations. We also found that aPKCλ/ζ phosphorylation and intracellular reactive oxygen species (ROS) production were involved in acacetin-induced GLUT4 translocation. Moreover, acacetin-activated AMPK inhibited intracellular lipid accumulation and increased 2-DG uptake in HepG2 cells.

CONCLUSION

Taken together, these results suggest that acacetin might be useful as an antidiabetic functional ingredient. Subsequent experiments using disease model animals are needed to verify our results.

Saussureae Involucratae Herba (Snow Lotus): Review of Chemical Compositions and Pharmacological Properties

Saussureae Involucratae Herba is the dried ground part of Saussurea involucrata (Kar. et Kir.) Sch.-Bip, which is also named as “Snow lotus” and being used in traditional Uyghur and/or Chinese medicine. This rare herb can be found at 4,000 m elevation in western part of Tianshan Mountain, Xinjiang China. According to China Pharmacopoeia (2015), the major pharmaceutical values of “Snow lotus” (Xuě liánhuā in Chinese) are alleviating rheumatoid arthritis, accelerating blood circulation and mitigating other “cold” syndromes. Traditionally, the clinical application of “Snow lotus” includes the treatments in inflammation-associated disorder, blood circulation acceleration and heat and dampness elimination. Recent studies suggested that “Snow lotus” possessed therapeutic effects associating with anti-cancer, anti-oxidation, adipogenesis suppression and neuroprotection activities, which were proposed to be related with its bioactive constitutes, i.e. acacetin, hispidulin, and rutin. In the present review, we aim to summarize pharmacological effects and underlying cell signaling pathways of “Snow lotus” in treating various medical problems.

Maslinic acid protects against obesity-induced nonalcoholic fatty liver disease in mice through regulation of the Sirt1/AMPK signaling pathway

Maslinic acid is a pentacyclic triterpenoid that is distributed in the peel of olives. Previous studies found that maslinic acid inhibited inflammatory response and antioxidant effects. We investigated whether maslinic acid ameliorates nonalcoholic fatty liver disease in mice with high-fat-diet (HFD)-induced obesity and evaluated the regulation of lipogenesis in hepatocytes. Male C57BL/6 mice fed a normal diet or HFD (60% fat, w/w) were tested for 16 wk. After the fourth week, mice were injected intraperitoneally with maslinic acid for 12 wk. In another experiment, HepG2 cells were treated with oleic acid to induce lipid accumulation or maslinic acid to evaluate lipogenesis. Maslinic acid significantly reduced body weight compared with HFD-fed mice. Maslinic acid reduced liver weight and liver lipid accumulation and improved hepatocyte steatosis. Furthermore, serum glucose, leptin, and free fatty acid concentrations significantly reduced, but the serum adiponectin concentration was higher, in the maslinic acid group than in the HFD group. In liver tissue, maslinic acid suppressed transcription factors involved in lipogenesis and increased adipose triglyceride lipase. In vitro, maslinic acid decreased lipogenesis by activating AMPK. These findings suggest that maslinic acid acts against hepatic steatosis by regulating enzyme activity involved in lipogenesis, lipolysis, and fatty acid oxidation in the liver.-Liou, C.-J., Dai, Y.-W., Wang, C.-L., Fang, L.-W., Huang, W.-C. Maslinic acid protects against obesity-induced nonalcoholic fatty liver disease in mice through regulation of the Sirt1/AMPK signaling pathway.

The Mechanism of Phillyrin from the Leaves of Forsythia suspensa for Improving Insulin Resistance

Three lignans, phillyrin, forsythia ester A, and rosin-β-D-furan glucose, were isolated from Forsythia suspensa which is a famous Traditional Chinese Medicine used for clearing heat and detoxifying, reducing swelling and dispersing knot, and dispersing wind heat. In this study, the effects of phillyrin, forsythia ester A, and rosin-β-D-furan glucose on insulin resistance of 3T3-L1 adipocytes were investigated by the method of glucose oxidase-peroxidase (GOD-POD) and the mechanism was assayed by the method of western blot. The results indicated that phillyrin, forsythia ester A, and rosin-β-D-furan glucose could improve the glucose uptake in 3T3-L1 adipocytes under insulin resistance (IR). Among them, phillyrin showed significant activity in increasing glucose consumption at the concentrations of 100 μM and 200 μM (P < 0.001). The mechanism of improving insulin resistance may be that phillyrin could raise the protein phosphorylation of IRS-1 and Akt and the expression levels of GLUT4 protein.

