Antineoplastic activity of a novel ruthenium complex against human hepatocellular carcinoma (HepG2) and human cervical adenocarcinoma (HeLa) cells.

Novel metal complexes have received much attention recently because of their potential anticancer activity. Notably, ruthenium-based complexes have emerged as good alternatives to the currently used platinum-based drugs for cancer therapy, with less toxicity and fewer side effects. The beneficial properties of Ru, which make it a highly promising therapeutic agent, include its variable oxidative states, low toxicity, and high selectivity for cancer cells. The present study evaluated the cytotoxic effects of a ruthenium complex, namely cis-[Ru(1,10-phenanthroline)2(imidazole)2]2+ (RuC), on human hepatocellular carcinoma (HepG2) and human cervical adenocarcinoma (HeLa) cells and analyzed metabolic parameters. RuC reduced HepG2 and HeLa cell viability at all tested concentrations (10, 50, and 100 nmol/L) at 48 h of incubation, based on the MTT, Crystal violet, and neutral red assays. The proliferation capacity of HepG2 cells did not recover, whereas HeLa cell proliferation partially recovered after RuC treatment. RuC also inhibited all states of cell respiration and increased the levels of the metabolites pyruvate and lactate in both cell lines. The cytotoxicity of RuC was higher than cisplatin (positive control) in both lineages. These results indicate that RuC affects metabolic functions that are related to the energy provision and viability of HepG2 and HeLa cells and is a promising candidate for further investigations that utilize models of human cervical adenocarcinoma and mainly hepatocellular carcinoma.

Effects of silymarin on angiogenesis and oxidative stress in streptozotocin-induced diabetes in mice.

The present study evaluated the effects of acute treatment with silymarin, an extract that is obtained from Silybum marianum, on angiogenesis, oxidative stress, and inflammation in normoglycemic and diabetic mice. Diabetes was induced by streptozotocin (80 mg/kg, intraperitoneal) in male Swiss mice, 6 weeks of age. A polyether-polyurethane sponge was surgically implanted in the back of the mice as a model of healing in both diabetic and normoglycemic animals that were treated with oral silymarin or water for 10 days. The pancreas, liver, kidneys, blood, and sponges were collected and analyzed. Diabetes led to impairments of antioxidant defenses, reflected by a reduction of pancreatic superoxide dismutase and hepatic and renal catalase and an increase in pancreatic lipoperoxidation. An inflammatory process was observed in diabetic mice, reflected by an increase in pancreatic tumor necrosis factor α (TNF-α) and the infiltration of inflammatory cells in islets. The number of vessels was lower in the implanted sponges in diabetic mice. Silymarin treatment attenuated this damage, restoring antioxidant enzymes and reducing pancreatic TNF-α and inflammatory infiltration. However, silymarin treatment did not restore angiogenesis or glycemia. In conclusion, treatment with silymarin red uced oxidative stress and inflammation that were induced in the model of streptozotocin-induced diabetes in several organs, without apparent toxicity. Silymarin may be a promising drug for controlling diabetic complications.

Ruthenium complex exerts antineoplastic effects that are mediated by oxidative stress without inducing toxicity in Walker-256 tumor-bearing rats.

The present study evaluated the in vivo antitumor effects and toxicity of a new Ru(II) compound, cis-(Ru[phen]2[ImH]2)2+ (also called RuphenImH [RuC]), against Walker-256 carcinosarcoma in rats. After subcutaneous inoculation of Walker-256 cells in the right pelvic limb, male Wistar rats received 5 or 10mgkg-1 RuC orally or intraperitoneally (i.p.) every 3 days for 13 days. A positive control group (2mgkg-1 cisplatin) and negative control group (vehicle) were also used. Tumor progression was checked daily. After treatment, tumor weight, plasma biochemistry, hematology, oxidative stress, histology, and tumor cell respiration were evaluated. RuC was effective against tumors when administered i.p. but not orally. The highest i.p. dose of RuC (10mgkg-1) significantly reduced tumor volume and weight, induced oxidative stress in tumor tissue, reduced the respiration of tumor cells, and induced necrosis but did not induce apoptosis in the tumor. No clinical signs of toxicity or death were observed in tumor-bearing or healthy rats that were treated with RuC. These results suggest that RuC has antitumor activity through the modulation of oxidative stress and impairment of oxidative phosphorylation, thus promoting Walker-256 cell death without causing systemic toxicity. These effects make RuC a promising anticancer drug for clinical evaluation.

Selective Cytotoxicity of 1,3,4-Thiadiazolium Mesoionic Derivatives on Hepatocarcinoma Cells (HepG2).

