Browsing by Author "Konczak, Izabela"

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Antioxidant Capacity and Phenolic Constituents of Malva Neglecta Wallr. and Plantago Lanceolata L. From Eastern Anatolia Region of Turkey
(Elsevier Gmbh, 2012) Dalar, Abdullah; Turker, Musa; Konczak, Izabela
Plantago lanceolata and Malva neglecta are two plants from eastern regions of Turkey used by the local population to cure multiple medical conditions, such as promoting maturation of abscesses, wound healing, abdominal pains and cancer. Both plants exhibited high oxygen radical absorbance capacity (ORAC assay) and total reducing capacity (ferric reducing antioxidant power, FRAP assay), comparable to or higher than herbs such as rosehip, cinnamon or oregano and multiple Chinese medicinal plants. Phenolic compounds were the major constituents of hydrophilic extracts and their levels correlated well with antioxidant activities. Leaf and flower/fruit, which are predominantly used as a medicine, contained the highest levels of phenolics, and comprised predominantly flavonoids and hydroxycinnamic acids. This may suggest that flavonoids and hydroxycinnamic acids play an essential role as physiologically active constituents of these traditional medicinal plants. Crown Copyright (C) 2012 Published by Elsevier GmbH. All rights reserved.
Botanicals From Eastern Anatolia Region of Turkey: Antioxidant Capacity and Phenolic Constituents of Endemic Herbal Medicines
(Elsevier Gmbh, 2012) Dalar, Abdullah; Konczak, Izabela
Antioxidant capacity and polyphenolic composition of four endemic medicinal plants from the Eastern Anatolia Region of Turkey; Verbascum cheiranthifolium Boiss. var. cheiranthifolium Boiss., Dactylorhiza chuhensis Renz & Taub., Eryngium bornmuelleri Nabelek and Centaurea karduchorum Boiss. were evaluated for the first time. Aqueous plant extracts, representing decoctions traditionally used for medical purposes by the local population, exhibited high total reducing capacities (ferric reducing antioxidant power assay) and oxygen radical scavenging abilities (oxygen radical absorbance capacity assay) comparable to or higher than numerous Chinese and Ayurvedic medicinal plants and commonly used medicinal herbs. Flavonoids and hydroxycinnamic acids were two major phenolic groups present in the extracts. Extracts of leaves and flowers which are predominantly used for medical purposes exhibited the highest antioxidant capacities and polyphenolic content. Beside their application as traditional medicine, leaves and flowers might be utilized as sources of natural antioxidants. Crown Copyright (C) 2012 Published by Elsevier GmbH. All rights reserved.
Centaurea Karduchorum Boiss. From Eastern Anatolia: Phenolic Composition, Antioxidant and Enzyme Inhibitory Activities
(Elsevier Gmbh, Urban & Fischer verlag, 2015) Dalar, Abdullah; Uzun, Yusuf; Mukemre, Muzaffer; Turker, Musa; Konczak, Izabela
The phenolic composition of lyophilized hydrophilic extracts obtained from root, stem, leaf and flower of Centaurea karduchorum Boiss. a medicinal plant endemic to Eastern Anatolia (Turkey) used as antidiabetic agent was characterized for the first time. Liquid chromatography mass spectrometry (LC/MS) analysis revealed that luteolin derivatives and chlorogenic acid were the dominating compounds contributing, respectively, from 16.1% (root) to 33.7% (stem) and from 7.3% (flower) to 12.0% (root) of total phenolics. Total reducing capacities of the extracts varied from 24.1 (root) to 38.5 (flower) mg gallic acid Eq./g DW [Folin-Ciocalteu assay] and from 274.0 (root) to 441.0 (stem) mu mol Fe2+/g DW [FRAP assay]. The oxygen radical absorbance capacity (ORAC assay) values varied from 930.5 (root) to 1853.5 (stem) mu mol trolox Eq./g DW. The leaf extract exhibited a pronounced inhibitory activity towards alpha-glucosidase (IC50: 0.63 +/- 0.00 mg/ml) and a weak inhibitory activity towards amylase (IC50: 14.63 +/- 0.67 mg/ml), which suggests a potential to reduce postprandial hyperglycaemia and supports its traditional use as antidiabetic agent. (C) 2015 Elsevier GmbH. All rights reserved.
