Anticancer Effects of Propolis Extracts Obtained Using the Cold Separation Method on Breast Cancer Cell Lines.

Propolis and its extracts show a wide spectrum of biological activity. Due to the necessity to use high temperatures and high polarity in the eluent, the obtained extracts are depleted of active compounds. The new, cold separation method allows obtaining a qualitatively better product containing a number of chemical compounds absent in extracts obtained using high-temperature methods. The purpose of our study was to evaluate the biological activity of propolis extracts produced with the cold separation method in four female breast cancer cell lines: MDA-MB-231, MDA-MB-468, MCF-7, and T-47D. The results of the breast cancer cell viability were obtained using the MTT test. Propolis extracts at 75 and 80% showed similar cytotoxicity against cancer cells, with the polyphenol fraction 75% being slightly more negative for cells. Propolis extracts at concentrations of 50, 75, and 100 µg/mL significantly reduced cell viability. With the exception of the MDA-MB-231 line, cell viability was also decreased after incubation with a concentration of 25 µg/mL. Our results suggest that propolis extracts obtained with the cold separation method may be considered as promising compounds for the production of health-promoting supplements.

Anticancer Effects of Propolis Extracts Obtained with the Cold Separation Method on PC-3 and DU-145 Prostate Cancer Cell Lines.

Plant extracts are increasingly tested for their biological activity and interactions with neoplastic cells. One of such sources of biologically active substances is propolis. This product has been known for thousands of years and is widely used in alternative, folk medicine. Articles describing its effects on the metabolism and cell signaling pathways of neoplastic cells derived from different organs are also published more and more frequently. The purpose of our study was to evaluate the biological activity of propolis extract produced with the cold separation method into hormone-dependent and hormone-independent prostate cancer cell lines. In our study, the propolis extracts showed at least an inhibitory effect on the growth of PC-3 and DU-145 neoplastic cells. Our results suggest that propolis extracts obtained with the cold separation method may be considered as promising compounds for the production of health-promoting supplements.

The Mitochondria-Independent Cytotoxic Effect of Leflunomide on RPMI-8226 Multiple Myeloma Cell Line.

Leflunomide, an anti-inflammatory agent, has been shown to be effective in multiple myeloma (MM) treatment; however, the mechanism of this phenomenon has not been fully elucidated. The aim of the study was to assess the role of mitochondria and dihydroorotate dehydrogenase (DHODH) inhibition in the cytotoxicity of leflunomide in relation to the MM cell line RPMI 8226. The cytotoxic effect of teriflunomide-an active metabolite of leflunomide-was determined using MTT assay, apoptosis detection, and cell cycle analysis. To evaluate DHODH-dependent toxicity, the cultures treated with teriflunomide were supplemented with uridine. Additionally, the level of cellular thiols as oxidative stress symptom was measured as well as mitochondrial membrane potential and protein tyrosine kinases (PTK) activity. The localization of the compound in cell compartments was examined using HPLC method. Teriflunomide cytotoxicity was not abolished in uridine presence. Observed apoptosis occurred in a mitochondria-independent manner, there was also no decrease in cellular thiols level. Teriflunomide arrested cell cycle in the G2/M phase which is not typical for DHODH deficiency. PTK activity was decreased only at the highest drug concentration. Interestingly, teriflunomide was not detected in the mitochondria. The aforementioned results indicate DHODH- and mitochondria-independent mechanism of leflunomide toxicity against RPMI 8226 cell line.

New benzenesulphonohydrazide derivatives as potential antitumour agents.

Cancer treatment remains a serious challenge worldwide. Thus, finding novel antitumour agents is of great importance. In the present study, nine new benzenesulphonohydrazide derivatives (1-9) were synthesized, and the chemical structures of the obtained compounds were confirmed by spectral analysis methods, including IR, 1H nuclear magnetic resonance (NMR) and 13C NMR. Experimental lipophilicity values were established using reversed phase-high performance thin layer chromatography. The antiproliferative activity of the synthesized compounds was tested against three tumour cell lines (769-P, HepG2 and NCI-H2170) and one normal cell line (Vero). Among the newly developed molecules, compound 4 exhibited generally the highest cytotoxicity across all tumour cell lines, and it was highly selective. However, higher selectivity towards the tested cancer cell lines was observed using compound 2, when compared with compound 4, which also exhibited significant antiproliferative activity against these tumour cells. In 769-P cells, compounds 5 and 6 were the most selective among all tested compounds. Compound 5 exhibited high cytotoxicity with an estimated IC50 value of 1.94 µM. In the NCI-H2170 cell line, compound 7 was the most cytotoxic and the most selective. In brief, the combination of fluorine and bromine substituents at the phenyl ring showed the most promising results, exerting high cytotoxicity and selectivity towards cancer cells. The renal adenocarcinoma cell line (769-P) appeared to be the most sensitive to the anticancer properties of the novel benzenesulphonohydrazones.

