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.     

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.     

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.     

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.     

Triterpene acids isolated from Lagerstroemia speciosa leaves as α‐glucosidase inhibitors

The potential antidiabetic activity of ethyl acetate extract of the leaves of Lagerstroemia speciosa (LSL) was investigated by α‐amylase and α‐glucosidase inhibition assay. Six pentacyclic triterpenes (oleanolic acid, arjunolic acid, asiatic acid, maslinic acid, corosolic acid and 23‐hydroxyursolic acid) were isolated from LSL. Their structures were determined by spectroscopic analysis and their α‐glycosidase and α‐amylase inhibitory activities were investigated. They exhibited no or weak inhibitory activity against α‐amylase and middle α‐glucosidase inhibitory activities. Corosolic acid, which shows best bioactivity against α‐glucosidase (IC₅₀ = 3.53 µg/mL), contributes most to the α‐glucosidase inhibitory activity of EtOAc extract. The kinetics of inhibition of corosolic acid was also discussed. Results from this study might provide the scientific evidence for LSL for the treatment of diabetes in traditional medicine. Copyright © 2008 John Wiley & Sons, Ltd.     

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.     

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.     

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.     

Dolichandroside A,a new α‐glucosidase inhibitor and DPPH free‐radical Scavenger from Dolichandrone falcata seem

A new phenylpropanoid glycoside, dolichandroside‐A, together with seven known compounds α‐lapachone, lapachol, aloesaponarin II, 8‐hydroxydehydroiso‐α‐lapachone, β‐sitosterol, 3,8‐dihydroxydehydroiso‐α‐lapachone and verbascoside were isolated from the active ethyl acetate soluble extract of heartwood of Dolichandrone falcata. All except for dolichandroside‐A are known compounds, but have been isolated for the first time from this plant. The structure of all these compounds was determined on the basis of 1D‐ and 2D‐NMR spectral data. All the isolates were tested for α‐glucosidase inhibitory and DPPH radical scavenging activity. This is the first report identifying DPPH scavenging activity and α‐glucosidase inhibitory activity in D. falcata. Furthermore, along with a new compound, dolichandroside‐A, this study also assigns for the first time α‐glucosidase inhibitory activity to verbascoside and aloe saponarin‐II. Copyright © 2008 John Wiley & Sons, Ltd.     

Parthenolide Inhibits the LPS‐induced Secretion of IL‐6 and TNF‐α and NF‐κB Nuclear Translocation in BV‐2 Microglia

Feverfew (Tanacetum parthenium [L.] Sch. Bip. [Asteraceae]) is a popular herbal treatment used to prevent and treat headache and migraine. Parthenolide (PTN), the sesquiterpene lactonic derivative that is the plant's major component, might be one of the ingredients that act on mediators of inflammation. In the present study, in cultured lipopolysaccharide (LPS)‐stimulated BV‐2 microglia pretreatment with PTN caused a dose‐dependent reduction of interleukin‐6 (IL‐6) secretion (29% by 200 nm, p < 0.001; 45% by 1 µm, p < 0.001; 98% by 5 µm, p < 0.001); at 5 µm, the highest concentration tested, it also reduced the secretion of TNF‐α (54%, p < 0.001). Western blotting analysis on separate cytoplasmic and nuclear extracts showed that PTN strongly reduced the translocation of nuclear factor (NF)‐κB to the cell nucleus. The reduction of microglial activation by inhibition of proinflammatory agents may help attenuate the onset and intensity of acute migraine attacks. These in vitro results provide an additional explanation for the efficacy of orally administered T. parthenium as an antimigraine agent. Copyright © 2012 John Wiley & Sons, Ltd.     

Daily Inhalation of α‐Pinene in Mice: Effects on Behavior and Organ Accumulation

In phytotherapy, essential oils tend to be used daily for a period of days or weeks, rather than in a single application. However, the literature contains very little information on repeated use of essential oils. In this study, we investigated the effects on behavior and the accumulation in the brain and liver of α‐pinene, an essential oil component, when inhaled by mice. Animals were individually housed in cages for 1 week. Mice inhaled α‐pinene or water vapor (negative control) for 90 min/day for 1 day, 3 days, or 5 days, and they were then submitted to the elevated plus maze test for 10 min. We used gas chromatography with flame ionization detection to quantify concentrations of α‐pinene in the brain and liver. There was significant anxiolytic‐like activity, which remained constant for the 5 days' inhalation of α‐pinene. On the other hand, the accumulation of α‐pinene in the brain and liver peaked on the third day of inhalation. The existence of stress related to the new environment appears to have affected the change in the accumulation of α‐pinene in the internal organs, keeping the anxiolytic‐like action constant. Copyright © 2013 John Wiley & Sons, Ltd.     

