Citotoksični i apoptotički učinak strukturno sličnih flavonoida na stanice roditeljske i otporne stanične linije karcinoma cerviksa

Flavonoids are phytochemicals characterized by a wide range of biological activities, including antioxidant activity, the ability to modulate enzyme or cell receptor activity patterns, and to interfere with essential biochemical pathways. Using HeLa cells of a human cervical carcinoma, and their drug-resistant HeLa CK subline, the effects of three structurally related flavonoids (quercetin, fisetin and luteolin) have been examined, in terms of their: (i) cytotoxicity, (ii) influence on intracellular glutathione (GSH) level, (iii) influence on glutathione S-transferase (GST) activity, and (iv) influence on the expression of apoptosis-related genes (PARP, Bcl-2, survivin). Fisetin was more toxic to resistant HeLa CK cell line than to parental cell line, causing decreased expression of survivin in the same cell line. Concentrations of 5 μM of the examined flavonoids caused PARP degradation in parental cell line, leading HeLa cell line into apoptotic cell death. The same event was not determined in the resistant cell line. Fisetin and luteolin induce glutathione and GST in the resistant cell line, pointing to complex cellular effects which could be responsible for higher sensitivity of the resistant cell line in comparison with the parental cell line. Prooxidative nature of the investigated flavonoids was not detected, so free radical formation is not responsible for the induction of GSH, GST and proapoptotic enzymes.Flavonoidi pripadaju skupini fitokemikalija koje imaju mnogo bioloških aktivnosti, i to antioksidativnu aktivnost, modulacijsko djelovanje na enzime i stanične receptore te djelovanje na osnovne biokemijske puteve. U ovom je radu istražen utjecaj tri strukturno slična flavonoida (kvercetin, fisetin i luteolin) na stanične linije karcinoma cerviksa, HeLa, te sublinije otporne na citostatike, HeLa CK. Utvrđen je: i) citotoksični učinak flavonoida, ii) utjecaj flavonoida na promjenu koncentracije unutarstaničnoga glutationa (GSH), iii) utjecaj flavonoida na aktivnost glutation S-transferaze (GST) i iv) utjecaj flavonoida na ekspresiju gena koji sudjeluju u apoptozi (PARP, Bcl-2, survivin). Fisetin je djelovao toksičnije na otpornu subliniju HeLa CK u usporedbi s roditeljskom staničnom linijom HeLa, uzrokujući smanjenje ekspresije proteina survivina. Zbog tih koncentracija flavonoida (5 μM) došlo je do razgradnje PARP proteina u roditeljskoj staničnoj liniji, uzrokujući apoptotičku staničnu smrt u liniji HeLa. Taj događaj nije uočen u otpornoj subliniji. Fisetin i luteolin uzrokuju indukciju glutationa i povećanu aktivnost GST u otpornoj subliniji, upućujući na složenost staničnih procesa koji bi mogli biti odgovorni za veću osjetljivost rezistentne sublinije u usporedbi s roditeljskom staničnom linijom. Prooksidativna priroda istraživanih flavonoida nije bila utvrđena, pa se može zaključiti da slobodni radikali nisu odgovorni za indukciju GSH, GST i proapoptotičkih enzima

Genotoksični učinak ekstrakta zelenog čaja na ljudske stanice raka grkljana u kulturi

Green tea (Camellia sinensis) contains several bioactive compounds which protect the cell and prevent tumour development. Phytochemicals in green tea extract (mostly flavonoids) scavenge free radicals, but also induce pro-oxidative reactions in the cell. In this study, we evaluated the potential cytotoxic and prooxidative effects of green tea extract and its two main flavonoid constituents epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) on human laryngeal carcinoma cell line (HEp2) and its crossresistant cell line CK2. The aim was to see if the extract and its two flavonoids could increase the sensitivity of the cisplatin-resistant cell line CK2 in comparison to the parental cell line. The results show that EGCG and green tea extract increased the DNA damage in the CK2 cell line during short exposure. The cytotoxicity of EGCG and ECG increased with the time of incubation. Green tea extract induced lipid peroxidation in the CK2 cell line. The pro-oxidant effect of green tea was determined at concentrations higher than those found in traditionally prepared green tea infusions.Zeleni čaj, koji je vrlo popularno piće, proizvodi se iz biljke Camellia sinensis i bogat je fl avonoidima za koje se smatra da imaju važnu ulogu u sprečavanju nastanka raka. Kao najvažniji mehanizmi djelovanja fl avonoida najčešće se spominju vezanje slobodnih radikala te sprečavanje nastanka reaktivnih kisikovih skupina. Cilj ovog rada bio je istražiti potencijalni genotoksični učinak ekstrakta zelenog čaja te epigalokatehin galata (EGCG) i epikatehin galata (ECG), fl avonoida koji se u zelenom čaju nalaze u najvišoj koncentraciji. Dobiveni su rezultati pokazali da EGCG i ekstrakt zelenog čaja izazivaju povećanu citotoksičnost otporne stanične linije raka grkljana CK2 nakon kraće inkubacije. Produljenjem vremena inkubacije povećava se citotoksičnost istraživanih spojeva. Također, ekstrakt zelenog čaja izaziva lipidnu peroksidaciju u CK2-stanicama. Prooksidativni učinak ekstrakta zelenog čaja u koncentracijama višim od onih prisutnih u infuzijskoj otopini dobivenoj tradicionalnim načinom, imaju prooksidativno djelovanje

