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Rheological characterization and storage stability of liposomes embedded into chitocan hydrogel
No full textRazličite vrste liposoma s azitromicinom (AZT): konvencionalni liposomi (CL), deformabilni liposomi (DL), propilenglikol liposomi (PGL) i kationski liposomi (CATL) uklopljeni su u hidrogel na bazi kitozana s ciljem postizanja prikladne viskoznosti za topikalnu primjenu na kožu. Dobivene formulacije liposomi-u-gelu (CL-HG, DL-HG, PGL-HG, CATL-HG) reološki su okarakterizirane rotacijskim i oscilacijskim testovima te im je ispitan pH. Dodatkom AZT-liposoma ili AZT-otopine (kontrola) u kitozanski gel (30 %, m/m) dolazi do blagog smanjenja viskoznosti gela, no formulacije i dalje zadržavaju viskoznost prikladnu za dermalnu primjenu te strukturu i ponašanje viskoelastičnih krutina (gelova). Nadalje, sve ispitivane formulacije liposomi-u-gelu pokazale su linearnu viskoelastičnu regiju (LVR), iz čega proizlazi da se ispitani uzorci neposredno nakon primjene mogu smatrati dobro dispergiranima i stabilnima. Reološka mjerenja su ponovljena nakon 30 dana skladištenja pri 4 °C, pri čemu je utvrđeno da formulacije liposomi-u-gelu nakon skladištenja pokazuju manju viskoznost u odnosu na viskoznost formulacije neposredno nakon izrade, ali uz zadržavanje viskoelastičnog ponašanja svojstvenog gelovima. Dodatak liposoma i AZT-otopine u izvorni gel uzrokovao je blago povišenje pH formulacija. Iako je nakon 30 dana skladištenja zabilježen statistički značajan pad pH svih formulacija, izmjerene vrijednosti i dalje su bile prikladne za dermalnu primjenu. Većina formulacija liposomi-u-gelu pokazala je zadovoljavajuću razinu stabilnosti tijekom 30-dnevnog skladištenja. Izuzetak je formulacija DL-HG koja je tijekom skladištenja toliko primijenila konzistenciju da nije bilo moguće provesti mjerenja nakon 30 dana, što upućuje na postojanje inkompatibilnosti između DL i kitozanskog gela, koju je potrebno potvrditi daljnjim ispitivanjima.Different types of azithromycin (AZT)-loaded liposomes: conventional liposomes (CL), deformable liposomes (DL), propylene glycol liposomes (PGL), and cationic liposomes (CATL) were embedded into a chitosan-based hydrogel to achieve suitable viscosity for topical application onto the skin. The obtained liposome-in-gel formulations (CL-HG, DL-HG, PGL-HG, CATL-HG) were rheologically characterized by rotational and oscillatory tests, and their pH was examined. Although the addition of AZT-liposomes or AZT-solution (control) into chitosan gel (30%, w/w) caused a slight decrease in gel viscosity, the formulations still retained viscosity suitable for dermal application and the structure and behavior of viscoelastic solids (gels). Furthermore, all tested liposome-in-gel formulations showed a linear viscoelastic region (LVR), indicating that the tested samples could be considered well-dispersed and stable immediately after preparation. Rheological measurements were repeated after 30 days of storage at 4 °C, revealing that liposome-in-gel formulations exhibited lower viscosity after storage compared to the viscosity of formulations immediately after preparation, while retaining viscoelastic behavior characteristic for gels. Liposomes and AZT-solution embedded into the chitosan gel caused a slight increase in the pH of the gel. Although a statistically significant decrease in pH was observed for all formulations after 30 days of storage, the measured values were still suitable for dermal application. Majority of liposome-in-gel formulations showed satisfactory stability during the 30-day storage. An exception was the DL-HG formulation, which underwent such a change in consistency during storage that measurements after 30 days were not possible, suggesting certain incompatibility between DL and chitosan gel, which needs to be confirmed by further research
Immunoglobulin G glycosylation in the prediction of therapeutic response and during anti-TNF therapy in Crohn's disease
