Determination of antioxidant activity of beta-blockers by HPLC-DPPH method

Kardiovaskularne bolesti imaju najveću prevalenciju i komorbiditete te najveći mortalitet u općoj populaciji. Dobro poznavanje patofizioloških mehanizama nastanka u kombinaciji s razumijevanjem farmakoloških učinaka dostupnih lijekova temelj je uspješnog liječenja. Beta-blokatori su nezamjenjivi lijekovi u indikacijama poput hipertenzije, angine pektoris, akutnog infarkta miokarda, sekundarne prevencije infarkta miokarda, srčane aritmije i zatajenja srca. Iako svi beta-blokatori dijele zajednički osnovni mehanizam djelovanja, među njima postoje određene razlike, kako u farmakokinetičkim i farmakodinamičkim svojstvima, tako i u dodatnim mehanizmima djelovanja. Upravo te razlike mogu izdvojiti jedan ili više lijekova kao lijekove izbora u odnosu na ostale pripadnike skupine, pogotovo u osoba s komorbiditetima. Cilj ovog rada bio je ispitati antioksidativni učinak beta-blokatora (atenolola, bisoprolola, karvedilola, nebivolola i propranolola) mjereći njihovu sposobnost hvatanja slobodnog 1,1,-difenil-2-pikrilhidrazil radikala. Korištena DPPH metoda temelji se na sposobnosti hvatanja slobodnog radikala potencijalnim antioksidansom (beta-blokatorom) pri čemu dolazi do smanjenja apsorbancije DPPH•. Analize su provedene tekućinskom kromatografijom visoke djelotvornosti. Svi uzorci pripremljeni su kao 1 mM otopine i analizirani u triplikatu, a rezultati izraženi kao antioksidativni kapacitet ekvivalentan standardu TROLOX-a. Na temelju dobivenih rezultata mjerljivu antioksidativnu aktivnost pokazali su atenolol i karvedilol. HPLC-DPPH metoda pokazala se brzom i učinkovitom za određivanje antioksidativne aktivnosti beta-blokatora s ciljem ispitivanja dodatnih mehanizama djelovanja pojedinih predstavnika ove široko primjenjivane skupine lijekova u kliničkoj praksi.Cardiovascular diseases have the highest prevalence and comorbidities as well as the highest mortality in the general population. Good knowledge of pathophysiological mechanisms of action combined with understanding the pharmacological effects of available drugs is the basis of successful treatment. Beta blockers are irreplaceable drugs in indications such as hypertension, angina pectoris, acute myocardial infarction, secondary myocardial infarction, cardiac arrhythmia and heart failure. Although all beta-blockers share a common basic mechanism of action, there are some differences between them, both in pharmacokinetic and pharmacodynamic properties, as well as in additional mechanisms of action. Those differences can distinguish one or more drugs as a drug of choice compared to other members of the group, especially in patients with comorbidities. The aim of this work was to examine the antioxidant effect of beta-blockers (atenolol, bisoprolol, carvedilol, nebivolol and propranolol) by measuring their ability to scavenge free 1,1-diphenyl-2-picrylhydrazyl radical. The DPPH method is based on the ability to capture free radicals with potential antioxidants (beta-blocker), which reduces DPPH• absorption. All samples were prepared as 1 mM solution and analyzed in triplicate and the results expressed as antioxidant capacity equivalent to TROLOX standard. Based on the obtained results, measurable antioxidant activity was demonstrated by atenolol and carvedilol. The HPLC-DPPH method has been shown to be rapid and effective in determining the antioxidant activity of the beta-blocker with the purpose of testing additional mechanisms of action of individual representatives of this widely used drug group in clinical practice