Dragana D. Četojević-Simin

Effect of rosehip (Rosa canina L.) phytochemicals on stable free radicals and human cancer cells

BACKGROUND The commercial development of plants as sources of antioxidants that can be used to enhance the properties of foods, for nutritional purposes and preservation as well as for prevention of oxidation-related diseases, is currently of major interest. Rosehip (Rosa canina L.) is a rich source of vitamin C and polyphenols. RESULTS Phytochemicals in rosehip tea were separated into three fractions: Fr1 (vitamin C, 39.17 mg kg(-1)), Fr2 (flavonoids, 451.05 µg kg(-1)) and Fr3 (phenolic acids, 504.69 µg kg(-1)). Quercetin and ellagic acid were the most abundant polyphenolic compounds. Rosehip fractions, primarily rosehip flavonoids (EC(50) = 49 mg L(-1)), showed high antioxidant activity towards 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH(•)). Cell growth effects of rosehip fractions were assessed in HeLa, MCF7 and HT-29 cell lines, with the lowest IC(50) values being determined for rosehip flavonoids, (80.63, 248.03 and 363.95 mg L(-1) respectively). However, the vitamin C fraction did not inhibit the growth of tested tumour cells. CONCLUSION The results of this study confirm that vitamin C and flavonoids are responsible for the antioxidant activity of rosehip tea, while only polyphenols contribute to its antiproliferative activity.

Toxicity assessment of metoprolol and its photodegradation mixtures obtained by using different type of TiO2 catalysts in the mammalian cell lines

Toxicity of metoprolol (MET) alone and in mixtures with its photocatalytic degradation intermediates obtained by using TiO2 Wackherr and Degussa P25 under UV irradiation in the presence of O2 was evaluated in vitro in a panel of three histologically different cell lines: rat hepatoma (H-4-II-E), human colon adenocarcinoma (HT-29) and human fetal lung (MRC-5). Both catalysts promoted a time-dependent increase in the toxicity of the photodegradation products, and those obtained using Degussa P25 photocatalyst were more toxic. The most pronounced and selective toxic action of MET and products of its photodegradation was observed in the hepatic cell line. The higher toxicity of the mixtures obtained using Degussa P25 catalyst could be explained by a different mechanism of MET degradation, i.e. by the presence or higher concentrations of some intermediates. Although the concentrations of intermediates obtained using TiO2 Wackherr catalyst were higher, they did not affect significantly the growth of the examined cell lines, indicating their lower toxicity. This suggests that a treatment aiming at complete mineralization should be performed bearing in mind that the type of catalyst, the concentration of target molecule, and the duration of the process are significant factors that determine the nature and toxicity of the resulting mixtures. Although the EC50 values of MET obtained in mammalian cell lines were higher compared to the bioassays for lower trophic levels, the time-dependent promotion of toxicity of degradation mixtures should be attributed to the higher sensitivity of mammalian cell bioassays.

Bioactivity of Lemon Balm Kombucha

There is inadequate published data referring to bioactivity of lemon balm tea and its Kombucha. The aim of this study, therefore, was to investigate antimicrobial, antiproliferative, genotoxic, and antigenotoxic potential of lemon balm tea and its Kombucha with consuming acidity. Antimicrobial activity was determined by agar-well diffusion method. Cell growth effects were determined in HeLa, MCF7, and HT-29 human tumor cell lines. Genotoxic and antigenotoxic effects were determined using chromosome aberration assay in Chinese hamster cell line CHO-K1. Differences between control and treated groups were evaluated using analysis of variance, at significance level of p < 0.05. Kombucha from lemon balm tea (Melissa officinalis L.) exibited antimicrobial activity against prokaryotic microorganisms independently of their cell wall structure (both Gram-positive and Gram-negative bacteria), while there was no observed activity against eukaryots (yeasts and moulds). There was absence of genotoxic effects while antigenotoxic effects of lemon balm Kombucha and tea were confirmed on MMC-damaged CHO-K1 cells. For the explanation of cell growth effects that were not concentration dependent, concept of hormesis was used. Antiproliferative activity was lower compared with traditional Kombucha and Satureja montana L. Kombucha, with lemon balm tea showing higher activity than its Kombucha.