Utjecaj flavonoida na razinu glutationa, peroksidaciju lipida i ekspresiju citokroma P450 CYP1A1 u staničnim linijama karcinoma grkljana

Flavonoids are phytochemicals exhibiting a wide range of biological activities, among which are antioxidant activity, the ability to modulate activity of several enzymes or cell receptors and possibility to interfere with essential biochemical pathways. Using human laryngeal carcinoma HEp2 cells and their drug-resistant CK2 subline, we examined the effect of five flavonoids, three structurally related flavons (quercetin, fisetin, and myricetin), one flavonol (luteolin) and one glycosilated flavanone (naringin) for: (i) their ability to inhibit mitochondrial dehydrogenases as an indicator of cytotoxic effect, (ii) their influence on glutathione level, (iii) antioxidant/prooxidant effects and influence on cell membrane permeability, and (iv) effect on expression of cytochrome CYP1A1. Cytotoxic action of the investigated flavonoids after 72 hours of treatment follows this order: luteolin>quercetin>fisetin>naringin>myricetin. Our results show that CK2 were more resistant to toxic concentrations of flavonoids as compared to parental cells. Quercetin increased the total GSH level in both cell lines. CK2 cells are less perceptible to lipid peroxidation and damage caused by free radicals. Quercetin showed prooxidant effect in both cell lines, luteolin only in HEp2 cells, whereas other tested flavonoids did not cause lipid peroxidation in the tested cell lines. These data suggest that the same compound, quercetin, can act as a prooxidant, but also, it may prevent damage in cells caused by free radicals, due to the induction of GSH, by forming less harmful complex. Quercetin treatment damaged cell membranes in both cell lines. Fisetin caused higher cell membrane permeability only in HEp2 cells. However, these two compounds did not enhance the damage caused by hydrogen peroxide. Quercetin, naringin, myricetin and fisetin increased the expression of CYP1A1 in both cell lines, while luteolin decreased basal level of CYP1A1 only in HEp2 cells. In conclusion, small differences in chemical structure of flavonoids led to drastic change of their biological effects.Flavonoidi su fitokemikalije koje imaju široki raspon bioloških učinaka, između ostalih antioksidativnu aktivnost, sposobnost mijenjanja aktivnosti pojedinih enzima ili staničnih receptora i mogućnost utjecaja na osnovne biokemijske putove. Korištenjem staničnih linija karcinoma grkljana čovjeka HEp2 i njihovih rezistentnih podlinija CK2, istražena je sposobnost pet flavonoida, tri strukturno slična flavona (kvercetin, fisetin i miricetin), jednog flavonola (luteolin) i jednoga glikoziliranog flavanona (naringin) da: (i) inhibiraju mitohondrijske dehidrogenaze koje služe kao pokazatelj citotoksičnog učinka, (ii) utječu na razinu glutationa, (iii) imaju antioksidativno/prooksidativno djelovanje i utječu na propusnost stanične membrane i (iv) utječu na ekspresiju citokroma CYP1A1. Citotoksično djelovanje ispitanih flavonoida nakon 72 sata bilo je u slijedu: luteolin > kvercetin > fisetin > naringin > miricetin. Dobiveni rezultati pokazali su da su stanice CK2 bile rezistentnije na toksične koncentracije flavonoida u usporedbi s roditeljskim stanicama. Kvercetin je povećao ukupnu razinu glutationa (GSH) u obje stanične linije. Stanice CK2 bile su manje podložne peroksidaciji lipida i oštećenjima uzrokovanim slobodnim radikalima. Kvercetin je pokazao prooksidativno djelovanje u obje stanične linije, luteolin samo u HEp2 stanicama, a ostali ispitani flavonoidi nisu uzrokovali peroksidaciju lipida. Ti podaci pokazuju da isti spoj, kvercetin, može djelovati kao prooksidans, ali također može spriječiti oštećenje stanica uzrokovanih slobodnim radikalima, zbog indukcije GSH, formiranjem manje štetnog kompleksa. Kvercetin oštećuje stanične membrane u obje stanične linije, dok fisetin povećava propusnost stanične membrane samo u HEp2 stanicama. No, ta dva spoja ne pojačavaju oštećenje stanične membrane vodikovim peroksidom. Kvercetin, naringin, miricetin i fisetin povećali su ekspresiju CYP1A1 u obje stanične linije, dok je luteolin smanjio ekspresiju CYP 1A1 u HEp2 stanicama. Iz tih se rezultata može zaključiti da male razlike u kemijskoj strukturi flavonoida uzrokuju značajne razlike u njihovu biološkom učinku

