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Phytochemical composition and antioxidant activity of the commercially available acerola extracts
No full textU ovom diplomskom radu ispitan je fitokemijski sastav i antioksidacijsko djelovanje različitih komercijalno
dostupnih ekstrakata acerole. Kvalitativna analiza flavonoida, fenolnih kiselina i trjeslovina provedena je
tankoslojnom kromatografijom (TLC) na tankom sloju silikagela koji je činio nepokretnu fazu uz smjesu
prikladnih otapala kao pokretne faze. U plodovima su, računajući Rf-vrijednosti (faktor zaostajanja) i
usporedbom boje i intenziteta zone fluorescencije ispitivanih i poredbenih otopina otkriveni rutin
(flavonoidi), kavena i klorogenska kiselina (fenolne kiseline) te galna kiselina (trjeslovine) u tragovima.
Spektrofotometrijsko određivanje sadržaja flavonoida i fenolnih kiselina izvršeno je pomoću UV-Vis
spektrofotometra mjerenjem maksimuma apsorbancije na prikladnim valnim duljinama. U ekstraktima ploda
određene su nešto niže vrijednosti navedenih bioaktivnih sastavnica nego što je bilo za očekivati prije
provođenja analize. Udio flavonoida u plodovima, izražen kao izokvercitrozid, kretao se od 0,003% do
0,046%, dok je sadržaj fenolnih kiselina bio u rasponu od 0,053% do 0,806% za ružmarinsku kiselinu,
odnosno od 0,048% do 0,995% za klorogensku kiselinu. Određivanje sadržaja trjeslovina
spektrofotometrijskim metodama nije provedeno budući da je TLC analiza pokazala jedva primjetne količine
istih u samo trima uzorcima, dok u ostalima nisu pronađeni. Sadržaj vitamina C analiziran je tekućinskom
kromatografijom visoke djelotvornosti. Antioksidacijska sposobnost ispitana je spektrofotometrijskim
metodama određivanja sposobnosti hvatanja DPPH slobodnog radikala te određivanja sposobnosti hvatanja
radikala dušikovog (II) oksida.In this diploma thesis, the phytochemical composition and antioxidant activity of various commercially
available acerola extracts were examined. Qualitative analysis of flavonoids, phenolic acids and tannins was
performed by thin layer chromatography (TLC) on a thin layer of silica gel, which formed the stationary
phase with a mixture of suitable solvents as the mobile phase. Rutin (flavonoids), caffeic and chlorogenic
acid (phenolic acids) and gallic acid (tannins) were detected in the fruits by calculating the Rf-values and
comparing the color and intensity of the fluorescence zone of the tested and standard solutions.
Spectrophotometric determination of the content of flavonoids and phenolic acids was performed using a UVVis spectrophotometer by measuring the absorbance maximum at appropriate wavelengths. In the fruit
extracts, slightly lower values of the mentioned bioactive components were determined than was to be
expected before conducting the analysis. The amount of flavonoids in the fruits, expressed as isoquercitroside,
varies from 0.003% to 0.046%, while the content of phenolic acids was ranged from 0.053% to 0.806% for
rosmarinic acid and 0.048% up to 0.995% for chlorogenic acid. Determination of the content of tannins by
spectrophotometric methods was not carried out, since the TLC analysis showed barely noticeable amounts
in only three samples, while none were found in the rest. Vitamin C content was analyzed by highperformance liquid chromatography. The antioxidant capacity was tested by spectrophotometric methods of
determining the ability to capture the DPPH free radical and determining the ability to capture the nitrogen
(II) oxide radical
Effects of resveratrol nanocrystals on angiogenesis and proliferation of Ehrlich ascites and solid tumour in mice
No full textResveratrol (3,5,4′-trihidroksi-stilben) jest potencijalan protutumorski spoj zbog svoje antioksidativne,
protuupalne, proapoptotičke, antiangiogene i antiproliferativne aktivnosti. Terapijska primjena
resveratrola ograničena je njegovim fizikalno-kemijskim i farmakokinetičkim svojstvima. Temeljem
navedenog, cilj rada bio je primijeniti resveratrol u obliku nanokristala te istražiti njegov učinak na rast
angiogenetski ovisnog, brzo rastućeg Ehrlichovog ascitesnog i solidnog tumora (EAT) te interakciju
nanokristala s biološkim tkivom kroz biokemijske i histološke promjene stanica bubrega, jetre i EAT.