No full textCrohnova bolest (CB) jedan je od oblika upalne bolesti crijeva koja može zahvatiti stijenku čitavog gastrointestinalnog sustava, od usta do rektuma, no najčešće je ograničena na distalni dio tankog crijeva (ileum) i debelo crijevo. Za takvu upalu kažemo da je kroničnog, diskontinuiranog i transmuralnog karaktera. Smatra se da je CB, odnosno upalna bolest crijeva općenito, posljedica pretjeranog imunosnog odgovora u probavnom traktu zbog narušene crijevne barijere, promijenjenog sastava crijevne mikrobiote i utjecaja okolišnih čimbenika kod osoba koja imaju genetičku predispoziciju za razvoj bolesti. Glavni ciljevi u liječenju CB-a jesu kontrola upale, postizanje remisije i njezino održavanje. U tu svrhu koriste se i biološki lijekovi poput antagonista faktora nekroze tumora, odnosno anti-TNF lijekovi. Ipak, takva je terapija izrazito skupa, ne mora biti prikladna za svakog bolesnika, a često dio bolesnika ne odgovora zadovoljavajuće na terapiju ili kasnije tijekom režima gubi odgovor na istu. Isto tako, mogu se razviti i nuspojave ili protutijela na sam lijek. U središtu ovog doktorskog rada jest imunoglobulin G (IgG). Istraživanja u području glikobiologije su pokazala da složeni oligosaharidi, odnosno glikani vezani na IgG imaju izravan učinak na njegovu izvršnu funkciju te da osobe oboljele od CB-a imaju drugačiji sastav ukupnih N-glikana serumskog IgG-a u odnosu na zdrave osobe. Stoga ova doktorska disertacija ima za cilj ispitati mogućnost predviđanja terapijskog odgovora na anti-TNF terapiju temeljem analize sastava N-glikoma serumskog IgG-a prije započinjanja terapije te istražiti longitudinalnu promjenu u sastavu N-glikoma serumskog IgG-a tijekom te iste terapije. Pritom je za istraživanje korišteno ukupno 1513 uzoraka krvnog seruma bolesnika s CB-om regrutiranih u sklopu studije PANTS (engl. Personalised Anti-TNF therapy in Crohn’s disease). U svrhu predviđanja terapijskog odgovora na anti-TNF terapiju korišteno je 1315 uzoraka krvnog seruma bolesnika s od CB-om, a dodatno prikupljenih 198 uzoraka krvnog seruma korišteno je kao druga vremenska točka zbog ispitivanja longitudinalne promjene u sastavu N-glikoma serumskog IgG-a kod istih bolesnika tijekom terapije. Iz uzoraka krvnog seruma pročišćen je IgG te je njegova N-glikozilacija analizirana metodom tekućinske kromatografije. Dobiveni rezultati pokazali su da tijekom primjene anti-TNF terapije dolazi do promjene u sastavu N-glikoma serumskog IgG-a bez obzira na terapijski odgovor. Preciznije, dolazi do smanjenja zastupljenosti agalaktoziliranih, a povećanja mono- i digalaktoziliranih te sijaliniziranih N-glikana IgG-a, što upućuje na smanjenje proupalnog potencijala serumskog IgG-a tijekom terapije. Nadalje, rezultati upućuju da sastav N-glikoma serumskog IgG-a prije započinjanja anti-TNF terapije ne sadrži informaciju o budućem terapijskom odgovoru te da se ne može koristiti u svrhu identificiranja bolesnika s CB-om koji neće primjereno odgovoriti na anti-TNF terapiju lijekovima.Crohn's disease is a type of inflammatory bowel disease that can affect the entire gastrointestinal system, from the mouth to the rectum. However, it most commonly affects the lower part of the small intestine (ileum) and the colon. Crohn's disease is represented by discontinued, chronic transmural inflammation of the gut. It is primarily a consequence of an exaggerated intestinal immune response, changes in the gut microbiota composition and exposure to certain environmental factors in individuals with a genetic predisposition to the disease. The main goals in the treatment of Crohn's disease are to control inflammation and to achieve and maintain remission. For this purpose, there are several therapeutic approaches available, including tumour necrosis factor antagonists (anti-TNF). However, this treatment can be quite expensive and may not be suitable for every patient. Some patients do not adequately respond to the anti-TNF therapy, lose their response over time, experience side effects or develop antibodies against the medication. The primary focus of this doctoral dissertation is on the total serum immunoglobulin G (IgG) N-glycosylation in Crohn's disease. Research in the field of glycobiology has shown that complex oligosaccharides called glycans have a direct impact on IgG effector function. Interestingly, patients with Crohn's disease have been found to have an altered composition of serum IgG N-glycans compared to healthy individuals. Therefore, this doctoral dissertation aims to study how the composition of total serum IgG N-glycans changes over time during anti-TNF therapy with infliximab and adalimumab. Additionally, it aims to explore the predictive potential of total serum IgG N-glycans in therapy response to anti-TNF drugs before initiating treatment. For those purposes, a total of 1513 serum samples were collected from CD patients as a part of the PANTS (Personalised Anti-TNF therapy in Crohn’s disease) study. From that number, 1315 serum samples were used to assess the prediction of therapy response to anti-TNF drugs. Additional 198 serum samples were collected at the second time point to explore the longitudinal change in the composition of total serum IgG N-glycome. The IgG was extracted from serum samples and its N-glycosylation pattern