Stjepan Orhanović

Prof. Dr. Stjepan Orhanović


Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

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

Representative Publications

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25 November 2016 in Parasites & Vectors
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Journal Article
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CMConcetta Maria Messina
Concetta Maria Messina
FPFederica Pizzo
Federica Pizzo
ASAndrea Santulli
Andrea Santulli
IBIvana Buselic
Ivana Buselic
MBMate Boban
Mate Boban
Ivona MladineoIvona Mladineo
Ivona Mladineo
In countries with elevated prevalence of zoonotic anisakiasis and high awareness of this parasitosis, a considerable number of cases that associate Anisakis sp. (Nematoda, Anisakidae) and different bowel carcinomas have been described. Although neoplasia and embedded larvae were observed sharing the common site affected by chronic inflammation, no association between the nematode and malignancy were directly proved. Similarly, no data are available about the effect of secretory and excretory products of infecting larvae at the host’s cellular level, except in respect to allergenic interaction. To test the mechanisms by which human non-immune cells respond to the larvae, we exposed the fibroblast cell line HS-68 to two Anisakis products (ES, excretory/secretory products; and EC, crude extract) and evaluated molecular markers related to stress response, oxidative stress, inflammation and apoptosis, such as p53, HSP70, TNF-α, c-jun and c-fos, employing cell viability assay, spectrophotometry, immunoblotting and qPCR. Both Anisakis products led to increased production of reactive oxygen species (ROS), especially in EC-treated cells. While the ES treatment induces activation of kinases suggesting inflammation and cell proliferation (or inhibition of apoptosis), in EC-treated cells, other signaling pathways indicate the inhibition of apoptosis, marked by strong upregulation of Hsp70. Elevated induction of p53 in fibroblasts treated by both Anisakis products, suggests a significantly negative effect on the host DNA. This study shows that in vitro cell response to Anisakis products can result in at least two different scenarios, which in both cases lead to inflammation and DNA damage. Although these preliminary results are far from proving a relationship between the parasite and cancer, they are the first to support the existence of conditions where such changes are feasible.

17 June 2024 in Antioxidants
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Ivana VrcaIvana Vrca
Ivana Vrca
SOStjepan Orhanović
Stjepan Orhanović
IPIvana Pezelj
Ivana Pezelj
KSKarolina Sušić
Karolina Sušić
Valerija DunkicValerija Dunkic
Valerija Dunkic
Marija NazlićMarija Nazlić
Marija Nazlić
Extracts from Veronica species (speedwells) are known for the various biological activities they show, such as cytotoxic, antimicrobial, anti-inflammatory, and antioxidant activities. Also, the plants from this genus are known as medicinal plants used in traditional medicine worldwide. Phenolic compounds are specialized metabolites that contribute to biological activity the most. Therefore, the aim of this research is identification and quantification of phenolic compounds present in three Veronica species (Veronica anagallis-aquatica L., Veronica persica Poir., and Veronica polita Fr.) using the liquid chromatography-mass spectrometry (LC-MS/MS) technique. All extracts were tested for antioxidant activity with two methods: DPPH (2,2-diphenyl-1-picrylhydrazyl) and ORAC (oxygen radical absorbance capacity). Also, standards for compounds that were detected in the highest amount in all species were also tested for antioxidant activity. Three different solvents (pure methanol, 80% ethanol, and water) were used for the extraction of phenolic components and their comparison in order to test their antioxidant activity as a final goal. The main compounds present in the tested Veronica extracts were: p-hydroxybenzoic acid, vanillic acid, caffeic acid, gentisic acid, and apigenin. V. anagallis-aquatica contained the highest amount of phenolic components in comparison with the two other tested species, V. persica and V. polita. Caffeic acid showed the highest antioxidant activity in both studied methods with an IC50 value for DPPH activity of 1.99 µg/mL. For the plant extracts, in general, methanolic/ethanolic extracts showed higher activity than water extracts in both methods which was expected, as organic solutions extract more phenolic compounds. This research points to the potential application of extracts of different Veronica species for antioxidant activity.

