Marina Bakmaz | Faculty of Pharmacy and Biochemistry, University of Zagreb (original) (raw)

Papers by Marina Bakmaz

Planta Medica, 2007

In this paper we report for the first time a method for the extraction of the protein fraction fr... more In this paper we report for the first time a method for the extraction of the protein fraction from Feijoa sellowiana Berg. fruit and its electrophoretic analysis. In addition we analyzed the protein fraction for its antioxidant activity and its effectiveness against different Gram-positive and Gram-negative bacteria both as American type culture collection (ATCC) standard and clinically isolated strains. Both antimicrobial and antioxidant activity resulted stronger respect to that previously obtained for the acetonic extract from the same fruit. Further, we study both activities also on the product of in vitro gastrointestinal digestion of F. sellowiana fruit proteins. The results showed that in vitro gastrointestinal digestion increased 10 fold the antioxidant activity, while the antimicrobial activity, tested only on ATCC strains, resulted from 2 to 4 fold increased. MTT assays showed the nontoxicity of these proteins both before and after digestion.

The flavonoids and phenolic acids and their esters present in propolis are considered to be a ric... more The flavonoids and phenolic acids and their esters present in propolis are considered to be a rich source of chemopreventive agents, since they possess various biological activities. We investigated water and ethanolic extracts of two chemotypes of propolis (poplar-type from Croatia, and alecrim-type from Brazil) with respect to their chemical composition and antiviral effects. The flavonoid content was anlyzed using two complementary colorimetric methods for flavones/flavonols and flavanones and dihydroflavonols. The samples as well as the main compounds present in propolis: naringenin, quercetin, chrysin, galangin and caffeic acid were tested for inhibitory activity on the replication of influenza viruses A/Germany/27, strain Weybridge (H7N7) and A/Aichi/2/68 (H3N2) in MDCK cells and herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2) in MDBK cells. Cytopathic effect was used as a measure of viral replication and the selectivity of inhibition was evaluated. The water and ethanolic extracts from Brazilian propolis as well as naringenin and caffeic acid significantly inhibited the growth of A/Weybridge with selectivity indices (SI) 15, 10, 10 and 6 respectively. None of the tested compounds showed antiviral activity against A/Aichi. Both water propolis extracts from Croatian and Brazilian sources as well as galangin and quercetin exhibited strong anti-HSV-1activity, with SI 20, 16.7, 15 and 10 respectively. The Brazilian water extract of propolis was less effective towards HSV-2 as was quercetin with SI 7.1 and 4 respectively. No correlation between flavonoids content and antiviral activity was observed.

Farmaceutski glasnik, 2004

* rad je prikazan na XXIX. stručnom skupu s međunarodnim sudjelovanjem u organizaciji Hr vatskog ... more * rad je prikazan na XXIX. stručnom skupu s međunarodnim sudjelovanjem u organizaciji Hr vatskog zavoda za javno zdravstvo i Sekcije za zdravstvenu ekologiju Hrvatskog farmaceut skog društva, a pod pokroviteljstvom Ministarstva zdravstva Republike Hrvatske. Skup je no sio naziv »Zdravlje kroz hranu i ljekovito bilje«, održan je u Zadru od 9. do 11. travnja 2003. i okupio je stotinjak sudionika s vrlo plodnim usmenim i poster priopćenjima.

