Snezana Markovic

Teucrium Plant Species as Natural Sources of Novel Anticancer Compounds: Antiproliferative, Proapoptotic and Antioxidant Properties

This study deals with total phenolic content, antiproliferative and proapoptotic activity of methanolic extracts from different Teucrium species and the effect on the prooxidant/antioxidant status in HCT-116 cells. The total phenolic content of the extracts was measured spectrophotometricaly and the obtained results ranged from 56.62 mg/g to 172.50 mg GA/g. The antiproliferative activity of methanolic extracts from different Teucrium species was determined using MTT cell viability assay, where IC50 value was used as a parameter for cytotoxicity. The type of cell death was explored by fluorescence microscopy using the acridin orange/ethidium bromide method. MTT assay showed that all extracts significantly reduced cell viability in a dose-dependent manner, with very low IC50 values. The highest content of phenolic compounds and the best cytotoxic activity on HCT-116 cells after 24 h of exposure was in T. chamaedrys extract, with IC50 values of 5.48 × 10−9 μg/mL. After 72 h, methanolic extract of T. arduini appeared to have the best cytotoxic activity on HCT-116, with IC50 values of 0.37 μg/mL. Treatments caused typical apoptotic morphological changes in HCT-116 cells and showed a high percentage of apoptotic cells. The results of the presented research indicate that some Teucrium extracts are a very rich source of phenols, which may directly contribute to high antiproliferative and proapoptotic activity.

Biological Effects, Total Phenolic Content and Flavonoid Concentrations of Fragrant Yellow Onion (Allium flavum L.)

The antioxidant, antibacterial and antiproliferative activities, total phenolic content and concentrations of flavonoids of A. flavum extracts were determined. The total phenolic content was determined with Folin-Ciocalteu reagent and it ranged between 42.29 to 80.92 mg GA/g. The concentration of flavonoids in various extracts of A. flavum was determined using spectrophotometric method with aluminum chloride and obtained results varied from 64.07 to 95.71 mg RU/g. The antioxidant activity was monitored spectrophotometrically and expressed in terms of IC50 (μg/ml), and its values ranged from 64.34 to 243.34 μg/ml. The highest phenolic content and capacity to neutralize DPPH radicals were found in acetone extract. Antibacterial efficacy was defined by determining minimum inhibitory and minimum bactericidal concentrations using microdilution method. Significant antibacterial activity, especially for ethyl acetate extract, was observed. The best activity was showed against G+ bacteria, Staphylococcus aureus ATCC 25923 and Bacillus subtilis, while Escherichia coli was one of the least sensitive bacteria. Antiproliferative activity of the methanolic extract on HCT- 116 cell line was determined by MTT assay. Results showed that A. flavum has good antiproliferative activity with IC50 values of 28.29 for 24 h and 35.09 for 72 h. Based on these results, A. flavum is a potential source of phenols as natural antioxidant, antibacterial and anticancer substance of high value. Phenolic content of extracts depend on the solvents used for extraction.

Electromagnetic field investigation on different cancer cell lines

BackgroundThere is a strong interest in the investigation of extremely low frequency Electromagnetic Fields (EMF) in the clinic. While evidence about anticancer effects exists, the mechanism explaining this effect is still unknown.MethodsWe investigated in vitro, and with computer simulation, the influence of a 50 Hz EMF on three cancer cell lines: breast cancer MDA-MB-231, and colon cancer SW-480 and HCT-116. After 24 h preincubation, cells were exposed to 50 Hz extremely low frequency (ELF) radiofrequency EMF using in vitro exposure systems for 24 and 72 h. A computer reaction-diffusion model with the net rate of cell proliferation and effect of EMF in time was developed. The fitting procedure for estimation of the computer model parameters was implemented.ResultsExperimental results clearly showed disintegration of cells treated with a 50 Hz EMF, compared to untreated control cells. A large percentage of treated cells resulted in increased early apoptosis after 24 h and 72 h, compared to the controls. Computer model have shown good comparison with experimental data.ConclusionUsing EMF at specific frequencies may represent a new approach in controlling the growth of cancer cells, while computer modelling could be used to predict such effects and make optimisation for complex experimental design. Further studies are required before testing this approach in humans.

Naphthoquinone rich Onosma visianii Clem (Boraginaceae) root extracts induce apoptosis and cell cycle arrest in HCT-116 and MDA-MB-231 cancer cell lines

Abstract In the present study, five root extracts of Onosma visianii Clem were investigated for their in vitro cytotoxic activity. On the basis of HPLC-PDA analysis, these extracts have proved to be a rich source of naphthoquinones as natural colourants for food and cosmetic industry. All investigated root extracts contain acetylshikonin, isobutyrylshikonin and α-methylbutyrylshikonin as major compounds. As the most abundant source of active compounds for antitumour therapy, acetone, chloroform and ethyl acetate extracts showed strong cytotoxic activity towards HCT-116 and MDA-MB-231 cancer cell lines. Also, these extracts induced apoptosis and cell cycle arrest in HCT-116 and MDA-MB-231 cancer cell lines.

Experimental and numerical investigation of electromagnetic field at different cancer cell lines

There is a strong interest of investigation of Extremely Low Frequency (ELF) ElectroMagnetic (EM) fields in the clinic. In this study we investigated experimentally in-vitro and in-sillico with computer simulation influence of 50 Hz EM field at three different cancer cell lines: breast cancer MDA-MB-231 and colon cancer SW-480 and HCT-116. Computer reaction-diffusion model with the net rate of cell proliferation and effect of electromagnetic field in time was developed. The fitting procedure for estimation of the computer model parameters was implemented. Experimental and computer model data have shown good comparison. These findings can open a new avenue for better controlling the growth of cancer cells at specific frequencies without affecting normal tissues, which may have a great influence in clinical oncology.

Estradiol decreases blood pressure in association with redox regulation in preeclampsia

ABSTRACT In this study, we tested a hypothesis that a short-term estradiol therapy may reduce blood pressure in preeclampsia by modulating plasma oxidative stress. The intramuscular injections of 10 mg 17-beta-estradiol were prescribed to preeclamptic pregnant women during the 3-day therapy before a labor induction. The analyses of mean arterial pressure (MAP), serum estradiol concentrations, plasma superoxide anion (O2.), hydrogen peroxide (H2O2), nitrites (NO2−), and peroxynitrite (ONOO−) were conducted before and during the therapy. We found that the plasma concentrations of oxidative stress markers, such as O2– and H2O2, are higher in preeclampsia and positively correlated with the MAP value. Moreover, it was shown that the plasma concentration of NO2– as an indicator of NO levels is higher in preeclampsia. A short-term intramuscular application of estradiol decreases the MAP value and the plasma concentration of O.–, H2O2, NO2−, and ONOO– in preeclampsia. A positive correlation between the decrease of MAP values and the decrease of plasma concentrations of O2–, H2O2, and ONOO– was found in preeclampsia during a short-term estradiol therapy. We conclude that the short-term estradiol therapy decreases the MAP value in preeclampsia by modulating the plasma oxidative stress. We speculate that the estradiol metabolism in preeclampsia is an important mechanism that contributes to vascular dysfunction.