Ellagic acid inhibits oxidized low-density lipoprotein (OxLDL)-induced metalloproteinase (MMP) expression by modulating the protein kinase C-α/extracellular signal-regulated kinase/peroxisome proliferator-activated receptor γ/nuclear factor-κB (PKC-α/ERK/PPAR-γ/NF-κB) signaling pathway in endothelial cells

Geraniin Ameliorates Hypertensive Vascular Remodelling in a Diet-Induced Obese Animal Model through Antioxidant and Anti-Inflammatory Effects

Geraniin, an ellagitannin, has shown a potent blood pressure-lowering effect in vivo. Therefore, this study aims to further characterize the ability of geraniin to attenuate hypertensive vascular dysfunction, a key feature of cardiovascular disease (CVD) development. Hypertension was induced in male Sprague-Dawley rats through feeding a high-fat diet (HFD) for eight weeks, followed by oral administration of 25 mg/kg/day geraniin for four weeks. The parameters of vascular dysfunction such as the structure and function of blood vessels as well as the vascular oxidative stress and inflammation were evaluated. The outcomes of geraniin-treated rats were compared with those of untreated rats on either a normal diet (ND) or HFD and with HFD-fed rats treated with captopril (40 mg/kg/day). We found that geraniin supplementation effectively ameliorated HFD-induced hypertension and abnormal remodelling of the thoracic aorta by suppressing excessive vascular superoxide (O₂^-) radical generation and overexpression of pro-inflammatory mediators in the circulating leukocytes. Furthermore, compared to the ND-fed rats, geraniin also independently promoted the significant enlargement of the thoracic aortic lumen for blood pressure reduction. Notably, the vascular benefits of geraniin were comparable to that of captopril. Collectively, these data suggest that geraniin can mitigate hypertensive vascular remodelling caused by overnutrition, which potentially abrogates the further development of CVDs.

Ellagic acid increases implantation rates with its antifibrotic effect in the rat model of intrauterine adhesion

Intrauterine adhesions (IUA) are defined as the adhesion of opposing endometrial tissue with dense fibrous adhesive bands within the uterine cavity. With the increase in cesarean sections and endometrial surgical procedures, intrauterine adhesions have become a problem with increasing incidence and decreasing implantation. The purpose of the study was to investigate the effect of ellagic acid (EA), a phenolic compound, on fibrosis in IUA model rats. Another goal of the study was to increase endometrial receptivity with EA. The groups in the study were planned as control, DMSO, EA, IUA, IUA+DMSO, and IUA+EA, with 8 Sprague Dawley rats in each group. EA was administered at a dose of 100 mg/kg/day for 35 days. At the end of the experiment, the uterine tissues of the rats were removed. Histochemical staining was used to validate the IUA model and determine the degree of fibrosis. The levels of some fibrosis-related genes and proteins in the obtained uterine tissues were evaluated. In addition, implantation rates were determined. In our findings, it was observed that the fibrotic structure was decreased in the treated IUA+EA group compared to the IUA group, while fibrotic improvement was supported by down-regulation of TGFβ1 activity and up-regulation of BMP7 activity. The increase in the expression of the endometrial marker LIF with EA treatment was consistent with the increase in implantation rates with treatment. As a result of the study, it can be said that EA applied as a treatment against IUA causes healing in uterine tissue by reducing fibrosis and increases implantation rates by increasing endometrial receptivity.

Neuropeptide Y regulates cholesterol uptake and efflux in macrophages and promotes foam cell formation

The dysregulation of lipid metabolic pathways (cholesterol uptake and efflux) in macrophages results in the formation of lipid‐dense macrophages, named foam cells, that participate in plaque formation. NPY binding to NPY receptors in macrophages can modulate cell functions and affect the process of atherosclerotic plaques. The present study aimed to determine whether NPY affects the formation of macrophage‐derived foam cells and its underlying mechanisms in macrophages. THP‐1‐derived macrophages were incubated with oxidized low‐density lipoprotein (ox‐LDL) and treated with different concentrations of NPY. We analysed the relative levels of proteins related to cholesterol uptake and efflux. We found that NPY effectively increased cholesterol uptake and intracellular cholesterol content via the Y1 and Y5 receptors, and this effect was blocked by Y1 and Y5 antagonists. Mechanistically, NPY enhanced the expression of SRA and CD36 via the PKC/PPARγ pathways, promoting macrophage cholesterol uptake. Moreover, NPY significantly decreased cholesterol efflux to the extracellular cholesterol acceptors ApoA1 and HDL in macrophages. NPY mediated decreases in ABCA1, ABCG1 and SR‐BI expression through the inhibition of the JAK/STAT3 pathways. Our results suggest that NPY binding to the Y1 and Y5 receptors enhances foam cell formation by regulating cholesterol uptake and efflux in macrophages.

Moracin D induces apoptosis in prostate cancer cells via activation of PPAR gamma/PKC delta and inhibition of PKC alpha

Herein, apoptotic mechanism of Moracin D was explored in prostate cancer cells in association with peroxisome proliferator-activated receptor gamma (PPAR-γ)-related signaling involved in lipid metabolism. Moracin D augmented cytotoxicity and sub G1 population in PC3 and DU145 prostate cancer cells, while DU145 cells were more susceptible to Moracin D than PC3 cells. Moracin D attenuated the expression of caspase-3, poly (ADP-ribose) polymerase (PARP), B-cell lymphoma 2 (Bcl-2), and B-cell lymphoma-extra-large (Bcl-xL) in DU145 cells. Consistently, Moracin D significantly augmented the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells in DU145 cells. Interestingly, Moracin D activated PPAR-γ and phospho-protein kinase C delta (p-PKC-δ) and inhibited phospho-protein kinase C alpha (p-PKC-α) in DU145 cells. Furthermore, STRING bioinformatic analysis reveals that PPAR-γ interacts with nuclear factor-κB (NF-κB) that binds to PKC-α/PKC-δ or protein kinase B (AKT) or extracellular signal-regulated kinase (ERK). Indeed, Moracin D decreased phosphorylation of NF-κB, ERK, and AKT in DU145 cells. Conversely, PPAR-γ inhibitor GW9662 reduced the apoptotic ability of Moracin D to activate caspase 3 and PARP in DU145 cells. Taken together, these findings provide a novel insight that activation of PPAR-γ/p-PKC-δ and inhibition of p-PKC-α are critically involved in Moracin D-induced apoptosis in DU145 prostate cancer cells.