Rezultati pokazuju da primjena otopine resveratrola (RSV) i suspenzije nanokristala resveratrola
(NANO-RSV) dovodi do značajnog smanjenja proliferacije tumorskih stanica u trbušnoj šupljini, te
smanjenja broja krvnih žila u potrbušnici, uz nisku sistemsku toksičnost. Prooksidativni učinak
resveratrola primijenjenog ip vodi kroničnoj upali, polarizaciji makrofaga od M1 prema M2 fenotipu te
skraćenom životnom vijeku nositelja tumora. U histopatološkim ispitivanjima, vidljiva je veća
hepatocelularna nekroza i apoptoza, jetrena fibroza oko središnje vene i degeneracija s manjim masnim
promjenama u miševa nakon obrade s RSV nego u miševa nakon obrade s NANO-RSV. Primjena RSV
i NANO-RSV vodi upali s proksimalnom tubularnom nekrozom i oticanjem bubrežnog glomerula,
zajedno s blagim povećanjem biokemijskih parametara kao pokazatelja narušenog funkcionalnog
kapaciteta bubrega. Intratumoralna primjena otopine resveratrola i nanokristala resveratrola u solidni
EAT pokazala je da dulja nazočnost nanokristala unutar tumorskog tkiva rezultira učinkovitijim
antiangiogenim i imunomodulatornim doza-ovisnim učinkom nanokristala u odnosu na otopinu
resveratrola te značajno većim preživljenjem nositelja tumora. Sažimajući navedeno, te uzimajući u
obzir dobrobit ljudi i ekološku sigurnost, mehanizam toksičnosti resveratrola i njegovih nanokristala
potrebno je detaljnije proučiti u cilju boljeg iskorištavanja pozitivnih učinaka nanokristala resveratrola
te smanjenja potencijalnih nuspojava njihove terapijske primjene.Resveratrol (3,5,4′ -trihydroxystilbene) is a potential antitumor agent due to its proven anti-oxidative,
anti-inflammatory, pro-apoptotic, anti-angiogenic and anti-proliferative properties. Nevertheless, his
therapeutic use is limited by its physico-chemical (poor solubility, photo instability) and
pharmacokinetic (rapid metabolism and elimination, low bioavailability) properties. The aim of this
study was to investigate the potential use of resveratrol (RSV) and its nanocrystals (NANO-RSV) as
antitumor agents in Ehrlich ascites tumour (EAT)-bearing mice in ascites and solid form and the
interaction of nanocrystals with biological tissue through biochemical and histological changes of
kidney, liver and EAT cells. The results show that the administration of resveratrol and its nanocrystals
lead to significant reductions in the proliferation of tumour cells in the abdominal cavity, and a reduction
of the number of blood vessels in the peritoneum, with low systemic toxicity. Due to pro-oxidative
effects of resveratrol after ip administration, chronic inflammation, macrophage polarisation from M1
to M2 phenotype as well as shorter lifespan of resveratrol-treated mice was observed. In
histopathological examinations, greater hepatocellular necrosis and apoptosis, hepatic fibrosis around
the central vein and degeneration with minor fatty change were observed with RSV than with NANORSV.
