Rats were fed semi-synthetic powdered diets containing 0% (Control) or 0.1% polyphenol extracts (Polyphenols) starting 3 days prior to CsA treatment (25 mg/kg, i.g. for 3 weeks). Tubules with and without injury, leukocytes, and TUNEL-positive cells in the cortex were counted in a blinded manner in 10 randomly selected fields per slide using a 40x objective lens after H&E and TUNEL staining, respectively. Percentages of tubules with injury are shown in A. The average numbers of leukocytes and TUNEL-positive cells per high power field (hpf) are shown in B and D, respectively. Cleaved caspase-3 (CC3) in kidney tissue was detected by immunoblotting (17 kDa) and quantified by densitometry (C). a, p<0.05 vs. control diet+vehicle; b, p<0.05 vs. polyphenol-containing diet+vehicle; c, p<0.05 vs. control diet+CsA (n = 4 per group).