Health Attributes of an Endemic Orchid From Eastern Anatolia, Dactylorhiza Chuhensis Renz&taub. - in Vitro Investigations
(Elsevier Gmbh, 2015) Dalar, Abdullah; Guo, Yu; Esim, Nevzat; Bengu, Aydin Sukru; Konczak, Izabela
Phytochemical composition and potential health attributes of Dactylorhiza chuhensis Renz&Taub., an endemic orchid from Eastern Anatolia, were investigated. Lyophilized methanol-based extracts obtained from leaf, flower, stem and tuber were investigated for the presence of phenolic compounds [Folin-Ciocalteu assay and high performance liquid chromatography analysis (HPLC)], antioxidant capacities [ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assay] and enzyme-inhibitory activities [lipase, alpha-amylase, alpha-glucosidase and angiotensin converting enzyme (ACE)]. The tuber, used as a traditional remedy and utilized by the pharmaceutical industry, had the lowest content of total phenolics, inferior antioxidant and enzyme-inhibitory activities. The highest phenolic content (44.9 +/- 0.8 mg GAE/g DW) was exhibited by the leaf extract, which also showed superior reducing (736.8 +/- 16.2 mu mol Fe2+/g DW) and oxygen radical scavenging capacities (2715.8 +/- 83.5 mu mol Trolox E/g DW). The inhibitory activities of the leaf extract toward alpha-amylase, alpha-glucosidase and ACE were moderate. Applied at non-toxic concentrations, the leaf extract effectively reduced accumulation of nitric oxide (NO) in lipopolysaccharide (LPS)-activated hepatocellular carcinoma (HepG2) cells. Further studies towards potential utilization of D. chuhensis leaf as a source of physiologically active phytochemcials are justified. Crown Copyright (C) 2015 Published by Elsevier GmbH. All rights reserved.
Phenolic Composition, Antioxidant and Enzyme Inhibitory Activities of Eryngium Bornmuelleri Leaf
(Springer, 2014) Dalar, Abdullah; Turker, Musa; Zabaras, Dimitrios; Konczak, Izabela
Eryngium bornmuelleri Nab. (TusI) is an endemic botanical from the Eastern Anatolia region of Turkey traditionally used for preparation of herbal tea. Within this study, phenolic composition, antioxidant capacities and inhibitory activities towards selected digestive enzymes of E. bornmuelleri leaf were investigated. Sequential extracts, obtained by extraction of plant tissue by ethanol, acetone and water exhibited pronounced antioxidant capacities and in a dose-dependent manner suppressed the metabolic syndrome related enzymes: alpha-amylase, alpha-glucosidase and pancreatic lipase. All extracts contained high levels of phenolic compounds. Flavonoid glycosides were the main phytochemicals detected, with rutin as the major compound (70 % of total phenolics). Chlorogenic, hydroxybenzoic and caftaric acids as well as traces of caffeic, ferulic and rosmarinic acids were also detected. Correlation analysis indicated that phenolic compounds were the major sources of the enzyme-inhibitory activities. This study suggests that E. bornmuelleri leaf extracts can modulate the metabolism of sugars and fats through inhibition of the relevant digestive enzymes.
Phenolic Contents, Antioxidant Capacities and Inhibitory Activities Against Key Metabolic Syndrome Relevant Enzymes of Herbal Teas From Eastern Anatolia
(Elsevier, 2013) Dalar, Abdullah; Konczak, Izabela
Six traditional herbal infusions from Eastern Anatolia region of Turkey were investigated for their potential to suppress metabolic syndrome. Hydrophilic lyophilized extracts representing herbal infusions exhibited comparable or superior levels of phenolic compounds and antioxidant capacity [ferric reducing antioxidant power (FRAP assay) and oxygen radical absorbance capacity (ORAC assay)] to commercially available black tea (Camellia sinensis) and numerous herbal infusions. All teas successfully suppressed the activities of key enzymes involved in metabolic syndrome: alpha-amylase, alpha-glucosidase, pancreatic lipase and angiotensin converting enzyme (ACE). Phlomis armeniaca, Salvia limbata and Plantago lanceolata exhibited weak inhibitory activities against alpha-amylase and pronounced inhibitory activities against alpha-glucosidase, which suggests potential anti-diabetic properties. Moreover, P. lanceolata exhibited pronounced inhibitory activity against pancreatic lipase. This study suggests potential anti-diabetic and anti-obesity activity of P. lanceolata herbal infusion, and supports its traditional use as anti-diabetic tea. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.
Phytochemical Divergence in 45 Accessions of Terminalia Ferdinandiana (Kakadu Plum)
(Elsevier Sci Ltd, 2014) Konczak, Izabela; Maillot, Fabien; Dalar, Abdullah
This study investigated the variations in the levels of phenolic compounds, vitamin C, sugars and antioxidant capacities of 45 newly collected accessions of Terminalia ferdinandiana (Kakadu plum), a native Australian fruit utilised in dietary supplement industry. Pattern recognition tools, principal component analysis (PCA) and agglomerative hierarchical clustering (AHC) were applied to understand interrelationships between the antioxidant capacities [Ferric reducing antioxidant power (FRAP) and Oxygen radical absorbance capacity (ORAC)] and antioxidant groups: phenolic compounds and vitamin C. On the basis of these parameters AHC classified samples into three main groups, with accessions 2, 8, 15, 6, 3 and 5 from the Northern Territory, Australia, representing superior quality fruits combining high levels of total phenolics (505.2 to 376.1 mg GA E/g DW), vitamin C (322.2 to 173.5 mg/g DW), with pronounced antioxidant capacities (FRAP: 5030.5 to 4244.9 mu mol Fe2+/g DW; ORAC: 3861.5 to 2985.6 mu mol Trolox E/g DW). Hydrolysable tannins and ellagic acid were identified as the major phenolic compounds. The levels of ellagic acid varied from 140.2 to 30.5 mg/g DW, which places Kakadu plum as a unique edible source of this compound. The levels of sugars varied from 619.0 to 130.0 mg Glu E/g DW. This study for the first time revealed a unique phytochemical profile and significant variability in phytochemical composition of Kakadu plum. These features create opportunities for selection of sources with different characteristics addressing the needs of the nutraceutical industry, food processors and the consumers of fresh fruit. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.