Inflammation with proximal tubular necrosis and renal glomerulus swelling were also observed,
together with slight elevation of several biochemical parameters in both the RSV and NANO-RSV
groups. Intra-tumoral administration of RSV and NANO-RSV showed that longer presence of
nanocrystals in the tumor tissue improves anti-angiogenic and immunomodulatory dose- depending
effects of resveratrol, including overall survival of the mice. With respect for human health and
environmental safety, the mechanisms of toxicity require further clarification in order to increase the
beneficial effects and reduce the possible risks of therapeutic application of RSV nanocrystals
Determination of antioxidant components in extracts of selected berry fruits
No full textBobičasto voće bogat je izvor bioaktivnih sastavnica među kojima se najviše ističu antocijani,
flavonoidi i fenolne kiseline za koje je poznato da posjeduju izražena antioksidativna svojstva. S
obzirom da se aronija, brusnica i borovnica danas ubrajaju među najpopularnije bobičaste plodove,
cilj ovog diplomskog rada bio je istražiti fitokemijski sastav i vrednovati antioksidativnu aktivnost
različitih komercijalno dostupnih suhih ekstrakata i onih pripremljenih od svježih plodova
hrvatskog porijekla. Dobiveni rezultati doprinose spoznajama o bioaktivnim sastavnicama
različitih ekstrakata bobičastih plodova i njihovom biomedicinskom potencijalu.Berry fruits are a rich source of bioactive components, among which the most prominent are
anthocyanins, flavonoids and phenolic acids, which are known to have pronounced antioxidant
properties. Considering that chokeberry, cranberry and blueberry are some of the most popular
berries today, the aim of this thesis was to investigate the phytochemical composition and evaluate
the antioxidant activity of various commercially available dry extracts and those prepared from
fresh fruits grown in Croatia. The obtained results contribute to current knowledge about the
bioactive components of various berry fruit extracts and their biomedical potential
Pharmacological modulation of glutamatergic transmission in the treatment of central nervous system diseases
No full textGlutamat je glavni ekscitatorni neurotransmiter u mozgu i kao takav je ključan za ekscitatornu
transmisiju. Poremećaj glutamatergičke transmisije može dovesti do razvoja širokog spektra bolesti
središnjeg živčanog sustava te ubrzati njihovu progresiju. Najčešća posljedica povećane
glutamatergičke transmisije je razvoj ekscitotoksičnosti uslijed pretjeranog otpuštanja glutamata i
aktivacije glutamatnih receptora. Modulacija ove transmisije može imati pozitivan učinak u terapiji niza
bolesti, kao što su epilepsija, shizofrenija, Alzheimerova bolest i mnoge druge.
Ovaj diplomski rad daje sistematski pregled terapijskih mogućnosti usmjerenih na modulaciju
glutamatergičke transmisije. Prikazane su pozitivne i negativne strane te farmakološke karakteristike
dostupnih lijekova. Zatim su prikazani lijekovi u prekliničkim i kliničkim fazama razvoja te oni čiji je
razvoj zaustavljen, ali koji pružaju kvalitetan temelj za razvoj novih lijekova. Rad se dotiče i drugih
mogućnosti farmakološke i ne-farmakološke modulacije glutamatergičke transmisije, poput genske
terapije. Temeljem velikog interesa za istraživanja neurobiologije i uključenosti glutamatergičke
transmisije u patofiziološke procese, kao i intenzivnog razvoja lijekova s modulatornim djelovanjem na
glutamatergički sustav, za očekivati je da će u budućnosti farmakološka modulacija ovog sustava biti
temelj liječenja širokog spektra bolesti SŽS-a.Glutamate is the primary excitatory neurotransmitter in the brain, playing a crucial role in excitatory transmission.
Disruptions in glutamatergic transmission can lead to the development of a wide range of central nervous system
disorders and accelerate their progression. The most common disturbance in glutamatergic transmission is the
development of excitotoxicity, which results from excessive glutamate release and activation of glutamate receptors.
Modulation of this transmission may have a beneficial effect in the treatment of various diseases, such as epilepsy,
schizophrenia, Alzheimer's disease and many others.
This review thesis provides a systematic overview of therapies focused on the modulation of glutamatergic
transmission. It presents both positive and negative aspects, as well as pharmacological characteristics of current
therapies. Additionally, drugs in preclinical and clinical development phases, as well as those whose development has
been discontinued but serve as a solid foundation for new drug development, are discussed. The thesis also examines
other pharmacological and non-pharmacological options for modulation of glutamatergic transmission, such as gene
therapy. Based on the significant interest in neurobiology research and the involvement of glutamategic transmission
in pathophysiology processes, as well as the intensive development of drugs with modulatory effects on glutamatergic
system, it is to be expected that in the future, pharmacological modulation of this system will form the foundation for
the treatment of a wide range of central nervous system diseases
Prevalence of fall-risk increasing drugs: a cross-sectional study in nursing homes
No full textCilj istraživanja: Cilj ovog rada je bio odrediti udio lijekova koji povećavaju rizik od padova u starijih osoba koje su
smještene u domovima za starije i nemoćne te istražiti povezanost FRID-ova s negativnim kliničkim ishodima.