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.     

Anxiolytic‐like Effect of α‐Asarone in Mice

The effects of α‐asarone in four assays predictive of anxiolytic activity in male mice were studied, with diazepam as a positive anxiolytic control. The use of the elevated plus‐maze test revealed that diazepam (2 mg/kg) or α‐asarone (3.5 mg/kg) increased the percentage of entries into open arms and of the time spent on open arms. In the light/dark transition test, as with 2 mg/kg diazepam, 7 mg/kg α‐asarone increased the time spent in the light area and the number of transitions between the two compartments. In the novel food consumption test, α‐asarone (3.5, 7 and 14 mg/kg) caused significant increases in food intake during 5 min as well as diazepam (0.5 mg/kg). In the marble burying test, α‐asarone also produced a significant inhibition of marble burying at doses of 14 and 28 mg/kg, as did diazepam (5 mg/kg). Thus, these findings indicated that α‐asarone exhibited an anxiolytic‐like effect. Further studies will be required to assess the generality of the present findings to other species and behavioral paradigms. Copyright © 2012 John Wiley & Sons, Ltd.     

The Protective Effect of α‐Hederin,the Active Constituent of Nigella sativa,on Lung Inflammation and Blood Cytokines in Ovalbumin Sensitized Guinea Pigs

In the present study, the preventive effect of two different concentrations of α‐hederin, the active constituent of Nigella sativa, on lung inflammation and blood cytokines in ovalbumin sensitized guinea pigs was examined. Forty eight male adult guinea pigs were divided into control (C), sensitized (S) and sensitized pretreated groups; with thymoquinone (S+TQ), low dose (S+LAH) and high dose of α‐hederin (S+HAH) and inhaled fluticasone propionate (S+FP). The lung histopathology and blood levels of IL‐4, IFN‐γ and IL‐17 were assessed. Compared to sensitized animals, all pathological changes improved significantly in pretreated groups (p < 0.001 to p < 0.05). These improvements in α‐hederin pretreated groups were similar to S+TQ and S+FP groups except cellular infiltration in S+LAH and S+HAH groups which was lower than S+TQ group (p < 0.05). The blood IL‐4 and IL‐17 levels in S+HAH groups showed a significant decrease compared to S group (p < 0.05) which were similar to S+TQ and S+FP groups. The level of IFN‐γ in S+LAH and S+HAH groups increased significantly compared to S group (p < 0.05) which was higher than S+FP group (p < 0.05). Blood IL‐4 in S+HAH group was significantly lower than S+LAH group (p < 0.05). In conclusion, α‐hederin could attenuate the lung inflammation and improve the changes of cytokines like thymoquinone and fluticasone in used dosages. Copyright © 2015 John Wiley & Sons, Ltd.     

Sour Cherry Seed Kernel Extract Increases Heme Oxygenase‐1 Expression and Decreases Representation of CD3+ TNF‐α + and CD3 + IL‐8+ Subpopulations in Peripheral Blood Leukocyte Cultures from Type 2 Diabetes Patients

The present study evaluates a hypothesis that sour cherry (Prunus cerasus) seed extracts (SCE) modulate CD3+ T lymphocyte activity in ways predictive of potential for uses of SCE in management of inflammatory diseases. Peripheral blood mononuclear cells (PBMC) from 12 type 2 diabetes (T2DM) patients and eight healthy control subjects were cultured 24 h with 100 ng/ml lipopolysaccharide (LPS) to increase inflammatory signaling and co‐incubated with 0.5–100 µg/ml SCE. Cultures were evaluated by two‐color flow cytometry for percent representation of CD3+ IL8+ and CD3 + TNF‐α + cells which express interleukin‐8 (IL‐8), and tumor necrosis factor‐α, (TNF‐α+) respectively, and by enzyme‐linked immunoassay for lymphocyte‐associated heme oxygenase‐1 (HO‐1, known to be induced by SCE). SCE dosage ranges of 0.5–100 µg/ml in cell cultures significantly suppressed LPS‐increased CD3 + TNF‐α + and CD3 + IL8+ representation from all participants (p < 0.05), with greater pharmacological effect noted in suppression of CD3 + TNF‐α + noted in cells from T2DM patients versus healthy control subjects. These effects correlated with increased HO‐1 expression in SCE‐treated PBMC from all subjects (p < 0.05). Since TNF‐α and IL‐8 are diagnostic/prognostic biomarkers for many inflammatory syndromes, the capacity of SCE to down‐regulate representation of cells that express them suggests potential for therapeutic use of SCE in T2DM and other diseases. Copyright © 2012 John Wiley & Sons, Ltd.     