Synthesis and in vitro bioactivity study of new hydrazide-hydrazones of 5-bromo-2-iodobenzoic acid.

In this study 14 novel hydrazide-hydrazones of 5-bromo-2-iodobenzoic acid (3-16) were synthesized on the basis of condensation reaction. The chemical structure of obtained derivatives was established on the basis of spectral data (1H NMR and 13C NMR) and the lipophilicity of synthesized molecules was determined with the use of RP-HPTLC chromatography. Synthesized hydrazide-hydrazones (3-16) were subjected to in vitro cytotoxicity assay and antimicrobial activity analysis against a panel of bacteria and fungi. Among newly synthesized derivatives (3-16), compound 5 was characterized by high, selective and the most diverse cytotoxicity to the cancer cell lines. Molecules 7 and 9 which were substituted with a nitro group in the phenyl ring also exhibited very significant inhibitory effect in the tumor cells and they were very selective. Similarly, compound 13 showed high antiproliferative activity against both cancer cell lines (769-P, HepG2) with satisfactory selectivity. In turn, molecule 8 was characterized by lower inhibitory effect in tumor cells but high selectivity. Derivative 16 proved to be toxic mainly to 769-P cells plausibly by the inhibition of COX-2 mediated signalling pathway. In summary, the introduction of chloro substituent or nitro group to the molecule proved to be most advantageous, providing high cytotoxicity and selectivity to tumor cells. However, the presence of indole scaffold appeared to be responsible for COX-2 inhibitory effect. Some of synthesized hydrazide-hydrazones possessed also moderate antimicrobial activity against a panel of microorganisms.

Pioglitazone as a modulator of the chemoresistance of renal cell adenocarcinoma to methotrexate.

Kidney cancer is one of the most lethal urological malignancies associated with a high risk of mortality. Recent studies have shown that several antidiabetic drugs may limit the risk of the growth of different types of cancer. Pioglitazone (PIO) belongs to a novel class of antidiabetic drugs called thiazolidinediones (TZDs), which are commonly used in the treatment of type 2 diabetes. This drug has been demonstrated to exert an inhibitory effect on cell growth in colon, prostatic, breast and pancreatic cancer lines. The aim of the present study was to assess the inhibitory effect of PIO on the proliferation of the renal adenocarcinoma cell line 769­P. In addition, the proapoptotic potential of combined treatment with PIO and methotrexate (MTX) was evaluated, as well as the impact of the above drugs on the cell cycle of the 769­P cells. The present study showed that PIO efficaciously inhibited the proliferation and viability of renal cancer cells, and it induced sub­G1 cell cycle arrest and a decrease in the number of cells in the G2 phase, which indicated cytotoxic activity. PIO also exhibited proapoptotic properties at the lowest dose applied (10 µM). Furthermore, combined therapy with PIO and MTX increased the sensitivity of tumor cells to MTX while at the same time this combined therapy did not exhibit a cytotoxic effect to normal kidney cells. In renal adenocarcinoma cells, the combination of the above cytostatic agent at the lowest dose administered (MTX, 5 µM) with the peroxisome proliferator­activated receptor Î³ agonist PIO exhibited better efficacy in triggering the process of apoptosis than that displayed by MTX alone.

Edaravone presents antidepressant-like activity in corticosterone model of depression in mice with possible role of Fkbp5, Comt, Adora1 and Slc6a15 genes.

