Purification and Identification of a Novel Protein Isolated from Panax quinquefolium and Evaluation of its In vitro Antioxidant Properties

Objective: A novel protein was first purified from Panax quinquefolius L.(AGNP), and in vitro antioxidant activities of AGNP were first studied in this work. Methods: AGNP was purified by Ion-exchange chromatography and Gel-filtration chromatography. The chemical characterizations of AGNP were tested by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE), high-pressure gel-filtration chromatography, MALDI-TOF-MS and HPLC. In vitro antioxidant effects were tested in simple antioxidant assay including 2,2-diphenylpicrylhydrazyl radical scavenging, superoxide radical(O_2~-) scavenging, hydroxyl radical(OH) scavenging, and ferric-reducing ability. Results: The results showed which the content of AGNP measured by Bradford method was 2.42 mg/m L and the subunit molecular weight of AGNP measured by sodium dodecyl sulfate–polyacrylamide gel electrophoresis(SDS-PAGE) was 15 kD. The AGNP molecular weight was 15, 114 Da both of SDS-PAGE and mass spectrum purity. The result of high-pressure gel-filtration chromatography demonstrated that the molecular weight of AGNP was 31,086 Da, which implied that AGNP was a homodimer. The in vitro Antioxidant results indicated that AGNP had obvious effects to remove the free radicals in vitro. Conclusion: In conclusion, AGNP had more powerful antioxidant capacity and it can be used as an effective natural antioxidant to alleviate oxidative stress.     

Antioxidant and Anti‐α‐glucosidase Compounds from the Rhizome of Peltiphyllum peltatum (Torr.) Engl

The antioxidant, anti‐α‐glucosidase and anticholinesterase effects of the alcohol extract of fresh underground rhizomes of Peltiphyllum peltatum were studied. A potent antioxidant activity accompanied by a selective α‐glucosidase effect was observed for the crude extract. Further activity‐guided fractionation (petroleum ether, chloroform, ethyl acetate, n‐butanol and water) resulted in the identification of the ethyl acetate fraction with the highest antioxidant effect. Gallic acid, methyl‐3‐O‐methyl gallate, catechin, gallocatechin, bergenin and 11‐O‐galloylbergenin were isolated from the ethyl acetate fraction. While all the isolated compounds did show a variable degree of radical scavenging effect, 11‐O‐galloylbergenin was identified as the selective α‐glucosidase inhibitor. The isolation, structural elucidation and biological effects of these compounds are discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

C‐Glycosyl Flavonoids from Beta vulgaris Cicla and Betalains from Beta vulgaris rubra: Antioxidant,Anticancer and Antiinflammatory Activities—A Review

The green beet (Beta vulgaris var. cicla L.) and red beetroot (B. vulgaris var. rubra L.) contain phytochemicals that have beneficial effects on human health. Specifically, the green beet contains apigenin, vitexin, vitexin‐2‐O‐xyloside and vitexin‐2‐O‐rhamnoside, while the red beetroot is a source of betaxanthins and betacyanins. These phytochemicals show considerable antioxidant activity, as well as antiinflammatory and antiproliferative activities. Vitexin‐2‐O‐xyloside, in combination with betaxanthins and betacyanins, exerts antiproliferative activity in breast, liver, colon and bladder cancer cell lines, through the induction of both intrinsic and extrinsic apoptotic pathways. A significant body of evidence also points to the role of these phytochemicals in the downregulation of the pro‐survival genes, baculoviral inhibitor of apoptosis repeat‐containing 5 and catenin beta‐1, as well as the genes controlling angiogenesis, hypoxia inducible factor 1A and vascular endothelial growth factor A. The multi‐target action of these phytochemicals enhances their anticancer activity. Vitexin‐2‐O‐xyloside, betaxanthins and betacyanins can be used in combination with conventional anticancer drugs to reduce their toxicity and overcome the multidrug resistance of cancer cells. In this review, we describe the molecular mechanisms that enable these dietary phytochemicals to block the proliferation of tumor cells and inhibit their pro‐survival pathways. Copyright © 2017 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.     