Toll‐like receptor 4‐mediated immunoregulation by the aqueous extract of Mori Fructus

The aqueous extract of Mori Fructus (MF) exerts a change of phenotype and a cytoprotective effect in macrophages. The present study was carried out to investigate the immunomodulating activity of MF on the expression of nitric oxide (NO), tumor necrosis factor alpha (TNF‐α), co‐stimulatory molecules and also interferon‐gamma (IFN‐γ) in macrophages and splenocytes. Toll‐like receptor 4 (TLR4) is a promising molecular target for immune‐modulating drugs. It was hypothesized that one possible upstream signaling pathway leading to immunoregulation of MF may be mediated by TLRs. Multiple signaling molecules (NF‐κB, ERK1/2, p38 and JNK) of the TLR4 signaling pathway were also detected. It was found that MF increased NO production and TNF‐α secretion in RAW 264.7 and peritoneal macrophages, co‐stimulatory molecules expression in peritoneal macrophages and IFN‐γ expression in splenocytes. Further studies indicated that MF could significantly induce the phosphorylation of signal molecules of MAPKs and the degradation of IκBα which finally led to the activation and nuclear translocation of nuclear factor‐κB (NF‐κB) for the target gene expression. All those notions disclosed that the aqueous extract MF is a new TLR4 activator, which induces a Th1 immune response as a consequence of induction of cytokines secretion, especially TNF‐α and IFN‐γ. Copyright © 2009 John Wiley & Sons, Ltd.     

Ameliorative Effects of Pine Bark Extract on Spermatotoxicity by α‐Chlorohydrin in Rats

We investigated the protective effects of pine bark extract (Pycnogenol®, PYC, Horphag Research Ltd., Route de Belis, France) against α‐chlorohydrin (ACH)‐induced spermatotoxicity in rats. Rats were orally administered ACH (30 mg/kg/day) with or without PYC (20 mg/kg/day) for 7 days. Administration of ACH significantly decreased sperm motility. α‐Chlorohydrin also caused histopathological alterations and apoptotic changes in caput epididymides. An increased malondialdehyde concentration and decreased glutathione content, as well as catalase and glutathione peroxidase activities were also found. In contrast, PYC treatment significantly prevented ACH‐induced spermatotoxicity, including decreased sperm motility, histopathological lesions, and apoptotic changes in the caput epididymis. Pycnogenol® also had an antioxidant benefit by decreasing malondialdehyde and increasing levels of the antioxidant glutathione and the activities of the antioxidant enzymes catalase and peroxidase in epididymal tissues. These results indicate that PYC treatment attenuated ACH‐induced spermatotoxicity through antioxidant and antiapoptotic effects. Copyright © 2013 John Wiley & Sons, Ltd.     

Expression of BDNF and TH mRNA in the Brain Following Inhaled Administration of α‐Pinene

Essential oils are mainly administered by inhalation. Administration by inhalation is considered to occur through two pathways, neurological transfer and pharmacological transfer. However, the relationship between the two routes is not clear. To clarify this relationship, we administered α‐pinene, which has an anxiolytic‐like effect, to mice. Emotional behavior and accumulation and expression of relevant mRNAs in the brain (brain‐derived neurotrophic factor (BDNF); tyrosine hydroxylase (TH)) were examined following inhaled administration of α‐pinene (10 μL/L air for 60 or 90 min). To evaluate the anxiolytic‐like effect, the elevated plus maze (EPM) test was used. Inhalation of α‐pinene for 60 min produced a significant increase in the total distance traveled in the EPM test compared with control (water). The concentration of α‐pinene in the brain after 60 min of inhalation was significantly increased compared with that after 90 min of inhalation. The expression of BDNF mRNA in the olfactory bulb and in the hippocampus was almost the same after 60 min of inhalation compared to that after 90 min of inhalation. The expression of TH mRNA in the midbrain after 60 min of inhalation was significantly increased compared with that of the control. Thus, an increase in α‐pinene in the brain induces an increase in TH mRNA expression and increases locomotor activity. The anxiolytic‐like effect may be related to both neurological transfer and pharmacological transfer. Copyright © 2014 John Wiley & Sons, Ltd.     

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.