Protective Effects of Licochalcone A Ameliorates Obesity and Non-Alcoholic Fatty Liver Disease Via Promotion of the Sirt-1/AMPK Pathway in Mice Fed a High-Fat Diet

Licochalcone A is a chalcone isolated from Glycyrrhiza uralensis. It showed anti-tumor and anti-inflammatory properties in mice with acute lung injuries and regulated lipid metabolism through the activation of AMP-activated protein kinase (AMPK) in hepatocytes. However, the effects of licochalcone A on reducing weight gain and improving nonalcoholic fatty liver disease (NAFLD) are unclear. Thus, the present study investigated whether licochalcone A ameliorated weight loss and lipid metabolism in the liver of high-fat diet (HFD)-induced obese mice. Male C57BL/6 mice were fed an HFD to induce obesity and NAFLD, and then were injected intraperitoneally with licochalcone A. In another experiment, a fatty liver cell model was established by incubating HepG2 hepatocytes with oleic acid and treating the cells with licochalcone A to evaluate lipid metabolism. Our results demonstrated that HFD-induced obese mice treated with licochalcone A had decreased body weight as well as inguinal and epididymal adipose tissue weights compared with HFD-treated mice. Licochalcone A also ameliorated hepatocyte steatosis and decreased liver tissue weight and lipid droplet accumulation in liver tissue. We also found that licochalcone A significantly regulated serum triglycerides, low-density lipoprotein, and free fatty acids, and decreased the fasting blood glucose value. Furthermore, in vivo and in vitro, licochalcone A significantly decreased expression of the transcription factor of lipogenesis and fatty acid synthase. Licochalcone A activated the sirt-1/AMPK pathway to reduce fatty acid chain synthesis and increased lipolysis and β-oxidation in hepatocytes. Licochalcone A can potentially ameliorate obesity and NAFLD in mice via activation of the sirt1/AMPK pathway.

Fumigaclavine C attenuates adipogenesis in 3T3-L1 adipocytes and ameliorates lipid accumulation in high-fat diet-induced obese mice

Fumigaclavine C (FC), an active indole alkaloid, is obtained from endophytic Aspergillus terreus (strain No. FC118) by the root of Rhizophora stylosa (Rhizophoraceae). This study is designed to evaluate whether FC has anti-adipogenic effects in 3T3-L1 adipocytes and whether it ameliorates lipid accumulation in high-fat diet (HFD)-induced obese mice. FC notably increased the levels of glycerol in the culture supernatants and markedly reduced lipid accumulation in 3T3-L1 adipocytes. FC differentially inhibited the expressions of adipogenesis-related genes, including the peroxisome proliferator-activated receptor proteins, CCAAT/enhancer-binding proteins, and sterol regulatory element-binding proteins. FC markedly reduced the expressions of lipid synthesis-related genes, such as the fatty acid binding protein, lipoprotein lipase, and fatty acid synthase. Furthermore, FC significantly increased the expressions of lipolysis-related genes, such as the hormone-sensitive lipase, Aquaporin-7, and adipose triglyceride lipase. In HFD-induced obese mice, intraperitoneal injections of FC decreased both the body weight and visceral adipose tissue weight. FC administration significantly reduced lipid accumulation. Moreover, FC could dose-dependently and differentially regulate the expressions of lipid metabolism-related transcription factors. All these data indicated that FC exhibited anti-obesity effects through modulating adipogenesis and lipolysis.

Effect of Enzymatic Treatment of Chrysanthemum indicum Linné Extracts on Lipid Accumulation and Adipogenesis in High-Fat-Diet-Induced Obese Male Mice

