Protective effect of aqueous saffron extract (Crocus sativus L.) and crocin, its active constituent, on renal ischemia-reperfusion-induced oxidative damage in rats

PURPOSE. The generation of reactive oxygen species and lipid peroxidation are associated with tissue injury following ischemic insult; therefore, the use of antioxidants appears rational in the improvement of kidney diseases therapy. The aim of the present study was to assess the effect of aqueous saffron extract (Crocus sativus L.) and its active constituent, crocin, on oxidative stress following renal ischemia-reperfusion injury (IRI) in rats. METHODS. The cellular redox status (thiobarbituric acid reactive species (TBARS) and total thiol levels) and antioxidant power (using ferric reducing/antioxidant power test) were assessed in control and ischemic groups. The left kidney was exposed to warm ischemia for 60 min followed by reperfusion for 90 min. The macerated aqueous extract of saffron (with doses of 5, 20 and 80 mg/kg, i.p.) and crocin (with doses of 50, 200 and 400 mg/kg, i. p.) were administrated prior to induction of ischemia. Normal saline (10 ml/kg, i. p.) was injected to control group and a sham group that did not have ischemia-reperfusion. RESULTS. Ischemia-reperfusion (IR) caused a significant increase in TBARS levels (p<0.001) and decrement in both antioxidant power ( FRAP value) (p<0.05) and total thiol concentration (p<0.001) in kidney homogenate samples. In crocin pretreated groups, a reduction in TBARS levels (from 85.8 +/- 5.4 to 20.9 +/- 1.5 nmol/g tissue, p<0.001; 400 mg/kg) and elevation in antioxidant power ( FRAP value) (from 3.05 +/- 0.16 to 4.15 +/- 0.16 mu mol/g tissue, p<0.001; 400 mg/kg) and total thiol concentrations (from 0.38 +/- 0.03 to 0.62 +/- 0.03 mM, p<0.001; 200 mg/ kg), as compared with control group, were observed. The aqueous extract also reduced lipid peroxidation products (from 85.8 +/- 5.4 to 15.9 +/- 2.6 nmol/g tissue, p<0.001; 80 mg/kg) and increased antioxidant power (from 2.98 +/- 0.11 to 5.97 +/- 0.56 mu mol/g tissue, p<0.001; 80 mg/ kg) in ischemia-reperfusion injured rat kidneys. CONCLUSION. This study therefore suggests that the aqueous saffron extract (Crocus sativus L.) and its active constituent, crocin, may be useful agents for the prevention of renal ischemia-reperfusion (IR)-induced oxidative injury in rats.