The potential neuroprotective benefits of curcumin against cisplatin neurotoxicity were investigated. Curcumin is a polyphenol derived from the rhizome of Curcuma longa whose pharmacological effects include antioxidant, anti-inflammatory and anti-cancer properties. Cisplatin is a potent chemotherapeutic drug with activity against a wide variety of tumors, although it has notorious side effects. Cisplatin neurotoxicity is clinically evident in patients that have undergone a full course of chemotherapy and develop a peripheral neuropathy that may affect the treatment regimen and the patient's qualify of life. In this study, we examined whether curcumin can protect against cisplatin neurite outgrowth inhibition in PC12 cells, which is an indicator of the protective potential against neuropathy. We also investigated whether curcumin affects cisplatin effectiveness by analyzing the modulation of p53 gene expression and its effect on cisplatin cytotoxicity in HepG2 tumor cells. Non-cytotoxic concentrations of curcumin reduced in vitro neurotoxicity of cisplatin in PC12 cells. The treatment of PC12 cells with cisplatin (10μg/mL) significantly reduced neurite outgrowth. The tested concentration of curcumin (1.0 and 10μg/mL) did not result in neurite toxicity but nevertheless diminished cisplatin-induced inhibition of neurite outgrowth by up to 50% (p<0.05). Our results indicate that curcumin does not compromise cisplatin's anticancer activity. Curcumin neither suppressed p53 mRNA transcription nor protected tumor cells against cisplatin cytotoxicity. These results indicate that curcumin may reduce cisplatin-induced neurotoxicity, and clinical studies should potentially be considered.

Deficiency of vitamin D3, a lipophilic micronutrient, plays a role in the development of some chronic diseases. Vitamin D3 deficiency affects 25-50% of the human population and has been associated with increased risk for development of hypertension. DNA damage induced by reactive oxygen species (ROS) occurs more often in hypertensive than in normotensive individuals, and vitamin D3 status can influence this relationship. The aim of this study was to evaluate whether a diet supplemented with (10,000 IU/kg) or deficient in (0 IU/kg) vitamin D3, compared to a vitamin D3 control diet (1000 IU/kg), would modulate DNA damage and ROS production in spontaneously hypertensive rats (SHR) and normotensive control Wistar-Kyoto (WKY) rats after 12 weeks of treatment. ROS production was assessed by measuring the oxidative burst of neutrophils. DNA damage was evaluated using the comet assay in peripheral blood and the micronucleus test in bone marrow and peripheral blood. Vitamin D3 supplementation did not induce DNA damage and did not change neutrophil ROS production in SHR and WKY rats. Vitamin D3 deficiency induced neutrophil ROS production and a high frequency of micronucleus formation in the bone marrow and peripheral blood of SHR rats only, and induced DNA damage (comet) in peripheral blood of both SHR and WKY rats. In conclusion, vitamin D3 deficiency showed a more pronounced effect on hypertensive animals. Population studies are needed to test whether this relationship also exists in humans.

Curcumin (CMN) is the principal active component derived from the rhizome of Curcuma longa (Curcuma longa L.). It is a liposoluble polyphenolic compound that possesses great therapeutic potential. Its clinical application is, however, limited by the low concentrations detected following oral administration. One key strategy for improving the solubility and bioavailability of poorly water-soluble drugs is solid dispersion, though it is not known whether this technique might influence the pharmacological effects of CMN. Thus, in this study, we aimed to evaluate the antioxidant and antigenotoxic effects of CMN formulated in a solid dispersion (CMN SD) compared to unmodified CMN delivered to Wistar rats. Cisplatin (cDDP) was used as the damage-inducing agent in these evaluations. The comet assay results showed that CMN SD was not able to reduce the formation of cDDP-DNA crosslinks, but it decreased the formation of micronuclei induced by cDDP and attenuated cDDP-induced oxidative stress. Furthermore, at a dose of 50 mg/kg b.w. both CMN SD and unmodified CMN increased the expression of Tp53 mRNA. Our results showed that CMN SD did not alter the antigenotoxic effects observed for unmodified CMN and showed effects similar to those of unmodified CMN for all of the parameters evaluated. In conclusion, CMN SD maintained the protective effects of unmodified CMN with the advantage of being chemically water soluble, with maximization of absorption in the gastrointestinal tract. Thus, the optimization of the physical and chemical properties of CMN SD may increase the potential for the therapeutic use of curcumin.

No abstract

Objective To evaluate the induction of DNA damage in peripheral blood mononuclear cells of patients with sickle cell disease, SS and SC genotypes, treated with hydroxyurea.Methods The study subjects were divided into two groups: one group of 22 patients with sickle cell disease, SS and SC genotypes, treated with hydroxyurea, and a Control Group composed of 24 patients with sickle cell disease who were not treated with hydroxyurea. Peripheral blood samples were submitted to peripheral blood mononuclear cell isolation to assess genotoxicity by the cytokinesis-block micronucleus cytome assay, in which DNA damage biomarkers – micronuclei, nucleoplasmic bridges and nuclear buds - were counted.Results Patients with sickle cell disease treated with hydroxyurea had a mean age of 25.4 years, whereas patients with sickle cell disease not treated with hydroxyurea had a mean age of 17.6 years. The mean dose of hydroxyurea used by the patients was 12.8mg/kg/day, for a mean period of 44 months. The mean micronucleus frequency per 1,000 cells of 8.591±1.568 was observed in the Hydroxyurea Group and 10.040±1.003 in the Control Group. The mean frequency of nucleoplasmic bridges per 1,000 cells and nuclear buds per 1,000 cells for the hydroxyurea and Control Groups were 0.4545±0.1707 versus 0.5833±0.2078, and 0.8182±0.2430 versus 0.9583±0.1853, respectively. There was no statistically significant difference between groups.Conclusion In the study population, patients with sickle cell disease treated with the standard dose of hydroxyurea treatment did not show evidence of DNA damage induction.