1 December 2006 in International Journal of Biological Macromolecules
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Journal Article
Closed access
SOStjepan Orhanović
Stjepan Orhanović
VPViljemka Bucevic Popovic
Viljemka Bucevic Popovic
MPM. Pavela-Vrančič
M. Pavela-Vrančič
DVD. Vujaklija
D. Vujaklija
VGV. Gamulin
V. Gamulin

18 April 2017 in The Protein Journal
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MŠMatilda Šprung
Matilda Šprung
BSBarbara Soldo
Barbara Soldo
SOStjepan Orhanović
Stjepan Orhanović
VPViljemka Bucevic Popovic
Viljemka Bucevic Popovic

30 October 2025 in Antioxidants
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Ivana VrcaIvana Vrca
Ivana Vrca
AMAntonija Mikrut
Antonija Mikrut
ŽFŽeljana Fredotović
Željana Fredotović
KAKarla Akrap
Karla Akrap
Dario KremerDario Kremer
Dario Kremer
Marija NazlićMarija Nazlić
Marija Nazlić
(1) Background: The conservation of plant resources is important because many wild plant populations are threatened by various influences. Growing plants from seeds is one way to ensure their survival. Comparing the biological potential of extracts between plants cultivated from seeds and wild plants provides information about their specialized metabolites. For this reason, this study compared the biological potential of phenolic extracts from four wild-collected species of the genus Veronica and the same four cultivated species. The studied species of the genus Veronica are V. anagallis-aquatica L., V. persica Poir., V. polita Fr. and V. hederifolia L. (2) Methods: The phenolic composition was investigated with LC-QTOF (Liquid Chromatography-Quadrupole Time-of-Flight). The main methods for biological activities were as follows: ORAC (Oxygen Radical Absorbance Capacity) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical for antioxidant activity, the disk diffusion test for antibacterial activity and the MTS test of cytotoxic activity. (3) Results: The major compound in all extracts was apigenin. Cultivated species showed higher antioxidative activity. Phenolic compounds isolated from the V. anagallis-aquatica species showed the highest cytotoxic effect on all tested lines. The extracts showed antibacterial activity on three bacterial strains: Streptococcus pyogenes, Listeria monocytogenes and L. innocua. Extracts of V. anagallis-aquatica showed the highest antibacterial activity, both from the natural habitat and cultivated habitat. (4) Conclusions: A comparison of the different activities tested for phenolic extracts between wild and cultivated species of the genus Veronica showed that cultivated species also have significant biological activity and are suitable for further research and applications.

23 December 2025 in Molecules
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ABAntonija Bulić
Antonija Bulić
IPIvana Pezelj
Ivana Pezelj
IUIvana Ujevic
Ivana Ujevic
TBTanja Bogdanović
Tanja Bogdanović
SOStjepan Orhanović
Stjepan Orhanović
Azaspiracids (AZAs) are marine polyether biotoxins produced by dinoflagellates that accumulate in filter-feeding organisms and pose a threat to human health and seafood safety. This study presents the first comprehensive analysis of azaspiracid analogs in shellfish from the Adriatic Sea with the use of high-resolution mass spectrometry. AZA-2 was quantified in samples collected from Šibenik Bay between January and May 2024, with the highest concentrations observed in early January. In addition to AZA-2, several known analogs (AZA-6, AZA-9, AZA-10, AZA-19, AZA-41, and AZA-43) and a potentially new analog (m/z 884.4928) were also detected. The fragmentation patterns of this new analog indicate a structural similarity to AZA-19 with a possible double bond modification. Potential pitfalls regarding the misinterpretation of spectra derived from molecules containing 13C atoms were recognized and addressed. The presence of multiple analogs, some of which have high toxic potential, suggests that regulatory practice should consider including more than three analogs in the monitoring program.