Određivanje antioksidativne aktivnosti aminosalicilata HPLC-DPPH metodom

master's thesis

• Title (english): Determination of antioxidant activity of aminosalicylates by HPLC-DPPH method
• Author: Borna Pavić
• Mentor: Ana Mornar Turk (mentor)
• Committee member: Ana Mornar Turk (predsjednik povjerenstva)
• Committee member: Daniela Amidžić Klarić (član povjerenstva)
• Committee member: Željan Maleš (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of pharmaceutical analysis); Zagreb
• Defense date and country: 2019-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Upalne bolesti crijeva obuhvaćaju skupinu kroničnih poremećaja koji uzrokuju upalu i ulceraciju tankog i debelog crijeva. Većina IBD-a može biti klasificirana kao ulcerozni kolitis i Crohnova bolest. Etiologija IBD-a i dalje ostaje nejasna, ali poznato je da oksidativna oštećenja bioloških membrana imaju važnu ulogu u oštećenju tkiva. Aminosalicilati se koriste više od 60 godina u liječenju IBD-a, a njihov najpoznatiji predstavnik je sulfasalazin. Osim inhibicije sinteze prostaglandina i leukotriena i smanjenja kemotaksije neutrofila, pokazano je da 5-ASA posjeduje antioksidativna svojstva i potencijalno je sredstvo za uklanjanje slobodnih radikala koji su odgovorni za patogenezu IBD. Cilj ovog rada bio je utvrditi antioksidativnu aktivnost 5-ASA i njegovih prolijekova mjerenjem sposobnosti hvatanja slobodnog DPPH radikala. Antioksidativna aktivnost (pro)lijekova određena je primjenom HPLC-DPPH metode, pri čemu je sintetski antioksidans, TROLOX, korišten kao standard, a dobivena vrijednost izražena kao ekvivalent TROLOX (TEAC). Na temelju dobivenih rezultata 0,1 mM otopina 5-ASA pokazala je najjaču antioksidativnu aktivnost, a zatim 1 mM otopina sulfasalazina. S druge strane, 1 mM otopina balsalazida i olsalazina pokazale su značajno manju antioksidativnu aktivnost. Ovi rezultati upućuju na činjenicu da veći dio antioksidativne aktivnosti aminosalicilata potječe iz 5-ASA. Oslobađanjem iz strukture prolijeka zbog enzimske razgradnje azo veze, antioksidativna aktivnost mogla bi biti dio terapijskog učinka sulfasalazina, olsalazina i balsalazida, čak i ako bi njihova aktivnost u obliku prolijeka bila mnogo slabija od same 5-ASA. Predložena HPLC-DPPH metoda pokazala se brzom i učinkovitom za određivanje antioksidativne aktivnosti aminosalicilata s ciljem ispitivanja dodatnih mehanizama djelovanja pojedinih predstavnika ove široko primjenjivane skupine lijekova u kliničkoj praksi.

Abstract (english)

The inflammatory bowel disease (IBD) involves chronic inflammation of digestive tract and it is determined either as Crohn’s disease, that takes place anywhere on the linings of the digestive tract, or ulcerative colitis, that causes inflammation only in the colon. Etiology of IBD remains unclear, but it is known that oxidative damage to biological membranes plays an important role in tissue damaging. Aminosalicylates have been in use for over 60 years in treatment of IBD and their most known representative, sulfasalazine. Besides the inhibition of prostaglandin and leukotriene synthesis and reduction of neutrophil chemotaxis it has been shown that 5-ASA possesses antioxidative properties and is a potential scavenger of free radicals that are responsible for the pathogenesis of IBD. Thus, the aim of this work was to determine the antioxidative power of 5-ASA and its prodrugs. The antioxidative potential of the drugs was determined using HPLC-DPPH method. Scavenging strength of compounds was shown using TROLOX as standard antioxidant and it was expressed as TROLOX equivalent antioxidant capacity (TEAC). Based on the results obtained, 0.1 mM 5-ASA solution showed the strongest antioxidant activity, and than 1 mM sulfasalazine solution. On the other hand, 1 mM solutions of balsalazide and olsalazine showed significantly low antioxidant activity. These results may imply that majority of the antioxidative power of aminosalicylates originate from 5-ASA. It is released from the structure of prodrugs due to enzymatic breakdown of azo bound, therefore, antioxidative effect could be part of therapeutic benefit of sulfasalazine, olsalazine and balsalazide even if their power in produg form was much weaker than 5-ASA itself. The proposed HPLC-DPPH method has been shown to be rapid and effective in determining the antioxidant activity of the aminosalicylate with the purpose of testing additional mechanisms of action of individual representatives of this widely used drug group in clinical practice.

• Keywords: aminosalicilati; antioksidativna aktivnost; HPLC-DPPH metoda
• Keywords (english): aminosalicylates; antioxidant activity; HPLC-DPPH method
• Language: croatian
• URN:NBN: urn:nbn:hr:163:536318
• 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: 2022-01-24 11:11:38