was analyzed using liquid chromatography. The results showed that the anti-TNF treatment in patients with Crohn's disease is associated with significant changes in the composition of total serum IgG N-glycans, regardless of therapy response. Specifically, the level of agalactosylated IgG N-glycans significantly decreased, while mono- and digalactosylated and sialylated glycans increased in their abundance, all of which suggest the reduced proinflammatory potential of serum IgG in patients with Crohn's disease during therapy. Furthermore, the results indicated that the composition of total serum IgG N-glycome at baseline does not hold predictive power to detect future non-responders to anti-TNF therapy
Investigation of calibration methods for direct desorption prior to gas chromatography
No full textThe determination of residual solvents in active substances, excipients, and medicines is mandatory during release testing and advisable throughout the entire drug manufacturing process. Official regulatory bodies recommend headspace-gas chromatography (HS-GC) as the analytical procedure of choice for identification and control of residual solvents in pharmaceuticals. The official headspace-gas chromatography methods assume that the sample can be made into a homogenous solution, which is then analyzed. However, not all compounds can be easily dissolved. A recently presented thermal desorber-gas chromatography (TD-GC) method, developed by the Pharmaceutical Analysis laboratory of KU Leuven and successfully used as an alternative way to determine residual solvents in complex matrices, was adapted and applied to determine residual solvents in different types of modified cellulose beads. Ideally, thermal desorption should be calibrated using gas-phase standards. However, in practice, gas-phase standards are expensive and difficult to obtain, so calibration is routinely done using liquid standards. Calibration becomes critical when thermal desorption is used for direct thermal extraction of residual solvents from solid samples because then the adsorption and desorption pathways of residual solvents in the sample and the reference differ significantly. Inline (ILC) and offline (OLC) liquid calibration were explored as potential calibration methods. After optimization of both methods, offline liquid calibration showed poorer recovery and precision compared to inline liquid calibration. So, inline liquid calibration was chosen as the preferred calibration method for this kind of analysis.Određivanje ostatnih otapala u aktivnim farmaceutskim supstancama, ekscipijensima i gotovim lijekovima je obavezno tijekom završnog ispitivanja, a preporučuje se tijekom cijelog procesa proizvodnje lijeka. Regulatorna tijela definiraju headspace–plinsku kromatografiju (HS-GC) kao preferiranu metodu za identifikaciju i određivanje ostatnih otapala u farmaceutskim oblicima. Službena metoda polazi od pretpostavke da se uzorak može otopiti te da se zatim analizira nastala otopina, no ne mogu se sve tvari lako homogenizirati. Nedavno opisana metoda analize plinskom kromatografijom s termalnom desorpcijom (TD-GC), uspješno razvijena u Laboratoriju za farmaceutsku analizu KU Leuvena-a kao alternativna metoda za analizu ostatnih otapala u složenom matriksu, prilagođena je i primjenjena za određivanje ostatnih otapala u više vrsta celuloznih zrnaca. Idealno, termalnu desorpciju bi trebalo kalibrirati standardima u plinskoj fazi, međutim plinski standardi su komplicirani za nabaviti, pa se kalibracija rutinski vrši tekućim standardima. Kalibracija metode je kritični korak u analizi u kojoj se termalni desorber koristi za izravnu desorpciju uzorka u čvrstom stanju, zbog toga što se tada značajno razlikuju adsorpcijski i desorpcijski putevi ostatnih otapala u uzorku i tekućem standardu. Inline (ILC) i offline (OLC) tekućinska kalibracija su istražene kao potencijalne kalibracijske metode. Po završetku optimizacije obiju metoda, offline tekućinska kalibracija je pokazala manji prinos i lošiju preciznost u usporedbi sa inline kalibracijom. Zbog toga je inline tekućinska kalibracija odabrana kao preferirana metoda kalibracije
Mold contamination of cereal crops during storage
No full textŽitarice su široko zastupljene u prehrambenoj industriji te iz tog razloga metode njihovog uzgoja i skladištenja moraju
biti strogo kontrolirane. Podložne su razvoju plijesni od kojih neke proizvode po zdravlje opasne mikotoksine, a
klimatske promjene i njihov direktan utjecaj na okolišne faktore poput temperature, padalina i razine ugljikovog dioksida
dovest će do promjena u zastupljenosti plijesni i mikotoksina na žitaricama.