Enzyme treatment of the foods and herbs has been used to improve the absorption rate the efficiency of plant extracts by converting the glycosides of the plant into aglycones. In this study, we examined the obesity-inhibitory effect of Chrysanthemum indicum Linné (CI) treated with enzymes such as viscozyme and tannase, which are highly efficient in converting glycosides to aglycones and then compared with untreated CI extract. The enzyme-treated CI ethanol extract (CIVT) was administered orally at various doses for 7 weeks in the high fat diet (HFD)-fed male mice. CIVT administration reduced the body weights, the food efficiency and the serum levels of lipid metabolism-related biomarkers, such as triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c) and leptin in the dose-dependent manner but not those high-density lipoprotein cholesterol (HDL-c) and adiponectin. CIVT also reduced considerably the total lipid amount in the liver and the size of adipocytes in the epididymal white adipose tissue (eWAT). CIVT effectively downregulated the adipogenesis-related transcription factors such as peroxisome proliferation activated receptor (PPAR)-γ and CCAAT/enhancer binding protein-α (C/EBP-α) but up-regulated PPAR-α, in the liver and eWAT. In addition, when compared to the enzyme-untreated CI 50% ethanol extract (CIEE), CIVT enhanced the reduction of body weight and lipid accumulation. Moreover, the viscozyme and tannase treatment of CI increased the flavonoid contents of the aglycone form. Therefore, our results support that the enzymatic treatment induced the production of aglycones for potentially suppressing the adipogenesis and lipid accumulation in HFD-fed mice. It suggests that CIVT might be an effective candidate for attenuating the over-weight and its related diseases.

Moringa oleifera Leaf Petroleum Ether Extract Inhibits Lipogenesis by Activating the AMPK Signaling Pathway

In recent years, obesity has become a key factor affecting human health. Moringa oleifera Lam. is a perennial tropical deciduous tree, which is widely used in human medicine due to its nutritional and unique medicinal value. It has a cholesterol-lowering effect, but its mechanism of action is unclear. In this study, we elucidated the inhibitory effect of M. oleifera leaf petroleum ether extract (MOPEE) on lipid accumulation by in vitro and in vivo experiments, and we described its mechanism of action. MOPEE suppressed adipogenesis in 3T3-L1 adipocytes in a dose-dependent manner and had no effect on cell viability at doses up to 400 μg/ml. Furthermore, MOPEE (400 μg/ml) significantly downregulated the expression of adipogenesis-associated proteins [peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding proteins α and β (C/EBPα and C/EBPβ), and fatty acid synthase (FAS)] and upregulated the expression of a lipolysis-associated protein [hormone-sensitive lipase (HSL)] in 3T3-L1 adipocytes. Additionally, MOPEE (400 μg/ml) significantly increased the degree of phosphorylation of AMP-activated protein kinase α (AMPKα) and acetyl-CoA carboxylase (ACC). An AMPK inhibitor reversed the MOPEE-induced activation of AMPKα and ACC in 3T3-L1 adipocytes. Animal experiments showed that, in high-fat diet (HFD) mice, MOPEE [0.5 g/kg body weight (BW)] effectively decreased BW; relative epididymal, perirenal, and mesenteric fat weight and fat tissue size; and hepatic fat accumulation. Furthermore, MOPEE markedly reduced the serum levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and aspartate aminotransferase (AST). Moreover, MOPEE significantly downregulated the expression of adipogenesis-associated proteins (PPARγ and FAS) and upregulated the expression of a lipolysis-associated protein [adipose triglyceride lipase (ATGL)] in HFD mice hepatic and epididymal fat tissue. Additionally, MOPEE markedly increased the degree of phosphorylation of AMPKα and ACC in HFD mice hepatic and epididymal fat tissue. Following ultrahigh-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS/MS) analysis, three phytocompounds (isoquercitrin, chrysin-7-glucoside, and quercitrin) were identified as compounds with relatively high levels in MOPEE. Among them, quercitrin showed excellent fat accumulation inhibitory activity, and the three compounds had synergistic effects in inhibiting adipogenesis. Taken together, MOPEE inhibits fat accumulation by inhibiting the adipogenesis and promoting the lipolysis, and this process is related to AMPK activation.

Synergistic Inhibitory Effects of Acacetin and 11 Other Flavonoids Isolated from Artemisia sacrorum on Lipid Accumulation in 3T3-L1 Cells

Artemisia sacrorum Ledeb., a Compositae forage plant in China, has been found to have an inhibitory effect on lipid accumulation. We selected 12 flavonoids, which we had isolated from A. sacrorum and had the potential to inhibit lipid accumulation in the literature or in our preliminary experiments, and grouped them into 11 compound combinations; we investigated their synergistic inhibitory effects on lipid accumulation in 3T3-L1 cells. In screening experiments, Oil-Red O staining, triglyceride levels, and lipid accumulation levels all indicated that combined acacetin and apigenin displayed a significant synergistic inhibitory effect and the best repeatability. Subsequent research showed that this combination could synergistically promote the phosphorylations of AMPK and ACC. Furthermore, to a different extent, that combination had significant synergistic inhibitory effects on various genes or proteins related to adipogenesis and lipogenesis. Thus, that combination could significantly reduce triglyceride levels and lipid accumulation compared with acacetin or apigenin acting alone.

