Papers by Izabela Konczak
Journal of Agricultural and Food Chemistry, Jan 1, 2012
... Yakup Kolcuoglu. Ramen Kumar Kole. Fragiskos Kolisis. Anna Kolossova. Michalis Komaitis. Mich... more ... Yakup Kolcuoglu. Ramen Kumar Kole. Fragiskos Kolisis. Anna Kolossova. Michalis Komaitis. Michael Komarek. Slavko Komarnytsky. Tamas Komives. Izabela Konczak. Fumio Kondo. Chuihua Kong. Deling Kong. Ling-Yi Kong. Weijun Kong. Zwe-Ling Kong. Christos Kontogiorgis ...
... blueberries throughout the project The Thai government for financial support in the form of m... more ... blueberries throughout the project The Thai government for financial support in the form of my scholarship Dr. Mary Mulholland at School of Chemistry, Faculty of Sciences, UNSW, Dr. IzabelaKonczak at CSIRO, Dr. Barry Macglasson and Liz Kabanoff at School of Natural ...
Biochemical Engineering Journal, Jan 1, 2003
Journal of Biomedicine and …, Jan 1, 1900
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British Journal of …, Jan 1, 2012
Journal of Herbal Medicine, Jan 1, 2012
Food Chemistry, Jan 1, 2012
Three commercially grown native herbs unique to Australia, Tasmannia pepper leaf (Tasmannia lance... more Three commercially grown native herbs unique to Australia, Tasmannia pepper leaf (Tasmannia lanceolata R. Br., Winteracea; TPL), anise myrtle (Syzygium anisatum Vickery, Craven & Biffen, Myrtaceae; AM) and lemon myrtle (Backhousia citriodora F. Muell, Myrtaceae; LM) as well as a reference sample bay leaf (Laurus nobilis L., Lauraceae; BL) were examined for potential cytoprotective properties. All native herbs exhibited greater cellular antioxidant activity as measured by the cellular antioxidant activity (CAA) assay than bay leaf and reduced the hydrogen peroxide (H 2 O 2 ) induced death of hepatocellular carcinoma (HepG2) cells by 25-50%. All herb extracts reduced the proliferation of colon (HT-29; IC 50 = 0.75-1.39 mg/ml), stomach (AGS; IC 50 = 0.59-1.88 mg/ml), bladder (BL13; IC 50 = 0.56-1.12 mg/ml) and liver (HepG2; IC 50 = 0.38-1.36 mg/ml) cancer cells. No significant reduction of cell viability of non-transformed colon (CCD-18Co; IC 50 > 2.0 mg/ml) and mixed stomach and intestine (Hs 738.St/Int; IC 50 > 2.0 mg/ml) cells was observed. Flow cytometry analysis and the results of the cytokinesis block micronucleus cytome (CBMNCyt) assay conducted with respectively, promyelocytic leukaemia (HL-60) and colon adenocarcinoma (HT-29) cells suggest an increase in apoptosis following treatment with the herb extracts. The occurrence of apoptotic cells coincided with an increase in caspase-3 enzyme activity. The results of the CBMNCyt assay suggested no direct DNA damage in colon adenocarcinoma (HT-29) cells as a result of treatment with all extracts, applied at final concentrations of 0.5 and 1.0 mg/ml. Crown
The British journal of …, Jan 1, 2012
Fruit antioxidants have many health benefits including prevention of cancer development. The nati... more Fruit antioxidants have many health benefits including prevention of cancer development. The native Australian bush fruit Illawarra plum (Podocarpus elatus Endl., Podocarpaceae) has a high content of anthocyanin-rich phenolics, with an antioxidant capacity at levels higher than most fruits. In the present study the molecular mechanisms of the anti-proliferative activity of Illawarra plum on colorectal cancer cells were investigated. Non-tumorigenic young adult mouse colonic (YAMC) cells and tumorigenic human colonic (HT-29) cells were treated with a polyphenolic-rich Illawarra plum extract (0 -1000 mg/ml). Illawarra plum had anti-proliferative properties in only the cancer cells, with growth suppressed in a dose-and time-dependent manner. Treatment of HT-29 cells with Illawarra plum extract (500 mg/ml; 24 h) was also associated with a 2-fold increase in apoptosis, and a cell cycle delay in the S phase (P, 0·01). Assessment of biomarkers for DNA damage revealed that plum treatment caused a 93 % down-regulation of telomerase activity (P,0·001) and a decrease in telomere length (up to 75 %; P,0·01). Treatment with Illawarra plum extract also induced morphological alterations to HT-29 cells that were suggestive of induction of autophagy, as the formation of cytoplasmic vacuoles was observed in many cells. This could be induced by the increased (6-fold) histone deacetylase (HDAC) activity (P, 0·001) and the trend for increased expression of the class III HDAC sirtuin 1. The present study has shown that Illawarra plum extract is able to reduce the proliferation of colon cancer cells by altering the cell cycle, increasing apoptosis and possibly inducing autophagy. The active ingredients in Illawarra plum may provide an alternative chemoprevention strategy to conventional chemotherapy.
Journal of Herbal Medicine, Jan 1, 2012
Plantago lanceolata and Malva neglecta are two plants from eastern regions of Turkey used by the ... more 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.