Toksikološki značaj i potencijalni rizik pri ekspoziciji polibromovanim difeniletrima

Polybrominated diphenyl ethers (PBDEs) represent group of persistant organic chemicals (POPs), usually used as flame retardant additives in a variety of matherials and commercial products. Since 2009, PBDEs have been placed on the list of POPs chemicals, covered by Stockholm convention which is aimed to limit or ban production, use, emission, import and export of persistent organic pollutants, due to human health and environmental protection. Predominant routes of human exposure by PBDEs are ingestion by food, inhalation or dermal. Based on experimental studies, targets for PBDEs toxicity are nervous system, liver, thyroid gland and development. According to International Agency for Research on Cancer (IARC) PBDEs are not classified as a carcinogens, whereas according to Environmental Protection Agency (EPA) only deca BDE is classified as possible human carcinogen. So far, PBDEs have not been incoporated in national legislative framework. There are no data on environmental contamination, occupational exposure and exposure of general population. Therefore, placing the data on PBDEs in the focus of publics could contribute to the process of risk characterisation, and give directions for risk management in the Republic of Serbia.Polibromovani difeniletri (PBDEs) su hemikalije koje se dodaju različitim proizvodima kojima smo okruženi u svakodnevnom životu da bi usporili i/ili sprečili izbijanja požara. Polibromovani difeniletri su 2009. godine pridruženi listi perzistentnih organskih polutanata (POPs) usvojenoj Stokholmskom konvencijom čiji je cilj da ograniči ili zabrani proizvodnju, upotrebu, emisiju ili uvoz i izvoz toksičnih supstanci označenih kao POPs radi zaštite zdravlja ljudi i životne sredine. Do ekspozicije ljudi PBDEs može doći ingestijom, inhalacijom, dermalno. Eksperimentalne studije ukazuju da PBDEs najznačajnije toksične efekte ispoljavaju na jetru, štitnu žlezdu, nervni sistem, rast i razvoj. Međunarodna agencija za istraživanje karcinoma (IARC) ne klasifikuje PBDEs kao karcinogene za ljude, a Američka agencija za zaštitu životne sredine (EPA) klasifikuje samo dekaBDE kao moguć karcinogen za ljude. U našoj zemlji PBDEs nisu inkorporirani u nacionalnu regulativu, nema podataka o nivou zagađenja životne sredine, o sadržaju ovih jedinjenja u radnom okruženju i ekpoziciji opšte populacije, stoga bi saznanja u ovoj oblasti doprinela procesu evaluacije i karakterizacije rizika, ali i dala smernice za upravljanje rizikom PBDEs hemikalijama u Republici Srbiji

Primena PROAST softvera za ispitivanje uticaja dekabromovanog difeniletra i/ili kadmijuma na homeostazu hormona štitaste žlezde kod pacova

