Astragaloside IV inhibits TGF‐β1‐induced epithelial‐mesenchymal transition through inhibition of the PI3K/Akt/NF‐κB pathway in gastric cancer cells

Astragaloside IV (AS‐IV) has been reported to possess anti‐metastasis activity in cancer cells. However, it is unknown whether AS‐IV could inhibit epithelial‐mesenchymal transition (EMT), a cellular de‐differentiation program that promotes metastasis, in cancer cells. The aim of this study was to study the effect and mechanism of AS‐IV on EMT in gastric cancer (GC) cells. The results showed that AS‐IV significantly inhibited cell viability, invasion, and migration of GC cells. The E‐cadherin to N‐cadherin switch and expression of Vimentin and metastasis‐related genes were induced by transforming growth factor β1 (TGF‐β1), whereas AS‐IV reversed the induction. In addition, AS‐IV inhibited TGF‐β1‐induced activation of PI3K/Akt/NF‐κB. Inhibition of the PI3K/Akt/NF‐κB pathway reversed TGF‐β1‐induced EMT. In conclusion, AS‐IV inhibited TGF‐β1‐induced EMT through inhibition of the PI3K/Akt/NF‐κB pathway in GC cells. AS‐IV might be an effective candidate for the treatment for GC.     

β‐Elemene inhibits peritoneal metastasis of gastric cancer cells by modulating FAK/Claudin‐1 signaling

Peritoneal metastasis is common in advanced gastric cancer patients and is typically associated with a worse prognosis. β‐Elemene is a natural compound that can be isolated from the Curcuma wenyujin plant and has been widely used in China to treat a variety of cancers. However, the anti‐metastatic impacts of β‐elemene on gastric cancer remain unknown. In our study, we found that β‐elemene significantly inhibited the migration and invasive capacity of gastric cells in vitro and inhibited the capacity of gastric cancer cells to peritoneally diffuse and metastasize in vivo. Mechanistically, we demonstrated that the anti‐metastatic effects of β‐elemene were exerted by downregulating the expression of Claudin‐1. Furthermore, β‐elemene was found to inhibit the metastatic capacity of cells by downregulating FAK phosphorylation, which regulated Claudin‐1. Overall, our result revealed that β‐elemene inhibited peritoneal metastases from gastric cancer by modulating the FAK/Claudin‐1 pathway.     

Protective effect of amygdalin on epithelial–mesenchymal transformation in experimental chronic obstructive pulmonary disease mice

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory pulmonary disease characterized by continuous, progressive limitation of airflow. Airway remodelling, which is correlated with epithelial–mesenchymal transitions (EMTs), is a typical pathophysiological change of COPD. Amygdalin, an active ingredient in the traditional Chinese medicine bitter almond with extensive pharmacological effects, was shown to inhibit tissue fibrosis in recent studies. In this study, a human bronchial epithelial cell line (BEAS‐2B) and mice were exposed to cigarette smoke, and EMT levels were investigated after treatment with different concentrations of amygdalin. Morphology was assessed by immunohistochemical staining. Evaluation of the expression of TGF‐β1, smad2/3, and p‐smad2/3 in lung tissue was conducted out via ELISA, Western blot, and real‐time PCR. The results showed that E‐cadherin expression was significantly increased, whereas vimentin, TGF‐β1, and phosphorylated smad2/3 (p‐smad2/3) expression was markedly decreased in the amygdalin‐treated groups compared with the model group. Therefore, our study demonstrated a protective role of amygdalin in the murine EMT process after COPD.     

A Comparative Study on the Inhibitory Effects of Different Parts and Chemical Constituents of Pomegranate on α‐Amylase and α‐Glucosidase

Pomegranate has been documented for the management of diabetes in Unani and Chinese medicine. This study compared the effects of the extracts of different pomegranate parts, including juice, peels, seeds and flowers, on carbohydrate digestive enzymes (α‐amylase and α‐glucosidase) in vitro. The methanolic flower extract inhibited α‐amylase and α‐glucosidase, while the methanolic peel extract inhibited α‐glucosidase selectively. The most active flower extract was subjected to water‐ethyl acetate partition. The ethyl acetate fraction was more potent than the water fraction in inhibiting both enzymes. Gallic acid and ellagic acid also showed selective inhibition against α‐glucosidase, and their presence in the ethyl acetate fraction was confirmed by HPLC‐DAD and HPLC‐HESI‐MS. Our findings suggest that the inhibition of carbohydrate digestive enzymes and their phenolic content may contribute to the anti‐hyperglycaemic effects of pomegranate flower and peel, and support their claims in diabetes. Copyright © 2012 John Wiley & Sons, Ltd.     