Isolation,Identification and Molecular Docking Studies of a New Isolated Compound,from Onopordon acanthium: A Novel Angiotensin Converting Enzyme (ACE) inhibitor

Ethnopharmacological relevance

Onopordon acanthium (also known as Scotch thistle) is a medicinal plant of the Asteraceae family that is widely distributed in Europe and Asia. This plant has been long used in traditional medicine as a hypotensive, cardiotonic and diuretic agent.

Aim of the study

The present study is designed to isolate an active compound with ACE inhibition activity from O. acanthium, measure antioxidant activity, predict domain specificity and pharmacokinetic properties of the isolated compound.

Materials and methods

Methanolic extract of O. acanthium seeds, has been subjected to a repeated column chromatography to give a pure compound with Angiotensin Converting Enzyme (ACE) inhibition activity. The ACE inhibition activity was determined using hippuryl-L-histidyl-L-leucine (HHL) as substrate in an in vitro ACE assay. Structure of the pure compound, isolated from O. acanthium has been established by spectroscopic methods, including Infrared (IR), Nuclear Magnetic Resonance (NMR) and Mass spectrum analysis. In addition, antioxidant activity of the new isolated compound, was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and compared with those of BHT and Trolox as positive controls. Enzyme type inhibition and ACE-C or N domain specificity of the new compound was further evaluated through molecular modeling and docking studies.

Results

Structure of the pure compound, isolated from O. acanthium (83±1% ACE inhibition activity at concentration of 330 μg/ml), has been established. The isolated compound possessed acceptable antioxidant activity (IC₅₀ value of 2.6±0.04 μg/ml) in comparison with BHT (IC₅₀ value of 10.3±0.15 μg/ml) and Trolox (IC₅₀ value of 3.2±0.06 μg/ml). Molecular docking predicted competitive type enzyme inhibition and approximately similar affinity of the isolated compound for ACE-C and N domains.

Conclusion

The results derived from computational and in vitro experiments, confirm the potential of the isolated compound, from O. acanthium as a new antihypertensive compound and give additional scientific support to an anecdotal use of O. acanthium in traditional medicine to treat cardiovascular disease such as hypertension.     

Anti‐Thrombotic Effect of a Novel Formula from Corni Fructus with Malic Acid,Succinic Acid and Citric Acid

Our previous investigation had confirmed the inhibition of platelet aggregation of a novel Corni fructus‐derived formula composed of malic acid, succinic acid and citric acid with a ratio of 3:2:2. The present study was to further evaluate the anti‐thrombotic effect of the formula in vivo. Mice of acute pulmonary thromboembolism, and rats of arterial thrombosis were used to determine the anti‐thrombotic effect of the formula. Histology analysis of endothelium was conducted with hematoxylin and eosin stain. TXB₂, 6‐K‐PGF_1α, cAMP, cGMP and NO in rat plasma were determined. In vitro assay of αIIbβ3 and phosphorylation of ERK1/2 were performed in ADP‐treated platelet. The formula significantly reduced the recovery time and mortality rate of mice with acute pulmonary thromboembolism. Remarkably extended occlusion time, decreased thrombus weight and more integrated endothelium were observed in rat with the formula. Enhanced 6‐K‐PGF_1α, cGMP and NO, but not TXB₂ and cAMP, were demonstrated in rat plasma with treatment of the formula. Finally, the formula was shown to inhibit αIIbβ3 expression and activation of ERK1/2 in platelet. The formula shows positive anti‐thrombotic effect. The direct interference on ADP activated signaling in platelet and regulation of endothelium function are two primary pathways involved in the action on thrombosis. Copyright © 2013 John Wiley & Sons, Ltd.     

Metabolic Management in Overweight Subjects with Naive Impaired Fasting Glycaemia by Means of a Highly Standardized Extract From Cynara scolymus: A Double‐blind,Placebo‐controlled,Randomized Clinical Trial