Ispitanici i metode: Istraživanje je provedeno kao neintervencijsko, presječno istraživanje u domovima za starije i
nemoćne osobe u tri regije Republike Hrvatske, u razdoblju od 2. kolovoza 2022. do 13. studenog 2022. godine .
Podaci o ispitanicima prikupljeni su pomoću InterRAITM validiranog upitnika temeljem razgovora sa štićenicima
domova za starije i nemoćne te medicinskih zapisa koje je ispitanik priložio prilikom ispitivanja, a uključivali su
osnovne informacije o pacijentu, funkcionalni status, povijest bolesti, propisane lijekove te podatke o hospitalizaciji i
posjeti hitnoj službi tijekom određenog razdoblja u prošlosti. Analiza FRID-ova provedena je upotrebom STOPPFall
alata.
Rezultati: U istraživanje je uključeno ukupno 225 ispitanika, prosječne životne dobi 82,52 ± 6,22 godine. Primjena
FRIDova zabilježena je kod 198 ispitanika (88%). Najveća zastupljenost primjene FRIDova bila je u Dalmaciji (n=71,
94,67%), a najmanja u Slavoniji (n=59, 78,67%). Najčešće korištene skupine FRIDova bili su benzodiazepini
(55,56%) i diuretici (47,11%), a od pojedinačnih lijekova tramadol (30,67%), furosemid (30,22%) i diazepam
(29,33%). Analiza podataka je pokazala kako postoji statistički značajna razlika u broju FRIDova ovisno o
zabilježenim padovima kod ispitanika u posljednjih 30 dana (p<0,001), prije 31-90 dana (p=0,003) i prije 91-180 dana
(p=0,020) kao i prijemu na hitnu službu unazad 90 dana (p=0,036). Utvrđeno je kako postoji statistički značajna
razlika u broju FRIDova u terapiji ispitanika ovisno o prisutnosti omaglice (p=0,020), vrtoglavice (p=0,047) i
nestabilnog hoda (p=0,003).
Zaključak: Učestalost propisivanja FRIDova kod štićenika domova za starije i nemoćne je bila vrlo visoka. Ispitanici
koji su iskusili padove, bili primljeni na hitnu službu, imali omaglicu, vrtoglavicu ili nestabilan hod su imali propisan
veći broj FRIDova. Pokazala se potreba za racionalizacijom terapije osoba u domovima za starije i nemoćne te
intervencijama poput depreskripcije.Objective: The aim of this work was to determine the proportion of fall risk increasing drugs (FRIDs) in older adults
who live in nursing homes and to explore the association of FRIDs with negative clinical outcomes.
Subjects and methods: The research was conducted as a non-interventional, cross-sectional study in nursing homes
across three different regions of Croatia in the period from August 2, 2022 to November 13, 2022. Dana collection was
carried out using interRAITM Long-Term Care Facilities (LTCF) Assessment form based on interviews and medical
records available from participants. Data included basic information about the patient, functional status, medical
history, prescribed medications, hospitalizations and visits to the emergency department within a certain period in the
past. Analysis of FRIDs was performed using the STOPPFall tool.
Results: The study included total of 225 older adults, mean age being 82.52 ± 6.22 years. The use of FRIDs was
recorded in 198 subjects (88%). The highest prevalence of FRIDs use was in Dalmatia (n=71, 94.67%), and the lowest
in Slavonia (n=59, 78.67%). The most frequently used groups of FRIDs were benzodiazepines (55,56%) and diuretics
(47,11%). Of the individual drugs categorized as FRIDs, the most commonly used were tramadol (30,67%),
furosemide (30,22%) and diazepam (29,33%). Data analysis showed that there is a statistically significant difference in
the number of FRIDs depending on the recorded falls in the last 30 days (p<0.001), 31-90 days ago (p=0.003) and 91-
180 days ago (p =0.020) as well as admission to the emergency department in the past 90 days (p=0.036). It was found
that there is a statistically significant difference in the number of FRIDs depending on the presence of dizziness
(p=0.020), vertigo (p=0.047) and unsteady gait (p=0.003).