Phloroglucinol Protects INS‐1 Pancreatic β‐cells Against Glucotoxicity‐Induced Apoptosis

Decreasing numbers, and impaired function, of pancreatic β‐cells are key factors in the development of type 2 diabetes. This study was designed to investigate whether phloroglucinol protected pancreatic β‐cells against glucotoxicity‐induced apoptosis using a rat insulinoma cell line (INS‐1). High glucose treatment (30 mM) induced INS‐1 cell death; however, the level of glucose‐induced apoptosis was significantly reduced in cells treated with 100‐μM phloroglucinol. Treatment with 10–100‐μM phloroglucinol increased cell viability and decreased intracellular levels of reactive oxygen species, nitric oxide, and lipid peroxidation dose‐dependently in INS‐1 cells pretreated with high glucose. Furthermore, phloroglucinol treatment markedly reduced the protein expression of Bax, cytochrome c, and caspase 9, while increasing anti‐apoptotic Bcl‐2 protein expression. Cell death type was examined using annexin V/propidium iodide staining, revealing that phloroglucinol markedly reduced high glucose‐induced apoptosis. These results demonstrated that phloroglucinol could be useful as a potential therapeutic agent for the protection of pancreatic β‐cells against glucose‐induced apoptosis. Copyright © 2015 John Wiley & Sons, Ltd.     

The anti‐inflammatory effect of baicalin on hypoxia/reoxygenation and TNF‐α induced injury in cultural rat cardiomyocytes

The aim of present study was to investigate the effect of baicalin on hypoxia/reoxygenation (H/R) injury in cardiomyocytes and the mechanisms involved, particularly in relation to cytokines. The cardiomyocytes for the H/R groups were placed into a hypoxic chamber for 12 h and then underwent reoxygenation for 1 h. The cells in the TNF‐α groups were administered 100 ng/mL rrTNF‐α and incubated for 13 h under normal conditions. The cells in the baicalin pretreatment groups were administered 10 μM baicalin 30 min prior to exposure to H/R or TNF‐α. It was observed that pretreatment with baicalin (10 μM) significantly reduced the cell damage and death induced by H/R or TNF‐α. In the culture medium of the H/R cells, the SOD activity increased, while TNF‐α was decreased by baicalin. The levels of IL‐6 in culture medium for H/R or TNF‐α treated cells were suppressed by baicalin pretreatment. In contrast, the levels of IL‐10 in culture medium for H/R or TNF‐α treated cells were significantly elevated by baicalin. Moreover, baicalin inhibited the nuclear translocation of NF‐κB induced by H/R or TNF‐α. In conclusion, baicalin may protect cardiomyocytes from H/R injury through an anti‐inflammatory mechanism. Copyright © 2009 John Wiley & Sons, Ltd.     

Pheophorbide A from Gelidium amansii improves postprandial hyperglycemia in diabetic mice through α‐glucosidase inhibition

This study was designed to determine the inhibitory effects of pheophorbide A on carbohydrate digesting enzymes and its ability to improve postprandial hyperglycemia in streptozotocin (STZ)‐induced diabetic mice. Pheophorbide A caused noticeable inhibitory effects on α‐glucosidase and α‐amylase, with half‐maximal inhibitory concentrations (IC₅₀) of 80.65 ± 5.90 and 76.48 ± 6.31 μM, respectively. The pheophorbide‐mediated inhibition of α‐glucosidase and α‐amylase was significantly more effective than that of the positive control, acarbose. The increase in postprandial blood glucose levels was more significantly suppressed in the pheophorbide A group than in the control group of STZ‐induced diabetic mice. In addition, the area under the curve was decreased by pheophorbide A intake in STZ‐induced diabetic mice. Our results suggested that pheophorbide A may help to improve postprandial hyperglycemia by inhibiting the activity of carbohydrate digesting enzymes.     

