Istvan Zupko

Prof. Istvan Zupko

orcid

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
21 November 2012 in PLOS ONE
Verified
Journal Article
Open access
PDF file
Attila HunyadiAttila Hunyadi
Attila Hunyadi
AMAna Martins
Ana Martins
THTusty-Jiuan Hsieh
Tusty-Jiuan Hsieh
ASAdrienn Seres
Adrienn Seres
IZIstvan Zupko
Istvan Zupko
The leaves of the white mulberry tree (Morus alba L.) are used worldwide in traditional medicine as anti-diabetics. Various constituents of mulberry leaves, such as iminosugars (i.e. 1-deoxynojirimicin), flavonoids and related compounds, polysaccharides, glycopeptides and ecdysteroids, have been reported to exert anti-diabetic activity, but knowledge about their contribution to the overall activity is limited. The objective of the present work was to determine the in vivo anti-diabetic activity of an extract of mulberry leaves (MA), and to examine to what extent three major constituents, chlorogenic acid, rutin and isoquercitrin, might contribute to the observed activity. Quantities of the three constituents of interest in the extract were determined by using HPLC-DAD. Activity was determined by using a type II diabetic rat model. After 11 days of per os administration of 250 or 750 mg/kg of MA or the corresponding amounts of each individual compound, a dose dependent decrease of non-fasting blood glucose levels were found for MA, chlorogenic acid and rutin, but not for isoquercitrin. Based on our results, chlorogenic acid and rutin might account for as much as half the observed anti-diabetic activity of MA, hence they can be considered as excellent markers for the quality control of mulberry products.

23 December 2008 in Phytotherapy Research
Verified
Journal Article
Closed access
PDF file
BCBoglárka Csupor‐Löffler
Boglárka Csupor‐Löffler
ZHZsuzsanna Hajdú
Zsuzsanna Hajdú
IZIstvan Zupko
Istvan Zupko
BRBorbála Réthy
Borbála Réthy
GFGeorge Falkay
George Falkay
JHJudit Hohmann
Judit Hohmann

30 January 2007 in Phytotherapy Research
Verified
Journal Article
Closed access
PDF file
ZHZsuzsanna Hajdú
Zsuzsanna Hajdú
JHJudit Hohmann
Judit Hohmann
PFPeter Forgo
Peter Forgo
TMTamás Martinek
Tamás Martinek
MDMáté Dervarics
Máté Dervarics
IMImre Máthé
Imre Máthé

Verified
Journal Article
Open access
PDF file
Codruta SoicaCodruta Soica
Codruta Soica
Danciu CorinaDanciu Corina
Danciu Corina
GSGermaine Savoiu-Balint
Germaine Savoiu-Balint
Florin BorcanFlorin Borcan
Florin Borcan
RARita Ambrus
Rita Ambrus
PMPetru Matusz
Petru Matusz
Betulinic acid, a very promising anti-melanoma agent, has very low water solubility that causes low bioavailability. To overcome this inconvenience, a highly water-soluble cyclodextrin was used (octakis-[6-deoxy-6-(2-sulfanyl ethanesulfonic acid)]-γ-cyclodextrin). The complex was physico-chemically analyzed using differential scanning calorimetry (DSC), X-ray and scanning electron microscopy (SEM) methods and then in vitro tested for its antiproliferative activity by the MTT assay and by cell cycle analysis. Finally, the complex was tested in vivo using an animal model of murine melanoma developed in C57BL/6J mice, where it caused a reduction in tumor volume and weight. The study revealed the beneficial influence of betulinic acid inclusion into the cyclodextrin in terms of antiproliferative activity and in vivo tumor development.

Verified
Journal Article
Open access
PDF file
MSMárta Szekeres
Márta Szekeres
ITIldikó Y. Tóth
Ildikó Y. Tóth
EIErzsébet ILLÉS
Erzsébet ILLÉS
AJAngela Jedlovszky-Hajdu
Angela Jedlovszky-Hajdu
IZIstvan Zupko
Istvan Zupko
ETEtelka Tombacz
Etelka Tombacz
Despite the large efforts to prepare super paramagnetic iron oxide nanoparticles (MNPs) for biomedical applications, the number of FDA or EMA approved formulations is few. It is not known commonly that the approved formulations in many instances have already been withdrawn or discontinued by the producers; at present, hardly any approved formulations are produced and marketed. Literature survey reveals that there is a lack for a commonly accepted physicochemical practice in designing and qualifying formulations before they enter in vitro and in vivo biological testing. Such a standard procedure would exclude inadequate formulations from clinical trials thus improving their outcome. Here we present a straightforward route to assess eligibility of carboxylated MNPs for biomedical tests applied for a series of our core-shell products, i.e., citric acid, gallic acid, poly(acrylic acid) and poly(acrylic acid-co-maleic acid) coated MNPs. The discussion is based on physicochemical studies (carboxylate adsorption/desorption, FTIR-ATR, iron dissolution, zeta potential, particle size, coagulation kinetics and magnetization measurements) and involves in vitro and in vivo tests. Our procedure can serve as an example to construct adequate physico-chemical selection strategies for preparation of other types of core-shell nanoparticles as well.

19 November 2012 in BMC Chemistry
Verified
Journal Article
Open access
PDF file
CRISTINA ADRIANA DEHELEANCRISTINA ADRIANA DEHELEAN
CRISTINA ADRIANA DEHELEAN
CSCodruta Soica
Codruta Soica
ILIonuţ Ledeţi
Ionuţ Ledeţi
MAMihaela Aluaş
Mihaela Aluaş
IZIstvan Zupko
Istvan Zupko
MMMelania Florina Munteanu
Melania Florina Munteanu
Background: Pentacyclic triterpenes, mainly betulin and betulinic acid, are valuable anticancer agents found in the bark of birch tree. This study evaluates birch bark extracts for the active principles composition. Results: New improved extraction methods were applied on the bark of Betula pendula in order to reach the maximum content in active principles. Extracts were analyzed by HPLC-MS, Raman, SERS and 13C NMR spectroscopy which revealed a very high yield of betulin (over 90%). Growth inhibiting effects were measured in vitro on four malignant human cell lines: A431 (skin epidermoid carcinoma), A2780 (ovarian carcinoma), HeLa (cervix adenocarcinoma) and MCF7 (breast adenocarcinoma), by means of MTT assay. All of the prepared bark extracts exerted a pronounced antiproliferative effect against human cancer cell lines. In vivo studies involved the anti-inflammatory effect of birch extracts on TPA-induced model of inflammation in mice. Conclusions: The research revealed the efficacy of the extraction procedures as well as the antiproliferative and anti-inflammatory effects of birch extracts.