In relation to commonly used no-observed-adverse-effect-level (NOAEL) point of departure, because of its statistical power and reliability, Benchmark dose (BMD) approach has been proposed as an alternative in dose-response assessment. The aim of this study was to derive BMD (10%) by means of PROAST software to quantify influence of cadmium (Cd) and/or decabrominated diphenyl ether (BDE209) on thyroid hormones homestasis. Study was conducted on male Wistar rats treated orally by gavage for 28 days by either single substances or their combination. Three groups of animals were dosed with Cd at levels of 2.5, 7.5 and 15 mg/kg b.w./day, three groups of animals were dosed with BDE209 at levels of 1000, 2000 or 4000 mg/kg b.w./day, while 9 groups received different dose mixtures of previously given dose levels of Cd and BDE209 (design 3 x 3). Results of the study have indicated that Cd+BDE209 mixtures are likely more potent to disrupt thyroid function than would be expected from the chemicals individually. Derived BMD - lower confidence limits (BMDL), if ratio BMD/BMDL is lt 10, were 9.4 mg Cd/kg b.w./day and 2155 mg BDE209/kg b.w./day for the effect on T3; and 6.22 mg Cd/kg b.w./day in the mixture with BDE209 2000 mg/kg b.w./day for the effect on FT3.Primena statistički dobijene Benchmark doze (BMD) u proceni rizika predstavlja alternativu najčešće korišćenoj 'dozi bez štetnog efekta' (NOAEL) zbog veće pouzdanosti u analizi odnosa doze i toksičnog efekta. Cilj ovog rada bio je izračunavanje BMD (10%) primenom PROAST softvera radi kvantitativne procene uticaja Cd i/ili BDE209 na homeostazu hormona štitaste žlezde. Ispitivanje je sprovedeno na mužjacima Wistar pacova koji su putem oralne sonde, tokom 28 dana, primali pojedinačne supstance ili njihove kombinacije. Kadmijum je primenjivan u dozama od 2,5, 7,5 i 15 mg Cd/kg t.m./dan, a BDE209 u dozama od 1000, 2000 i 4000 mg BDE209/kg t.m./dan, dok je ostalih devet grupa životinja primalo kombinacije hemikalija (dizajn 3 x 3). Rezultati studije ukazuju da smeša Cd i BDE209 verovatno izaziva intenzivniji poremećaj funkcije štitaste žlezde nego svaka od supstanci pojedinačno. Izračunate Benchmark doze (10%), odnosno odgovarajuće donje granice pouzdanosti (BMDL), uz uslov da je BMD/BMDL lt 10, iznose 9,4 mg Cd/kg t.m./dan i 2155 mg BDE209/kg t.m./dan za efekte na T3 hormon, a za efekat na FT3 hormon 6,22 mg Cd/kg t.m/dan u smeši sa BDE209 od 2000 mg/kg

Characterization of S-layer proteins of potential probiotic starter culture Lactobacillus brevis SF9B isolated from sauerkraut

Abstract S-layers represent the simplest biological membranes developed during the evolution and are one of the most abundant biopolymers on Earth. Current fundamental and applied research aim to reveal the chemical structure, morphogenesis and function of S-layer proteins (Slps). This is the first paper that describes the Slps of certain Lactobacillus brevis strain isolated from sauerkraut. The whole genome sequence (WGS) analysis of the L. brevis SF9B strain uncovered three genes encoding the putative Slps, but merely one, identified as similar to the SlpB of L. brevis ATCC 14869, was expressed. Slp-expressing SF9B cells exhibited increased survival in simulated gastrointestinal (GI) conditions and during freeze-drying. Their survival in stress conditions was additionally enhanced by microencapsulation, especially when using alginate with gelatine as a matrix. Thus prepared cells were subjected to simulated GI conditions and their mortality was only 0.28 ± 0.45 log CFU/mL. Furthermore, a correlation between the high surface hydrophobicity and the remarkable aggregative capacity of SF9B strain was established. The results indicate a prominent role of Slps in adhesion to mucin, extracellular matrix (ECM) proteins, and particularly to Caco-2 cells, where the removal of Slps utterly abolished the adhesiveness of SF9B cells for 7.78 ± 0.25 log CFU/mL.Peer reviewe

Citotoksično djelovanje meda obične planike (Arbutus unedo L.), ekstrakta i homogentizinske kiseline na stanične linije CAL 27, HepG2 i Caco-2