Chelidonine inhibits TNF‐α‐induced inflammation by suppressing the NF‐κB pathways in HCT116 cells

Nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB) is a complex that regulates several hundreds of genes, including those involved in immunity and inflammation, survival, proliferation, and the negative feedback of NF‐κB signaling. Chelidonine, a major bioactive, isoquinoline alkaloid ingredient in Chelidonium majus, exhibits antiinflammatory pharmacological properties. However, its antiinflammatory molecular mechanisms remain unclear. In this work, we explored the effect of chelidonine on TNF‐induced NF‐κB activation in HCT116 cells. We found chelidonine inhibited the phosphorylation and degradation of the inhibitor of NF‐κB alpha and nuclear translocation of RELA. Furthermore, by inhibiting the activation of NF‐κB, chelidonine downregulated target genes involved in inflammation, proliferation, and apoptosis. Chelidonine also inhibited mitogen‐activated protein kinase pathway activation by blocking c‐Jun N‐terminal kinase and p38 phosphorylation. These results suggest that chelidonine may be a potential therapeutic agent against inflammatory diseases in which inhibition of NF‐κB activity plays an important role.     

Theacrine attenuates epithelial mesenchymal transition in human breast cancer MDA‐MB‐231 cells

Theacrine, a purine alkaloid structurally similar to caffeine, has recently become of interest as a potential therapeutic compound. Here, we investigated the antimetastatic potential of theacrine on human breast cancer MDA‐MB‐231 cells. We observed that theacrine can reverse epithelial‐to‐mesenchymal transition (EMT), which resulted in a decrease in the levels of mesenchymal markers (Fibronectin, Vimentin, N‐cadherin, Twist, and Snail) and an increase in the levels of epithelial markers (Occludin and E‐cadherin) in the cells. Additionally, theacrine attenuates TGF‐β‐induced EMT, cell adhesion, migration, and invasion in MDA‐MB‐231 cells. Overall, our results suggest that theacrine may inhibit the breast cancer cell metastasis by reversing the EMT process.     

α‐Glucosidase Inhibitors from the Stems of Embelia ribes

From the ethyl acetate extract of the stems of Embelia ribes (Myrsinaceae), a new alkenylresorcinol, embeliphenol A (1), together with 11 known compounds have been isolated. Their structures were elucidated on the basis of spectroscopic data. All compounds possessed significant α‐glucosidase inhibitory activity in a concentration‐dependent manner, except for 2 and 9. Compounds 1, 3–6, 8, and 12 showed more potent inhibitory activity, with IC₅₀ values ranging from 10.4 to 116.7 μM, than that of a positive control acarbose (IC₅₀, 214.5 μM). Copyright © 2014 John Wiley & Sons, Ltd.     

Identification of higenamine as a novel α1‐adrenergic receptor antagonist

The α₁‐adrenoceptor (α₁‐AR) antagonists are potential candidates for the treatment of blood pressure. Higenamine (HG) is a novel α₁‐AR antagonist. In this study, we investigated the effects of HG in HEK293A cells transfected with α_1A‐, α_1B‐, and α_1D‐AR in vitro, rat mesenteric artery ex vivo, Wistar–Kyoto rats and spontaneously hypertensive rats in vivo. The radioligand binding assay showed that HG competitively inhibited the binding of [³H]‐prazosin to α₁‐AR in a concentration‐dependent manner. The affinities (pKi) of HG for the cloned α_1A‐, α_1B‐, and α_1D‐AR were 6.57, 6.48, and 6.35, respectively, indicating that HG displayed no selectivity for the three α₁‐AR subtypes. In in vitro studies, HG was able to blunt inositol monophosphate production. It also displayed an inhibitory effect on the influx and entry of calcium ions and phosphorylation of extracellular signal‐regulated kinase 1 and 2 induced by phenylephrine (PE). In ex vivo studies, PE caused a dose‐dependent inotropic response curve, and the pA₂ value for HG was 6.86 ± 0.29. In addition, the in vivo results showed that HG could decrease the blood pressure in normotension, spontaneous hypertension, and PE‐induced hypertension models. These results indicate that HG can directly bind to α₁‐AR and it appears to be a novel antagonist for α₁‐AR, which may contribute to its hypotensive effect.     