In this work, we evaluated the cytotoxicity of mesoionic 4-phenyl-5-(2-Y, 4-X or 4-X-cinnamoyl)-1,3,4-thiadiazolium-2-phenylamine chloride derivatives (MI-J: X=OH, Y=H; MI-D: X=NO2, Y=H; MI-4F: X=F, Y=H; MI-2,4diF: X=Y=F) on human hepatocellular carcinoma (HepG2), and non-tumor cells (rat hepatocytes) for comparison. MI-J, M-4F and MI-2,4diF reduced HepG2 viability by ~ 50% at 25 µM after 24-h treatment, whereas MI-D required a 50 µM concentration, as shown by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. The cytotoxicity was confirmed with lactate dehydrogenase assay, of which activity was increased by 55, 24 and 16% for MI-J, MI-4F and MI-2,4diF respectively (at 25 µM after 24 h). To identify the death pathway related to cytotoxicity, the HepG2 cells treated by mesoionic compounds were labeled with both annexin V and PI, and analyzed by flow cytometry. All compounds increased the number of doubly-stained cells at 25 µM after 24 h: by 76% for MI-J, 25% for MI-4F and MI-2,4diF, and 11% for MI-D. It was also verified that increased DNA fragmentation occurred upon MI-J, MI-4F and MI-2,4diF treatments (by 12%, 9% and 8%, respectively, at 25 µM after 24 h). These compounds were only weakly, or not at all, transported by the main multidrug transporters, P-glycoprotein, ABCG2 and MRP1, and were able to slightly inhibit their drug-transport activity. It may be concluded that 1,3,4-thiadiazolium compounds, especially the hydroxy derivative MI-J, constitute promising candidates for future investigations on in-vivo treatment of hepatocellular carcinoma.

Uncaria tomentosa exerts extensive anti-neoplastic effects against the Walker-256 tumour by modulating oxidative stress and not by alkaloid activity.

This study aimed to compare the anti-neoplastic effects of an Uncaria tomentosa (UT) brute hydroethanolic (BHE) extract with those of two fractions derived from it. These fractions are choroformic (CHCl3) and n-butanolic (BuOH), rich in pentacyclic oxindole alkaloids (POA) and antioxidant substances, respectively. The cancer model was the subcutaneous inoculation of Walker-256 tumour cells in the pelvic limb of male Wistar rat. Subsequently to the inoculation, gavage with BHE extract (50 mg.kg(-1)) or its fractions (as per the yield of the fractioning process) or vehicle (Control) was performed during 14 days. Baseline values, corresponding to individuals without tumour or treatment with UT, were also included. After treatment, tumour volume and mass, plasma biochemistry, oxidative stress in liver and tumour, TNF-α level in liver and tumour homogenates, and survival rates were analysed. Both the BHE extract and its BuOH fraction successfully reduced tumour weight and volume, and modulated anti-oxidant systems. The hepatic TNF-α level indicated a greater effect from the BHE extract as compared to its BuOH fraction. Importantly, both the BHE extract and its BuOH fraction increased the survival time of the tumour-bearing animals. Inversely, the CHCl3 fraction was ineffective. These data represent an in vivo demonstration of the importance of the modulation of oxidative stress as part of the anti-neoplastic activity of UT, as well as constitute evidence of the lack of activity of isolated POAs in the primary tumour of this tumour lineage. These effects are possibly resulting from a synergic combination of substances, most of them with antioxidant properties.

Effects of statins on liver cell function and inflammation in septic rats.

BACKGROUND: Several studies suggest that the presence of statins may be beneficial during sepsis, but this idea is controversial. The aim of this study was to investigate the effects of long-term statin treatment in the livers of septic animals, focusing on its antioxidant, antiinflammatory, and metabolic properties. MATERIALS AND METHODS: Male Wistar rats were treated orally with simvastatin, atorvastatin, or vehicle once a d. After 30 d, sepsis was induced by cecal ligation and puncture (CLP) in Control, Simvastatin-treated, and Atorvastatin-treated groups, while the Sham group underwent only laparotomy. The Basal Simvastatin and Basal Atorvastatin groups received only their respective drugs without surgery. Twenty-four h after CLP or laparotomy, samples were collected from anesthetized rats for evaluation of hepatic oxidative stress, liver histology, hepatic mitochondria enzyme activity, leukocyte counts in blood and peritoneal cavity, gene expression of hepatic superoxide dismutase and TNF-2, and plasma biochemistry. RESULTS: Most parameters that we tested exhibited expected changes upon sepsis induction. However, statin treatment only improved liver mitochondrial enzymatic activity. In other parameters, simvastatin and atorvastatin failed to protect the liver against injuries incurred upon the CLP-induced polymicrobial sepsis model. CONCLUSIONS: Pretreatment with simvastatin or atorvastatin alone before sepsis induction improved mitochondrial activity in the liver; however, this result was not reproduced in other biomarkers of liver function and leukocyte migration during sepsis. Future studies should be performed to evaluate whether statins can be combined with other drugs to increase the efficacy of sepsis therapy.