Za potrebe ovog eksperimentalnog rada prikupljeni su uzorci pšenice, kukuruza i ječma iz istočne, središnje i sjeverne
Hrvatske. Radi se o ukupno 90 uzoraka iz skladišta prikupljenih u ožujku 2021. godine kako bi se identificirale plijesni
porasle na ovim žitaricama i odredila njihova koncentracija. Nakon analize i statističke obrade podataka veća pažnja
posvećena je rodovima Penicillium, Fusarium i Aspergillus koji su najčešći kontaminanti ovih žitarica.
Rezultati su pokazali da najznačajniju koncentraciju plijesni na žitaricama pokazuju uzorci kukuruza u sve tri hrvatske
regije na podlogama MEA i DRBC (reda veličine 106 i 107). Rod Penicillium zastupljen je na svim uzorcima žitarica
dok se rod Fusarium posebno ističe na uzorcima kukuruza. Rod Aspergillus, proizvođač aflatoksina, pokazuje najveću
učestalost na uzorcima pšenice i kukuruza istočne Hrvatske.
Za adekvatno skladištenje žitarica važno je osigurati odgovarajuće uvjete temperature, vlage i razine ugljikovog dioksida
u korištenim skladištima kako ne bi došlo do prekomjerne kontaminacije i gubitaka na usjevima. Uz kontrolirane uvjete
u proizvodnji važno je podignuti svijest populacije o klimatskim promjenama, troškovima koje one donose u
poljoprivredi i tome kako će one posredno utjecati na žitarice široko zastupljene u našoj prehrani.Cereal crops are widely spread in food industry and for that reason methods of their cultivation and storage have to be
strictly controlled. They are susceptible to mold growth and some of developed mold types have the ability to produce
mycotoxins dangerous for our health. Climate change directly influences environmental factors such as temperature,
precipitation and carbon dioxide levels which will affect representation of molds and mycotoxins in crops.
For the purpose of this experimental work, samples of wheat, maize and barley were collected form eastern, middle and
northern parts of Croatia. That includes 90 samples in total collected from storage units in March 2021 with the purpose
of identifying grown molds on these crops and determining their concentration. After the analysis and statistical data
processing more attention was given to Penicillium, Fusarium and Aspergillus species, most common contaminants of
these crops.
Results have shown that the most significant mold concentration was observed in maize samples in all three Croatian
regions on MEA and DRBC medium (orders of magnitude 106 and 107). Penicillium species was observed in all analysed
samples while Fusarium species was particularly noted in maize samples. Aspergillus species, producer of aflatoxins,
was identified most frequently in wheat and maize samples from eastern Croatian region.
