## 3 Results
### In Vivo Studies  
After characterizing the materials, levels of renal MDA as an index of lipid peroxidation were evaluated in the different animal groups as shown in Figure 2. We observed a significant increase in the renal MDA content in the I/R group (\(p<0.001\)), which was due to the enhanced lipid peroxidation. Our results also indicate that the SP and NESP did not significantly alter the renal MDA contents (4.52 \(\pm\) 0.22 and 4.0 \(\pm\) 0.14 nmol/mg, respectively) compared to the control group (3.23 \(\pm\) 0.35 nmol/mg) (\(p=0.99\), \(p=0.94\), respectively). Even though the SP decreased the MDA levels in the I/R group (6.11 \(\pm\) 0.25 nmol/mg) compared to the untreated I/R group (8.42 \(\pm\) 0.45 nmol/mg) (\(p<0.05\)), there was still a significant difference in the MDA levels compared to the control group (3.23 \(\pm\) 0.35 nmol/mg) (\(p<0.05\)). However, the NESP in the I/R group completely normalized the increased MDA levels and, within this context, it can be asserted that there was no significant difference of NESP + I/R compared to the control group (\(p=0.98\)). Furthermore, there was a significant difference between the NESP-treated I/R group (3.9 \(\pm\) 0.34 nmol/mg) and SP-treated I/R group (6.11 \(\pm\) 0.25 nmol/mg) in renal MDA content as shown in Figure 2 (\(p<0.05\)). Figure 1: Dynamic Light Scattering autocorrelation function of microemulsions. Figure 3 shows the differences in the levels of GSH in the kidney of different animal groups. There was a significant decrease in the GSH content of I/R group (12.3 \(\pm\) 0.23 \(\mu\)mol/g) compared to the control rats (26.42 \(\pm\) 1.2 \(\mu\)mol/g) (\(p\) < 0.001). Administration of SP to I/R group increased the renal GSH content (18.0 \(\pm\) 0.31 \(\mu\)mol/g) compared to I/R group (12.3 \(\pm\) 0.23 \(\mu\)mol/g) (\(p\) < 0.05), but could not completely restore the decreased GSH content compared to the control rats (\(p\) < 0.01). However, oral administration of NESP to I/R rats corrected the decreased levels of GSH (25.0 \(\pm\) 0.56 \(\mu\)mol/g) without any significant difference compared to the control rat experiment (26.42 \(\pm\) 1.2 \(\mu\)mol/g) (\(p\) = 0.99). Furthermore, NESP administration to the I/R group induced greater increase in renal GSH (25.0 \(\pm\) 0.56) compared to the SP-treated I/R group (18 \(\pm\) 0.31) (\(p\) < 0.01). Administration of SP and NESP to healthy rats could not significantly alter renal GSH content compared to control rats (\(p\) = 1.0, \(p\) = 0.73, respectively) (Figure 3). Figure 3: Renal glutathione (GSH) levels in different animal groups (\(n\) = 8) at the end of interventions: Control, ischemic/reperfusion (I/R), spironolactone (SP), nano-encapsulated spironolactone (NESP), spironolactone-treated I/R (SP + I/R) and NESP-treated I/R (NESP + I/R) groups. **\(p\) < 0.01 and ***\(p\) < 0.001 (compared to control group). # \(p\) < 0.05 and ***\(p\) < 0.001 (compared to I/R group). **\(p\) < 0.01 (difference between SP-treated I/R group and NESP-treated I/R group). Figure 2: Levels of renal malondialdehydedehyde (MDA), an index of lipid peroxidation, in different animal groups (\(n\) = 8) at the end of interventions: Control, ischemic/reperfusion (I/R), spironolactone (SP), nano-encapsulated spironolactone (NESP), spironolactone-treated I/R (SP + I/R) and NESP-treated I/R (NESP + I/R) groups. *\(p\) < 0.05 and ***\(p\) < 0.001 (compared to control group). # \(p\) < 0.05 and ***\(p\) < 0.001 (compared to I/R group). # \(p\) < 0.05 and ***\(p\) < 0.001 (compared to I/R group). # \(p\) < 0.05 (difference between SP-treated I/R group and NESP-treated I/R group). Renal activities of SOD and CAT at the end of experiments have been demonstrated in Figure 4. There was a significant decrease in the renal SOD activity in thel/R group (7.1 \(\pm\) 0.23 U/mg) than the control group (11.59 \(\pm\) 0.11 U/mg) (_p_ < 0.001).