Acacetin regulated the reciprocal differentiation of Th17 cells and Treg cells and mitigated the symptoms of collagen-induced arthritis in mice

BACKGROUND AND AIM

The immune-regulative effect of acacetin on the development of autoimmune arthritis remains unexplored. This study aims to investigate the potential effect of acacetin on the treatment of collagen-induced arthritis (CIA) in mice and clarify its underlying mechanism.

METHODS AND RESULTS

In a type II collagen (CII)-induced autoimmune arthritis model, acacetin significantly repressed the incidence of CIA, prevented the pathological alteration, and reduced CII-specific IgG and IgG1 levels. Flow cytometry assay suggested that the recipients of acacetin showed the expansion of Treg cells and the decreasing Th17 cells in spleen and inguinal lymph nodes after the initiation of CIA. In vitro experiment suggested that in addition to altering the pro-inflammatory production in dendritic cells, engagement of acacetin relieved the generation of Th17 cells and maintained the ratio of Treg cells under Th17-polarized condition. The addition of acacetin inhibited the T cell proliferation, as well as the expression of the transcriptional coactivator TAZ, which regulated the balance of Treg/Th17 immunity, in a dose-dependent manner.

CONCLUSION

Our data demonstrated that acacetin mitigated the development of CIA and might be a potential agent for the treatment of autoimmune arthritis.

Antiobesity Effect of Tricin, a Methylated Cereal Flavone, in High-Fat-Diet-Induced Obese Mice

The antiobesity potential of tricin, a methylated cereal flavonoid, was examined using a high-fat-diet-induced obese mice model. The body weight ( P < 0.01) and body fat mass ( P < 0.05) were significantly decreased in the high-dose tricin supplementation group (TH: 200 mg/kg diet) in comparison to the high fat diet control group (CON) after a 12-week feeding trial. The serum (60.9 ± 2.09 mg/dL) and hepatic triglyceride levels (45.3 ± 4.42 nmol/mg protein) in the TH group were significantly decreased in comparison to the CON group (78.3 ± 5.09 mg/dL, 76.3 ± 8.10 nmol/mg protein), respectively. This antiobesity effect was attributed to a decrease in the expression of lipogenic markers crucial for fat synthesis in the liver (fatty acid synthase, stearoyl-CoA desaturase 1, elongation of long-chain fatty acids family member 6, glycerol-3-phosphate acyltransferase, and diglyceride acyltransferase) and suppressed expression of transcription factors associated with adipocyte differentiation (peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α). These lipid-lowering effects are mediated by the activation of adenosine 5'-monophosphate-activated protein kinase.

The Natural Flavone Acacetin Confers Cardiomyocyte Protection Against Hypoxia/Reoxygenation Injury via AMPK-Mediated Activation of Nrf2 Signaling Pathway

The present study investigates the potential signal pathway of acacetin in cardioprotection against ischemia/reperfusion injury using an in vitro hypoxia/reoxygenation model in primary cultured neonatal rat cardiomyocytes and H9C2 cardiomyoblasts. It was found that acacetin (0.3–3 μM) significantly decreased the apoptosis and reactive oxygen species production induced by hypoxia/reoxygenation injury in cardiomyocytes and H9C2 cardiomyoblasts via reducing the pro-apoptotic proteins Bax and cleaved-caspase-3 and increasing the anti-apoptotic protein Bcl-2. In addition, acacetin not only suppressed the release of pro-inflammatory cytokines TLR-4 and IL-6 induced by hypoxia/reoxygenation injury, but also increased the secretion of anti-inflammatory cytokine IL-10. Moreover, acacetin increased Nrf2 and HO-1 in a concentration-dependent manner, and rescued SOD1 and SOD2 reduction induced by hypoxia/reoxygenation insult. These beneficial effects of acacetin disappeared in cells with silenced Nrf2, suggesting that Nrf2 activation participates in the cardioprotective effect of acacetin against hypoxia/reoxygenation insult. However, acacetin-induced Nrf2 activation was not observed in cells with silenced AMPK and in ventricular tissues of rat hearts treated with the AMPK inhibitor Compound C and subjected to ischemia/reperfusion injury. Our results demonstrate for the first time that AMPK-mediated Nrf2 activation is involved in the cardiomyocytes protection of acacetin against hypoxia/reoxygenation injury by activating a series of intracellular signals involved in anti-oxidation, anti-inflammation, and anti-apoptosis.