Tomato waste: Carotenoids content, antioxidant and cell growth activities.

The carotenoid content, antioxidant and cell growth activities of tomato waste extracts, obtained from five different tomato genotypes, was investigated. High performance liquid chromatography was used to identify and quantify the main carotenoids present in tomato waste extracts. The antioxidant activity of tomato waste extracts was tested using spectrophotometric methods, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and reducing power assay. The highest DPPH scavenging activity (IC50 = 0.057 mg/ml) was obtained for Bačka extract. The Knjaz extract showed the best reducing power (IC50 = 2.12 mg/ml). Cell growth effects were determined in HeLa, MCF7 and MRC-5 cell lines by sulforhodamine B test. Anti-proliferative effects were observed in all cell lines at higher concentrations (⩾ 0.125 mg/ml). The carotenoid contents exhibited a strong correlation with antioxidant and anti-proliferation activity. The results obtained indicated that tomato waste should be regarded as potential nutraceutic resource and may be used as a functional food ingredient.

Comparative study of biological activities and phytochemical composition of two rose hips and their preserves: Rosa canina L. and Rosa arvensis Huds.

The aim of this study was to compare phenolic profile, vitamin C content, antioxidant, anti-inflammatory and cytotoxic activity of rose hips and the preserves (purée and jam) of two Rosa species: renowned Rosa canina L. and unexplored Rosa arvensis Huds. The liquid chromatography-tandem mass spectrometry analysis of 45 phenolics resulted in quantification of 14 compounds, with quercitrin, gallic and protocatechuic acids as the most dominant. High antioxidant potential of R. canina and a moderate activity of R. arvensis extracts were determined through several assays. Purée of both species and methanol extract of air-dried R. canina hips showed some anti-inflammatory (cyclooxygenase-1 and 12-lipooxygense inhibition potency) activity. Purée of R. canina exerted cytotoxic activity only against the HeLa cell line among several others (HeLa, MCF7, HT-29 and MRC-5). The presented results support traditional use of rose hips and their fruit preserves as food with health and nutritional benefits.

Efficient removal of sulcotrione and its formulated compound Tangenta® in aqueous TiO2 suspension: Stability, photoproducts assessment and toxicity.

The photocatalytic degradation of the herbicide sulcotrione (0.05 mM) and its formulated compound Tangenta® in aqueous suspensions of TiO2 Degussa P25 was examined as a function of the different operational parameters. The optimum of the catalyst loading was found to be 2.0 mg mL(-1) under UVA light. In the first stage of the reaction, the photocatalytic degradation of sulcotrione alone and in Tangenta® followed the pseudo-first order kinetics, in which the heterogeneous catalysis proceeds via OH and holes. Further, it can be concluded that degradation rate of sulcotrione alone is about two times higher compared to formulated compound. The results showed that the disappearance of sulcotrione led to the formation of three organic intermediates and ionic byproducts (Cl(-), SO4(2-), acetate and formate), whereas their mineralization was about 90% after 4 h. Tentative photodegradation pathways were proposed and discussed. Also, there was no significant toxicity observed after the irradiation of sulcotrione solution and Tangenta® formulation using TiO2 catalyst on three mammalian cell lines.

