Figure 1. Represented light microscopy of paraffin sections viewed under polarized light of rat kidneys in each groups. Arrows indicate the crystals in the cortex, tubular, and medulla (x40) of rat at 30 days. There were no deposits in intact control group (A). Ethylene-glycol-induced urolithic group showed significant increased levels of crystal deposits (B). Positive control group (k citrate, C); Preventive treated groups of Crocus sativus aqueous extract (25, 50 and 100 mg/kg, D, E, F respectively) and curative treated groups (50 and 100 mg/kg, G, H respectively).