Structural analysis and prediction of potent bioactive molecule for eNOS protein through molecular docking

Reactive oxygen species by uncoupled eNOS is linked to endothelial dysfunction. Ellagic acid (EA), a polyphenol possesses numerous biological activities including radical scavenging. whether EA exerts a vasculo-protective effect via antioxidant mechanisms in blood vessels remains unknown. Molecular docking provides an initial model of protein and molecular interactions in various physiological and/or pathological functions. To identify a eNOS modulatory biomolecule through molecular docking as possible vascular protective agent. On the basis of binding affinities and other physicochemical features, a molecular docking-based approach was used to classify and evaluate eNOS binding micronutrients found in natural sources, Lipinski's rule was used taking into account their adsorption, delivery, metabolism, and excretion (ADME). An insilico approach focused on the ligand-protein interaction technique to determine the therapeutic potential of certain phytochemical-based drugs for the vascular remodelling.20 bioactive molecules were screened, docking analysis on human eNOS proteins was performed. The best poses for target protein was established based on binding energy and inhibition constant. EA and caffeine acid are the strongest candidates for eNOS protein functional norms. This provides a novel insight into the interaction properties of known human eNOS protein with EA and used as a therapeutic agent in various pathologies. Predicting interaction of ellagic acid with eNOS protein by molecular docking in endothelial dysfunction.

Putative role of natural products as Protein Kinase C modulator in different disease conditions

INTRODUCTION

Protein kinase C (PKC) is a promising drug target for various therapeutic areas. Natural products derived from plants, animals, microorganisms, and marine organisms have been used by humans as medicine from prehistoric times. Recently, several compounds derived from plants have been found to modulate PKC activities through competitive binding with ATP binding site, and other allosteric regions of PKC. As a result fresh race has been started in academia and pharmaceutical companies to develop an effective naturally derived small-molecule inhibitor to target PKC activities. Herein, in this review, we have discussed several natural products and their derivatives, which are reported to have an impact on PKC signaling cascade.

METHODS

All information presented in this review article regarding the regulation of PKC by natural products has been acquired by a systematic search of various electronic databases, including ScienceDirect, Scopus, Google Scholar, Web of science, ResearchGate, and PubMed. The keywords PKC, natural products, curcumin, rottlerin, quercetin, ellagic acid, epigallocatechin-3 gallate, ingenol 3 angelate, resveratrol, protocatechuic acid, tannic acid, PKC modulators from marine organism, bryostatin, staurosporine, midostaurin, sangivamycin, and other relevant key words were explored.

RESULTS

The natural products and their derivatives including curcumin, rottlerin, quercetin, ellagic acid, epigallocatechin-3 gallate, ingenol 3 angelate, resveratrol, bryostatin, staurosporine, and midostaurin play a major role in the management of PKC activity during various disease progression.

CONCLUSION

Based on the comprehensive literature survey, it could be concluded that various natural products can regulate PKC activity during disease progression. However, extensive research is needed to circumvent the challenge of isoform specific regulation of PKC by natural products.

The Anti-Inflammatory Properties of Phytochemicals and Their Effects on Epigenetic Mechanisms Involved in TLR4/NF-κB-Mediated Inflammation

Innate immune response induces positive inflammatory transducers and regulators in order to attack pathogens, while simultaneously negative signaling regulators are transcribed to maintain innate immune homeostasis and to avoid persistent inflammatory immune responses. The gene expression of many of these regulators is controlled by different epigenetic modifications. The remarkable impact of epigenetic changes in inducing or suppressing inflammatory signaling is being increasingly recognized. Several studies have highlighted the interplay of histone modification, DNA methylation, and post-transcriptional miRNA-mediated modifications in inflammatory diseases, and inflammation-mediated tumorigenesis. Targeting these epigenetic alterations affords the opportunity of attenuating different inflammatory dysregulations. In this regard, many studies have identified the significant anti-inflammatory properties of distinct naturally-derived phytochemicals, and revealed their regulatory capacity. In the current review, we demonstrate the signaling cascade during the immune response and the epigenetic modifications that take place during inflammation. Moreover, we also provide an updated overview of phytochemicals that target these mechanisms in macrophages and other experimental models, and go on to illustrate the effects of these phytochemicals in regulating epigenetic mechanisms and attenuating aberrant inflammation.

CHEMICAL CONSTITUENTS OF GEUM RIVALE L. AND THEIR BIOLOGICAL ACTIVITY

The aim of the study is to review the literature data on the chemical constituents of arial and underground parts of Geum rivale L. (Rosaceae) and the pharmacological activity of its extracts and individual compounds.

Materials and methods. The study was carried out using Internet resources (Google Scholar, PubMed) and library databases (e-Library, Scopus, Web of Science). The main research methods were a review and analysis of the literature data on the topic for the period from 1958 up to the present.

