Changes in renal pathology as a result of treatment with the ethyl acetate (EA) extract of Tripterygium wilfordii Hook F. (a) Kidney from the vehicle group showed glomerulonephritis, tubular dilation and atrophy, and heavy cell infiltration in perivascular and interstitial region. Kidney sections from the mice of the (b) EAlow and (c) EAhigh groups showed normal glomeruli and tubules. Slight cell infiltration in perivascular regions was seen in (b). Results shown are representative of 14 animals of each group. Arrows indicate representative glomeruli. (d) Glomerular, interstitial and perivascular disease was scored from (0) to (4+) as described in Materials and methods. Numbers of mice examined are indicated in parentheses. *p < 0.05, **p < 0.01, ***p < 0.001, EAlow or EAhigh versus vehicle. Original magnification × 400.