PubMed, Dec 1, 2003

Thin-layer chromatography of ethanolic extract of propolis (EEP) from the continental and Adriati... more Thin-layer chromatography of ethanolic extract of propolis (EEP) from the continental and Adriatic regions of Croatia showed that 72.2% of propolis samples contain galangin, 88.8% of samples contain kaempferol, naringenin and apigenin and 66.6% of samples contain caffeic acid. Caffeic acid, pinocembrin, galangin, chrysin and naringenin were analyzed by HPLC. In all samples, pinocembrin was the dominant flavonoid. In samples from the Adriatic region, concentration of pinocembrin ranged from 0.03 to 6.14% (x = 2.87%) and in the continental region samples from 0 to 4.74% (x = 2.84%). Chrysin was found in all propolis samples in a concentration ranging from 0.22 to 5.32% (x = 1.86%) in the continental region samples and from 0.03 to 3.64% (x = 1.96%) in samples from the Adriatic region. Chrysin was followed by naringenin, ranging from 0 to 1.14% (x = 0.42%) in samples from the Adriatic region and from 0.22 to 2.41% (x = 0.60%) in the continental region samples. Concentration of caffeic acid ranged from 0 to 10.11% (x = 2.69%) in the Adriatic region samples and from 0.27 to 2.67% (x = 1.37%) in samples from the continental region of Croatia. Results of HPLC analyses suggest that propolis samples collected from various parts of Croatia do not differ markedly in contents of chrysin, pinocembrin, naringenin and galangin but differ in the concentration of caffeic acid. All EEPs significantly inhibited the growth of Bacillus subtilis in comparison with the control (80% ethanol) (p < 0.05), showing inhibition zones of 16 +/- 2 mm for samples from the continental region, and of 18 +/- 3 mm for samples from the Adriatic region. There was no significant difference in antimicrobial activity of EEPs from the continental and Adriatic regions of Croatia, suggesting that bactericidal activity depends on synergism of all phenolic compounds.

PubMed, Dec 1, 2005

Propolis ethanolic solutions are the most used propolis products on the market for the treatment ... more Propolis ethanolic solutions are the most used propolis products on the market for the treatment of minor ulcers in the mouth, angina, thrush or skin infections. Since it is still an unofficial drug in pharmacy, we analyzed the contents of flavonoids in ten commercially available ethanolic solutions of propolis from the Croatian market using two complementary colorimetric methods. Antimicrobial activities, determined with the diffusion method, against six bacterial species (Bacillus subtilis NCTC 8236, Staphylococcus aureus ATCC 25923, Streptococcus pyogenes ATCC 12204, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 10536, Pseudomonas aeruginosa ATCC 27853, and one yeast-like fungus Candida albicans ATCC 10231 were compared. Results of flavonoids analysis suggested that the contents of flavones and flavonols in the products were uniform and ranged from 0.14 to 0.41%, but the content of flavanones varied greatly from 0.43 to 18.78%. Total flavonoid content, as the sum of two colorimetric methods, in propolis products was between 0.78 and 18.92%, and most products had the flavonoids content below 9%. All products with the total flavonoids content above 1% showed antimicrobial activity against the four Gram-positive bacterial species tested, and against P. aeruginosa and the yeast-like fungus C. albicans. Total flavonoids contents, expressed as the sum of two colorimetric methods, could be useful methods for estimating the flavonoid contents of propolis products. Our results indicate that the quality of commercially available propolis products requires verification.

PubMed, Mar 1, 2004

Spectrometric analyses of flavonoids in twenty propolis samples, collected from ten different geo... more Spectrometric analyses of flavonoids in twenty propolis samples, collected from ten different geographic localities in northern Croatia using two complementary methods, are reported. Flavones and flavonols were determined using aluminum chloride and expressed as quercetine equivalent while flavanones were determined using 2,4-dinitrophenylhydrazine and expressed as naringenin. Contents of flavones and flavonols were similar for most samples and ranged from 2 to 2.3%, except for one sample with a concentration of 1.3% and one sample in which it was not possible to detect flavones and flavonols. The content of flavanones in propolis samples is very variable. 55% of samples contained flavanones between 15 and 24% and 45% of samples between 4 and 14%. Total levels of flavonoids in raw propolis samples ranged between 5 and 26%; for the majority of samples (75%), the total level of flavonoids ranged between 15 and 25.9%. The high variability of flavanone concentration will affect the biological activity of propolis preparations.