Conclusion: The study found high prevalence of FRID prescriptions among older residents in nursing homes in
Croatia. Those who had experienced falls, been admitted to the emergency department, or had symptoms such as
dizziness, vertigo, and unsteady gait were prescribed a higher number of FRIDs. The results highlight the need to
rationalize therapy for older adults in nursing homes and to consider interventions such as deprescribing inappropriate
FRIDs
Optimization of the method for determining the content of iron, zinc and manganese in zeolite clinoptilolite samples by total reflection x-ray fluorescence spectrometry
No full textZnačajna detoksifikacijska, antioksidativna i imunomodulatorna svojstva zeolita klinoptilolita potaknula su zanimanje
za primjenu klinoptilolita u medicini. Brojna istraživanja pokazala su iznimno pozitivne učinke primjene klinoptilolita
na zdravlje zbog čega raste njegova popularnost te broj proizvoda dostupnih na tržištu. Kako bi se osigurala učinkovitost
i sigurnost njegove primjene potrebno je pronaći i optimizirati analitičke metode koje omogućuju efikasnu, brzu i jeftinu
analizu.
TXRF je analitička tehnika koja se zbog svoje osjetljivosti, preciznosti, ekonomske isplativosti te mogućnosti
jednostavne i brze analize čvrstog uzorka u obliku suspenzija nameće kao idealna tehnika za određivanje sadržaja teških
metala u uzorcima zeolita. Ova tehnika ne zahtijeva potrošnju pogonskih plinova ni tekućina za hlađenje, a za samu
analizu potrebna je vrlo mala količina uzorka i reagensa, zbog čega možemo reći da slijedi principe „zelene kemije“.
Cilj ovog diplomskog rada bio je ispitati analitički potencijal primjene TXRF-a za određivanje sadržaja željeza, cinka i
mangana u uzorku zeolita klinoptilolita koji je pripremljen u obliku suspenzije te odrediti optimalne uvjete pripreme
uzorka. Uz pomoć Box-Behnkenovog eksperimentalnog dizajna ispitan je utjecaj mase uzorka, disperzijskog sredstva
i volumena uzorka suspenzije nanesenog na nosač na promatrani odziv (sadržaj željeza, cinka i mangana).
Rezultati istraživanja pokazuju da su optimalni uvjeti za pripremu uzoraka: i) masa uzorka - 20 mg, ii) disperzijsko
sredstvo - 1% Triton x-100, iii) volumen uzorka nanesenog na nosač - 10 μL. Također, dobiveni rezultati pokazali su
kako je TXRF vrlo točna i pouzdana metoda za određivanje sadržaja ispitivanih elemenata u uzorcima zeolita
klinoptilolita pripremljenih u obliku suspenzije.The significant detoxifying, antioxidant, and immunomodulatory properties of clinoptilolite zeolite have sparked interest
in its application in medicine. Numerous studies have shown remarkably positive effects of clinoptilolite application on
health, leading to an increase in its popularity and the number of products available on the market. In order to ensure the
effectiveness and safety of its application, it is necessary to find and optimize analytical methods that allow for efficient,
fast, and cost-effective analysis.
Total reflection X-ray fluorescence (TXRF) is an analytical technique that, due to its sensitivity, precision, costeffectiveness, and the ability to perform simple and rapid analysis of solid samples in the form of suspensions, emerges
as an ideal technique for determining the content of heavy metals in zeolite samples. This technique does not require the
consumption of carrier gases or cooling liquids, and it only requires very small amounts of sample and reagents for the
analysis, which aligns with the principles of "green chemistry."
The aim of this thesis was to examine the analytical potential of TXRF for determining the content of iron, zinc, and
manganese in clinoptilolite zeolite samples prepared as suspensions, as well as to determine the optimal sample
preparation conditions. Using the Box-Behnken experimental design, the influence of sample mass, dispersing agent,
and volume of sample applied to the carrier on the observed response (content of iron, zinc, and manganese) was
investigated.