Phytochemical Pro File and Biological Activities of Anatolian Plantain (Plantago Anatolica)
(Elsevier, 2020) Mukemre, Muzaffer; Konczak, Izabela; Uzun, Yusuf; Dalar, Abdullah
The phytochemical profile and potential biological activities of Plantago anatolica Tutel & R. Mill., a traditional endemic food plant of Eastern Anatolia, Turkey, were studied. The study included analysis of phytochemical and mineral compositions of lyophilized sequential extracts (n-hexane, chloroform, ethyl acetate, acetone, ethanol and water) and traditional preparations (herbal infusion, decoction and cold water extraction) obtained from aerial parts of the P. anatolica plant, followed by evaluation of their antioxidant capacities and inhibitory activities towards enzymes involved in metabolic syndrome. Chromatographic studies showed that phenolic compounds (caffeic and chlorogenic acids, apigenin and kaempferol), and fatty acids (palmitic and linolenic acids) and an aromatic compound benzotiazole were the major phytochemicals. The ethanol extract and the herbal infusion extracted the most caffeic acid. These two preparations showed significant oxygen radical absorbance capacity (1.9 and 1.0 mmol Trolox equivalent/g dw, respectively), high ferric reducing antioxidant power (0.9 and 0.7 mmol Fe2+/g dw, respectively), 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity (IC50: 0.87 and 0.34 mg/ml, respectively), and ferric chelation activities (IC50: 0.09 mg/ml). Both preparations showed high inhibitory activities towards a-glucosidase (IC50 of 0.8 and 0.6 mg/ml, respectively), and lipase (IC50 of 72 and 44 mu g/ml, respectively) but low inhibitory activities towards a-amylase (IC50: 4.31 and 5.32 mg/ml, respectively). These results highlighted the potential of P. anatolica as a source of phytochemicals with strong antioxidant and enzyme inhibitory properties for application in the food and biopharmaceutical industries.
Sempervivum Davisii: Phytochemical Composition, Antioxidant and Lipase-Inhibitory Activities
(Taylor & Francis Ltd, 2017) Uzun, Yusuf; Dalar, Abdullah; Konczak, Izabela
Context: Sempervivum davisii Muirhead (Crassulaceae) is a traditional medicinal herb from Eastern Anatolia. To date the composition of phytochemicals and physiological properties of this herb were not subjected to any research. Objective: This study identifies compounds in S. davisii hydrophilic extracts and evaluates their potential biological properties. Materials and methods: Ethanol-based lyophilized extracts were obtained from aerial parts of plant (10 g of ground dry plant material in 200 mL of acidified aqueous ethanol, shaken for 2 h at 22 degrees C with supernatant collected and freeze-dried under vacuum). Phytochemical composition was investigated by liquid chromatography mass spectrometry (LC-MS/MS, phenolics) and gas chromatography mass spectrometry (GC-MS, volatiles). Phenolic compounds were quantified by high-performance liquid chromatography (HPLC) and the Folin-Ciocalteu assay. Subsequently, antioxidant capacity [ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) assays] and enzyme inhibitory properties (isolated porcine pancreatic lipase) of the extracts were determined. Results: Polyphenolic compounds were the main constituents of lyophilized extracts, among which kaempferol glycosides and quercetin hexoside dominated. The extracts exhibited potent antioxidant (FRAP values of 1925.2-5973.3 mu M Fe2+/g DW; ORAC values of 1858.5-4208.7 mu M Trolox Eq./g DW) and moderate lipase inhibitory (IC50: 11.6-2.96 mg/mL) activities. Volatile compounds (nonanal, dehydroxylinalool oxide isomers, 2-decenal, 2-undecenal, 2,6-di-tetr-butylphenol) were also found. Conclusions: Phenolic compounds with the dominating kaempferol and quercetin derivatives are the sources of potent antioxidant properties of S. davisii hydrophilic extracts. The extracts exhibit moderate inhibitory properties towards isolated pancreatic lipase.