Bioactivity of Meeker and Willamette raspberry (Rubus idaeus L.) pomace extracts

Taking into account the substantial potential of raspberry processing by-products, pomace extracts from two raspberry cultivars, Meeker and Willamette, were investigated. Total phenolic, flavonoid and anthocyanin contents were determined. Willamette pomace extract (EC₅₀=0.042 mg/ml) demonstrated stronger 2,2-diphenyl-1-picrylhydrazyl DPPH radical-scavenging activity than did Meeker pomace extract (EC₅₀=0.072 mg/ml). The most pronounced cell growth inhibition effect was obtained in the breast adenocarcinoma cell line, reaching EC50 values of 34.8 and 60.3 μg/ml for Willamette and Meeker extracts, respectively. Both extracts demonstrated favourable non-tumor/tumor cell growth ratios and potently increased the apoptosis/necrosis ratio in breast adenocarcinoma and cervix carcinoma cells. In reference and wild bacterial strains, minimal inhibitory concentrations (MIC) were achieved in a concentration range from 0.29 to 0.59 mg/ml, and minimal bactericidal concentrations (MBC) in a range from 0.39 to 0.78 mg/ml. The results indicate significant antioxidant, antiproliferative, proapoptotic and antibacterial activities of raspberry pomace and favour its use as a functional food ingredient.

Phenolic profile, antioxidant, anti-inflammatory and cytotoxic activities of black (Tuber aestivum Vittad.) and white (Tuber magnatum Pico) truffles

The aim of this study was a comprehensive investigation on phenolic profile, antioxidant, anti-inflammatory and cytotoxic activity of the still insufficiently explored black summer truffles (Tuber aestivum Vittad.) and white (Tuber magnatum Pico) truffles. Methanol and water extracts, obtained by maceration and Soxhlet extraction, were examined. Forty-five phenolics was studied using LC-MS/MS: presence of 14 compounds was confirmed, with the most dominant being p-hydroxybenzoic acid, baicalein and kaempferol (T. aestivum), epicatechin and catechin (T. magnatum). Moderate antioxidant activity of both species was determined through several assays. Only T. magnatum showed anti-inflammatory potential by inhibiting COX-1 and 12-LOX pathway products synthesis. Methanol extracts exerted cytotoxicity against some tumour cell lines (HeLa, MCF7, HT-29), besides the prominent activity of water extracts towards breast adenocarcinoma (MCF7). To conclude, these results support further investigations of phytochemicals and biological activity towards verification of nutraceutical use of both species.

Photocatalytic degradation of the herbicide clomazone in natural water using TiO2: kinetics, mechanism, and toxicity of degradation products.

The photocatalytic degradation of the herbicide clomazone (0.05mM) in aqueous suspensions of TiO2 Degussa P25 was examined as a function of the different operational parameters. The optimum concentration of the catalyst was found to be 0.50mgmL(-1) under UV light at the pH 10.3. In the first stage of the reaction, the photocatalytic degradation of clomazone followed the pseudo-first order kinetics, with and the heterogeneous catalysis proceeding via OH radicals. The results also showed that the disappearance of clomazone led to the formation of a number of organic intermediates and ionic byproducts, whereas its complete mineralization occurred after about 55min. Tentative photodegradation pathways were proposed and discussed. A comparison of the evolution of toxicity that was evaluated in vitro in rat hepatoma (H-4-II-E) and human fetal lung (MRC-5) cell lines with the degradation kinetics indicates that the irradiation contributed to the decrease of the toxicity of the mixture that is no longer dominated by the parent compound. The study also encompassed the effect of the quality of natural water on the rate of removal of clomazone.

Estimation of in vivo and in vitro exposure to bisphenol A as food contaminant

The goal of this cross-sectional study was to examine the occurrence of bisphenol A (BPA) in the morning spot urine taken from 145 female volunteers of various ages. Total urine BPA concentration was detected in 38.6% samples in the 0.92-70.96 μg/g Cr range. The majority of BPA + women belonged to the 25 + body mass index (BMI) group (54.5% were overweight and 43.4% were obese women). Occurrence of BPA in the urine samples was higher at 40 + ages. The maximum BPA concentration of 70.96 μg/g Cr was detected in the urine sample of an obese woman. It is known that BPA is highly toxic in vitro. In this study BPA impaired significantly the growth of all investigated cell lines, i.e. the EC50 values were reached at very low concentrations, in the range from 3.24 to 34.85 μg/mL. The obtained in vivo results suggest that a higher exposure to BPA could contribute to weight problems in women and the absence of the BPA in vitro selective toxicity studies indicates to its general toxic mode of action and raises awareness of the health risks associated with its ubiquitous presence in the environment.