Results. For the period from 1958 up to the present more than 80 components in the arial and underground parts of G. rivale have been identified.  Among them there were components of the essential oil, phenolic acids and coumarins, aglycones of flavonoids, including luteolin, apigenin, quercetin and kaempferol, as well as a number of their glycosides and glucuronides, ellagitannins (hemin A, B, C, D, pedunculagin, stachiurin/casuarinin, tellimagrandin I). Some aspects of the pharmacological activity of total extracts and individual secondary metabolites of G. rivale have been studied, anti-inflammatory, antioxidant, antimicrobial, antiviral activities have been experimentally confirmed.

Conclusion. The analysis of the literature data showed that a further study of the composition of metabolites of G. rivale and their pharmacological activity is an urgent task, the solution of which will expand the range of use of this plant in medical practice and consider G. rivale as a promising source of pharmaceutical substances for the creation of new drugs and biologically active additives.

Optimized Ellagic Acid-Ca Pectinate Floating Beads for Gastroprotection against Indomethacin-Induced Gastric Injury in Rats

A peptic ulcer is an alimentary tract injury that leads to a mucosal defect reaching the submucosa. This work aimed to optimize and maximize ellagic acid (EA) loading in Ca pectinate floating beads to maximize the release for 24 h. Three factors were selected: Ca pectinate concentration (X1, 1–3 w/v %), EA concentration (X2, 1–3 w/v %) and the dropping time (X3, 10–30 min). The factorial design proposed eight formulations. The optimized EA–Ca pectinate formulation was evaluated for the gastric ulcer index and the oxidative stress parameter determination of gastric mucosa. The results indicated that the optimum EA–Ca pectinate formula significantly improved the gastric ulcer index in comparison with raw EA. The protective effect of the optimized EA–Ca pectinate formula was further indicated by the histopathological features of the stomach. The results of the study indicate that an EA formulation in the form of Ca pectinate beads would be effective for protection against gastric ulcers because of Nonsteroidal anti-inflammatory drugs (NSAID) administration.

The protective effect of Ellagic acid (EA) in osteoarthritis: An in vitro and in vivo study

Osteoarthritis (OA), a progressive joint disorder, is principally characterized by the degeneration and destruction of the articular cartilage. Ellagic acid (EA), a natural polyphenol found in berries and nuts has shown potent anti-inflammatory effects, however, its effects and underlying mechanisms on OA have seldom been systematically illuminated. In this study, we reported the anti-inflammatory effects of Ellagic acid (EA) in the progression of OA in both in vitro and in vivo experiments. in vitro study, IL-1β-induced expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), Nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), prostaglandin E2 (PGE2), and interleukin-6 (IL-6) were inhibited by Ellagic acid (EA). Moreover, Ellagic acid (EA) down-regulated the IL-1β-stimulated matrix metalloproteinase-13 (MMP-13) and thrombospondin motifs 5 (ADAMTS-5) while up-regulated the collagen of type II and aggrecan. Mechanistically, we revealed that Ellagic acid (EA) suppressed nuclear factor kappa B (NF-κB) signaling in IL-1β -induced chondrocytes. And Ellagic acid (EA)-induced protectiveness in OA development was also shown by the DMM model. Taken together, our data indicate that Ellagic acid (EA) may serve as a potential drug for OA treatment.

Dietary natural products as epigenetic modifiers in aging-associated inflammation and disease

Covering: up to 2020Chronic, low-grade inflammation is linked to aging and has been termed "inflammaging". Inflammaging is considered a key contributor to the development of metabolic dysfunction and a broad spectrum of diseases or disorders including declines in brain and heart function. Genome-wide association studies (GWAS) coupled with epigenome-wide association studies (EWAS) have shown the importance of diet in the development of chronic and age-related diseases. Moreover, dietary interventions e.g. caloric restriction can attenuate inflammation to delay and/or prevent these diseases. Common themes in these studies entail the use of phytochemicals (plant-derived compounds) or the production of short chain fatty acids (SCFAs) as epigenetic modifiers of DNA and histone proteins. Epigenetic modifications are dynamically regulated and as such, serve as potential therapeutic targets for the treatment or prevention of age-related disease. In this review, we will focus on the role for natural products that include phytochemicals and short chain fatty acids (SCFAs) as regulators of these epigenetic adaptations. Specifically, we discuss regulators of methylation, acetylation and acylation, in the protection from chronic inflammation driven metabolic dysfunction and deterioration of neurocognitive and cardiac function.

Chinese Sweet Leaf Tea (Rubus suavissimus) Mitigates LPS-Induced Low-Grade Chronic Inflammation and Reduces the Risk of Metabolic Disorders in a C57BL/6J Mouse Model

Chronic exposure to minute doses of endotoxin elicits intestinal inflammation and impairs the gut barrier function, potentially resulting in systemic inflammation with elevated concentrations of biomarkers associated with metabolic syndrome. This study aimed to investigate the preventive effects of the Rubus suavissimus S. Lee leaf extract in a model of low-grade systemic inflammation. The predominant compounds found in the leaf extract are gallic acids, ellagic acid, and rubusoside. Results of the present study showed that R. suavissimus leaf extract supplementation could help preserve intestinal barrier integrity by upregulating the expression of the tight junction proteins [e.g., zonula occluden-1 (ZO-1) and junctional adhesion molecule-1 (JAMA)] and mucin (MUC)-4 and also suppress the release of plasmatic proinflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-6, and monocyte chemotactic protein (MCP)-1, while restoring the production of anti-inflammatory adiponectin. We subsequently determined that the leaf extract contributes to restoring glucose metabolic homeostasis through maintaining insulin sensitivity. Furthermore, our mechanistic finding demonstrated that the R. suavissimus leaf extract supplementation prevented systemic inflammation-driven impaired insulin sensitivity in white adipose tissues (WATs) by modulating the expression of peroxisome-proliferator-activated receptor-γ (PPAR-γ) and insulin receptor subset-1 (IRS-1). Altogether, our findings suggest that the above supplementation contributes to restoring immune and metabolic homeostasis to enhance the overall health of the host thereby preventing the early onset of metabolic disorders such as obesity and type 2 diabetes.

