Sadržaj ukupnih fenola i antioksidativni učinak in vitro metanolnih ekstrakata vrsta roda Globularia

master's thesis

• Title (english): Total phenolic content and antioxidative effect in vitro of methanolic extracts of species from the Globularia genus
• Author: Josipa Medić
• Mentor: Kroata Hazler Pilepić (mentor)
• Committee member: Kroata Hazler Pilepić
• Committee member: Željan Maleš
• Committee member: Sandra Jurić
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of pharmaceutical botany); Zagreb
• Defense date and country: 2015-07-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Globularia alypum biljka je koja se koristi kao antidijabetik, a u prijašnjim istraživanjima potvrđeno je da posjeduje i značajni antioksidativni učinak. U ovom radu uspoređen je ukupni sadržaj fenola i antioksidativni učinak u uvjetima in vitro metanolnih ekstrakata četiri vrste roda Globularia: G. alypum, G. cordifolia, G. meridionalis i G. punctata. Za pripremu ekstrakata korištene su četiri različite metode: kuhanje u refluksnim uvjetima, ultrazvučna ekstrakcija, maceracija te kisela maceracija. Za određivanje sadržaja fenola korištena je metoda temeljena na Folin-Ciocalteuovom fenolnom reagensu s galnom kiselinom kao standardom, dok je za određivanje antioksidativnog kapaciteta korišten ABTS test gdje je standard bio Trolox. Rezultati su pokazali da ukupna količina fenola kod pojedine vrste varira ovisno o načinu pripreme ekstrakata: od 9,08 ± 0,61 (macerat G. meridionalis) do 24,83 ± 0,36 mg ekvivalenta galne kiseline/g suhog biljnog materijala (dekokt G. meridionalis). Najveću količinu fenola sadržavali su uzorci vrste G. cordifolia, G. meridionalis i G. punctata pripremljeni kuhanjem u refluksnim uvjetima. Vrsta G. alypum bila je najbogatija fenolima u uzorku pripremljenom maceracijom, pri čemu je sadržavala gotovo dvostruko veću količinu fenola od uzoraka preostale tri vrste pripremljenih na isti način. Što se tiče antioksidativnog učinka, rezultati su varirali od 7,44 ± 2,67 (macerat G. cordifolia) do 38,62 ± 1,53 mg ekvivalenta Troloxa/g suhog biljnog materijala (dekokt G. punctata). Najveći antioksidativni učinak pokazali su uzorci pripremljeni kuhanjem u refluksnim uvjetima, posebno oni vrsta G. meridionalis i G. punctata. Kao što je to bio slučaj i sa sadržajem fenola, macerat vrste G. alypum imao je veći antioksidativni kapacitet od ostalih uzoraka pripremljenih maceracijom.

Abstract (english)

Globularia alypum is a plant used as an antidiabetic and previous investigations have also proven its significant antioxidative effect. In this thesis, total phenolic content and antioxidative effect in vitro of methanolic extracts of four species of Globularia genus were compared. The investigated species were: G. alypum, G. cordifolia, G. meridionalis and G. punctata. Four different methods were used for the preparation of extracts: boiling under reflux conditions, ultrasound extraction, maceration and acid maceration. For determination of total phenolic content, the method based on Folin-Ciocalteu's reagent was used, with gallic acid as the standard substance, while ABTS test was used for determination of antioxidative capacity. The standard substance was Trolox. The results have shown that total phenolic content varies for each species depending on the type of extract preparation: from 9.08 ± 0.61 (G. meridionalis macerate) to 24.83 ± 0.36 mg gallic acid equivalent/g dry plant material (G. meridionalis decoct). The highest total phenolic contents were found in samples of G. cordifolia, G. meridionalis and G. punctata species prepared by boiling under reflux conditions. G. alypum species was the richest in phenols in the sample prepared by maceration, containing almost double the amount of phenols found in the remaining three species prepared in the same way. Considering the antioxidative effect, the results varied from 7.44 ± 2.67 (G. cordifolia macerate) to 38.62 ± 1.53 mg Trolox equivalent/g dry plant material (G. punctata decoct). The highest antioxidative effect was shown by samples prepared by boiling under reflux conditions, especially those of G. meridionalis and G. punctata species. As in the case of total phenolic content, G. alypum macerate had higher antioxidative capacity than other samples prepared by maceration.

• Keywords: Globularia alypum; antioksidativni učinak; ABTS; Folin-Ciocalteuov reagens; fenoli
• Keywords (english): Globularia alypum; antioxidative effect; ABTS; Folin-Ciocalteu's reagent; phenols
• Language: croatian
• URN:NBN: urn:nbn:hr:163:021574
• 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: Access restricted to students and staff of home institution
• Created on: 2016-01-20 14:26:18