Flavonoids from Acer okamotoanum Inhibit Adipocyte Differentiation and Promote Lipolysis in the 3T3-L1 Cells

Brown Algae Dictyopteris divaricata Attenuates Adipogenesis by Modulating Adipocyte Differentiation and Promoting Lipolysis through Heme Oxygenase-1 Activation in 3T3-L1 Cells

The present study aims to explore the probable anti-adipogenesis effect of Dictyopteris divaricata (D. divaricata) in 3T3-L1 preadipocytes by regulating heme oxygenase-1 (HO-1). The extract of D. divaricata retarded lipid accretion and decreased triglyceride (TG) content in 3T3-L1 adipocytes but increased free glycerol levels. Treatment with the extract inhibited lipogenesis by inhibiting protein expressions of fatty acid synthase (FAS) and lipoprotein lipase (LPL), whereas lipolysis increased by activating phosphorylation of hormone-sensitive lipase (p-HSL) and AMP-activated protein kinase (p-AMPK). The extract inhibited adipocyte differentiation of 3T3-L1 preadipocytes through down-regulating adipogenic transcription factors, including peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), and sterol regulatory element-binding protein 1 (SREBP1). This is attributed to the triggering of Wnt/β-catenin signaling. In addition, this study found that treatment with the extract activated HO-1 expression. Pharmacological approaches revealed that treatment with Zinc Protoporphyrin (ZnPP), an HO-1 inhibitor, resulted in an increase in lipid accumulation and a decrease in free glycerol levels. Finally, three adipogenic transcription factors, such as PPARγ, C/EBPα, and SREBP1, restored their expression in the presence of ZnPP. Analysis of chemical constituents revealed that the extract of D. divaricata is rich in 1,4-benzenediol, 7-tetradecenal, fucosterol, and n-hexadecanoic acid, which are known to have multiple pharmacological properties.

Afzelin protects against doxorubicin-induced cardiotoxicity by promoting the AMPKα/SIRT1 signaling pathway

BACKGROUND

Doxorubicin (DOX), a chemotherapeutic drug, could relieve the progressions of various diseases. However, its clinical application is limited due to its cardiotoxicity. This study aimed to investigate the effects of afzelin (a flavonol glycoside found in Houttuynia cordata) on the cardiotoxicity induced by DOX.

METHODS

In ex-vivo, H9C2 cells were incubated with 20, 40, or 80 μM afzelin for 12 h, followed by the treatment with 1 μM DOX for 12 h. In vivo, C57BL/6 J mice were intraperitoneally injected with 4 mg/kg/day DOX on days 1, 7, and 14. Meanwhile, starting from day 1, mice were intragastrically administrated with 5 mg/kg/day or 10 mg/kg/day afzelin for 20 days. The cardiac function of mice was evaluated by detecting hemodynamic parameters using the M-mode echocardiography.

RESULTS

DOX decreased the cell survival rate, and elevated apoptotic rate, as well as induced the oxidative stress and mitochondrial dysfunction in H9C2 cells. All these changes were alleviated by afzelin treatment in a concentration-dependent manner. The results were further proven by the mitigation of cardiac injury in vivo, as evidenced by the elevation of fractional shortening, heart weight/tibia length, and the rate of the increase/decrease of left ventricular pressure in mice subjected to DOX-induced cardiotoxicity. Furthermore, afzelin upregulated the expression of p-AMP-activated protein kinase alpha (AMPKα) and sirtuin1 (SIRT1). Dorsomorphin (an AMPKα inhibitor) abrogated the anti-cardiotoxicity effects of afzelin in H9C2 cells induced by DOX.

CONCLUSION

Afzelin protected against DOX-induced cardiotoxicity by promoting the AMPKα/SIRT1 signaling pathway.

Management of Obesity-Related Inflammatory and Cardiovascular Diseases by Medicinal Plants: From Traditional Uses to Therapeutic Targets

Inflammation is a crucial factor in the development and progression of cardiovascular diseases (CVD). Cardiac remodeling in the presence of persistent inflammation leads to myocardial fibrosis and extracellular matrix changes, which reduce cardiac function, induce arrhythmias, and finally, cause heart failure. The majority of current CVD treatment plans concentrate on reducing risk factors such as hyperlipidemia, type 2 diabetes, and hypertension. One such strategy could be inflammation reduction. Numerous in vitro, animal, and clinical studies indicate that obesity is associated with low-grade inflammation. Recent studies have demonstrated the potential of medicinal plants and phytochemicals to cure and prevent obesity and inflammation. In comparison to conventional therapies, the synergistic effects of several phytochemicals boost their bioavailability and impact numerous cellular and molecular targets. Focusing on appetite, pancreatic lipase activity, thermogenesis, lipid metabolism, lipolysis and adipogenesis, apoptosis in adipocytes, and adipocyte life cycle by medicinal plants and phytochemicals represent an important goal in the development of new anti-obesity drugs. We conducted an extensive review of the literature and electronic databases, including Google Scholar, PubMed, Science Direct, and MedlinePlus, for collecting data on the therapeutic effects of medicinal plants/phytochemicals in curing obesity and its related inflammation and CVD diseases, including cellular and molecular mechanisms, cytokines, signal transduction cascades, and clinical trials.