The aim of this study is to evaluate the efficacy of a dietary supplementation with an extract from Cynara scolymus (Cs) on the glucose pattern in a group of patients with naïve impaired fasting glycaemia (IFG). A randomized, double‐blind, placebo‐controlled trial has been performed in 55 overweight subjects with IFG (fasting blood glucose [FBG]: 6.11 ± 0.56 mmol/l). These subjects were randomly assigned to supplement their diet with either an extract from Cs (600 mg/d) (26 subjects) or placebo (29 matched subjects) for 8 weeks. The decrease of FBG was the primary endpoint. The assessment of Homeostatic Metabolic Assessment (HOMA), glycosylated haemoglobin, A1c‐Derived Average Glucose (ADAG), lipidic pattern and anthropometric parameters were the secondary endpoints. The within groups and percent changes from baseline were analyzed by the signed rank test. The comparison between groups was performed by Wilcoxon's two sample test. The supplemented group had significant decreases of: FBG (?9.6%), HOMA (?11.7%), glycosylated haemoglobin (?2.3%), ADAG (?3.1%) and lipidic pattern. The placebo group did not show any significant difference. Compared with the placebo, the supplemented group showed a significant difference in FBG, HOMA and lipidic pattern. These data demonstrate the efficacy of Cs extract on the reduction of glycometabolic parameters in overweight subjects with IFG. Copyright © 2013 John Wiley & Sons, Ltd.     

The effect of l‐carnitine supplementation on serum levels of omentin‐1, visfatin and SFRP5 and glycemic indices in patients with pemphigus vulgaris: A randomized,double‐blind,placebo‐controlled clinical trial

Pemphigus vulgaris (PV) is a chronic autoimmune disorder with potentially fatal outcomes. The aim of this study was to investigate the effect of l ‐carnitine (LC) on secreted frizzled‐related protein‐5 (SFRP5), omentin, visfatin, and glycemic indices in PV patients under corticosteroid treatment. In this randomized, double‐blind, placebo‐controlled clinical trial, 52 patients with PV were divided randomly into two groups to receive 2 g of LC or a placebo for 8 weeks. Serum levels of SFRP5, omentin, visfatin, and also glycemic indices were evaluated at the baseline and end of the study. LC supplementation significantly decreased the serum level of visfatin (95% CI [?14.718, ?0.877], p = .05) and increased the serum levels of SFRP5 (95%CI [1.637, 11.380], p < .006) and omentin (95% CI [9.014, 65.286], p < .01). However, LC supplementation had no significant effects on the serum levels of glycemic factors such as insulin (95% CI [?1.125, 3.056], p = .426), fasting blood sugar (95% CI [?4.743, 3.642], p = .894), homeostatic model assessment of insulin resistance (95% CI [?0.305, 0.528], p = .729), and quantitative insulin‐sensitivity check index (95% CI [?0.016, ?0.010], p = .81). LC supplementation decreased visfatin serum level and increased omentin‐1 and SFRP5 serum levels in patients with PV. However, it has no significant effect on the serum levels of insulin and glycemic indices.     

Efficacy of a Standardized Extract of Prunus mume in Liver Protection and Redox Homeostasis: A Randomized,Double‐Blind,Placebo‐Controlled Study

The antioxidant, anti‐inflammatory and hepatoprotective effects of Prunus mume (PM) have previously been demonstrated. This double‐blind, placebo‐controlled study was designed to evaluate the influence of two doses of a food supplement, made of 150 mg of a standardized PM extract on liver transaminases, lipid profile, glycemia, neopterin and reduced and oxidized thiols in plasma and erythrocytes, during a 3‐month treatment period, in healthy subjects with transaminases levels between 20 and 40 UI/L. Forty‐five subjects (56.0 ± 11.6 years) were enrolled. The results showed a beneficial and statistically significant effect versus placebo of PM extract on liver function, with a decrease versus baseline in alanine aminotransferase (47%), aspartate aminotransferase (7%), gamma‐glutamyl transpeptidase (15%) and glycemia (11%). The lipid profile modification was also positive with an increase versus baseline in HDL cholesterol (13%), and a decrease in LDL/HDL ratio (12%) and triglycerides (8%). The antioxidant action of PM translated into a decrease in oxidized glutathione, reduced/oxidized cysteine‐glycine, oxidized cysteine (intracellular pro‐oxidant) and neopterin (inflammation biomarker), was associated with an increase in reduced glutathione. These results are in favor of the use of a standardized extract of P. mume for the support of liver health and prevention of common metabolic and inflammation‐based diseases. Copyright © 2016 John Wiley & Sons, Ltd.