Oxidized low density lipoprotein induces endothelial-to-mesenchymal transition by stabilizing Snail in human aortic endothelial cells

The endothelial-to-mesenchymal transition (EndMT) of endothelial cells contributes to the development of atherosclerosis. Oxidized low density lipoprotein (ox-LDL) is a highly risk factor for atherosclerosis. However, whether ox-LDL causes EndMT and the underlying mechanism are unclear. We report here that ox-LDL treatment is able to induce EndMT in human aortic endothelial cells (HAECs), and that the ox-LDL-induced EndMT is strictly dependent on the presence of its innate receptor, ox-LDL Receptor-1 (LOX-1). In addition, ox-LDL specifically upregulates EndMT transcriptional factor Snail, and knockdown of Snail completely attenuates ox-LDL-induced EndMT, indicating an essential role of Snail in mediating this effect. Mechanically, ox-LDL induces Snail stabilization by inhibiting its ubiquitination, which is in part attributed to inhibited GSK-3β activity. Hence, our findings suggest that inducing EndMT of aortic endothelial cells by ox-LDL might contribute to its detrimental role in promoting atherosclerosis development.

Pomegranate polyphenols and urolithin A inhibit α-glucosidase, dipeptidyl peptidase-4, lipase, triglyceride accumulation and adipogenesis related genes in 3T3-L1 adipocyte-like cells

ETHNOPHARMACOLOGICAL RELEVANCE

Pomegranate fruit is considered an antidiabetic medicine in certain systems of traditional medicine. In addition, pomegranate polyphenols are known as powerful antioxidants with beneficial effects such as the reduction of oxidative / inflammatory stress and the increase of protective signalling such as antioxidant enzymes, neurotrophic factors and cytoprotective proteins.

AIM OF THE STUDY

This work evaluates the effects of pomegranate juice, its main polyphenols known as ellagic acid and punicalagin, as well as its main metabolite urolithin A, on physiological and pharmacological targets of metabolic diseases such as obesity and diabetes.

MATERIALS AND METHODS

For this purpose, enzyme inhibition bioassays of lipase, α-glucosidase and dipeptidyl peptidase-4 were carried out in cell-free systems. Similarly, adipocytes derived from 3T3-L1 cells were employed to study the effects of ellagic acid, punicalagin and urolithin A on adipocyte differentiation and triglyceride (TG) accumulation.

RESULTS

Pomegranate juice, ellagic acid, punicalagin and urolithin A were able to inhibit lipase, α-glucosidase and dipeptidyl peptidase-4. Furthermore, all tested compounds but significantly the metabolite urolithin A displayed anti-adipogenic properties in a dose-dependent manner as they significantly reduced TG accumulation and gene expression related to adipocyte formation such as adiponectin, PPARγ, GLUT4, and FABP4 in 3T3-L1 adipocytes.

CONCLUSION

These results may explain from a molecular perspective the beneficial effects and traditional use of pomegranate in the prevention of metabolic-associated disorders such as obesity, diabetes and related complications.

Quantification of phenolics in Syzygium cumini seed and their modulatory role on tertiary butyl-hydrogen peroxide-induced oxidative stress in H9c2 cell lines and key enzymes in cardioprotection

The study quantified the major phenolics in different fractions of Syzygium cumini seeds and evaluated their cardioprotective efficacy. Gallic acid, ellagic acid, cinnamic acid, quercetin, syringic acid and ferulic acid were the major polyphenols present in different fractions of Syzygium cumini seeds. The cardioprotective effect of Syzygium cumini seed fractions in modulating angiotensin converting enzyme (ACE), HMG-CoA reductase, LDL oxidation and tertiary butyl hydrogen peroxide (TBHP) induced oxidative stress in H9c2 cardiac cell lines were investigated. Syzygium cumini effectively attenuated the cellular oxidative stress in H9c2 cardiomyoblasts. These fractions possessed inhibitory potential against ACE, HMG-CoA reductase and LDL oxidation. Molecular docking studies of the predominant polyphenols with ACE and HMG-CoA proteins revealed the binding interactions of these compounds, thus confirming their modulation of activity. The present study demonstrated the cardioprotective efficacy of Syzygium cumini seed fractions which can be attributed to the presence of phenolic acids and flavonoids.

Understanding the mode-of-action of Cassia auriculata via in silico and in vivo studies towards validating it as a long term therapy for type II diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

Cassia auriculata (CA) is used as an antidiabetic therapy in Ayurvedic and Siddha practice. This study aimed to understand the mode-of-action of CA via combined cheminformatics and in vivo biological analysis. In particular, the effect of 10 polyphenolic constituents of CA in modulating insulin and immunoprotective pathways were studied.

MATERIALS AND METHODS

In silico target prediction was first employed to predict the probability of the polyphenols interacting with key protein targets related to insulin signalling, based on a model trained on known bioactivity data and chemical similarity considerations. Next, CA was investigated in in vivo studies where induced type 2 diabetic rats were treated with CA for 28 days and the expression levels of genes regulating insulin signalling pathway, glucose transporters of hepatic (GLUT2) and muscular (GLUT4) tissue, insulin receptor substrate (IRS), phosphorylated insulin receptor (AKT), gluconeogenesis (G6PC and PCK-1), along with inflammatory mediators genes (NF-κB, IL-6, IFN-γ and TNF-α) and peroxisome proliferators-activated receptor gamma (PPAR-γ) were determined by qPCR.

