Objective: To investigate the nephroprotective effect of quercetin (QT) against renal injury induced by titanium dioxide nanoparticles (NTiO2) in rats.
Methods: NTiO2-intoxicated rats received 50 mg/kg of NTiO2 for seven days. The QT + NTiO2 group was pretreated with QT for seven days before being administered NTiO2. Uric acid, creatinine, and blood urea nitrogen were considered to be biomarkers of nephrotoxicity. Catalase (CAT) and superoxide dismutase (SOD) activities and renal levels of malondialdehyde (MDA) were measured to assess the oxidative stress caused by NTiO2.
Results: NTiO2 significantly increased the plasma level of the biomarkers. It also significantly decreased the activities of CAT (P = 0.008) and SOD (P = 0.004), and significantly increased the MDA levels (P = 0.007). NTiO2 caused proximal tubule damage, the accumulation of red blood cells, the infiltration of inflammatory cells, and reduced the glomerular diameters, as well as induced apoptosis in the proximal tubules. Pre-treatment with QT attenuated the histological changes, normalised the plasma biomarkers, suppressed oxidative stress, ameliorated the activities of CAT (P = 0.007) and SOD (P = 0.006), and reduced apoptosis (P < 0.001).
Conclusion: QT was found to have a potent protective effect against nephrotoxicity induced by NTiO2 in rats. It also reduced apoptosis caused by NTiO2.
MATERIALS AND METHODS: Thirty-five inbred female Sprague Dawley rats aged 43 days were administered with three weekly doses of N-methyl-N-nitrosourea (NMU) intraperitoneally (ip) at 50 mg/kg body weight. Animals were randomized (beginning from 10 mm tumor size) into four TAM-treated (50, 100, 200 and 500 μg/day) groups of six animals each, and another group (n=6) treated with TAM 100 μg/day at starting tumour size of 15 mm. The animals were treated by oral gavage daily for 8 weeks before sacrifice.
RESULTS: Serum urea and creatinine, and overall physical tumor burden were significantly modulated in animals treated with variable doses of TAM compared to the untreated controls (n=5). Final body weight and tumor number were significantly different in the 10 mm-treated animals compared to those treated at 15 mm. There were no significant differences in histopathological features among all the groups.
CONCLUSIONS: Our findings suggest the importance of standardizing tumour size and drug doses before initiation of treatment, particularly in the direct comparison of basic end-tumour physical parameters.