Strawberry tree (Arbutus unedo L.) honey (STH), also known as “bitter honey”, is a traditional medicine widely used in the Mediterranean area. Regardless of geographical origin, it usually has a very high content of phenolic compounds and strong antioxidant capacity. Yet, little is still known about the effects of STH, its phenolic extract (STHE), and its main bioactive compound – homogentisic acid (HGA) – at the cell level. The aim of this study was to estimate total phenolic content, DPPH radical scavenging activity, and ferric reducing antioxidant power of STH made in Croatia and investigate cytotoxic and pro-oxidative effects of STH, STHE and HGA on three human cell lines: tongue squamous cell carcinoma (CAL 27), hepatocellular carcinoma (HepG2), and epithelial colorectal adenocarcinoma cells (Caco-2) cells. These substances were tested at four concentrations (0.5–5× average human daily intake of STH) and over 30 min and 1 and 2 h. Croatian STH had a total phenolic content of 1.67 g gallic acid equivalents (GAE) per kg of honey, DPPH radical scavenging activity of 2.96 mmol Trolox equivalents (TE) per kg of honey, and ferric reducing antioxidant power (FRAP) of 13.5 mmol Fe2+ per kg of honey. Our results show no clear and consistent time- or concentration-dependent cytotoxicity in any of the cell lines. ROS levels in all the three cell types at almost all exposure times were not significantly higher than control. The most important observation is that the tested substances have low cytotoxicity and high biocompatibility, regardless of concentration, which is a good starting point for further research of their biological effects in other models.Med obične planike (Arbutus unedo L.) (STH), poznat kao “gorki med”, tradicionalno se koristi u narodnoj medicini na sredozemnom području. Bez obzira na zemljopisno podrijetlo, obično ima vrlo visok udio fenolnih spojeva i snažan antioksidacijski kapacitet. Ipak, još uvijek se malo zna o učincima STH-a, njegova ekstrakta (STHE), kao i dominantnoga fenolnog spoja – homogentizinske kiseline (HGA) – na staničnoj razini. Cilj ovoga istraživanja bio je utvrditi ukupni sadržaj fenola, antioksidacijski kapacitet metodom DPPH i FRAP u STH-u, proizvedenome u Hrvatskoj, te ispitati citotoksične i prooksidacijske učinke STH-a, STHE-a i HGA-e na tri ljudske stanične linije: karcinoma pločastih stanica jezika (CAL 27), hepatocelularnoga karcinoma jetre (HepG2) i adenokarcinoma epitela debelog crijeva (Caco-2). STH, STHE i HGA ispitani su u četirima koncentracijama (0,5–5× prosječni dnevni unos STH-a u ljudi) i tijekom 30 minuta te tijekom jednog i dva sata. Hrvatski STH imao je visok ukupan sadržaj fenola (1,67 g ekvivalenata galne kiseline po kg meda i snažan antioksidacijski kapacitet (2,96 mmol Trolox ekvivalenata po kg meda i 13,5 mmol Fe2+ po kg meda). Dobiveni rezultati ne pokazuju jasnu i dosljednu citotoksičnost, ovisno o vremenu ili koncentraciji, ni u jednoj staničnoj liniji. Razine reaktivnih kisikovih vrsta u svim trima tipovima stanica u gotovo svim vremenima izlaganja nisu bile značajno veće od kontrole. Najvažnije je zapažanje da ispitivane tvari imaju nisku citotoksičnost i visoku biokompatibilnost, bez obzira na koncentraciju, što je dobra polazna točka za daljnja istraživanja njihovih bioloških učinaka na drugim modelima

Structural characterisation of novel exopolysaccharide biosynthesized by potential probiotic strain Lactobacillus fermentum D12

Lactobacillus fermentum D12, biosynthesize exopolysaccharides, is released in large amounts in MRS broth supplemented with glucose. High Performance Size Exclusion Chromatography (HPSEC), 1H-NMR, GC and GC-MS analysis revealed that this strain produces three different types of EPOLs; the first homopolysaccharide (HoPOL) of a molecular weight of 400 kDa and two different low molecular weight heteropolysaccharides (HePOLs) of less than 2 kDa. 2D-NMR spectroscopy analysis revealed that HoEPOL, with the highest molecular mass, is composed of repeating units of D-glucose linked by an α-1,4-glycosidic bond, where 20% of the glucose subunits is acetylated at C-3. Further chromatographic analyses and NMR experiments showed that each HePOL contained mannose, glucose and galactose in an averaged relative molar ratio of 1.78:0.87:1 and 6.38:1.6:1, respectively. Since a probiotic strain survival in rigorous gastrointestinal (GI) conditions is the first probiotic selection criterion to be met, and with respect to efficient survival of D12 strain in GIT in vitro (bacteria counts ≥106 CFU ml-1) the potential probiotic role of Lb. fermentum D12 was evaluated. Also, sensitivity to different antibiotics, minimum inhibitory concentrations (MICs), antagonistic activity and analysis of fermentation of different carbohydrates using API 50 CHL media of this potential probiotic strain was assessed

