Utjecaj bisfenola A na parametre oksidacijskog stresa u korjenčićima luka (Allium cepa L.)

master's thesis

• Title (english): The effect of bisphenol A on oxidative stress parameters in onion (Allium cepa L.) roots
• Author: Klara Blažeka
• Mentor: Ana-Marija Domijan (mentor)
• Committee member: Ana-Marija Domijan (predsjednik povjerenstva)
• Committee member: Maja Bival Štefan (član povjerenstva)
• Committee member: Marijan Marijan (član povjerenstva); MBZ: 335524
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of pharmaceutical botany); Zagreb
• Defense date and country: 2022-11-24, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Cilj ovog rada bio je ispitati fitotoksičnost i oksidacijski stres kao mehanizam toksičnosti bisfenola A (BPA) u korjenčićima običnog luka (Allium cepa L.). Korjenčići lukovica luka (n = 10) bili su izloženi ili destiliranoj vodi (negativna kontrola) ili otopinama BPA (koncentracijski raspon 1-50 mg/l) kroz tri dana. Nakon trodnevne izloženosti, izvagana je masa svježeg tkiva korjenčića svake od lukovica te je pripremljen homogenat korjenčića luka u 5 % TCA (100 mg tkiva u 0,5 ml 5 % TCA). U supernatantu tako pripremljenog homogenata određeni su parametri oksidacijskog stresa: sadržaj reduciranog glutationa (GSH) i malondialdehida (MDA), a u talogu homogenata određen je sadržaj proteinskih karbonila. Sadržaj GSH određen je metodom prema Ellmanu (1959), MDA tiobarbituratnim testom, a proteinski karbonili metodom prema Levinu i sur. (1990), derivatizacijom karbonilne skupine proteina uz DNPH. Dobiveni rezultati statistički su obrađeni studentovim t-testom (Excell, MS Office). Masa svježeg tkiva korjenčića luka tretiranih otopinama BPA (1-50 mg/l) bila je niža u odnosu na negativnu kontrolu te je značajno smanjenje mase zabilježeno već nakon izloženosti BPA u koncentraciji 5 mg/l. Pad mase svježega tkiva s povećanjem koncentracije BPA ukazuje na fitotoksično djelovanje BPA na korjenčiće običnog luka. Sadržaj GSH bio je značajno niži u odnosu na kontrolu nakon izloženosti BPA u koncentraciji 1 mg/l. Značajan porast u odnosu na negativnu kontrolu sadržaja proteinskih karbonila zabilježen je nakon izloženosti BPA u koncentraciji 10 mg/l, a MDA nakon izloženosti 25 mg/l. Pad razine antioksidansa (GSH) i porast razine parametara oksidacijskog oštećenja lipida i proteina (MDA i proteinski karbonili) upućuju na to da je BPA izazvao oksidacijski stres u modelnom organizmu. Dobiveni rezultati pokazuju da BPA uzrokuje oksidacijsko oštećenje staničnih struktura te se može zaključiti da je oksidacijski stres jedan od mehanizama toksičnog učinka BPA.

Abstract (english)

The aim of this study was to explore phytotoxicity and oxidative stress as a mechanism of bisphenol A (BPA) toxicity in onion roots (Allium cepa L.). Roots of onion bulbs (n = 10) were exposed to either distilled water (negative control) or BPA solutions (concentration range 1-50 mg/l) for three days. After a three-day exposure, the fresh root weight of each bulb was weighed, and in 5% TCA a homogenate of onion roots was prepared (100 mg of tissue in 0.5 ml of 5% TCA). In the supernatant of prepared homogenate oxidative stress parameters: the content of reduced glutathione (GSH) and malondialdehyde (MDA) was determined, and in the homogenate’s precipitate the content of protein carbonyls was assessed. The GSH content was determined based on the Ellman method (1959), MDA by using the thiobarbiturate test and the content of protein carbonyls was determined according to Levin et al. (1990), by derivatization of the proteins’ carbonyl group with DNPH. The obtained results were statistically analysed by student’s t-test (Excel, MS Office).The fresh tissue weight of onion roots treated with BPA (in concentration range 1-50 mg/l) was lower compared to the negative control, and a significant decrease in roots fresh weight was recorded already after exposure to BPA in concentration of 5 mg/l. The decrease in fresh tissue weight with increasing BPA concentration indicates that BPA had phytotoxic effect on onion roots. The exposure to BPA in concentration of 1 mg/l significantly decreased the content of GSH compared to the control. A significant increase compared to the negative control in the content of protein carbonyls was recorded after exposure to BPA in concentration of 10 mg/l, and MDA after exposure to BPA in concentration of 25 mg/l. A decrease in the level of antioxidants (GSH) and an increase in the level of lipid and protein oxidative damage parameters (MDA and protein carbonyls) indicate that BPA caused oxidative stress in the model organism. The obtained results imply that BPA caused oxidative damage to cellular structures, thus can be concluded that oxidative stress is one of the mechanisms of BPA toxicity.

• Keywords: bisfenol A; Allium test; oksidacijski stres; glutation; malondialdehid; proteinski karbonili
• Keywords (english): bisphenol A; Allium test; oxidative stress; glutathione; malondialdehyde; protein carbonyls
• Language: croatian
• URN:NBN: urn:nbn:hr:163:730980
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-11-28 15:04:39