Luteoloside attenuates anoxia/reoxygenation‐induced cardiomyocytes injury via mitochondrial pathway mediated by 14‐3‐3η protein

Ischemia/reperfusion (I/R) injury is the major cause of acute cardiovascular disease worldwide. 14‐3‐3η protein has been demonstrated to protect myocardium against I/R injury. Luteoloside (Lut), a flavonoid found in many Chinese herbs, exerts myocardial protection effects. However, the mechanism remains unclear. We hypothesize that the cardioprotective role of Lut is exerted by regulating the 14‐3‐3η signal pathway. To investigate our hypothesis, an in vitro I/R model was generated in H9C2 cardiomyocytes by anoxia/reoxygenation (A/R) treatment. The effects of Lut on cardiomyocytes with A/R injury were assessed by determining the cell viability, lactate dehydrogenase levels, intracellular reactive oxygen species levels, mitochondrial permeability transition pores (mPTP) openness, caspase‐3 activity, and apoptosis rate. The effects on protein expression were tested using western blot analysis. Lut attenuated A/R‐induced injury to cardiomyocytes by increasing the expression of 14‐3‐3η protein and cell viability; decreasing levels of lactate dehydrogenase, reactive oxygen species, mPTP openness, caspase‐3 activity, and low apoptosis rate were observed. However, the cardioprotective effects of Lut were blocked by AD14‐3‐3ηRNAi, an adenovirus knocking down the intracellular 14‐3‐3η expression. In conclusion, to our knowledge, this is the first study to demonstrate that Lut protected cardiomyocytes from A/R‐induced injury via the regulation of 14‐3‐3η signaling pathway.     

Anti‐diabetic Activity of Swertiamarin is due to an Active Metabolite,Gentianine, that Upregulates PPAR‐γ Gene Expression in 3T3‐L1 cells

We have previously shown the anti‐diabetic effects of swertiamarin; however, pharmacokinetic analysis showed that swertiamarin had a plasma half‐life of 1.3 h. Gentianine is an active metabolite of swertiamarin that possesses a pharmacophoric moiety. The aim of this study was to explore the possibility whether the anti‐diabetic effect of swertiamarin is due to gentianine. Swertiamarin treatment had no significant effect on adipogenesis, or the mRNA expression of PPAR‐γ and GLUT‐4; however, there was a significant increase in the mRNA expression of adiponectin. On the other hand, treatment with gentianine significantly increased adipogenesis, which was associated with a significant increase in the mRNA expression of PPAR‐γ, GLUT‐4 and adiponectin. These findings suggest, for the first time, that the anti‐diabetic effect of swertiamarin is due to gentianine, an active metabolite of swertiamarin. Copyright © 2012 John Wiley & Sons, Ltd.     

Hydroxy‐Safflower Yellow A inhibits the TNFR1‐Mediated Classical NF‐κB Pathway by Inducing Shedding of TNFR1

Hydroxy‐safflower yellow A (HSYA) is the major active component of safflower, a traditional Asia herbal medicine well known for its cardiovascular protective activities. The purpose of this study was to investigate the effect of HSYA on TNF‐α‐induced inflammatory responses in arterial endothelial cells (AECs) and to explore the mechanisms involved. The results showed that HSYA suppressed the up‐regulation of ICAM‐1 expression in TNF‐α‐stimulated AECs in a dose‐dependent manner. High concentration (120 μM) HSYA significantly inhibited the TNF‐α‐induced adhesion of RAW264.7 cells to AECs. HSYA blocked the TNFR1‐mediated phosphorylation and degradation of IκBα and also prevented the nuclear translocation of NF‐κB p65. Moreover, HSYA reduced the cell surface level of TNFR1 and increased the content of sTNFR1 in the culture media. TNF‐α processing inhibitor‐0 (TAPI‐0) prevented the HSYA inhibition of TNFR1‐induced IκBα degradation, implying the occurrence of TNFR1 shedding. Furthermore, HSYA induced phosphorylation of TNF‐α converting enzyme (TACE) at threonine 735, which is thought to be required for its activation. Conclusively, HSYA suppressed TNF‐α‐induced inflammatory responses in AECs, at least in part by inhibiting the TNFR1‐mediated classical NF‐κB pathway. TACE‐mediated TNFR1 shedding can be involved in this effect. Our study provides new evidence for the antiinflammatory and anti‐atherosclerotic effects of HSYA. Copyright © 2016 John Wiley & Sons, Ltd.     