RESULTS

In silico analysis shows that several of the top 20 enriched targets predicted for the constituents of CA are involved in insulin signalling pathways e.g. PTPN1, PCK-α, AKT2, PI3K-γ. Some of the predictions were supported by scientific literature such as the prediction of PI3K for epigallocatechin gallate. Based on the in silico and in vivo findings, we hypothesized that CA may enhance glucose uptake and glucose transporter expressions via the IRS signalling pathway. This is based on AKT2 and PI3K-γ being listed in the top 20 enriched targets. In vivo analysis shows significant increase in the expression of IRS, AKT, GLUT2 and GLUT4. CA may also affect the PPAR-γ signalling pathway. This is based on the CA-treated groups showing significant activation of PPAR-γ in the liver compared to control. PPAR-γ was predicted by the in silico target prediction with high normalisation rate although it was not in the top 20 most enriched targets. CA may also be involved in the gluconeogenesis and glycogenolysis in the liver based on the downregulation of G6PC and PCK-1 genes seen in CA-treated groups. In addition, CA-treated groups also showed decreased cholesterol, triglyceride, glucose, CRP and Hb1Ac levels, and increased insulin and C-peptide levels. These findings demonstrate the insulin secretagogue and sensitizer effect of CA.

CONCLUSION

Based on both an in silico and in vivo analysis, we propose here that CA mediates glucose/lipid metabolism via the PI3K signalling pathway, and influence AKT thereby causing insulin secretion and insulin sensitivity in peripheral tissues. CA enhances glucose uptake and expression of glucose transporters in particular via the upregulation of GLUT2 and GLUT4. Thus, based on its ability to modulate immunometabolic pathways, CA appears as an attractive long term therapy for T2DM even at relatively low doses.

Urolithin A attenuates ox-LDL-induced endothelial dysfunction partly by modulating microRNA-27 and ERK/PPAR-γ pathway

SCOPE

Endothelial dysfunction and inflammation are both common events occurring during the development of atherosclerosis. Previous studies have shown that urolithins, the intestinal microflora metabolites of ellagitannin, exhibit anti-inflammation and antioxidative properties. This study aims to investigate the protective effect of urolithin A (UA) on ox-LDL-induced (where ox-LDL is oxidized low-density lipoprotein) endothelial dysfunction and possible modes of action.

METHODS AND RESULTS

Human artery endothelial cells were incubated with 50 μg/mL ox-LDL and various concentrations of UA for 24 h. UA improved the productions of nitric oxide and endothelial nitric oxide synthase in a dose-dependent manner. UA markedly reduced the expressions of ICAM-1 (intercellular adhesion molecule 1) and MCP-1 (monocyte chemotactic protein 1) and further attenuated THP-1 (human acute monocytic leukemia cell line) cell adhesion. In addition, UA suppressed expressions of tumor necrosis factor α, interleukin 6, and endothelin 1, and increased PPAR-γ (peroxisome proliferators activated receptor gamma) mRNA expression. Moreover, UA decreased miR-27 expression, and overexpression of miR-27 by adding pre-miR-27 abolished the ability of UA to improve ox-LDL-induced PPAR-γ decrease. Furthermore, UA significantly downregulated phosphorylated ERK1/2 (where ERK is extracellular signal-regulated kinase) while decreasing interleukin 6 level and elevating PPAR-γ.

CONCLUSIONS

UA could alleviate endothelial dysfunction induced by ox-LDL partially through modulating miR-27 expression and ERK/PPAR-γ pathway.

Amentoflavone protects hippocampal neurons: anti-inflammatory, antioxidative, and antiapoptotic effects

Amentoflavone is a natural biflavone compound with many biological properties, including anti-inflammatory, antioxidative, and neuroprotective effects. We presumed that amentoflavone exerts a neuroprotective effect in epilepsy models. Prior to model establishment, mice were intragastrically administered 25 mg/kg amentoflavone for 3 consecutive days. Amentoflavone effectively prevented pilocarpine-induced epilepsy in a mouse kindling model, suppressed nuclear factor-κB activation and expression, inhibited excessive discharge of hippocampal neurons resulting in a reduction in epileptic seizures, shortened attack time, and diminished loss and apoptosis of hippocampal neurons. Results suggested that amentoflavone protected hippocampal neurons in epilepsy mice via anti-inflammation, antioxidation, and antiapoptosis, and then effectively prevented the occurrence of seizures.

Modulating effect of Biophytum sensitivum extract on rats with acetic acid-induced ulcerative colitis

CONTEXT

Traditionally, Biophytum sensitivum (L.) DC (Oxalidaceae) is used in Indian medicine to treat diseases include stomachache, convulsions, cramps, inflammation, and ulcer.

OBJECTIVE

The present study examines the effect of aerial parts of B. sensitivum (methanol extract) on a murine model of ulcerative colitis (UC).

MATERIALS AND METHODS

UC was induced by intracolonic injection of 3% acetic acid in Wistar rats. B. sensitivum (50 or 100 mg/kg b wt) or reference drug sulfasalazine (100 mg/kg b wt) was administrated intra-peritoneally for 5 consecutive days before induction of colitis.

