Uniform Master's Study Programme Pharmacy
Lidija Kač (Author), Marija Sollner Dolenc (Mentor), Bojana Žegura (Co-mentor)

Abstract

Bisfenol A je ena izmed najbolj razširjenih sintezno pridobljenih spojin na svetu. Zaradi obsežne proizvodnje in uporabe za izdelavo številnih izdelkov, s katerimi prihajamo ljudje v stik vsakodnevno, je vseprisoten v okolju, človekova izpostavitev onesnažilu pa je postala praktično neizogibna. Bisfenol A je znan hormonski motilec in izkazuje številne škodljive učinke na organizme. Ugotovitvam o njegovem škodljivem delovanju so sledili ukrepi omejitve njegove proizvodnje oziroma popolne prepovedi njegove uporabe v določene namene, na tržišče pa so vstopile nove spojine, po strukturi in fizikalno-kemijskih lastnostih podobne bisfenolu A, ki jih imenujemo strukturni analogi bisfenola A. Postavlja se vprašanje, ali je njihova uporaba tudi bolj varna za okolje in ljudi. Glede na njihovo vse večjo razširjenost smo ljudje lahko izpostavljeni tudi večim analogom bisfenola A hkrati, zato so potrebne dodatne raziskave tudi na področju izpostavitve njihovim kompleksnim mešanicam. Najbolj razširjen in raziskan po svojih učinkih je bisfenol A, sledijo mu bisfenoli S, F in AF. Največ študij obravnava njihove mehanizme toksičnega delovanja preko motenja hormonskega sistema, manj pa je raziskano njihovo genotoksično delovanje. V magistrski nalogi smo se omejili na raziskovanje citotoksičnega in genotoksičnega delovanja bisfenolov A, S, F in AF ter njihovih kompleksnih mešanic v celični liniji humanega hepatoma (HepG2). Citotoksično delovanje smo ugotavljali s testom MTS, genotoksično delovanje pa z analizo prisotnosti dvoverižnih prelomov DNA preko zaznavanja žarišč γ-H2AX s pretočno citometrijo. Najprej smo proučili delovanje vsakega posameznega bisfenola pri izbranih koncentracijah, nato pa delovanje njihovih kompleksnih mešanic pri koncentracijah značilnih za okolje in človekovo izpostavitev. Teste smo izvedli pri dveh časovnih izpostavitvah, 24 in 72 ur. Rezultati naše magistrske naloge so pokazali, da je za celice HepG2 izmed vseh proučevanih bisfenolov najbolj citotoksičen bisfenol AF, najmanj citotoksičen pa bisfenol A, saj pri nobeni testirani koncentraciji, tako po 24- kot 72-urni izpostavitvi ni povzročil znižanja celične živosti. Največje genotoksično delovanje sta izkazala bisfenola F in AF. Po 24-urni izpostavitvi sta povečala število dvoverižnih prelomov DNA pri dveh najvišjih testiranih koncentracijah (10 in 20 μg/mL). Po 72-urni izpostavitvi je bisfenol F deloval genotoksično pri koncentraciji 20 μg/mL, medtem ko bisfenol AF pri necitotoksičnih koncentracijah ni povečal števila dvoverižnih prelomov DNA. Bisfenol A je deloval genotoksično pri najvišji testirani koncentraciji (20 μg/mL) po 72-urni izpostavitvi. Bisfenol S ni povzročil povečanja števila dvoverižnih prelomov DNA v celicah HepG2 pri nobeni testirani koncentraciji, tako po 24 kot po 72 urah. Kompleksne mešanice bisfenolov A, S, F in AF pri koncentracijah značilnih za okolje oziroma človekovo izpostavitev, tako po 24- kot tudi po 72-urni izpostavitvi, niso znižale celične živosti, prav tako niso povzročile povečanja števila dvoverižnih prelomov DNA v celicah HepG2.

Keywords

bisfenoli A;bisfenoli S;bisfenoli F;bisfenoli AF;dvoverižni prelomi DNA;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL FFA - Faculty of Pharmacy
Publisher: [L. Kač]
UDC: 577.27+615.9(043.3)
COBISS: 4653169 Link will open in a new window
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Other data

Secondary language: English
Secondary title: Cytotoxic and genotoxic activity of bisphenols A, S, F, AF and their mixtures in HEPG2 cell line
Secondary abstract: Bisphenol A is one of the most widespread chemicals in the world. Due to its massive production and applications it is ubiquitous in the environment and various consumer products used daily. Human exposure to bisphenol A has become practically unavoidable. Bisphenol A is a well-known endocrine disruptor and exhibits many toxic effects on living organisms. Publication of studies demonstrating its toxic effects was followed by regulations of its production or complete prohibition of its use in various applications. The regulations were followed by introduction of structurally similar chemicals, with similar physio-chemical properties, called bisphenol analogues on the global market. But the question arises, if bisphenol analogues are also safer for the environment and if their exposure to humans is less hazardous. Due to their widespread occurrence, human co-exposure to multiple bisphenol analogues should also be researched. Among all the bisphenols currently used in industrial applications, bisphenol A is the most ubiquitous and most researched, followed by bisphenols S, F and AF. Most studies are focused on their toxic effects exhibited via their disruption of endocrine system, while not many data exist regarding their genotoxicity. In our research we examined cytotoxic and genotoxic potential of bisphenols A, S, F, AF and their complex mixtures on human hepatoma cell line (HepG2). To determine their cytotoxicity MTS test was used. For determination of their genotoxic activity we analyzed the presence of DNA double strand breaks, by indirect detection of γ-H2AX foci using flow cytometry. We examined bisphenols A, S, F and AF respectively at different concentrations after 24- and 72-hour exposure of HepG2 cells to each chemical. We also assessed cytotoxic and genotoxic activity of complex mixtures of bisphenol analogues on HepG2 cells, at concentrations that are found in the environment and concentrations relevant for human exposure after 24-hour and 72-hour exposure time. The results of our research showed that bisphenol AF exhibited the highest cytotoxic effect in HepG2 cells, whereas the least cytotoxic was bisphenol A. Bisphenol A did not reduce cell viability at any of the tested concentrations after 24- nor 72-hour exposure. Bisphenols F and AF exhibited the highest genotoxic effect. After 24-hour exposure time they caused an increase in DNA double strand breaks at concentrations 10 μg/mL and 20 μg/mL. After 72-hour exposure time bisphenol F caused an increase in DNA double strand breaks at concentration 20 μg/mL, whereas bisphenol AF did not show any genotoxic effect at non-cytotoxic concentrations. Bisphenol A induced an increase in DNA double strand breaks in HepG2 cells at the highest tested concentration (20 μg/mL) after 72-hour exposure time. The least genotoxic was bisphenol S which did not induce an increase in DNA double strand breaks in HepG2 cells after 24-hour nor 72-hour exposure time. Exposure of the HepG2 cells to complex mixtures of bisphenols A, S, F and AF at concentrations relevant for the environment and human exposure, did not affect cell viability, neither induce an increase in DNA double strand breaks, after 24-hour nor 72-hour exposure time.
Secondary keywords: Citotoksičnost;Genotoksičnost;
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. Ljubljana, Fak. za farmacijo
Pages: IX, 61 str.
ID: 12040848