Catalpol provides a protective effect on fibrillary Aβ1–42‐induced barrier disruption in an in vitro model of the blood–brain barrier

Excessive amyloid beta (Aβ) deposition in brain is mainly responsible for cell damage and blood–brain barrier (BBB) disruption in Alzheimer's disease (AD). Catalpol, an iridoid glucoside extracted from the root of Rehmannia glutinosa Libosch, has neuroprotective effect against AD. It is unclear whether catalpol has a protective effect on Aβ‐induced BBB leakage. We employed an immortalized endothelial cell line (bEnd.3) and astrocytes co‐culture to mimic a BBB model in vitro and investigated the effect of catalpol on BBB. We found that treatment with catalpol decreased BBB hyperpermeability induced by fibrillar Aβ_1–42. Data from western blotting showed that catalpol prevented fibrillar Aβ_1–42‐induced bEnd.3 cell apoptosis through mitochondria‐dependent and death receptor pathways; decreased the levels of matrix metalloproteinases (MMPs), MMP‐2, MMP‐9, and the receptor for advanced glycation end products; and increased the levels of tight junction proteins (ZO‐1, occludin, and claudin‐5), low‐density lipoprotein receptor‐related protein 1, and P‐glycoprotein in fibrillar Aβ_1–42‐treated bEnd.3 cells. Moreover, catalpol also enhanced soluble Aβ efflux across the fibrillar Aβ_1–42‐treated bEnd.3 cells BBB monolayer model. Altogether, our results suggest that catalpol alleviate fibrillar Aβ_1–42‐induced BBB disruption, enhance soluble Aβ clearance, and offer a feasible therapeutic application in AD treatment.     

Analgesic and diuretic properties of α‐santalone from Polygonum flaccidum

Polygonum flaccidum Meissn. is an annual herb, native to Bangladesh, and well known for its analgesic, anti‐inflammatory, diuretic, purgative and insecticidal properties, and also for its use against snake‐bites. The analgesic and the diuretic properties of α‐santalone (1), isolated from the aerial parts of Polygonum flaccidum, were assessed by the acetic‐acid‐induced writhing method and the Lipschitz test, respectively. Complete ¹H and ¹³C NMR data of 1 are also presented. Copyright © 2010 John Wiley & Sons, Ltd.     

Medicinal Plants Traditionally Used for Treatment of Obesity and Diabetes Mellitus – Screening for Pancreatic Lipase and α‐Amylase Inhibition

In order to find new pancreatic lipase (PL) and α‐amylase inhibitors from natural sources for the treatment of obesity and related diseases as diabetes mellitus II, 23 medicinal plants with weight‐reducing, serum glucose‐reducing or related potential were investigated. Methanolic and water extracts of the plants were evaluated by using two in vitro test systems. Our findings have shown that the methanolic extract of Hibiscus sabdariffa L. (Malvaceae) showed high inhibitory activities to PL (IC₅₀: 35.8 ± 0.8 µg/mL) and α‐amylase (IC₅₀: 29.3 ± 0.5 µg/mL). Furthermore, the methanolic extract of Tamarindus indica L. (Leguminosae) showed a high anti‐lipase (IC₅₀: 152.0 ± 7.0 µg/mL) and the aqueous extract a high anti‐amylase (IC₅₀: 139.4 ± 9.0 µg/mL) activity. This work provides a priority list of interesting plants for further study with respect to the treatment of obesity and associated diseases. Copyright © 2015 John Wiley & Sons, Ltd.