Fitokemijska karakterizacija i biološki učinci odabranih vrsta roda Thymus L.

doctoral thesis

• Title (english): Phytochemical characterization and biological effects of selected Thymus species
• Author: Marija Kindl
• Mentor: Sanda Vladimir-Knežević (mentor)
• Committee member: Marijana Zovko Končić (predsjednik povjerenstva)
• Committee member: Renata Jurišić Grubešić (član povjerenstva)
• Committee member: Donatella Verbanac (član povjerenstva); MBZ: 133213
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of pharmacognosy); Zagreb
• Defense date and country: 2016, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy
• Universal decimal classification (UDC): 615 - Pharmacology. Therapeutics. Toxicology

Abstract

U okviru ovog doktorskog rada po prvi put je provedeno opsežno usporedno istraživanje fitokemijskog sastava i bioloških učinaka odabranih vrsta roda Thymus hrvatske flore (T. longicaulis C. Presl, T. praecox Opiz subsp. polytrichus (A. Kerner ex Borbás) Jalas, T. pulegioides L., T. serpyllum L. subsp. serpyllum i T. striatus Vahl). Kvalitativna i kvantitativna analiza biološki aktivnih sastavnica provedena je primjenom kromatografskih tehnika (TLC, RP-HPLC-DAD, LC-ESI-MS/MS i GC-MS) i spektrofotometrijskih metoda. Ružmarinska kiselina je bila najzastupljenija polifenolna sastavnica svih istraživanih vrsta. Većina
identificiranih flavonoida bila je iz skupine flavona. Najveći broj pripadao je derivatima luteolina, dok se udjelom isticao skutelarin. Istraživane Thymus vrste značajno su se razlikovale prema sadržaju i sastavu eteričnog ulja. Vrste T. longicaulis i T. pulegioides bile su bogate timolom i/ili karvakrolom, dok je 1,8-cineol bio glavna sastavnica vrste T. serpyllum subsp. serpyllum. U eteričnom ulju planinskih vrsta T. praecox subsp. polytrichus i T. striatus prevladavali su seskviterpenski spojevi. Biološki učinci eteričnih ulja, biljnih ekstrakata i fenolnih sastavnica ispitani su u prikladnim in vitro eksperimentalnim sustavima.
Eterična ulja odabranih Thymus vrsta inhibirala su rast bakterija S. aureus, E. faecalis i E. coli. Ustanovljeno je da se uklapanjem eteričnih ulja u liposome zadržava isti ili se može postići bolji antibakterijski učinak. Istraživanim biljnim ekstraktima dokazana su snažna antioksidacijska svojstva temeljena na sposobnosti hvatanja slobodnih radikala, redukciji i keliranju iona željeza te sposobnost inhibicije lipidne peroksidacije. Thymus ekstrakti su pokazali sposobnost inhibicije Src tirozin kinaze te su
smanjili produkciju proupalnog citokina IL-6 u splenocitima Balb/C miševa. Rezultati provedenih fitokemijskih i bioloških istraživanja pokazali su da, među Thymus vrstama koje rastu u Hrvatskoj, tankolisna majčina dušica (T. longicaulis) ima najveći potencijal za primjenu u farmaciji, usporediv s farmakopejskom vrstom T. vulgaris.

Abstract (english)

In this doctoral thesis, a comprehensive comparative study of the phytochemical composition and biological effects of selected Thymus species (T. longicaulis C. Presl, T. praecox Opiz subsp. polytrichus (A. Kerner ex Borbás) Jalas, T. pulegioides L., T. serpyllum L. subsp. serpyllum i T. striatus Vahl) from Croatian flora was conducted for the first time. Qualitative and quantitative chemical analyses of bioactive compounds were carried out using various chromatographic (TLC, RP-HPLC-DAD, LC-ESI-MS/MS and GC-MS) and spectrophotometric methods. Rosmarinic acid was found to be the most abundant polyphenolic constituent of all investigated species. Most of the identified flavonoids were from the group of flavones, the largest number belonged to luteolin derivatives, while scutellarin was present with the highest concentration. The investigated Thymus species were significantly different according to the content and composition of
essential oils. Thymol and/or carvacrol were found to be the main components of essential oils of T. longicaulis and T. pulegioides, while T. serpyllum subsp. serpyllum was rich in 1,8-cineole. The mountain species T. praecox subsp. polytrichus and T. striatus were characterised by a high percentage of sesquiterpenes. The biological effects of essential oils, plant extracts and phenolic constituents were studied using different in vitro assays. Selected Thymus essential oils inhibited growth of bacterial strains S. aureus, E. faecalis and E. coli. It was found that encapsulation of essential oils in liposomes can maintain or even improve their antibacterial efficiency. The studied plant extracts displayed strong antioxidant properties by acting as free radical scavengers and reducing agents and, additionally, by chelating transition metals and inhibiting lipid peroxidation. The Thymus extracts showed Src tyrosine kinase inhibitory activity and they
reduced the production of proinflammatory cytokine IL-6 in Balb/C mice splenocytes. The results of phytochemical and biological investigations suggest that, among Croatian Thymus species, T. longicaulis has the greatest potential for pharmaceutical usage comparable to that of pharmacopoeial species T. vulgaris.

• Keywords: Thymus spp.; eterično ulje; ružmarinska kiselina; flavonoidi; antibakterijski učinak; antioksidacijski učinak; Src tirozin kinaza; interleukin-6
• Keywords (english): Thymus spp.; essential oil; rosmarinic acid; flavonoids; antibacterial effect; antioxidant effect; Src tyrosine kinase; interleukin-6
• Language: croatian
• URN:NBN: urn:nbn:hr:163:090627
• Study programme: Title: Pharmacy and biochemistry; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor znanosti (doktor znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2016-05-10 09:21:11