For adequate storage of crops it is important to ensure proper temperature, moisture and carbon dioxide level conditions
in used facilities to escape high contamination levels and unwanted effects on crop yield. Along with controlled
conditions in manufacturing, it is important to raise awareness about climate change, expenses it will cause in agriculture
and how it will affect crops which are widely spread in our diet
Selectivity of the voltammetric method for the simulataneous determination of pimavanserin and levodopa
No full textPimavanserin je antipsihotik s velikim potencijalom u liječenju deluzija i halucinacija u Parkinsonovoj bolesti, vrlo čestoj kroničnoj neurodegenerativnoj bolesti. Svrha ovog rada bila je ispitivanje selektivnosti voltametrijske metode prilikom istovremenog određivanja pimavanserina i levodope u kombinaciji s različitim lijekovima i tvarima. Za ispitivanje je odabrana pravokutnovalna voltametrijska tehnika, a mjerenja su napravljena na površini elektrode od staklastog ugljika koja je modificirana nanomaterjalima (smjesa grafenovih nanopločica i grafitiziranih višeslojnih ugljikovih nanocjevčica 1:1, koncentracije 1 mg/mL, u 0,3% Nafionu), uz prethodno pretkoncentriravanje analita tijekom 60 sekundi, pri frekvenciji 75 Hz, amplitudi pulsa od 20 mV i porastu potencijala 4 mV. Ispitivanjem je ustanovljeno kako pimavanserin i levodopa međusobno ne interferiraju pri mjerenju novom voltametrijskom metodom. Strujni vrh pimavanserina nalazio se pri vrijednosti potencijala od 1,07 V, a strujni vrh levodope pri 0,37 V. Utvrđena su i područja linearnosti za oba lijeka. Tvari koje se mogu pronaći u tjelesnim tekućinama, kao što su glukoza, natrijev klorid, kalijev klorid, karbonati, fosfati i mokraćna kiselina, ne smetaju prilikom istovremenog određivanja pimavanserina i levodope. Neki lijekovi kao što su kvetiapin i ropinirol smetaju u određivanju pimavanserina, budući da su im oksidacijski vrhovi preblizu oksidacijskom vrhu pimavanserina i s njime interferiraju. Oksidacijski pik dopamina opažen pri 0,37 V nije utjecao na mogućnost određivanja pimavanserina, ali jest na određivanje levodope pri koncentraciji većoj od 5x10-7 mol/dm3, što je značajno više od njegove očekivane koncentracije u serumu. Entakapon u mjerenjima nije utjecao na mogućnost određivanja pimavanserina i levodope, budući da njegov strujni vrh na potencijalu 0,54 V ne interferira ni sa strujnim vrhom pimavanserina niti sa strujnim vrhom levodope.Pimavanserin is an antipsychotic with great potential in the treatment of delusions and hallucinations in Parkinson's disease, a very common chronic neurodegenerative disease. The aim of these thesis was examination of selectivity of votammetric method during simultaneous determination of pimavanserin and levodopa in combination with different drugs and substances. For examination was chosen square wave voltammetry technique, and the measurements were made on the surface of glassy carbon electrode, which was modified with nanomaterials (mixture of graphene nanoplates and graphitized multi-walled carbon nanotubes 1:1, concentration of 1 mg/mL, in 0,3% Nafion), with previous preconcentration of analyte for 60 seconds, at the frequency of 75 Hz, with pulse amplitude of 20 mV and increase of potential of 4mV. Determination have proven that pimavanserin and levodopa don't interfere with each other when they are measured with new voltammetric method. Pimavanserin shown current peak at potential of 1,07 V, and levodopa shown current peak at 0,37 V. Linearity ranges for both drugs were also determined. Substances that can be found in body liquids, such as glucose, sodium chloride, potassium chloride, carbonates, fosfates and uric acid, do not interfere in simultaneously determination with pimavanserin and levodopa. Some medications such as quetiapine and ropinirole interfere in determination of pimavanserin, because their oxidation peaks are too close to oxidation peak pimavanserin and with it they interfere. Oxidation peak of dopamine observed at 0,37 V din't affect on possibillity of determination of pimavanserin, but it interfere with possibillity of determination of levodopa at concentration higher than 5x10-7 mol/dm3 , what is significantly higher than expected serum concentration. In the measurements, entacapone did not affect the ability to determine pimavanserin and levodopa, since its current peak at a potential of 0.54 V doesn't interfere with the current peak of pimavanserina or the current peak of levodopa
The role of mycotoxins in hyalohyphomycosis
