Curcumin (CMN) has been well studied due to its economic and medical importance. Traditional Egyptian Medicine claims the use of its powder against biliary disorders, anorexia, coryza, cough, diabetic wounds, hepatic disorder, rheumatism and sinusitis. The current study was designed to examine the possible beneficial effect of CMN in preventing the acute renal failure and related oxidative stress caused by chronic administration of cyclosporine (CsA) in rats. The study included two experiments, the first one was carried out to follow up the changes that could occur in kidney function as a result of cyclosporine (CsA) administration. Cyclosporine administration exerted significant (P< 0.01) elevation of serum urea, creatinine, potassium (K), parathormone (PTH), malondialdehyde (MDA) and asymmetrical dimethylarginine (ADMA). Meanwhile, cyclosporine treatment exerted significant (P< 0.01) decline in the level of serum sodium (Na) and total nitric oxide (NO), the content of kidney reduced glutathione (GSH) and the activities of glutathione peroxidase (G px), catalase (CAT) and superoxide dismutase (SOD) as compared with their corresponding normal rats. In the second experiment, the nephritic rats were treated with curcumin and remarkable corrections were occurred in all previous parameters. Thus, the current investigation was designed to examine the possible beneficial effect of CMN in preventing the renal failure and related oxidative stress caused by administration of CsA in rats.

The thioredoxin reductase gene TRR1 has been reported to be overexpressed when Candida albicans is exposed to oxidative stress. To elucidate the role of TRR1 in the response to oxidative stress and in the pathogenicity of C. albicans, we attempted to disrupt both alleles of this gene using gene-disruption cassettes containing LEU2 and HIS1 as selection markers. The disruption cassettes were transformed into C. albicans SN87 (leu2, his1) to knockout both TRR1 alleles. Despite the successful creation of heterozygous TRR1 mutants, several attempts to create homozygous mutants were unsuccessful, indicating that this gene is required for survival. Exposure to different concentrations of hydrogen peroxide indicated that the heterozygotic mutants, NZ1 (TRR1/trr1, LEU2/leu2) and NZ2 (TRR1/trr1, HIS1/his1), were more sensitive to oxidative stress, compared with wild-type. Virulence studies carried out in mice revealed that the average survival time of mice infected with wild-type C. albicans was 4 days, whereas the average survival time of mice infected with the NZ1 and NZ2 mutants was 17.2 and 16.8 days, respectively. These results indicate that TRR1 is crucial for C. albicans survival and pathogenicity.