Antioxidant activities of solvent extracts from endemic Cyclamen mirabile Hildebr. tubers and leaves

In this study, solvent extracts were prepared from different parts of Cyclamen mirabile (CM) and their antioxidant activities were evaluated. Other antioxidant properties of all extracts of CM tubers and leaves, including free radical scavenging activity, reducing power and total phenolic compound content, were also determined. Leaves extracts of CM exhibited higher antioxidant activity than tuber extracts with all the types of solvent used. All concentrations of petroleum ether, acetone, methanol and water extracts of CM leaves showed higher antioxidant activities than that of 0.5 mg of á-tocopherol (42%) and close to BHT (99.30%) and had 96.60, 96.00, 96.10 and 97.40% inhibition of lipid peroxidation of linoleic acid at same doses, respectively. All extracts of CM tubers and leaves had effective free radical scavenging and reducing power. In addition, total phenolic compounds in all the extracts of CM tubers and leaves were determined as pyrocatechol equivalents.Key words: Cyclamen mirabile, antioxidant activity, reducing power, scavenging activity, total phenolic compoun

Fatty acid composition of fl owers of Crepis foetida subsp. rhoeadifolia from Turkey

This study aims to describe the fatty acid composition of flowers of Crepis foetida subsp. rhoeadifolia. In order todefine qualitative and quantitative profile, fatty acids were derived to their methyl esters, and then these wereanalyzed by gas chromatography - flame ionization detector. 20 fatty acids were determined in the oil. Palmitic(C 16:0), myristic (C 14:0), and linoleic acids (18:2 ω6) were found to be major fatty acids. Total saturatedfatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids (PUFA) were 62.67%, 17.54%, and19.79%, respectively. Also, total essential fatty acids (EFA) were determined ad 14.48%. Therefore, the oil canbe considered as a new source of PUFA, especially EFA

Screening of the antioxidant, antimicrobial and DNA damage protection potentials of the aqueous extract of Asplenium ceterach DC.

In this study, in vitro antioxidant, antimicrobial and DNA damage protection potentials of the aqueous extract of Asplenium ceterach was firstly evaluated in addition to its total phenolic and flavonoid contents. Antioxidant activity was determined by five complementary test systems named β- carotene/linoleic acid, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, reducing power, chelating effect and phosphomolibdenum methods. Except for chelating effect assay, the extract exhibited remarkable activity potential. Antimicrobial activity was determined by agar-well diffusion and minimum inhibitory concentration tests. In this case, Shigella dysenteriae and Staphylococcus aureus were found to be the most sensitive microorganisms. According to the electrophoretic pattern of pBR322 plasmid DNA after treatment with UV and H2O2, supercoiled DNA was successfully protected in the presence of 20 mg/ml or above concentrations of aqueous extract.Key words: Antioxidant activity, antimicrobial activity, DNA damage protection, Asplenium ceterach

Assessment of apigenin-7-glucoside and luteolin-7-glucoside as multi-targeted agents against Alzheimer's disease: a molecular docking study

Although the incidence of Alzheimer's disease (AD) is increasing in society, unfortunately, no definite progress has been made in treating this disease yet. In this study, the potential of apigenin-7-glucoside (A7G) and luteolin-7-glucoside (L7G) to be used as multi-targeted agents in AD was investigated by molecular docking calculations against the acetylcholinesterase (AChE), butyrylcholinesterase (BChE), amyloid precursor protein (APP) and 42-residue beta-amyloid peptide (Aβ). A7G and L7G exhibited very high binding affinity (-9.42 and -9.60 kcal/mol for A7G; -9.30 and -9.90 kcal/mol for L7G) to AChE and BChE, respectively, while the affinities of these two flavonoid glycosides towards APP and Aβ peptide (-6.10 and -6.0 kcal/mol for A7G; -6.30 and -6.10 kcal/mol for L7G) were moderately strong. Compared to rivastigmine, A7G and L7G exhibited a highly significant binding affinity, even stronger than rivastigmine, for AChE and BChE. Although A7G showed a more drug-like physicochemical character than L7G, both ligands were within the normal range for ADMET and did not show high affinity for cellular proteins, according to the results of SwissTarget analysis. According to the STITCH interaction analysis, both ligands had the potential to inhibit enzymes predominantly in the inflammatory pathway (ADIPOQ, NOS1, NOS2 and NOS3). As a result, A7G and L7G exhibit multi-targeted agent properties in AD. Our results should also be verified by experimental enzyme inhibition studies, which may be performed simultaneously on AChE, BChE, APP, and Aβ peptides

Phytochemistry and biological activity of Onosma rascheyana extracts (Boiss.)