Farmaceutski glasnik, Nov 12, 2003

Biljna masna ulja su kruti ili tekuci trigliceridi masnih kiselina. Mogu sadržavati male kolicine... more Biljna masna ulja su kruti ili tekuci trigliceridi masnih kiselina. Mogu sadržavati male kolicine drugih lipida kao sto su voskovi, slobodne masne kiseline, djelomicni gliceridi ili nesaponificirane tvari. U farmaceutskoj praksi najcesce se koriste bademovo rafinirano, maslinovo rafinirano i ricinusovo djevicansko ulje kao monopreparati ili kao sastavnice za izradu farmaceutskih prpravaka, a ricinusovo ulje i peroralno kao laksans. Za neskodljivo djelovanje masnih ulja vrlo je važno dobro poznavati njihovu kakvocu koja ovisi o mnogim cimbenicima: nacin dobivanja, cuvanje na prikladnoj temperaturi, zasticenost od svjetlosti i kisika, starost ulja, cistoca u smislu kolicine prisutnih stranih masnih ulja (DAB) ili masnih kiselina i sterola (Ph. Eur.). Provjera kakvoce masnih ulja provodi se prema propisima monografija za pojedina ulja ? prema Ph. Eur. za identifikaciju najvažnija je provjera mirisa, od fizikalnih metoda relativna gustoca, indeks refrakcije i opticka rotacija te od sadržaja kiselinski, hidroksilni, jodni i peroksidni broj te broj saponifikacije i neosapunjive tvari. Iskustvo pokazuje kako su spomenute konstante, a osobito peroksidni broj, u uskoj svezi s nacinom cuvanja ulja odnosno njihovom kakvocom. U ovom smo radu prikazali promjene vrijednosti peroksidnog i kiselinskog broja te broja saponifikacije s obzirom na starost ulja (svaka 3 mjeseca) na tri biljna ulja ? bademovo, maslinovo i ricinusovo ulje te na ribljem ulju (n = 9+3). Sva su ulja cuvana na propisan nacin (t = 10 ? 2oC ). Određivanje se provodilo prema propisima Ph. Eur. 4. Prema vrijednostima zahtjeva za peroksidni broj niti jedno ulje nije zadovoljilo vec nakon 3. mjeseca s time da je najveci porast broja imalo bademovo ulje.Vrijednosti za kiselinski broj i broj saponifikacije za sva ulja bile su u granicama dozvoljenih vrijednosti i na kraju 9. mjeseca. Prema dobivenim rezultatima može se zakljuciti kako je vrijednost peroksidnog broja dobar pokazatelj kakvoce biljnih masnih ulja te se preporucuje kontrola kakvoce ulja putem određivanja peroksidnog broja zbog pozitivne korelacije između jednostavnosti, financijske isplativosti i vrijednosti podataka koji proizlaze iz ovog određivanja.

Prehlada i gripa su respiratorne virusne bolesti visoke ucestalosti među populacijom te uzrokuju ... more Prehlada i gripa su respiratorne virusne bolesti visoke ucestalosti među populacijom te uzrokuju velike socijalno-ekonomskih probleme (izostanak s posla). Osim prevencije gripe (aktivnom imunizacijom), za smanjenje simptoma i trajanja prehlada i gripe, osim “ klasicnih” lijekova kao npr. analgetika, antipiretika, dekongestiva, ekspektoransa i sl. na tržistu je prisutan veliki broj biljnih pripravaka koji se deklariraju kao imunomodulatori odnosno imunostimulansi. Prema Wagneru i Wiesenaueru (1995) pod biljnim imunomodulatorima smatraju se one biljne vrste odn. sastavnice koje za cilj imaju profilaksu i terapiju kronicnih (i recidivirajucih) mijesanih infekcija (bakterijskih i virusnih) ; profilaksu oportunistickih infekcija kod rizicnih pacijenata ; pomocnu terapiju kod primjene citostatika i antibiotika i posljedicne imunosupresije, autoimunih bolesti i profilakse metastaza. U tu svrhu najupotrebljavanije su biljke: vrste roda Echinacea (E. purpurea, E. pallida, E. angustifolia) ; Eleuterococcus senticosus ; Eupatorium perfoliatum i E. cannabinum ; Baptisia tinctoria ; Viscum album ; Thuja officinalis ; Calendula officinalis ; Chamomilla recutita ; Achyrocline saturoioides ; Panax ginseng i dr.). Određene lipofilne i polarne sastavnice izolirane iz nadzemnih i podzemnih dijelova biljnih vrsta roda Echinacea pokazuju imunomodulirajuci ucinak in vitro i in vivo. Dugostoljetna etnobotanicka iskustva uporabe ovih biljnih vrsta nisu ukazala na toksicnost niti na znacajne nus-pojave, ali manjkaju znanstveno zabilježeni podaci o bioraspoloživosti, sinergizmu i potentnosti sastavnica s imunomodulatornim ucincima kao i podaci o standardizaciji pripravaka i klinicke studije. Njemacka komisija l Er preporuca primjenu istjestenog soka iz svježih (tek ubranih) nadzemnih dijelova vrste Echinacea purpurea (kao i pripravke u ucinkovitoj dozi stabilizirane s etanolom) kao pomocnu terapiju kod prehlade i gripe, kronicnih infekcija gornjih disnih putova i donjeg urinarnog sustava tesko zarastavajucih rana i kronicnih cireva. Kod gripe se također preporuca koristenje pripravaka iz korijena vrste E. pallida.