RESULTS

In the present study, we demonstrated for the first time that the administration of B. sensitivum (50 mg/kg b wt) was found to inhibit colitis by lowering macroscopic score (up to 3.66 ± 0.77) and also showed significant reduction (p < 0.01) in lactate dehydrogenase (LDH) and myeloperoxidase (MPO) activities. Furthermore, a significant reduction (p < 0.01) in mucosal content of lipid peroxidation (LPO), glutathione (GSH), superoxide dismutase (SOD), and nitric oxide (NO) confirms that B. sensitivum could significantly inhibit colitis. The study showed significant reduction (p < 0.01) in colonic tumor necrosis factor-α (TNF-α), interleukin-1-β (IL-1β), and IL-6 levels as well as the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) after treatment compared with the colitis control group. The histopathological study also confirms the foregoing findings. Treatment with B. sensitivum was also able to inhibit the activation and translocation of transcription factors, nuclear factor (NF)-κB subunits (p65/p50).

CONCLUSION

These results suggest that B. sensitivum exhibits protective effect against acetic acid-induced UC.

Ginkgo biloba extract inhibits oxidized low-density lipoprotein (oxLDL)-induced matrix metalloproteinase activation by the modulation of the lectin-like oxLDL receptor 1-regulated signaling pathway in human umbilical vein endothelial cells

BACKGROUND

The overexpression of matrix metalloproteinases (MMPs) induced by oxidized low-density lipoprotein (oxLDL) has been found in atherosclerotic lesions. Previous reports have identified that oxLDL, via the upregulation of lectin-like ox-LDL receptor 1 (LOX-1), modulates the expression of MMPs in endothelial cells. Ginkgo biloba extract (GbE), from Ginkgo biloba leaves, has often been considered as a therapeutic compound for cardiovascular and neurologic diseases. However, further investigation is needed to ascertain the probable molecular mechanisms underlying the antiatherogenic effects of GbE. The aim of this study was to investigate the effects of GbE on oxLDL-activated MMPs of human endothelial cells and to test the involvement of LOX-1 and protein kinase C (PKC)-α, extracellular signal-regulated kinase (ERK), and peroxisome proliferator-activated receptor-γ (PPAR-γ).

METHODS

Human umbilical vein endothelial cells were stimulated with oxLDL, with or without GbE treatment. LOX-1 signaling and MMPs expression were tested by Western blotting or activity assay. Further, protein expression levels of PKC-α, ERK, nuclear factor-κB, and PPAR-γ were investigated by Western blotting.

RESULTS

GbE inhibited the oxLDL-caused upregulation of MMP-1, MMP-2, and MMP-3. Pretreating with GbE reduced oxLDL-activated LOX-1 expression. Furthermore, pharmacologic inhibitors of free radicals, Ca(++), PKC, and GbE, inhibited the oxLDL-induced ERK and nuclear factor-κB activation. Lastly, GbE ameliorated the oxLDL-inhibited PPAR-γ function.

CONCLUSIONS

Data obtained in this study indicate that GbE actives its protective effects by regulating the LOX-1-mediated PKC-α/ERK/PPAR-γ/MMP pathway, resulting in the suppression of reactive oxygen species formation and, ultimately, the reduction of MMPs expression in endothelial cells treated with oxLDL.

Effects of vitamin E on peroxisome proliferator-activated receptor γ and nuclear factor-erythroid 2-related factor 2 in hypercholesterolemia-induced atherosclerosis

Atherosclerosis and associated cardiovascular complications such as stroke and myocardial infarction are major causes of morbidity and mortality. We have previously reported a significant increase in mRNA levels of the scavenger receptor CD36 in aortae of cholesterol-fed rabbits and shown that vitamin E treatment attenuated increased CD36 mRNA expression. In the present study, we further investigated the redox signaling pathways associated with protection against atherogenesis induced by high dietary cholesterol and correlated these with CD36 expression and the effects of vitamin E supplementation in a rabbit model. Male albino rabbits were assigned to either a control group fed with a low vitamin E diet alone or a test group fed with a low vitamin E diet containing 2% cholesterol in the absence or presence of daily intramuscular injections of vitamin E (50mg/kg). To elucidate the mechanisms by which vitamin E supplementation alters the effects of hypercholesterolemia in rabbit aortae, we measured peroxisome proliferator-activated receptor γ (PPARγ), ATP-binding cassette transporter A1 (ABCA1), and matrix metalloproteinase-1 (MMP-1) mRNA levels by quantitative RT-PCR and the expression of MMP-1, nuclear factor-erythroid 2-related factor 2 (Nrf2), and glutathione S-transferase α (GSTα) protein by immunoblotting. The increased MMP-1 and decreased GSTα expression observed suggests that a cholesterol-rich diet contributes to the development of atherosclerosis, whereas vitamin E supplementation affords protection by decreasing MMP-1 and increasing PPARγ, GSTα, and ABCA1 levels in aortae of rabbits fed a cholesterol-rich diet. Notably, protein expression of Nrf2, the antioxidant transcription factor, was increased in both the cholesterol-fed and the vitamin E-supplemented groups. Although Nrf2 activation can promote CD36-mediated cholesterol uptake by macrophages, the increased induction of Nrf2-mediated antioxidant genes is likely to contribute to decreased lesion progression. Thus, our study demonstrates that Nrf2 can mediate both pro- and antiatherosclerotic effects.

Intestinal anti-inflammatory activity of ellagic acid in the acute and chronic dextrane sulfate sodium models of mice colitis

ETHNOPHARMACOLOGICAL RELEVANCE

Pomegranate (Punica granatum L.; Lythraceae) has traditionally been used for the treatment of various inflammatory diseases, including ulcerative colitis (UC). Because its fruits and extracts are rich in ellagitannins, which release ellagic acid when hydrolyzed, consumption of pomegranate products is currently being widely promoted for their potential health effects, including the prevention of inflammatory diseases and cancer. To evaluate the anti-inflammatory effects of ellagic acid on dextran sulfate sodium (DSS)-induced acute and chronic experimental colitis in two different strains of mice and to elucidate its possible mechanisms of action.

