Systemic oxidative stress induced by Diabetes and Residual Oil Fly Ash Inhalation

Abstract

The importance of evaluating the systemic effects of diabetic subjects exposed to air pollution is notorious, specially to the relevance that both factors have in the world socio‐economic scenario. The aim of the present study is to evaluate the effects of diabetes and chronic exposure to “residual oil fly ash” (ROFA) in the rat systemic oxidative stress. The animals were divided into four groups: diabetic: treated with ROFA (DM POL) − 50μg of ROFA/10μL of saline, intranasal instillation (i.n.); diabetic (DM NPOL) ‐ 10μL of saline, i.n; non‐diabetic treated with ROFA (ND POL) − 50μg of ROFA/10μL of saline, i.n. and non‐diabetic (ND NPOL) ‐ 10μL of saline, i.n., for 60 days. The diabetes was induced by 60mg/kg, i.p. streptozotocin administration. Blood sample was collected on the 30º and 60° days of treatment to evaluate SOD and catalase activity and the lipid peroxidation (through the concentration of malondialdeyde ‐MDA‐). After 30 days, we observed that ND POL animals showed higher levels of SOD comparing to the other groups (p<0.05) while catalase and MDA concentration did not show difference among the groups. After 60 days, the diabetic groups (DM POL and DM NPOL) showed increased levels of MDA. SOD activity was not statistically different among the groups (p> 0.05) while catalase showed statistically increased in the DM POL, DM NPOL and ND POL groups as compared to the control group ND NPOL (p<0.05). The global mortality rate of the DM POL group was 46% while in the other groups this rate was 0%. All deaths occurred after the 30° day of treatment with ROFA. The present study suggests that diabetic condition increases the susceptibility of health adverse effects induced by ROFA instillation and that oxidants could be involved in these effects.Support: FFFCMPA