Kombinirano djelovanje kadmija i dekabromiranog difenil etera na hormone štitnjače u štakora

The aim of this study was to see how a mixture of cadmium (Cd) and decabrominated diphenyl ether (BDE209) affect thyroid function, namely thyroid-stimulating hormone (TSH), thyroxin (T4), free thyroxin (FT4), triiodothyronin (T3), and free triiodothyronin (FT3) in Wistar rats (eight per group) receiving either a single substance or their combination by gavage for 28 days. Three groups were receiving Cd alone in the doses of 2.5 mg kg-1, 7.5 mg kg-1, or 15 mg kg-1 b. w. a day, three groups were receiving BDE209 in the doses of 1000 mg kg-1, 2000 mg kg-1, or 4000 mg kg-1 b. w. a day, while nine groups were receiving different mixtures of Cd and BDE209 in these doses (3x3 design). The results have indicated that the Cd+BDE209 mixtures more potently disrupt thyroid hormone homeostasis than would be expected from these chemicals alone.Cilj ovoga istraživanja bio je utvrditi na koji način smjesa kadmija (Cd) i dekabromiranog difenil etera (BDE209) djeluje na aktivnost štitnjače. Određivane su aktivnosti stimulirajućega hormona štitnjače (TSH), tiroksina (T4), slobodnog tiroksina (FT4), trijodtironina (T3) te slobodnog trijodtironina (FT3) kao parametara koji upućuju na funkcionalnost štitnjače. Kao eksperimentalni testni sustav korišteni su Wistar štakori (n=8 po grupi), kojima je tijekom 28 dana dozirana pojedinačna tvar ili smjesa kadmija i dekabromiranog difeniletera. Životinje su bile podijeljene u tri grupe koje su primale tri različite doze kadmija: 2,5 mg kg-1, 7,5 mg kg-1 i 15 mg kg-1 tjelesne težine po danu. Tri grupe životinja primale su tri različite doze BDE209: 1000 mg kg-1, 2000 mg kg-1, odnosno 4000 mg kg-1 tjelesne težine po danu. Preostale životinje bile su podijeljene u devet grupa kojima su bile dozirane različite koncentracije kadmija i dekabromiranog difenil etera (3x3 dizajn). Rezultati pokazuju da Cd+BDE209 smjesa u većoj mjeri remeti homeostazu hormona štitnjače u odnosu na pojedinačne spojeve

Association of Vitamins D, B9 and B12 with Obesity-Related Diseases and Oral Microbiota Composition in Obese Women in Croatia

Research background. Oral microbiota has become an important factor in obesity, but its association with obesity-related diseases and serum 25-hydroxy vitamin D [25(OH)D] and B complex amounts is still uncertain. The main aim of the paper is to determine the variation in oral microbiota composition as a response to the vitamin status and obesity-related diseases in obese females from Croatia. We hypothesized that the prevalence of probiotic or pathogenic bacteria in the oral cavity of obese women in Croatia depends on the amounts of vitamin B9 (folic acid), B12 and 25(OH)D in serum and/or hypertension, diabetes and prediabetes diagnosis. Experimental approach. To test the defined research hypothesis, female individuals with body mass index (BMI)≥30 kg/m2 (N=70) were recruited to participate in this study. Obese women were divided into groups according to BMI value, diagnosis of obesity-related diseases and amount of micronutrient in blood. For the quantitative determination of folic acid, vitamin B12 and 25(OH)D in serum, an electrochemiluminescence protein binding assay (ECLIA) was performed. Microorganisms isolated from the saliva of obese women were analyzed by MALDI-TOF mass spectrometer. Results and conclusions. The presented results do not support the hypothesis that the prevalence of probiotic or pathogenic bacteria in the oral cavity of obese women in Croatia depends on the amount of micronutrients. On the other hand, hypertension and diabetes/prediabetes favour the growth of oral pathogens, specifically increased levels of Candida sp. Novelty and scientific contribution. To the best of our knowledge, this is the first study showing the relationship between obesity, micronutrient amount, oral microbiota composition, and the incidence of obesity-related disease. We included only obese women from Croatia, so it is regionally specific. Also, we have shown that oral microbiota composition is not connected with micronutrient deficiencies but only with obesity-related diseases