The research results indicate that the optimal conditions for sample preparation are: i) sample mass - 20 mg, ii) dispersing
agent - 1% Triton x-100, iii) volume of sample applied to the carrier - 10 μL. Furthermore, the obtained results have
demonstrated that TXRF is a highly accurate and reliable method for determining the content of the tested elements in
clinoptilolite zeolite samples prepared as suspensions
Optimization of a procedure for performing in vitro release of ciprofloxacin from vesicular phospholipid gels
No full textFormulacije vezikularnih fosfolipidnih gelova (VFG), koje su se međusobno razlikovale
fosfolipidnim sastavom, prisustvom polimera (kitozan) i suotapala (propilenglikol), pripremljene
su hidratizacijom fosfolipida u vodenoj otopini ciprofloksacina uz primjenu visokotlačnog
homogenizatora. Srednji promjer liposoma unutar VFG-a kretao se od 126 do 176 nm, uz indeks
polidisperznosti manji od 0,43 te zeta potencijal od +25 do +33 mV, dok je uspješnost uklapanja
iznosila od 25 do 31%. Ispitivanje in vitro oslobađanja ciprofloksacina iz VFG-a provedena je
primjenom metode membranske difuzije tijekom 30 sati. Ispitivanja su provedena u vodi te u puferu
pH 7,4 kao medijima za oslobađanje. Kao kontrola služila je vodena otopina ciprofloksacina.
Optimizacija postupka provedena je na formulaciji koja je sadržavala samo SPC 100, te su pod istim
uvjetima provedena ispitivanja s formulacijama koje su uz SPC 100 sadržavale SLPC-80 i
propilenglikol (elastični dvoslojevi), odnosno SPC 100 i kitozan. Oslobađanje je bilo najbrže iz
formulacije karakterizirane elastičnim fosfolipidnim dvoslojevima, dok su druge dvije formulacije,
kojima se fosfolipidni dvosloj sastojao od SPC 100, odnosno SPC 100 i kitozana, osiguravale sporije
oslobađanje lijeka (neovisno o korištenom dijalizacijskom mediju).Vesicular phospholipid gels (VPG), differing in phospholipid composition, presence of chitosan
and/or propylene glycol, were prepared by hydration of phospholipids in an aqueous solution of
ciprofloxacin, followed by homogenization in a high-pressure homogenizer. The mean diameters of
liposomes inside the VPGs ranged from 126 to 176 nm, with a polydispersity indexes less than 0.43,
and zeta potentials from +25 to +33 mV, while the encapsulation efficiency amounted from 25 to
31%. A membrane diffusion method was applied to test in vitro release of ciprofloxacin from the
different VPGs in water and buffer, pH 7.4 during 30 hours. An aqueous solution of ciprofloxacin
served as a control. Optimization of in vitro release conditions was conducted on VPG composed of
only SPC 100. The optimized conditions were applied for performing in vitro release studies from
VPGs which, in addition to SPC 100, contained SLPC 80 and propylene glycol (elastic bilayers), or
SPC 100 and chitosan. Somewhat faster release of ciprofloxacin was achieved from the VPG
characterized by elastic bilayers, while the other two formulations of VPGs exhibited slower drug
release, regardless of the dialysis medium used
Multielement analysis of tea infusions by total-reflection X-ray fluorescence spectrometry
No full textČaj se smatra jednim od najčešće konzumiranih bezalkoholnih pića na svijetu, stoga je nužno
poznavati njegovog sastav i djelovanje na organizam čovjeka. Za pozitivne učinke čaja većim
dijelom su zaslužni organski spojevi poput katehina koji djeluju kao antioksidansi te su time
i više istraženi od samog anorganskog sastava čaja, ali minerali prisutni u čaju također mogu
biti od iznimne važnosti. Neki od njih, poput kalija, kalcija, mangana, željeza, nikla, bakra i
cinka su esencijalni elementi, bez čijeg bi unosa normalna funkcija organizma bila narušena.