Chronic exposure to environmental-like stress leads to dysregulation of hypothalamic-pituitary-adrenal (HPA) axis and to appearance of oxidative stress, which is implicated in the development of depression-like behaviour. Edaravone (3-methyl-1-phenyl-2-pyrazoline-5-one) exhibits a neuroprotective effect attributed to the potent free radical scavenging. This study was designed to assess antidepressant-like activity of edaravone based on behavioural tests in the animal model of depression. Furthermore, to elucidate its mechanisms, the expression of Fkbp5, Comt, Adora and Slc6a15 genes involved in turnover of neurotransmitters was analysed. In order to evaluate the antioxidant features of edaravone, DNA's oxidative damage was determined. The mice were injected subcutaneously (sc) with 40 mg/kg corticosterone, chronically for 21 days. Paroxetine (10 mg/kg) (a selective serotonin reuptake inhibitor) and edaravone (10 mg/kg) were administered separately (ip) 30 min prior to the corticosterone injection. After 21-days of treatment with respective drugs, the mice were decapitated and the prefrontal cortex was rapidly dissected and used for determination of DNA's oxidative damage and the real-time PCR analysis. Edaravone ameliorated behavioural impairments in sucrose preference test (SPT) and forced swim test (FST). A possible role in Fkbp5, Comt, Adora1 and Slc6a15 genes' expression in mediating this effect is postulated. Both edaravone and paroxetine have no effect on corticosterone-induced DNA's oxidative damage.

Altered expression of genes involved in brain energy metabolism as adaptive responses in rats exposed to chronic variable stress; changes in cortical level of glucogenic and neuroactive amino acids.

Brain metabolism is closely associated with neuronal activity and enables the accurate synthesis and function of neurotransmitters. Although previous studies have demonstrated that chronic stress is associated with the overproduction of reactive oxygen species (ROS), which leads to oxidative stress and the disruption of glucose metabolism, the molecular mechanisms and cerebral gluconeogenesis in depression have not yet been completely elucidated. In order to examine this subject, the present study evaluated changes in the expression of selected genes involved in the glycolytic pathway and the levels of glucogenic and neuroactive amino acids in the brain of rats exposed to chronic variable stress. Male Wistar rats (50­55 days old, weighing 200­250 g) were divided into two groups: control and stressed, and the rats in the stressed group were exposed to stress conditions for 40 days. Depressive­like states were observed and recorded by measuring the body weight and forced swim test (FST). The mRNA levels of Slc2a3 (coding GLUT3) and Tfam (activator of mitochondrial transcription and a participant in mitochondrial genome replication) were markedly increased, while a decrease in the expression of Ldhb and GAPDH was also observed. These modifications were associated with the redirection of glucose metabolism to appropriate defensive pathways under chronic stress conditions, and an increased ability to maintain mitochondrial function as potential adaptive responses. A marked reduction of glucogenic and neuroactive amino acids levels indicate the support of energy metabolism by stimulation of the gluconeogenesis pathway. The findings of the present study provide a novel insight into the molecular and biochemical events that impact the development of depression under chronic stress conditions, and they may identify novel targets for therapeutic intervention.

Novel 2,3­disubstituted 1,3­thiazolidin­4­one derivatives as potential antitumor agents in renal cell adenocarcinoma.

Cancer represents one of the main causes of mortality in developed countries. In particular, the overall survival of patients with renal cell carcinoma (RCC) remains poor and the available cytostatic agents are insufficient. Therefore, there is an urgent requirement to identify more effective and safer anticancer drugs. Recently, the evaluation of antitumor activity appeared to be promising for thiazolidinone derivatives. The present study presents the synthesis and the cytotoxicity assays of 1,3­thiazolidin­4­ones. The newly synthesized substances were screened in vitro against selected cancer human renal cell adenocarcinoma cells (769­P), human hepatoblastoma­derived cells (HepG2) and normal green monkey kidney cells (GMK) as a reference cell line. N­[2­(4­methylphenyl)­4­oxo­1,3­thiazolidin­3­yl]acetamide and N­[2­(4­methylphenyl)­4­oxo­1,3­thiazolidin­3­yl]benzamide displayed significant antiproliferative activity towards 769­P. To elucidate the mechanisms of the cytotoxic actions, additional studies on the cell cycle and apoptosis were performed. The aforementioned compounds were responsible for G1 cell cycle arrest and the decrease in cell distribution in the G2 phase in a dose­dependent manner, which prevents mitotic divisions of the 769­P cells. In addition, these novel 2,3­disubstituted 1,3­thiazolidin­4­ones slightly induced apoptosis in 769­P in a dose­dependent manner. It was hypothesized that the 4­methylphenyl group at position 2 of the thiazolidin­4­one scaffold may be regarded as a promising moiety for further development of this group of compounds. Therefore, benzamide moiety appeared to be crucial for triggering cells to apoptotic cell death.