Albizia julibrissin Exerts Anti-Obesity Effects by Inducing the Browning of 3T3L1 White Adipocytes

This study investigated the effects of the Albizia julibrissin Leaf extracts (AJLE) on adipocytes using 3T3-L1 cells. AJLE inhibited adipogenesis by reducing the expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding proteins (C/EBPs) that regulate enzymes involved in fat synthesis and storage, and subsequently reduced intracellular lipid droplets, glycerol-3-phosphate dehydrogenase (GPDH), and triglyceride (TG). AJLE also increased the expression of brown adipocyte markers, such as uncoupling protein-1 (UCP-1), PR/SET domain 16 (PRDM16), and bone morphogenetic protein 7 (BMP7) by inducing the differentiation of brown adipocytes, as shown by a decrease in the lipid droplet sizes and increasing mitochondrial mass. AJLE increased the expression of transcription factor A, mitochondrial (TFAM), mitochondrial DNA (mtDNA) copy number, and UCP-1 protein expression, all of which are key factors in regulating mitochondrial biogenesis. AJLE-induced browning was shown to be regulated by the coordination of AMPK, p38, and SIRT1 signaling pathways. The ability of AJLE to inhibit adipogenesis and induce brown adipocyte differentiation may help treat obesity and related diseases.

Effect of sea buckthorn extract on production performance, serum biochemical indexes, egg quality, and cholesterol deposition of laying ducks

The purpose of this experiment was to study the effect of sea buckthorn extract (SBE) supplementation on the production performance, serum biochemical indexes, egg quality, and cholesterol deposition of laying ducks. A total of 240 23-week-old laying ducks (female ducks) with similar body weight were randomly divided into four treatment groups with 6 replicates of 10 each. The experimental groups were fed diets supplemented with 0, 0.5, 1.0, and 1.5 g/kg of SBE, respectively. The results showed that the addition of 1.0 g/kg SBE to the diet had significant increase (P < 0.05) in average egg weight and feed conversion ratio. The inclusion of SBE showed the significant improvement (P < 0.05) in yolk weight, shell strength, egg white height and haugh unit. Ducks fed with 1.0 and 1.5 g/kg SBE displayed a significant decrease (P < 0.05) in yolk cholesterol. The significant improvements were observed in the contents of total amino acid essential amino acids, non-essential amino acids, umami amino acids, monounsaturated fatty acids, and docosahexenoic acids of eggs (P < 0.05) when supplemented with SBE. However, the contents of total saturated fatty acids, polyunsaturated fatty acids, n-3 polyunsaturated fatty acids and n-6 polyunsaturated fatty acids in eggs showed decrease when ducks fed with SBE diets (P < 0.05). SBE diets may reduce (P < 0.05) the levels of serum total cholesterol, triglyceride, and low-density lipoprotein cholesterol, while increased (P < 0.05) the levels of serum superoxide dismutase, total antioxidant capacity, and glutathione catalase compared to the control. The levels of serum immunoglobulin G, immunoglobulin A and immunoglobulin M were improved in SBE diets (P < 0.05) in comparation to the control. The addition of SBE to diets can improve feed nutrient utilization, increase egg weight, optimaze egg quality and amino acid content in eggs, reduce blood lipids, improve fatty acid profile and yolk cholesterol in eggs, and increase antioxidant capacity and immunity in laying ducks.

The Flavonol Quercitrin Hinders GSK3 Activity and Potentiates the Wnt/β-Catenin Signaling Pathway