Cilj ovog istraživanja bio je odrediti utjecaj određenih parametara pripreme čajnih infuza i
parametara same TXRF analize za multielementnu analizu infuza crne i zelene čajne
mješavine komercijalno dostupne na hrvatskom tržištu. Ispitan je utjecaj duljine pripreme
infuza čajne mješavine (2, 5, 10, 30 i 60 minuta) i duljine mjerenja (600, 1000 i 2000 s) na
sadržaj elemenata od interesa za ljudsko zdravlje. Za većinu elemenata, niti duljina pripreme
infuza niti duljina mjerenja nisu imale statistički značajan učinak na njihov sadržaj. Odabrani
parametri (2 min i 600 s) su primijenjeni za elementarnu analizu svih prikupljenih uzoraka. U
svim ispitivanim uzorcima detektirani su i određen je sadržaj kalija, kalcija, mangana, željeza,
bakra, cinka, broma, rubidija i stroncija dok je nikal detektiran i određen u šest od devet
uzoraka. U najvećim količinama prisutni su kalij, kalcij pa zatim mangan, izuzev uzoraka koji
imaju dodatak cinka, dok su u najmanjim količinama prisutni nikal i bakar. Koncentracija
mangana u svim uzorcima znatno je veća u odnosu na sadržaj ostalih elemenata u tragovima.
Sadržaj cinka značajan je samo u uzorcima s njegovim dodatkom. Kalij, kalcij, željezo, bakar,
brom, rubidij, stroncij i ekstrahirani su u količini koja nije dovoljna da bi infuzi čajnih
mješavina mogli poslužiti kao dobar izvor tih elemenata.Tea is one of the most consumed non-alcoholic beverages in the world, therefore it is necessary
to know its composition and effect on the human body. The positive effects of tea are largely
due to organic compounds such as catechins, which act as antioxidants and are therefore more
researched than the inorganic composition of tea itself, but the minerals present in tea can also
be extremely important. Some of them, such as potassium, calcium, manganese, iron, nickel,
copper and zinc are essential elements, without which the normal function of the organism
would be impaired.The aim of this study was to determine the effect of certain parameters of
the preparation of tea infusions and the parameters of the TXRF analysis itself for the
multielemental analysis of black and green tea infusions commercially available on the Croatian
market.It was examined how the length of preparation of the tea infusion (2, 5, 10, 30 and 60
minutes) and the length of measurement (600, 1000 and 2000 s) affects the content of elements
which are important for human health. For the majority of minerals, neither the length of
infusion preparation nor the length of measurement had a statistically significant effect on their
content. The selected parameters (2 min and 600 s) were applied for elemental analysis of all
collected samples.Potassium, calcium, manganese, iron, copper, zinc, bromine, rubidium and
strontium were present in all samples. Nickel was present in six of the nine samples. Potassium
and calcium followed by manganese were present in the largest quantities in all samples, with
the exception of two sample which had artificially added zinc. Nickel and copper were present
in the smallest quantities. The concentration of manganese, in all samples, was significantly
higher than the content of other trace elements. The zinc content was significant only in the
samples with its addition. Potassium, calcium, iron, copper, bromine, rubidium, strontium and
nickel were present in an amount that is not sufficient for tea infusions to serve as a good source
of these elements
Total reflection X-ray fluorescence analysis of pharmaceutical products: basic principles and analytical procedures
No full textElementarna onečišćenja mogu dospjeti u farmaceutski proizvod u raznim fazama njegovog razvoja,
transporta i skladištenja te utjecati na djelatnu tvar, stabilnost farmaceutskog proizvoda ili sama
imati neželjene učinke na ljudsko zdravlje. Zbog toga je elementarna analiza ovakvih uzoraka i
određivanje elementarnih onečišćenja od velikog značaja te postoji potreba za brzim i osjetljivim
analitičkim tehnikama koje se mogu koristiti za takve analize. Uz to, teži se da tehnike slijede načela
„zelene kemije“. U tom smislu, TXRF se nameće kao jedna važna tehnika za kvalitativnu i
kvantitativnu elementarnu analizu. TXRF je spektroskopska tehnika koja se temelji na principu
totalne refleksije rendgenskih zraka, a zbog male količine uzorka potrebnog za analizu, IUPAC
definira TXRF kao tehniku mikroanalize. Znanstvena istraživanja o primjeni TXRF tehnike u analizi
