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.

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.

New hydrazide-hydrazones and 1,3-thiazolidin-4-ones with 3-hydroxy-2-naphthoic moiety: Synthesis, in vitro and in vivo studies.

In this research we synthesized, identified and evaluated new hydrazide-hydrazones (1-3) and 1,3-thiazolidin-4-one derivatives (4-6) for in vitro and in vivo activity. New hydrazide-hydrazones (1-3) were obtained by the condensation reaction of 3-hydroxy-2-naphthoic acid hydrazide with appropriate aldehydes. Synthesized hydrazide-hydrazones (1-3) were subjected to cyclization reaction with mercaptoacetic acid which afforded with new 1,3-thiazolidin-4-one derivatives (4-6). Among 1,3-thiazolidin-4-one derivatives tested (4-6), compound 6 exhibited highest and most selective cytotoxicity towards human renal adenocarcinoma cells (769-P) and it did not affect the growth of normal cells (H9c2, GMK). Whereas its hydrazide-hydrazone (compound 3) showed significant antiproliferative activity against both tested human cancer cell lines: renal adenocarcinoma (769-P) and hepatocellular carcinoma (HepG2), however with less selectivity. The in vivo studies focused on the antinociceptive activity of newly synthesized 1,3-thiazolidin-4-one derivatives (4-6). The preliminary screening of novel compounds showed that 1,3-thiazolidin-4-one derivatives (4-6) are safe and not toxic against CNS of mice. Among tested derivatives one compound (6) displayed significant analgesic activity.

The beneficial effects of resveratrol on steatosis and mitochondrial oxidative stress in HepG2 cells.

Nonalcoholic fatty liver disease (NAFLD) is currently one of the most common chronic liver diseases, especially in developed countries. One group of substances with a potential use in the treatment of NAFLD are plant polyphenols, represented by resveratrol. The aim of this study was to evaluate the effect of resveratrol on steatosis and oxidative stress in HepG2 cells. The steatosis of cells was carried out using free fatty acids: oleic or palmitic acid and their mixtures. Steatosis was visualized using the intracellular lipid staining by Nile Red dye with a fluorescence microscope. This study also determined the viability of cells and mitochondrial membrane potential. The current study showed that fatty acids and their mixtures induced fat overloading in HepG2 cells. In the group of cells incubated with oleic acid (OA), observed changes were moderate with prevailing micro-vesicular steatosis. In case of cells incubated with palmitic acid (PA) and the mixtures of fatty acids, micro- and macro-vacuolar steatosis occurred in most of the cells. Resveratrol decreased steatosis in HepG2 cells induced by OA, PA, as well as their mixtures, and in most of experimental groups did not reduce cells viability. Resveratrol reduced the oxidative stress in HepG2 cells treated with fatty acids mixtures.