In recent years, it has been determined that Onosma species exhibit interesting biological/pharmacological activities. The aim of this study was to analyze the chemical composition, antioxidant and enzyme inhibitory activities of the methanol (MeOH), water and ethyl acetate extracts obtained from the aerials parts of Onosma rascheyana (Boiss.). The chemical compositions of the extracts were determined using spectrophotometric and chromatographic methods. Biological activities of the extracts were determined using antioxidant and enzyme inhibitory test systems. The MeOH extract was found to be rich in both phenolics and flavonoids (31.55 mg GAEs/g and 15.20 mg REs/g, respectively). The MeOH extract also contained higher amounts of 4-hydroxybenzoic and p-coumaric acids compared to other phytochemicals. The MeOH extract exhibited remarkable activity in all antioxidant test systems. However, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS) scavenging assay resulted in superiority of water extract (88.90 mg TEs/g). The relative antioxidant capacity indices (RACI) of the extracts and the correlations between these values and antioxidant activities confirmed the high activity of the MeOH extract. In the α-amylase, α-glucosidase, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity tests, the ethyl acetate extract showed high activity, while the tyrosinase inhibitory activity assay resulted in the superiority of the MeOH extract (59.72 mg KAEs/g). It was concluded that the extracts of O. rascheyana could be used as alternative agents in the food, cosmetic and medical industries due to their antioxidant and enzyme inhibitory activities

GC/MS Evaluation and In Vitro Antioxidant Activity of Essential Oil and Solvent Extracts of an Endemic Plant Used as Folk Remedy in Turkey: Phlomis bourgaei

This study was outlined to examine the chemical composition of hydrodistilled essential oil and in vitro antioxidant potentials of the essential oil and different solvent extracts of endemic Phlomis bourgaei Boiss. used as folk remedy in Turkey. The chemical composition of the oil was analyzed by GC and GC-MS, and the predominant components in the oil were found to be β-caryophyllene (37.37%), (Z)-β-farnesene (15.88%), and germacrene D (10.97%). Antioxidant potentials of the solvent extracts and the oil were determined by four testing systems including β-carotene/linoleic acid, DPPH, reducing power, and chelating effect. In β-carotene/linoleic acid assay, all extracts showed the inhibition of more than 50% at all concentrations. In DPPH, chelating effect, and reducing power test systems, the water extract with 88.68%, 77.45%, and 1.857 (absorbance at 700 nm), respectively, exhibited more excellent activity potential than other extracts (hexane, ethyl acetate and methanol) and the essential oil at 1.0 mg/mL concentration. The amount of the total phenolics and flavonoids was the highest in this extract (139.50 ± 3.98 μg gallic acid equivalents (GAEs)/mg extract and 22.71 ± 0.05 μg quercetin equivalents (QEs)/mg extract)

Phytochemical Analysis, Antioxidant, and Antimicrobial Activities of Ducrosia flabellifolia: A Combined Experimental and Computational Approaches

Ducrosia flabellifolia Boiss. is a rare desert plant known to be a promising source of bioactive compounds. In this paper, we report for the first time the phytochemical composition and biological activities of D. flabellifolia hydroalcoholic extract by using liquid chromatography-electrospray tandem mass spectrometry (ESI-MS/MS) technique. The results obtained showed the richness of the tested extract in phenols, tannins, and flavonoids. Twenty-three phytoconstituents were identified, represented mainly by chlorogenic acid, followed by ferulic acid, caffeic acid, and sinapic acid. The tested hydroalcoholic extract was able to inhibit the growth of all tested bacteria and yeast on agar Petri dishes at 3 mg/disc with mean growth inhibition zone ranging from 8.00 ± 0.00 mm for Enterococcus cloacae (E. cloacae) to 36.33 ± 0.58 mm for Staphylococcus epidermidis. Minimal inhibitory concentration ranged from 12.5 mg/mL to 200 mg/mL and the hydroalcoholic extract from D. flabellifolia exhibited a bacteriostatic and fungistatic character. In addition, D. flabellifolia hydroalcoholic extract possessed a good ability to scavenge different free radicals as compared to standard molecules. Molecular docking studies on the identified phyto-compounds in bacterial, fungal, and human peroxiredoxin 5 receptors were performed to corroborate the in vitro results, which revealed good binding profiles on the examined protein targets. A standard atomistic 100 ns dynamic simulation investigation was used to further evaluate the interaction stability of the promising phytocompounds, and the results showed conformational stability in the binding cavity. The obtained results highlighted the medicinal use of D. flabellifolia as source of bioactive compounds, as antioxidant, antibacterial, and antifungal agent