farmaceutskih uzoraka kao što su djelatne tvari, lijekovi i dodaci prehrani pokazuju potencijal
njezine primjene za analizu takvih uzoraka, a kod TXRF tehnike vidljiva je primjena načela zelene
kemije jer je za analizu potrebna mala količina uzorka i reagensa, smanjena je uporaba štetnih
kemikalija i količine energije te se stvara manje štetnog otpada.Elemental impurities may enter the pharmaceutical product at various stages of development,
transportation and storage and may affect the active pharmaceutical ingredient and stability of the
pharmaceutical product or have adverse effects on human health. For this reason, elemental analysis
of these samples and the determination of elemental impurities is of great importance, and there is a
need for fast and sensitive analytical techniques that can be used for such analysis. Moreover, the
methods should comply with the principles of "green chemistry". In this sense, TXRF is presented
as one important technique for qualitative and quantitative elemental analysis. TXRF is a
spectroscopic technique based on the principle of total reflection of X-rays. Because a small amount
of sample is required for analysis, IUPAC defines TXRF as a microanalysis technique. Scientific
studies on the application of TXRF technique in the analysis of pharmaceutical samples such as
active pharmaceutical ingredients, drugs and dietary supplements demonstrate the potential of its
use in the analysis of such samples. The application of „green chemistry“ principles to the TXRF
technique is evident in the small amount of samples and reagents required for analysis, the use of
less harmful chemicals and energy and the generation of less harmful waste
Examination of the biological activity of extracts of winter savory (Satureja montana L.) rich in flavonoids for use in phytopharmacy and cosmetics
No full textIzgledu i zdravlju ljudske kože oduvijek se obraćala velika pozornost i briga. Oksidativni stres, starenje, sunčeve UV zrake i upalne bolesti epidermisa i dermisa uzokuju neželjene promjene ljudske kože koje se liječe i ispravljaju kozmetičkim pripravcima. Trenutno postojeće sastavnice kozmetičkih proizvoda imaju mogućnost ispoljavanja nuspojava pa postoji potreba za otkrivanjem novih terapijskih mogućnosti iz prirodnih izvora. Ekstrakti primorskog vriska dobiveni ekstrakcijom s glicerolom i HP-β-CD sadrže visoke koncentracije flavonoida i posebice luteolin-7-O-glukozida. U ispitivanjima biološke aktivnosti ekstrakti su ostvarili izvrsnu antioksidativnu aktivnost (ispitanu pomoću DPPH metode i redukcijske snage) i protuupalno djelovanje (određeno ispitivanjem inhibicije lipoksigenaze i denaturacije ovalbumina). Također, ispitana je inhibitorna aktivnost ekstrakata na enzimima ljudske kože tirozinazi, elastazi i hijaluronidazi. Dok za tirozinazu i elastazu ekstrakti nisu ostvarili značajan stupanj inhibicije, ekstrakti su uspješno inhibirali enzim hijaluronidazu. Zahvaljujući tome, ekstrakti vrste S. montana mogu se razmotriti kao potencijalne nove komponente u budućim kozmetičkim pripravcima namijenjenima očuvanju zdravlja i postizanju željenog izgleda kože.Great attention and care have always been paid to the appearance and health of human skin. Oxidative stress, aging, the sun's UV rays and inflammatory diseases of the epidermis and dermis cause unwanted changes in human skin that are treated and corrected with cosmetic preparations. The currently existing components of cosmetic products have the possibility of side effects, so there is a need to discover new therapeutic possibilities from natural sources. Winter savory extracts obtained by extraction with glycerol and HP-β-CD contain high concentrations of flavonoids and luteolin-7-O-glucoside in particular. In biological activity tests, the extracts achieved excellent antioxidant activity (tested by DPPH method and reducing power) and anti-inflammatory activity (determined by lipoxygenase inhibition and ovalbumin denaturation tests). The inhibitory activity of extracts on human skin enzymes tyrosinase, elastase and hyaluronidase was also tested. While the extracts did not achieve a significant degree of inhibition of tyrosinase and elastase, they successfully inhibited the enzyme hyaluronidase. Thus, the extracts obtained from S. montana can be considered as potential new components in future cosmetic preparations intended to preserve health and achieve the desired appearance of the skin