An Integrated Proteomics and Bioinformatics Approach Reveals the Anti-inflammatory Mechanism of Carnosic Acid

Drastic macrophages activation triggered by exogenous infection or endogenous stresses is thought to be implicated in the pathogenesis of various inflammatory diseases. Carnosic acid (CA), a natural phenolic diterpene extracted from Salvia officinalis plant, has been reported to possess anti-inflammatory activity. However, its role in macrophages activation as well as potential molecular mechanism is largely unexplored. In the current study, we sought to elucidate the anti-inflammatory property of CA using an integrated approach based on unbiased proteomics and bioinformatics analysis. CA significantly inhibited the robust increase of nitric oxide and TNF-α, downregulated COX2 protein expression, and lowered the transcriptional level of inflammatory genes including Nos2, Tnfα, Cox2, and Mcp1 in LPS-stimulated RAW264.7 cells, a murine model of peritoneal macrophage cell line. The LC-MS/MS-based shotgun proteomics analysis showed CA negatively regulated 217 LPS-elicited proteins which were involved in multiple inflammatory processes including MAPK, nuclear factor (NF)-κB, and FoxO signaling pathways. A further molecular biology analysis revealed that CA effectually inactivated IKKβ/IκB-α/NF-κB, ERK/JNK/p38 MAPKs, and FoxO1/3 signaling pathways. Collectively, our findings demonstrated the role of CA in regulating inflammation response and provide some insights into the proteomics-guided pharmacological mechanism study of natural products.

Tomatidine Attenuates Airway Hyperresponsiveness and Inflammation by Suppressing Th2 Cytokines in a Mouse Model of Asthma

Tomatidine is isolated from the fruits of tomato plants and found to have anti-inflammatory effects in macrophages. In the present study, we investigated whether tomatidine suppresses airway hyperresponsiveness (AHR) and eosinophil infiltration in asthmatic mice. BALB/c mice were sensitized with ovalbumin and treated with tomatidine by intraperitoneal injection. Airway resistance was measured by intubation analysis as an indication of airway responsiveness, and histological studies were performed to evaluate eosinophil infiltration in lung tissue. Tomatidine reduced AHR and decreased eosinophil infiltration in the lungs of asthmatic mice. Tomatidine suppressed Th2 cytokine production in bronchoalveolar lavage fluid. Tomatidine also blocked the expression of inflammatory and Th2 cytokine genes in lung tissue. In vitro, tomatidine inhibited proinflammatory cytokines and CCL11 production in inflammatory BEAS-2B bronchial epithelial cells. These results indicate that tomatidine contributes to the amelioration of AHR and eosinophil infiltration by blocking the inflammatory response and Th2 cell activity in asthmatic mice.

Fucoxanthin attenuates fatty acid-induced lipid accumulation in FL83B hepatocytes through regulated Sirt1/AMPK signaling pathway

The fucoxanthin, isolated from brown algae, was reported to have multiple biological functions to anti-inflammation, anti-tumor, and ameliorated obesity in mice. In this study we investigated whether fucoxanthin could inhibit lipids accumulation in FL83B hepatocytes. FL83B cells were induced as fatty liver cell model by 0.5 mM oleic acid for 48 h, and treated with various concentration of fucoxanthin for 24 h. The results demonstrated that fucoxanthin significantly suppressed lipid accumulation and decreased lipid peroxidation in hepatocytes. Fucoxanthin could decrease lipogenesis-related transcription factor expression, including sterol regulatory element-binding proteins 1c and peroxisome proliferator-activated receptor γ. It also reduced fatty acid synthase expression and increased adipose triglyceride lipase and the phosphorylation of hormone-sensitive lipase production for lipolysis. Furthermore, fucoxanthin significantly increased phosphorylation of AMP-activated protein kinase (AMPK), and decreased activity of acetyl-CoA carboxylase for regulating fatty acid synthesis. The results suggest that fucoxanthin is an effective marine nature compound for increasing lipolysis and inhibiting lipogenesis in oleic acid induced fatty liver cells through promoted Sirt1/AMPK pathway.