MATERIALS AND METHODS

In the acute UC model, female Balb/C mice were treated with DSS (5%) for seven days while concomitantly receiving a dietary supplement of ellagic acid (2%). In the chronic UC model, female C57BL/6 mice received four week-long cycles of DSS (1% and 2%) interspersed with week-long recovery periods along with a diet supplemented with ellagic acid (0.5%).

RESULTS

In acute model of UC, ellagic acid ameliorated disease severity slightly as observed both macroscopically and through the profile of inflammatory mediators (IL-6, TNF-α, and IFN-γ). In the chronic UC model, ellagic acid significantly inhibited the progression of the disease, reducing intestinal inflammation and decreasing histological scores. Moreover, mediators such as COX-2 and iNOS were downregulated and the signaling pathways p38 MAPK, NF-κB, and STAT3 were blocked.

CONCLUSIONS

Our study reinforces the hypothetical use of ellagic acid as an anti-inflammatory complement to conventional UC treatment in chronic UC patients and could be considered in the dietary prevention of intestinal inflammation and related cancer development.

Amentoflavone inhibits iNOS, COX-2 expression and modulates cytokine profile, NF-κB signal transduction pathways in rats with ulcerative colitis. Int Immunopharmacol. 2013;17:907-916. [PMID: 24126114 DOI: 10.1016/j.intimp.2013.09.022]

Ulcerative colitis is a chronic inflammatory disorder characterized by oxidative stress, leucocyte infiltration and upregulation of pro-inflammatory cytokines. The aim of the present study was to examine the effect of amentoflavone on a murine model of ulcerative colitis (UC). UC was induced by intracolonic injection of 3% acetic acid in male Wistar rats. amentoflavone (10 mg/kg·b.wt) or reference drug sulfasalazine (100 mg/kg·b.wt) was administrated intra-peritoneally for 5 consecutive days before induction of colitis with acetic acid. Administration of amentoflavone was found to reduce the extent of inflammatory colonic injury. This was manifested by a decrease in the score of mucosal injury, by lowered colonic wet weight as well as vascular permeability and diminished lactate dehydrogenase (LDH) and myeloperoxidase (MPO) activity reflecting reduced leukocyte infiltration. Furthermore, the mucosal content of lipid peroxidation (LPO), glutathione (GSH), superoxide dismutase (SOD), nitric oxide (NO) activity confirms that amentoflavone could significantly inhibit colitis. The treatment also reduced significantly the colonic tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and IL-6 levels as well as the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) compared to colitis control group. The histopathological studies also confirm the foregoing findings. amentoflavone was also able to inhibit the activation and translocation of transcription factors, nuclear factor (NF)-κB subunits (p65/p50). These results suggest that amentoflavone exhibits protective effect in acetic acid-induced ulcerative colitis which might be due to its modulation of oxidant/anti-oxidant balance, down-regulation of productions and expressions of pro-inflammatory cytokines, inflammatory mediators and inhibition of NF-κB signal transduction pathways.

Density functional predictions of antioxidant activity and UV spectral features of nasutin A, isonasutin, ellagic acid, and one of its possible derivatives

The antioxidant ability of ellagic acid and some of its derivatives was explored at density functional level of theory within the framework of the following three different reaction mechanisms: hydrogen atom transfer (HAT), electron transfer followed by proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET). Computations were performed in gas phase and in both water and methanol media. Results show that the HAT mechanism is preferred by this class of compounds in all environments, although, in principle, polar solvents should promote the SET-PT and SPLET mechanisms. Among the considered compounds, the derivative not yet experimentally characterized seems to be the most promising candidate as antioxidant. For a more detailed spectroscopic characterization and to help in the identification of these compounds, the simulated UV spectra of all investigated molecules were done by using the time-dependent formulation of density functional theory (TDDFT).

Simultaneous Determination of Gallic Acid, Ellagic Acid, and Eugenol in Syzygium aromaticum and Verification of Chemical Antagonistic Effect by the Combination with Curcuma aromatica Using Regression Analysis

This study was designed to perform simultaneous determination of three reference compounds in Syzygium aromaticum (SA), gallic acid, ellagic acid, and eugenol, and to investigate the chemical antagonistic effect when combining Curcuma aromatica (CA) with SA, based on chromatographic analysis. The values of LODs and LOQs were 0.01-0.11  μ g/mL and 0.03-0.36  μ g/mL, respectively. The intraday and interday precisions were <3.0 of RSD values, and the recovery was in the range of 92.19-103.24%, with RSD values <3.0%. Repeatability and stability were 0.38-0.73% and 0.49-2.24%, respectively. Compared with the content of reference and relative peaks in SA and SA combined with CA (SAC), the amounts of gallic acid and eugenol were increased, while that of ellagic acid was decreased in SAC (compared with SA), and most of peak areas in SA were reduced in SAC. Regression analysis of the relative peak areas between SA and SAC showed r (2) values >0.87, indicating a linear relationship between SA and SAC. These results demonstrate that the components contained in CA could affect the extraction of components of SA mainly in a decreasing manner. The antagonistic effect of CA on SA was verified by chemical analysis.

