Protective effects of increasing vitamin E and a doses on cisplatin-induced oxidative damage to kidney tissue in rats.

OBJECTIVE: Cisplatin (DDP, cis-diamminedichloroplatinium II) is one of the most potent chemotherapeutic antitumor drugs, but is able to generate reactive oxygen species (ROS) and it also inhibits the activity of antioxidant enzymes in renal tissue. In the present study, we investigated the preventive effect of 100, 200 and 400 mg/kg b.w. doses of vitamin E (VE), and 25, 50, and 100 mg/kg b.w. doses of vitamin A (VA) combination on malondialdehyde (MDA), nitric oxide (NO), and glutathione (GSH) levels and superoxide dismutase (SOD) activity in cisplatin-induced toxicity in rat kidneys. Our literature survey indicated a lack of any experimental study showing the beneficial effect of VA on cisplatin-induced MDA, NO, GSH and SOD changes. For this reason, we hoped that this study would provide a unique contribution in that respect. MATERIALS AND METHODS: 59 Wistar rats (11 to replace prematurely lost animals) were used. 48 evaluable rats were divided into 8 groups (n = 6 in each group): control group, DDP alone (5 mg/kg b.w.) group, 3 VE combination treatment groups of VE100+DDP, VE200+DDP, and VE400+DDP, and 3 VA combination treatment groups of VA25+DDP, VA50+DDP, and VA100+DDP. Kidney MDA, GSH, NO levels and SOD activities were determined for the assessment of oxidant-antioxidant balance. RESULTS: While in the DDP group the tissue levels of MDA and NO were found to be significantly higher than in the control group, GSH levels and SOD activities were significantly lower. MDA and NO levels were found to be significantly lower and GSH levels and SOD activities significantly higher in the VE200+DDP and VE400+ DDP groups when compared with the DDP alone group. MDA and NO levels were found to be significantly lower in the VA50+DDP and VA100+DDP groups when compared with the DDP alone group. However, identical comparisons with the DDP alone group showed significantly higher GSH levels and SOD activities in the VA25+DDP, VA50+DDP, and VA100+DDP groups. Among the VE100+ DDP, VE200+DDP, and VE400+DDP groups, and VA25+ DDP, VA50+DDP, and VA100+DDP groups, MDA and NO levels decreased and GSH levels and SOD activities increased steadily and significantly as the doses of VE and VA increased. CONCLUSION: These vitamins would be effective in protecting against cisplatin-induced tissue damage in rat kidneys. It is possible that the toxic effect of cisplatin is somehow minimized by a compensatory mechanism involving VE and VA via induction of antioxidant enzyme activities following intraperitoneal injection of DDP.

Effects of vitamin A on doxorubicin-induced chromosomal aberrations in bone marrow cells of rats.

The present study was carried out to evaluate the role of vitamin A (VA) on the induction of chromosomal aberrations (CA) in rat bone marrow cells and to investigate its modulating effect on chromosomal damage induced by doxorubicin (DXR). Wistar rats were treated with VA (7.5, 15 and 30 microg/kg body wt) once a day for 2 days by gavage before injecting DXR (90 mg/kg body wt). Rats in the control group were treated with corresponding doses of water and olive oil. Animals treated with the medium dose of VA (15 microg/kg body wt) plus single dose of DXR presented a statistically significant reduction in total number of CA and in number of abnormal metaphases (P < 0.05). However, when compared with control and DXR groups, the low and high VA doses (7.5 and 30 microg/kg body wt) were found to be less efficient than the medium dose VA (15 microg/kg body wt) in terms of parameters analyzed. Furthermore, the high dose of VA group (30 microg/kg body wt) was found to be clastogenic (P < 0.05). This study concludes that the protective effect of VA against chromosome damage is dose dependent.