Contradictory ethnobotanical data about abortive and teratogenic effects of rosemary (Rosmarinus ... more Contradictory ethnobotanical data about abortive and teratogenic effects of rosemary (Rosmarinus officinalis L., Lamiaceae) induced us to examine the influence of the water extract from rosemary leaves on the reproduction and postnatal progress of experimental animals. Rosemary leaves were collected in Mediterranean part of Croatia and prepared as 15%(w/V) solution in hot water (RE). Wistar female rats (n=6) were used for testing the influence of RE on the reproduction, growth and progress of the coming generation related to the control group (CG) (n=6). RE was applied daily ad libidum from the beginning of the mating till brood. From 6 female rats in the CG the number of born rats was 59 and in the treated group with RE 38 young. Interestingly, differences in the sex of new born rats were noticed in the tested group with RE (74% of females and 26% of males -ratio 3:1) compared to the CG (48% of females and 52% of males -ratio 1:1). The growth of young rats in the both of groups after the 1st and 2nd month old was also attended where faster postnatal development with RE in grow of young rats during first month was noticed. During the 1 st month the body weigh of young rats from females on RE increased rapidly (mean p SD, male 116.7 p 17.1, female 94.7 p 17.6g, p 0.05). RE did not express abortive nor teratogenic effects on rats, but influence on sex of the coming generation has been noticed.

Farmaceutski glasnik, 2004

Biological & Pharmaceutical Bulletin, 2007

The radioprotective effects of propolis and polyphenolic compounds from propolis on the radiation... more The radioprotective effects of propolis and polyphenolic compounds from propolis on the radiation-induced mortality of mice exposed to 9 Gy of g g-irradiation were studied. Intraperitoneal (i.p.) treatment of mice at doses of 100 mg kg ؊1 body weight of propolis (water or ethanolic extract; WSDP or EEP) or its polyphenolic compounds (quercetin, naringin caffeic acid, chrysin) consecutively for 3 d before irradiation, delayed the onset of mortality and reduced the symptoms of radiation sickness. All test compounds provided protection against hematopoietic death (death within 30 d after irradiation). The greatest protection was achieved with quercetin; the number of survivors at the termination of the experiment was 63%. According to statistical analyses by the Kaplan-Meier method and the log-rank test, a significant difference between test components and control was found (pϽ0.001). Treatment with test components after lethal irradiation was ineffective. These results suggest that propolis and its polyphenolic compounds given to mice before irradiation protect mice from the lethal effects of whole-body irradiation.

Acta Pharmaceutica, 2003

Propolis or bee-glue is a sticky substance collected in the hives by the honeybee (Apis mellifica... more Propolis or bee-glue is a sticky substance collected in the hives by the honeybee (Apis mellifica L., Apidae) from various tree sources. In the northern hemisphere (Europe, North and South America and western Asia), the tree sources are: Populus spp., Betula spp., Ul-

Acta Pharmaceutica, 2005

Planta Medica, 2007

Farmaceutski glasnik, 2004

PubMed, Dec 1, 2003

PubMed, Dec 1, 2005

PubMed, Mar 1, 2004

Farmaceutski glasnik, Nov 12, 2003

Farmaceutski glasnik, 2004

Biological & Pharmaceutical Bulletin, 2007

Acta Pharmaceutica, 2003

Acta Pharmaceutica, 2005