The Wnt/β-catenin signaling pathway dictates cell proliferation and differentiation during embryonic development and tissue homeostasis. Its deregulation is associated with many pathological conditions, including neurodegenerative disease, frequently downregulated. The lack of efficient treatment for these diseases, including Alzheimer’s disease (AD), makes Wnt signaling an attractive target for therapies. Interestingly, novel Wnt signaling activating compounds are less frequently described than inhibitors, turning the quest for novel positive modulators even more appealing. In that sense, natural compounds are an outstanding source of potential drug leads. Here, we combine different experimental models, cell-based approaches, neuronal culture assays, and rodent behavior tests with Xenopus laevis phenotypic analysis to characterize quercitrin, a natural compound, as a novel Wnt signaling potentiator. We find that quercitrin potentiates the signaling in a concentration-dependent manner and increases the occurrence of the Xenopus secondary axis phenotype mediated by Xwnt8 injection. Using a GSK3 biosensor, we describe that quercitrin impairs GSK3 activity and increases phosphorylated GSK3β S9 levels. Treatment with XAV939, an inhibitor downstream of GSK3, impairs the quercitrin-mediated effect. Next, we show that quercitrin potentiates the Wnt3a-synaptogenic effect in hippocampal neurons in culture, which is blocked by XAV939. Quercitrin treatment also rescues the hippocampal synapse loss induced by intracerebroventricular injection of amyloid-β oligomers (AβO) in mice. Finally, quercitrin rescues AβO-mediated memory impairment, which is prevented by XAV939. Thus, our study uncovers a novel function for quercitrin as a Wnt/β-catenin signaling potentiator, describes its mechanism of action, and opens new avenues for AD treatments.

Ribes fasciculatum Ameliorates High-Fat-Diet-Induced Obesity by Elevating Peripheral Thermogenic Signaling

Ribes fasciculatum has been consumed as a food and as a traditional medicine for treating autoimmune diseases and aging in diverse countries. A previous study showed that a mixture of Ribes fasciculatum and Cornus officinalis prohibited adipocyte differentiation and lipid accumulation in preadipocytes and suppressed diet-induced obesity. Nevertheless, the mechanism of R. fasciculatum to regulate energy homeostasis solely through thermogenic signaling remains unclear. Thus, we investigated its effects on energy homeostasis using R. fasciculatum fed to C57BL/6 mice with a 45% high-fat diet. Chronic consumption of R. fasciculatum decreased the body weight of obese mice with increasing food intakes and improved metabolic-syndrome-related phenotypes. Therefore, we further tested its thermogenic effects. Cold chamber experiments and qPCR studies indicated that R. fasciculatum elevated thermogenic signaling pathways, demonstrated by increased body temperature and uncoupling protein 1 (UCP1) signaling in the white and brown adipose tissues. Afzelin is one major known compound derived from R. fasciculatum. Hence, the isolated compound afzelin was treated with preadipocytes and brown adipocytes for cell viability and luciferase assay, respectively, to further examine its thermogenic effect. The studies showed that the response of afzelin was responsible for cell viability and the increased UCP1. In conclusion, our data indicated that R. fasciculatum elevated peripheral thermogenic signaling through increased UCP1 via afzelin activation and ameliorated diet-induced obesity.

Kaempferol 3-Rhamnoside on Glutamate Release from Rat Cerebrocortical Nerve Terminals Involves P/Q-Type Ca2+ Channel and Ca2+/Calmodulin-Dependent Protein Kinase II-Dependent Pathway Suppression

Excess synaptic glutamate release has pathological consequences, and the inhibition of glutamate release is crucial for neuroprotection. Kaempferol 3-rhamnoside (KR) is a flavonoid isolated from Schima superba with neuroprotective properties, and its effecton the release of glutamate from rat cerebrocortical nerve terminals was investigated. KR produced a concentration-dependent inhibition of 4-aminopyridine (4-AP)-evoked glutamate release with half-maximal inhibitory concentration value of 17 µM. The inhibition of glutamate release by KR was completely abolished by the omission of external Ca²⁺ or the depletion of glutamate in synaptic vesicles, and it was unaffected by blocking carrier-mediated release. In addition, KR reduced the 4-AP-evoked increase in Ca²⁺ concentration, while it did not affect 4-AP-evoked membrane potential depolarization. The application of selective antagonists of voltage-dependent Ca²⁺ channels revealed that the KR-mediated inhibition of glutamate release involved the suppression of P/Q-type Ca²⁺ channel activity. Furthermore, the inhibition of release was abolished by the calmodulin antagonist, W7, and Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) inhibitor, KN62, but not by the protein kinase A (PKA) inhibitor, H89, or the protein kinase C (PKC) inhibitor, GF109203X. We also found that KR reduced the 4-AP-induced increase in phosphorylation of CaMKII and its substrate synapsin I. Thus, the effect of KR on evoked glutamate release is likely linked to a decrease in P/Q-type Ca²⁺ channel activity, as well as to the consequent reduction in the CaMKII/synapsin I pathway.