Pomegranate: a fruit that ameliorates metabolic syndrome

Pomegranate is an ancient fruit that is still part of the diet in the Mediterranean area, the Middle East, and India. Health-promoting effects have long been attributed to this fruit. Modern research corroborates the use of pomegranate as a folk remedy for diabetes and metabolic syndrome, and is responsible for a new evaluation of nutritional and pharmaceutical aspects of pomegranate in the general public. In the last decade, industry and agricultural production have been adapted to meet higher market demands for pomegranate. In vivo and in vitro studies have demonstrated that pomegranate exerts hypoglycaemic effects, including increased insulin sensitivity, inhibition of α-glucosidase, and impact on glucose transporter type 4 function, but is also responsible for a reduction of total cholesterol, and the improvement of blood lipid profiles, as well as anti-inflammatory effects through the modulation of peroxisome proliferator-activated receptor pathways. These effects may also explain how pomegranate-derived compounds function in the amelioration of adverse health effects caused by metabolic syndrome. Pomegranate contains polyphenols such as ellagitannins and anthocyanins, as well as phenolic acids, fatty acids and a variety of volatile compounds. Ellagitannins are some of the most prevalent compounds present in pomegranate, and may be responsible for certain benevolent characteristics associated with pomegranate. A brief overview of rising health problems due to obesity will be provided, followed by characterisation of the biological activity, bioavailability, and safety of pomegranate and pomegranate-derived compounds. Although the fruit is consumed in many countries, epidemiological and clinical studies are unavailable. Additional research is necessary to corroborate the promise of current in vivo and in vitro findings.

Dietary supplementation of an ellagic acid-enriched pomegranate extract attenuates chronic colonic inflammation in rats

Dietary polyphenols present in Punica granatum (pomegranate), such as ellagitannins and ellagic acid (EA) have shown to exert anti-inflammatory and antioxidant properties. This study was designed to evaluate the effects of a dietary EA-enriched pomegranate extract (PE) in a murine chronic model of Cronh's disease (CD). Colonic injury was induced by intracolonic instillation of trinitrobenzensulfonic acid (TNBS). Rats were fed with different diets during 30 days before TNBS instillation and 2 weeks before killing: (i) standard, (ii) PE 250 mg/kg/day, (iii) PE 500 mg/kg/day, (iv) EA 10 mg/kg/day and (v) EA 10 mg/kg/day enriched-PE 250 mg/kg/day. Inflammation response was assessed by histology and MPO activity and TNF-α production. Besides, colonic expressions of iNOS, COX-2, p38, JNK, pERK1/2 MAPKs, IKBα and nuclear p65 NF-κB were studied by western blotting. MPO activity and the TNF-α levels were significantly reduced in dietary fed rats when compared with TNBS group. Similarly, PE and an EA-enriched PE diets drastically decreased COX-2 and iNOS overexpression, reduced MAPKs phosporylation and prevented the nuclear NF-κB translocation. Dietary supplementation of EA contributes in the beneficial effect of PE in this experimental colitis model and may be a novel therapeutic strategy to manage inflammatory bowel disease (IBD).

55-week treatment of mice with the unani and ayurvedic medicine pomegranate flower ameliorates ageing-associated insulin resistance and skin abnormalities

PPARs play a pivotal role in regulating lipid and glucose homeostasis and are involved in diverse biological activities in skin. Pomegranate flower (PGF, an antidiabetic therapy in Unani and Ayurvedic medicines) has been previously demonstrated to activate both PPARalpha/gamma. Here, we found that treatment of mice with the diet containing PGF powder over 55 weeks attenuated ageing-induced abnormal increases in the homeostasis model assessment of insulin resistance, glucose concentrations during oral glucose tolerance test, and adipose insulin resistance index. The diet tended to decrease the excessive peri-ovary fat mass. It, however, increased the thinned subcutaneous fat thickness. In addition, the diet restored decreases in skin water content, epidermis thickness, and collagen density in corium. Thus, our results demonstrate that long-term treatment with the Unani and Ayurvedic therapy ameliorates ageing-induced insulin resistance, which is associated with reversal of ageing-induced fat redistribution. Further, PGF attenuates ageing-mediated undesirable skin abnormalities.

Ellagic acid coordinately attenuates Wnt/β-catenin and NF-κB signaling pathways to induce intrinsic apoptosis in an animal model of oral oncogenesis

PURPOSE

Constitutive activation of the Wnt signaling pathway and its downstream effectors plays a key role in neoplastic transformation. The objective of this study was to investigate the effect of ellagic acid, a plant-derived polyphenol on Wnt/β-catenin signaling and its downstream circuits- NF-κB and mitochondrial apoptosis in the 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis model.

METHODS

Hamsters were divided into six groups. The right buccal pouches of animals in groups 1-4 were painted with 0.5% DMBA three times a week for 14 weeks. Animals in groups 2-4 received in addition basal diet containing ellagic acid at a concentration of 0.1, 0.2, and 0.4% in the diet. Group 5 animals were given 0.4% ellagic acid alone. Group 6 animals served as control. The expression of the members of Wnt and NF-κB signaling and intrinsic apoptosis was evaluated by western blot analysis.

RESULTS

Dietary supplementation of 0.4% ellagic acid suppressed the development of HBP carcinomas by preventing the constitutive activation of Wnt pathway through the downregulation of Fz, Dvl-2, GSK-3β and nuclear translocation of β-catenin. Abrogation of Wnt signaling by ellagic acid was also associated with inactivation of NF-κB and modulation of key components of the mitochondrial apoptotic network.

CONCLUSIONS

Our findings suggest a functional crosstalk between Wnt and NF-κB signaling pathways in HBP carcinomas that is blocked by ellagic acid supplementation. Dietary ellagic acid that targets the Wnt/β-catenin pathway as well as its downstream signaling mediators is a unique candidate for cancer chemoprevention.