No full textHijalohifomikoze su bolesti uzrokovane plijesnima s hijalinim (prozirnim) hifama te mogu biti lokalizirane, najčešće kod imunokompetentnih, ili diseminirane infekcije, najčešće kod imunokompromitiranih osoba. Najčešće lokalizirane infekcije su onihomikoza, keratitis i infekcija kože, dok su diseminirane infekcije učestale kod hematoloških bolesnika. Oportunističke hijalohifomicete koje uzrokuju hijalohifomikoze su vrste rodova Fusarium, Scedosporium, Acremonium, Scopulariopsis, Paecilomyces i Purpureocillium. Mikotoksini su sekundarni metaboliti plijesni, nisu važni za njihov rast i razvoj te je njihova uloga nedovoljno istražena. Klinički su najznačajnije vrste roda Fusarium koje proizvode mikotoksine trihotecene (T-2, HT-2, DON, NIV), zearalenon i njegove derivate (α-ZOL, β-ZOL), fumonizine (FB1), fuzarinsku kiselinu i emergentne mikotoksine (ENN, BEA, MON, FUS). Među njima, fuzarinska kiselina ima ulogu čimbenika virulencije jer pojačava virulenciju F. oxysporum tijekom infekcije. DON, T-2, FB1 i MON povećavaju osjetljivost intestinalnog sustava na enteričke bakterije (Salmonella Typhimurium i E. coli), povećavaju invazivnost tih bakterija i produljuju vrijeme izlječenja što pokazuje njihovo „posredničko“ virulentno djelovanje. Većina fuzarijskih mikotoksina ima proupalni učinak, posebice u intestinalnom sustavu što može doprinijeti virulenciji pravih i oportunističkih patogenih mikroba. Vrsta Scedosporium apiospermum tijekom infekcije proizvodi mikotoksin gliotoksin i niz peptida koji imaju citotoksično i imunosupresivno djelovanje što doprinosi njihovoj virulenciji. Vrste roda Acremonium visoki potencijal tvorbe sekundarnih metabolita od kojih bi neki mogli imati i ulogu u virulenciji. Tehnika LC-MS/MS omogućila je otkrivanje velikog broja sekundarnih metabolita plijesni čiju ulogu u virulenciji tek treba istražiti, što će doprinijeti unaprjeđenju dijagnostike i razvoju terapijskih sustava za liječenje hijalohifomikoza.Hyalohyphomycoses are diseases caused by molds with hyaline (transparent) hyphae and can be localized, most often in immunocompetent people, or disseminated infections, most often in immunocompromised people. The most common localized infections are onychomycosis, keratitis and skin infection, while disseminated infections are common in hematological patients. Opportunistic hyalohyphomycetes that cause hyalohyphomycosis are species of the genera Fusarium, Scedosporium, Acremonium, Scopulariopsis, Paecilomyces and Purpureocillium. Mycotoxins are secondary metabolites of mold, not important for their growth and development, and their role is insufficiently studied. The most clinically significant species is Fusarium spp. whose mycotoxins are trichothecenes (T-2, HT-2, DON, NIV), zearalenone and its metabolites (α-ZOL, β-ZOL), fumonisins (FB1), fusaric acid and emergent mycotoxins (ENN, BEA, MON, FUS). Among them, fusaric acid plays the role of virulence factor because it enhances the virulence of F. oxysporum during infection. DON, T-2, FB1 and MON increase the sensitivity of the intestinal system to enteric bacteria (Salmonella Typhimurium and E. coli), increase the invasiveness of these bacteria and prolong the healing time, which shows their "intermediate" virulence effect. Most fusarium mycotoxins have a pro-inflammatory effect, especially in the intestinal system, which can contribute to the virulence of true and opportunistic pathogenic microbes. The species Scedosporium apiospermum produces mycotoxin gliotoxin during infection and a number of peptides that have cytotoxic and immunosuppressive effects, which contributes to their virulence. Species of the Acremonium genus have a high potential for the formation of secondary metabolites, some of which could also play a role in virulence. The LC-MS/MS technique enabled the detection of a large number of secondary metabolites of mold whose role in virulence has yet to be investigated, which will contribute to the improvement of diagnostics and the development of therapeutic systems for the treatment of hyalohyphomycosis
Phytotherapy of skin lesions
