Utjecaj hidrokinona na aktivnost antioksidacijskih enzima i oštećenje DNA u bubregu, jetri i mozgu štakora

master's thesis

• Title (english): Effect of hydroquinone on antioxidative enzyme activity and DNA damage in rat kidney, liver and brain
• Author: Vanja Popović
• Mentor: Vesna Benković (mentor)
• Committee member: Vesna Benković (predsjednik povjerenstva)
• Committee member: Renata Matoničkin Kepčija (član povjerenstva)
• Committee member: Antun Alegro (član povjerenstva)
• Committee member: Duje Lisičić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2017-11-22, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Hidrokinon je spoj koji nastaje bioaktivacijom arbutina, točnije razgradnjom arbutina pod djelovanjem enzima β-glukozidaze i alkalnih uvjeta u ljudskom organizmu. Hidrokinon je pokazao kancerogene osobine u istraživanjima kronične toksičnosti kod glodavaca gdje je dokazano da potiče nastanak benignih tumora jetre i bubrega kao i mononuklearne leukemije. Cilj ovog istraživanja je utvrditi učinak hidrokinona na nivo oksidativnog stresa spektrofotometrijskim mjerenjem aktivnosti superoksid dismutaze i katalaze, kao i određivanjem stupnja lipidne peroksidacije mjerenjem koncentracije malondialdehida, te mogući genotoksični učinak primjenom standardne izvedbe komet testa u alkalnim uvjetima. Istraživanje je izvršeno na stanicama bubrega, jetre i mozga štakora soja Lewis oba spola tretiranih hidrokinonom u koncentraciji od 200 mg/kg tijekom 28 dana. Dobiveni rezultati upućuju da hidrokinon blago povećava stupanj lipidne peroksidacije, ali ne utječe na aktivnost antioksidacijskih enzima katalaze i superoksid dismutaze. Hidrokinon pokazuje statistički značajno povećanje primarnih oštećenja DNA na stanicama bubrega mužjaka štakora za parametre intenziteta repa i repnog momenta. Na stanicama jetre ženki štakora zabilježeno je statistički značajno povećanje oštećenja DNA za sva tri parametra komet testa. No budući da su izmjerene razine oštećenja ispod 10%, hidrokinon pokazuje nizak genotokičan potencijal. Temeljem rezultata može se zaključiti da dozvoljena dnevna doza hidrokinona nije toksična za stanice bubrega, jetre i mozga.

Abstract (english)

Hydroquinone is pharmacologically active metabolite of arbutin, is released from arbutin by the action of enzyme β-glucosidase and alkali conditions in human organism. Hydroquinone has shown carcinogenic properties in chronic toxicity studies in rodents where it has been shown that hydroquinone stimulate benign liver and kidney tumors as well as mononuclear leukemia. The purpose of this study is to determine the effect of hydroquinone on the oxidative stress level by spectrophotometric measurements of superoxide dismutase and catalase activity, as well as the determination of lipid peroxidation by measuring the concentration of malondialdehyde and the possible genotoxic effect using a standard comet assay in alkaline conditions. This research was carried out on kidney, liver and brain of Lewis breed rats of both gender treated with hydroquinone in concentration of 200 mg/kg during 28 days. The results indicate that hydroquinone slightly increases a level of lipid peroxidation but does not affect the activity of the antioxidant enzymes catalase and superoxide dismutase. Hydroquinone shows a statistically relevant increase of primary DNA damage in male rats kidney cells for parameters the tail intensity and tail moment. There was a statistically relevant increase in DNA damage for all three parameters of the comet assay on female rats liver cells. But since they measured levels of damage do not exceed 10% DNA in comet tail, hydroquinone shows low genotoxic potential. Based on the indicated results it can be concluded that the permitted daily dose of hydroquinone is not toxic to the cells of the kidneys, liver and brain.

• Keywords: oksidativni stres; hidrokinon; lipidna peroksidacija; antioksidacijski enzimi; komet test; genotoksičnost
• Keywords (english): oxidative stress; hydroquinone; lipid peroxidation; antioxidant enzymes; comet assay; genotoxicity
• Language: croatian
• URN:NBN: urn:nbn:hr:217:344866
• Study programme: Title: Experimental Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra eksperimentalne biologije (magistar/magistra eksperimentalne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-02-05 08:44:29