α-Glucosidase Inhibitory Activity and Anti-Adipogenic Effect of Compounds from Dendrobium delacourii

Chemical investigation of Dendrobium delacourii revealed 11 phenolic compounds, and the structures of these compounds were determined by analysis of their NMR and HR-ESI-MS data. All compounds were investigated for their α-glucosidase inhibitory activity and anti-adipogenic properties. Phoyunnanin E (10) and phoyunnanin C (11) showed the most potent α-glucosidase inhibition by comparing with acarbose, which was used as a positive control. Kinetic study revealed the non-competitive inhibitors against the enzyme. For anti-adipogenic activity, densifloral B (3) showed the strongest inhibition when compared with oxyresveratrol (positive control). In addition, densifloral B might be responsible for the inhibition of adipocyte differentiation via downregulating the expression of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT enhancer-binding protein alpha (C/EBPα), which are major transcription factors in adipogenesis.

Rhubarb hydroxyanthraquinones act as antiobesity agents to inhibit adipogenesis and enhance lipolysis

Rhubarb as an herbal medicine has been shown to exhibit antiadipogenic activity. This study evaluated and compared the lipid-lowering activity of five rhubarb hydroxyanthraquinones (HAQs), including chrysophanol, aloe emodin, emodin, physcion, and rhein, aiming to identify candidate compounds for obesity treatment. Examination of the antiobesity effects of HAQs in 3T3-L1 adipocytes and high-fat diet (HFD)-induced obese rats showed that these anthraquinone compounds inhibited lipid accumulation in 3T3-L1 cells before and after differentiation. Emodin and rhein showed greater inhibition than the other compounds; dosage at 50 μM reduced intracellular triglyceride (TG) by about 30% in the differentiated adipocytes. Both compounds also revealed lipolytic effects to increase glycerol release from adipocytes. Adipokine overexpression induced by differentiation was downregulated by emodin and rhein through mitogen-activated protein kinase (MAPK) signaling. Despite their structural similarity, emodin and rhein exhibited different mechanisms on adipogenesis and lipid metabolism. Rhein restrained lipid deposition by controlling adipogenic transcriptional factors and lipolytic lipases during differentiation. The lipid-lowering effects of emodin did not use these pathways but reduced levels of lipogenic enzymes. HFD consumption in rats significantly increased body weight, visceral fat mass and adipocyte size, which were attenuated by intraperitoneal delivery of emodin or rhein. Rhein showed greater amelioration of obesity than emodin, decreasing plasma cholesterol by 29% and 14%, respectively. HAQs also suppressed cytokine upregulation in the liver and adipose tissues of obese rats. Rhein is a potential antiobesity agent through its ability to regulate obesity-associated adipogenesis, lipolysis and inflammation.

Revealing the mechanism of "Huai Hua San" in the treatment of ulcerative colitis based on network pharmacology and experimental study

ETHNOPHARMACOLOGICAL RELEVANCE

"Huai Hua San" (HHS) is one of the first hundred ancient classic prescriptions drugs, which is commonly used to treat hemorrhoids, colitis, and other symptoms of wind heat in stool. However, the potential molecular mechanism of action of this substance remains unclear.

AIMS OF THE STUDY

In this study, we explored the active compounds of HHS for the treatment of ulcerative colitis (UC), predicted the potential targets of the drug, and studied its mechanism of action through network pharmacology via in vitro and in vivo experiments.

MATERIALS AND METHODS

First, we identified the active compounds and key targets of HHS for treating UC via network pharmacology. The key signaling pathways associated with the anti-inflammatory effect of HHS were analyzed. The anti-inflammatory effects of HHS and its active compounds were studied using the RAW264.7 inflammatory cell model in vitro. Furthermore, we used the dextran sulfate sodium (DSS) mouse model to explore the efficacy and mechanism of HHS in UC in vivo, and the expression level of key proteins were detected by Western blotting.

RESULTS

In all, 23 compounds and 97 targets were obtained from TCMSP database, PharmMapper database, and GeneCards database. After enrichment via Kyoto Encyclopedia of Genes and Genomes (KEGG), HIF-1 signaling pathway, PI3K/AKT signaling pathway, and VEGF signaling pathway were identified to be the top three signaling pathways associated with UC treatment. The results of molecular docking showed that the docking scores of the top 10 active compounds were higher than the threshold values. In vitro, different concentrations of HHS and the four main active compounds could effectively inhibit the release of inflammatory cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1 β. In vivo, HHS could alleviate UC symptoms.

CONCLUSION

Taken together, the treatment of UC with HHS may alleviate the inflammatory response of the colon, and HHS mainly inhibits the EGFR/PI3K/AKT/HIF-1/VEGF signaling pathways.

Special Issue "Flavonoids and Their Disease Prevention and Treatment Potential": Recent Advances and Future Perspectives

In recent years, the interest in flavonoids as dietary bioactives to prevent human diseases, as well as their candidacy as pharmaceutical leads, has exponentially expanded [...].