α-Tocopherol Ameliorates Redox Equilibrium and Reduces Inflammatory Response Caused by Chronic Variable Stress.

Chronic exposure to stress factors contributes to the development of depression by generating excess of reactive oxygen species which leads to oxidative stress and inflammatory processes. The aim of the study was to assess the potential protective properties of α-tocopherol supplementation on the rats exposed to chronic variable stress (CVS). Male Wistar rats (50-55 days old, weighing 200-250 g) were divided into three groups (n=10): control, stressed, and stressed and receiving (+)-α-tocopherol solution in a dose of 100 mg/kg/day. Rats in the stressed groups were exposed to CVS for 40 days. Markers of redox disorders (glutathione reduced and oxidized levels, GSH/GSSG ratio, glutathione peroxidase, glutathione reductase activities, total antioxidant status, and lipid peroxidation) and inflammatory response (IL-1ß, IL6, and TNF-α) were determined in the blood. Additionally, molecular biomarkers of depression (expression of Fkbp5 and Tph2) were studied in hippocampus. The biochemical analysis was inconclusive about the presence of oxidative stress in the blood of rats exposed to CVS. However, changes in all parameters suggest presence of redox equilibrium disorders. Similarly, activation of inflammatory processes was observed as a result of CVS. Molecular effects of environmental stress in hippocampus were also observed. Generally, α-tocopherol ameliorated redox equilibrium disorders, tempered inflammatory response, and protected from changes in determined molecular markers of depression.

Resveratrol Limits Lipogenesis and Enhance Mitochondrial Activity in HepG2 Cells.

PURPOSE: The aim of this study was to evaluate the effect of resveratrol on de novo lipogenesis in HepG2 cells caused by high glucose concentrations. Increased lipogenesis in the liver is the main reason for the development of nonalcoholic fatty liver disease (NAFLD) - currently one of the most common chronic liver diseases. In developed countries, this disease is mostly associated with nutritional disorders, resulting from the increasing consumption of monosaccharides. Resveratrol is a natural polyphenol with a promising potential for NAFLD treatment. METHODS: The steatosis of HepG2 cells was visualized using the intracellular lipid staining by Nile Red dye with a fluorescence microscope. This study also evaluated the effect of resveratrol on the mitochondrial activity (MitoTracker Green staining), dsDNA (Hoechst 33342 staining) and the viability of HepG2 cells treated with high glucose concentrations (25 and 33 mM). RESULTS: Current study showed that high glucose concentrations induced fat-overloading in HepG2 cells (microvacuolar steatosis occurred in most of the cells). Resveratrol (20 µM) limits the steatosis induction in HepG2 cells by glucose and increased the mitochondrial activity of cells. Resveratrol did not affect the viability of HepG2 cells. CONCLUSION: This beneficial effect could be helpful in the treatment of NAFLD.

Preliminary studies evaluating cytotoxic effect of combined treatment with methotrexate and simvastatin on green monkey kidney cells.

Patients, affected by neoplastic disease, take usually other drugs and this may lead to a number of often rather unpredictable interactions. The statins are among the most commonly prescribed drugs in medicine but have also adverse side effects and come into interactions with other drugs. The aim of this study was to investigate the cytotoxic effect of methotrexate (5.5 or 16.5 micromol/L), simvastatin (100 or 300 micromol/L) and their combination on green monkey kidney (GMK) cells culture using cytotoxicity detection kit LDH. Besides, the effect of above drugs on the cells viability was estimated by MTT test. After 6, 12 or 24 h of simultaneous incubation of GMK cells with methotrexate (5.5 micromol/L) and simvastatin (100 micromol/L) the cytotoxicity (about 10%) of the drugs was found in LDH test. Cytotoxicity of combination: methotrexate (5.5 micromol/L) with simvastatin (300 micromol/L) after 6 or 12 h of incubation with GMK cells was similar (about 10%), but after 24 h of incubation, cytotoxicity increased to 21%. The significant increase of the cytotoxicity (about 30%) was found after 24 h incubation of GMK cells with methotrexate (16.5 micromol/L) and simvastatin (100 micromol/L). In the MTT assay, the decrease in the cells viability was found also after 12 and 24 h of GMK cells incubation with methotrexate (5.5 or 16.5 micromol/L) and simvastatin (100 or 300 micromol/L). These results suggest the adverse effect of combined application of both drugs on GMK cells especially after 24 h of incubation.