No full textKako je vanjski izgled iznimno bitan u suvremenom društvu, ubrzano raste potreba za tvarima i preparatima koji će poboljšati izgled kože. Kožne lezije različite patologije otežavaju svakodnevan život i zdravlje, kako fizičko tako i psihičko. Ovaj rad daje pregled kliničkih studija odabranih biljnih vrsta od kojih su neke već pronašle svoje mjesto u proizvodima za njegu kože. U rad su uključene sljedeće biljne vrste: Aloe barbadensis, Achillea millefolium, Calendula officinalis, Centella asiatica i Lavandula angustifolia. Fokus rada bio je na učinku ispitivanih biljnih vrsta na sekundarne kožne lezije kao što su ulceracije, postoperativne rane i kraste. Sve studije, izuzev jedne, primjenjivale su pripravke ekstrakata odabranih biljnih vrsta topikalno na leziju. Prema rezultatima studija svi biljni preparati su učinkoviti u poboljšanju cijeljenja ispitivanih kožnih rana. One pomažu u smanjenju eritema, boli, edema, ekhimoze, izgleda rane itd. Za A. vera i C. officinalis su potrebna dodatna istraživanja zbog oprečnih rezultata studija za određenu indikaciju.As external appearance is important in today's society, the need for substances and products that will improve the appearance of the skin is growing rapidly. Skin lesions of various pathologies make everyday life and health more difficult, both physically and mentally. This thesis provides an overview of clinical studies of selected plant species, of which some have already found their place in skin care products. The following plant species were included in the study: Aloe barbadensis, Achillea millefolium, Calendula officinalis, Centella asiatica, and Lavandula angustifolia. Secondary skin lesions, such as ulcerations, postoperative wounds and scabs, are the focus of this paper. All but one study applied extracts of selected plant species topically to the skin lesion. According to the results of the studies, all herbal preparations were effective in improving the wound healing of the examined skin lesions. They help reduce erythema, pain, edema, ecchymosis, wound appearance, etc. A. vera and C. officinalis require further research due to conflicting study results for a particular indication
Polyphenolic compounds and antioxidant activity of Myrtilli fructus siccus
No full textU okviru ovog diplomskog rada istražen je fitokemijski sastav i antioksidacijska svojstva suhog ploda samonikle borovnice (Vaccinium myrtillus L., Ericaceae) koja raste u Hrvatskoj, te njenog vodenog-etanolnog ekstrakta. Metodom tankoslojne kromatografije u borovničinom plodu je dokazana prisutnost polifenolnih sastavnica. Spektrofotometrijskim metodama određen je sadržaj trjeslovina, fenolnih kiselina, antocijana i flavonoida u plodu i vodeno-etanolnom ekstraktu. Antioksidacijska aktivnost vodeno-etanolnog ekstrakta suhog borovničinog ploda procjenjena je na temelju sposobnost hvatanja NO i DPPH radikala i uspoređena sa učinkom standardnih antioksidansa. Utvrđeno je da je plod borovnice bogat izvor polifenolnih spojeva, posebice antocijana, i posjeduje antioksidativna svojstva. Dobiveni rezultati doprinose znanstvenim spoznajama o fitokemijskom sastavu i biološkoj aktivnosti droge Myrtilli fructus siccus hrvatskog porijekla.In this thesis, the phytochemical composition and antioxidant properties of the dry fruit of wild bilberry (Vaccinium myrtillus L., Ericaceae) growing in Croatia, and its water-ethanol extract, were investigated. The presence of polyphenolic components in the bilberry fruit was proven by the method of thin-layer chromatography. The contents of tannins, phenolic acids, anthocyanins and flavonoids in the fruit and water-ethanol extract were determined by appropriate spectrophotometric methods. The antioxidant activity of the water-ethanol extract of dry bilberry fruit was evaluated based on the ability to scavenge NO and DPPH radicals and compared with the effect of standard antioxidants. It has been established that the bilberry fruit is a rich source of polyphenolic compounds, especially anthocyanins, and has antioxidant properties. The obtained results contribute to scientific knowledge on the phytochemical composition and biological activity of the herbal drug Myrtilli fructus siccus of Croatian origin
The effect of olive leaf extract on the metabolic activity of human melanoma cell lines A375 and A375M
No full textZbog nedovoljno efikasnih i opasnih terapijskih opcija za liječenje melanoma, potrebno je istražiti potencijalne alternativne terapijske pristupe. Cilj je ovoga rada ispitati kako primjena ekstrakta lista masline (O. europaea) sorte 'Rosinjola' (sinonim 'Rošinjola', 'Rovinježa') i 'Istarska bjelica' (sinonim 'Bianchera') utječe na metabolizam i preživljavanje humanih stanica staničnih linija melanoma A375, melanoma s visokom sposobnošću metastaziranja A375M i spontano imortaliziranih keratinocita HaCaT. Za određivanje metaboličke aktivnosti stanica nakon 48-satne izloženosti različitim koncentracijama ekstrakta lista masline korišten je kolorimetrijski MTS test CellTiter 96®AQueous One Solution Cell Proliferation Assay. Rezultati su obrađeni prikladnim statističkim metodama pomoću programa GraphPad Prism, verzija 10.0.2 te je izračunata vrijednost IC50. Utvrđeno je da jačina i obrazac učinka ovisi o tipu stanične linije i primijenjenoj koncentraciji ekstrakta. Najintenzivnije djelovanje uočeno je