Phenolic, polysaccharidic and lipidic fractions of mushrooms from northeast Portugal: chemical compounds with antioxidant properties

Mushrooms do not constitute a significant portion of the human diet, but their consumption continues to increase due to their functional benefits and presence of bioactive compounds. Some of those compounds can be found in the phenolic, polysaccharidic and lipidic fractions of edible and inedible species. Herein, those fractions of five wild mushrooms (Coprinopsis atramentaria, Lactarius bertillonii, Lactarius vellereus, Rhodotus palmatus and Xerocomus chrysenteron) from Northeast Portugal were studied for their chemical composition and antioxidant properties. Protocatechuic, p-hydroxybenzoic, p-coumaric and cinnamic acids were found in the phenolic fraction, ramnose, xylose, fucose, arabinose, fructose, glucose, manose, mannitol, sucrose, maltose and trehalose were quantified in polysaccharidic fraction, linoleic and stearic (only in Lactarius sp.) acids, and β- and γ-tocopherols were the main compounds in the lipidic fraction. C. atramentaria and X. chrysenteron phenolic fractions gave the highest free radical scavenging activity, reducing properties and lipid peroxidation inhibition in brain homogenates, which is in agreement with its highest content in total phenolics. Furthermore, among the polysaccharidic fractions C. atramentaria also gave the highest antioxidant activity, which is accordingly with its highest total polysaccharides content and sugars obtained after hydrolysis.The authors are grateful to Fundação para a Ciência e a Tecnologia (FCT, Portugal) and COMPETE/QREN/EU (research project PTDC/AGR-ALI/110062/2009) for financial support. L. Barros (BPD/4609/2008) and S.A. Heleno (BD/70304/2010) also thank FCT, POPH-QREN and FSE. The GIP-USAL is financially supported by the Spanish Ministerio de Ciencia e Innovación through the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063), and Junta de Castilla y León (Grupo de Investigación de Excelencia, GR133)

Rhaponticum acaule (L) DC essential oil: chemical composition, in vitro antioxidant and enzyme inhibition properties

Background: α-glucosidase is a therapeutic target for diabetes mellitus (DM) and α-glucosidase inhibitors play a vital role in the treatments for the disease. Furthermore, xanthine oxidase (XO) is a key enzyme that catalyzes hypoxanthine and xanthine to uric acid which at high levels can lead to hyperuricemia which is an important cause of gout. Pancreatic lipase (PL) secreted into the duodenum plays a key role in the digestion and absorption of fats. For its importance in lipid digestion, PL represents an attractive target for obesity prevention. Methods: The flowers essential oil of Rhaponticum acaule (L) DC (R. acaule) was characterized using gas chromatography-mass spectrometry (GC-MS). The antioxidant activities of R. acaule essential oil (RaEO) were also determined using 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), reducing power, phosphomolybdenum, and DNA nicking assays. The inhibitory power of RaEO against α-glucosidase, xanthine oxidase and pancreatic lipase was evaluated. Enzyme kinetic studies using Michaelis-Menten and the derived Lineweaver-Burk (LB) plots were performed to understand the possible mechanism of inhibition exercised by the components of this essential oil. Results: The result revealed the presence of 26 compounds (97.4%). The main constituents include germacrene D (49.2%), methyl eugenol (8.3%), (E)-β-ionone (6.2%), β-caryophyllene (5.7%), (E,E)-α-farnesene (4.2%), bicyclogermacrene (4.1%) and (Z)-α-bisabolene (3.7%). The kinetic inhibition study showed that the essential oil demonstrated a strong α-glucosidase inhibiton and it was a mixed inhibitor. On the other hand, our results evidenced that this oil exhibited important xanthine oxidase inhibitory effect, behaving as a non-competitive inhibitor. The essential oil inhibited the turkey pancreatic lipase, with maximum inhibition of 80% achieved at 2 mg/mL. Furthermore, the inhibition of turkey pancreatic lipase by RaEO was an irreversible one. Conclusion: The results revealed that the RaEO is a new promising potential source of antioxidant compounds, endowed with good practical applications for human health. Keywords: α-glucosidase, Antioxidant activity, Chemical composition, Pancreatic lipase inhibition, Rhaponticum acaule essential oil, Xanthine oxidase