Nutrition and …, Jan 1, 2011
Plant Cell Reports, Jan 1, 2000
CITATIONS 37 READS 92 5 authors, including: Some of the authors of this publication are also work... more CITATIONS 37 READS 92 5 authors, including: Some of the authors of this publication are also working on these related projects: Phytochemical analysis and evaluation of potential health properties of sequential extractions obtained from Plantago anatolica (TUBITAK 215S046) View project Izabela Konczak UNSW Australia
Food Research International, Jan 1, 2011
A high level of antioxidant activity of lipophilic fractions obtained from commercially grown nat... more A high level of antioxidant activity of lipophilic fractions obtained from commercially grown native Australian fruits, as evaluated in the oxygen radical absorbance capacity assay for lipophilic antioxidants (ORAC-L), was identified for the first time. The level of contribution of lipophilic fractions varied from 5.8% (quandong) to 30.7% (riberry) of the total oxygen radical scavenging capacity (ORAC-T). Vitamin E components -αtocopherol, γ-tocopherol and δ-tocopherol and luteinwere identified as the main sources of this activity. Among the evaluated sources, Kakadu plum emerges as a fruit with unique nutritional qualities: it exhibited a superior ORAC-T value (430.0 μM trolox eq/g fresh weight, TEq/g FW) with 26.7% contribution of the lipophilic fraction. The major compounds of Kakadu plum's lipophilic fraction were α-tocopherol (1.022 ± 0.1 mg/100 g, FW), lutein (0.26 ± 0.01 mg/100 g FW) and chlorophyll a and b (2.72 ± 0.1 and 0.54 ± 0.1 mg/100 g FW, respectively). With regards to mineral content, the levels of major minerals, such as potassium, phosphorus, calcium, magnesium, and trace elements such as iron, zinc, manganese, selenium and copper as well as cobalt, nickel, aluminium and led in native Australian fruits are similar to the levels of these elements in a range of vegetables and frutis produced and consumed elsewhere.
Food Chemistry, Jan 1, 2012
Polyphenolic-rich fractions obtained from three native Australian herbs: Tasmannia pepper leaf, a... more Polyphenolic-rich fractions obtained from three native Australian herbs: Tasmannia pepper leaf, anise myrtle and lemon myrtle were characterised with regards to their composition, antioxidant capacities and inhibitory activities against a-glucosidase, pancreatic lipase and angiotensin I-converting enzyme, using in vitro models. Ellagic acid and derivatives were the dominant compounds of anise myrtle and lemon myrtle fractions, accompanied by flavonoids (catechin, myricetin, hesperetin, and quercetin). Tasmannia pepper leaf fraction comprised chlorogenic acid and quercetin derivatives, exhibited the highest oxygen radical absorbance capacity and effectively inhibited a-glucosidase (IC 50 : 0.83 mg/ml) and pancreatic lipase (IC 50 : 0.60 mg/ml). Anise myrtle and lemon myrtle fractions had pronounced a-glucosidase-inhibitory activities (IC 50 : 0.30 and 0.13 mg/ml, respectively) and were less effective against lipase. Enzyme-inhibitory activities showed various levels of correlation with the levels of total phenolics and antioxidant capacities, indicating a specificity of individual phenolic compounds present in the isolated fractions to complex with proteins.
Food Research International, Jan 1, 2012
Tagetes erecta, Cosmos sulphureus, Antigonon leptopus and Bougainvillea glabra are edible flowers... more Tagetes erecta, Cosmos sulphureus, Antigonon leptopus and Bougainvillea glabra are edible flowers frequently used by the ethnic population of northern Thailand for preparation of salads and flower teas. The main constituents of ethanolic extracts of these flowers, identified with the help of a high-performance liquid chromatography (HPLC) method, were phenolic acids and flavonoids. T. erecta flowers contained the highest level of phenolic compounds, 1107.5 mg/100 g dry weight (DW), which was 3-to 4-fold the level of phenolic compounds in three other flowers evaluated in this study. Lyophilised aqueous extract of T. erecta had the highest Folin-Ciocalteu value (212 ± 9.0 mgGAE/g DW) and exhibited the highest total reducing capacity (Ferric Reducing Antioxidant Power, FRAP assay; 329.4 ± 21.8 μmol Fe 2+ /g DW) and cellular antioxidant activity (CAA assay; EC 50 = 413 μg/ml). However A. leptopus extract exhibited a superior oxygen free radical scavenging ability (oxygen radical absorbance capacity, ORAC-H assay). The extracts were evaluated for their abilities to suppress the proliferation of human cancer cells associated with the digestion system and to inhibit the activity of two enzymes, α-glucosidase and pancreatic lipase. A pronounced anti-proliferative activity against the colorectal adenocarcinoma (HT-29) cells exhibited T. erecta extract (IC 50 = 1.5 mg/ml), while A. leptopus was most active against the gastric adenocarcinoma (AGS) (IC 50 = 0.2 mg/ml) and bladder cancer cells (BL-13) (IC 50 = 0.9 mg/ml). T. erecta extract was identified as an efficient inhibitor of α-glucosidase enzyme (IC 50 = 0.06 mg/ml). T. erecta, C. sulphureus and B. glabra extracts equally inhibited the activity of pancreatic lipase (IC 50 : 4.82 and 4.60 mg/ml, respectively). The results obtained in this study for the first time identified a number of potential health-enhancing properties of aqueous extracts obtained from edible flowers consumed by the indigenous people of Thailand.
Journal of Food …, Jan 1, 2011
Nutrition and cancer, Jan 1, 2011
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Papers by Izabela Konczak