Introduction. Nephrotoxicity is one of the important side effects of anthracycline antibiotics. The aim of this study was to investigate the effects of nicotinamide (NAD), an antioxidant agent, against nephrotoxicity induced by doxorubicin (DXR). Methods. The rats were divided into control, NAD alone, doxorubicin (20 mg/kg, i.p.) and DXR plus NAD (200 mg/kg, i.p.) groups. At the end of the 10th day, kidney tissues were removed for light microscopy and analysis. The level of tissues' catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), inducible nitric oxide (iNOS) and endothelial nitric oxide (eNOS) activities were determined. Results. The activities of CAT, GPx, and GSH were decreased, and Po was increased in renal tissue of doxorubicin group compared with other groups. The tissue of the doxorubicin group showed some histopathological changes such as glomerular vacuolization and degeneration, adhesion to Bowman's capsule and thickening and untidiness of tubular and glomerular capillary basement membranes. Histopathological examination showed that NAD prevented partly DXR-induced tubular and glomerular damage. Conclusions. Pretreatment with NAD protected renal tissues against DXR-induced nephrotoxicity. Preventive effects of NAD on these renal lesions may be via its antioxidant and anti-inflammatory action.

No abstract

Flavopiridol is a flavone that inhibits several cyclin-dependent kinases and exhibits potent growth-inhibitory activity, apoptosis and G1-phase arrest in a number of human tumor cell lines. Flavopiridol is currently undergoing investigation in human clinical trials. The present study focused on the effect of flavopiridol in cell proliferation, cell cycle progression and apoptosis in prostate cancer stem cells (CSCs). Therefore, cluster of differentiation 133 (CD133)+high/CD44+high prostate CSCs were isolated from the DU145 human prostate cancer cell line. The cells were treated with flavopiridol in a dose- and time-dependent manner to determine the inhibitory effect. Cell viability and proliferation were analyzed and the efficiency of flavopiridol was assessed using the sphere-forming assay. Flavopiridol was applied to monolayer cultures of CD133high/CD44high human prostate CSCs at the following final concentrations: 100, 300, 500 and 1000 nM. The cultures were incubated for 24, 48 and 72 h. The half maximal inhibitory concentration (IC50) value of the drug was determined as 500 nM for monolayer cells. Dead cells were analyzed prior and subsequent to exposure to increasing flavopiridol doses. Annexin-V and immunofluorescence analyses were performed for the evaluation of apoptotic pathways. According to the results, flavopiridol treatment caused significant growth inhibition at 500 and 1000 nM when compared to the control at 24 h. G0/G1 analysis showed a statistically significant difference between 100 and 500 nM (P<0.005), 100 and 1000 nM (P<0.001), 300 and 1000 nM (P<0.001), and 500 and 1000 nM (P<0.001). Flavopiridol also significantly influenced the cells in the G2/M phase, particularly at high-dose treatments. Flavopiridol induced growth inhibition and apoptosis at the IC50 dose (500 nM), resulting in a significant increase in immunofluorescence staining of caspase-3, caspase-8 and p53. In conclusion, the present results indicated that flavopiridol could be a useful therapeutic agent for prostate CSCs by inhibiting tumor growth and malignant progression, and inducing apoptosis.

The aim of this study is to evaluate the effects of hypercholesterolemia in thoracic aorta (TA), mesenteric artery (MA), renal artery (RA), and corpus cavernosum (CC) isolated from cholesterolfed rabbits. For determination of the maximum detrimental effect, vasorelaxation and vasoconstriction results of arteries and CC have been compared. Animals were fed with a diet that contained 2% w/w cholesterol and 2% w/w high cholesterol plus resveratrol (4 mg kg -1 per day) for 6-week duration. Total cholesterol levels in the plasma were measured. Vascular and endothelial functions in RA, TA, MA, and CC were assessed by isolated tissue bath with cumulative doses of acetylcholine and sodium nitroprusside. The statistical significance of differences of groups was analyzed by means of one-way ANOVA or Student's t-test. P-values o0.05 were considered significant. There have been no significant changes on plasma total cholesterol levels between cholesterol and cholesterol þ resveratrol-treated groups. Vasorelaxation responses to acetylcholine in resveratroltreated group showed significant changes when compared with hypercholesterolemic group. No statistically significant differences were seen between non-receptor-mediated vasorelaxation responses between the three groups. Resveratrol might be an effective treatment in the prevention of atherosclerotic changes in arteries and CC. The initial effects of hypercholesterolemia on erectile dysfunction and endothelial dysfunction may be precluded with resveratrol. This protective effect may also ensure the prevention of coronary arterial diseases and renovascular diseases in hypercholesterolemic patients.

Trabectedin (Yondelis, ET-743) is a marine-derived tetrahydroisoquinoline alkaloid. It is originally derived from the Caribbean marine tunicate Ecteinascidia turbinata and currently produced synthetically. Trabectedin is active against a variety of tumor cell lines growing in culture. The present study focused on the effect of trabectedin in cell proliferation, cell cycle progression, apoptosis and spheroid formation in prostate cancer stem cells (CSCs). Cluster of differentiation (CD) 133+high/CD44+high prostate CSCs were isolated from the DU145 and PC-3 human prostate cancer cell line through flow cytometry. We studied the growth-inhibitory effects of trabectedin and its molecular mechanisms on human prostate CSCs and non-CSCs. DU-145 and PC-3 CSCs were treated with 0.1, 1, 10 and 100 nM trabectedin for 24, 48 and 72 h and the growth inhibition rates were examined using the sphere-forming assay. Annexin-V assay and immunofluorescence analyses were performed for the detection of the cell death. Concentration-dependent effects of trabectedin on the cell cycle were also evaluated. The cells were exposed to the different doses of trabectedin for 24, 48 and 72 h to evaluate the effect of trabectedin on the number and diameter of spheroids. According to the results, trabectedin induced cytotoxicity and apoptosis at the IC50 dose, resulting in a significant increase expression of caspase-3, caspase-8, caspase-9, p53 and decrease expression of bcl-2 in dose-dependent manner. Cell cycle analyses revealed that trabectedin induces dose-dependent G2/M-phase cell cycle arrest, particularly at high-dose treatments. Three-dimensional culture studies showed that trabectedin reduced the number and diameter of spheroids of DU145 and PC3 CSCs. Furthermore, we have found that trabectedin disrupted cell-cell interactions via E-cadherin in prostasphere of DU-145 and PC-3 CSCs. Our results showed that trabectedin inhibits cellular proliferation and accelerates apoptotic events in prostate CSCs; and may be a potential effective therapeutic agent against prostate cancer.