kod stanične linije A375, zatim kod HaCaT, a najslabije kod stanične linije A375M. Daljnja su istraživanja potrebna kako bi se utvrdilo koje su sastavnice ekstrakta odgovorne za uočeni učinak i kojim se molekularnim mehanizmima taj učinak ostvaruje.Due to insufficiently effective and dangerous therapeutic options for the treatment of melanoma, it is necessary to explore potential alternative therapeutic approaches. The aim of this thesis is to examine how the application of olive leaf extract (O. europaea) of the variety 'Rosinjola' (synonymous to 'Rošinjola', 'Rovinježa') and 'Istarska bjelica' (synonymous to 'Bianchera') affects the metabolism and survival of human melanoma cell line A375, highly metastatic human melanoma cell line A375M and spontaneously immortalized keratinocytes cell line HaCaT. For determining the metabolic activity of cells after a 48-hour exposure to different concentrations of olive leaf extract, the colorimetric MTS test CellTiter 96®AQueous One Solution Cell Proliferation Assay was used. The results were analyzed using the appropriate statistical methods within the GraphPad Prism program, version 10.0.2, and the IC50 value was calculated. The strength and pattern of the effect was found to depend on the type of cell line used and the applied concentration of the extract. The most intense effect was observed with the A375 cell line, followed by HaCaT, and the weakest with the A375M cell line. Further research is needed to determine which components of the extract are responsible for the observed effect and by which molecular mechanisms is this effect achieved
Critical evaluation of energy dispersive X-ray fluorescence spectrometry for multielemental analysis of coffee
No full textKava je jedan od najpopularnijih napitaka diljem svijeta stoga je ispitivanje sastava kave od iznimne
važnosti kako za proizvođače tako i za potrošače. Minerali zastupljeni u kavi su, osim za kvalitetu
krajnjeg proizvoda, bitni sa zdravstvenog gledišta jer neki od njih djeluju kao antioksidansi,
sudjeluju u biološkim procesima u organizmu, a određeni posjeduju i toksične učinke. Cilj ovog rada
bio je kritički procijeniti EDXRF tehniku za multielementarnu analizu uzoraka čiste kave, instant
kave i kave s dodacima koristeći rezultate dobivene ICP-OES tehnikom kao referentne vrijednosti.
Ispitani su najbolji način pripreme uzorka za EDXRF analizu, najprikladniji uvjeti mjerenja te
najtočniji način kvantifikacije uzoraka. Za provjeru kvalitete rezultata dobivenih primjenom ICPOES
tehnike analizirana su tri organska referentna materijala te uspoređena sa spomenutim
rezultatima. Nadalje, različite kemometrijske tehnike kao što su PCA i PLS-DA primijenjene su na
dobivene podatke kako bi se istražio njihov potencijal za klasifikaciju različitih vrsta kava. Dobiveni
rezultati u ovom radu pokazali su da mogu biti korisni za uspostavljanje pouzdane jednostavne
metode za multielementarnu analizu različitih uzoraka kave pomoću EDXRF-a, kao i za pružanje
dobre osnove za daljnju primjenu EDXRF spektara kao otiska uzorka u drugim studijama sljedivosti
i/ili provjere autentičnosti prehrambenih proizvoda u budućnosti.Coffee is one of the most popular beverages around the world, which is why studying the
composition of coffee is extremely important for both producers and consumers. The minerals
contained in coffee are, not only important for the quality of the final product, but also for health as
some of them act as antioxidants, and are involved in biological processes in the body, while others
have toxic effects. The aim of this work was to critically evaluate the EDXRF technique for the
multielemental analysis of samples of pure coffee, instant coffee and coffee with additives using the
results obtained with the ICP-OES technique as reference values. The best method of sample
preparation for EDXRF analysis, the most suitable measurement conditions and the most accurate
method for quantifying the samples were examined. In order to verify the quality of the results
obtained with the ICP-OES technique, three organic reference materials were analyzed and
compared with the aforementioned results. Finally, different chemometric methods such as PCA and
PLS-DA were applied to the data obtained to investigate their potential for the classification of
different coffee varieties. It is concluded that the results obtained in this work can be useful to
establish a reliable simple method for the multielemental analysis of different coffee samples by
EDXRF and provide a good basis for further application of EDXRF spectra as sample fingerprint ing
in other traceability and/or authentication studies of food in the future