Objective: This experimental study was designed to determine the changes in tissue levels of malondialdehyde, end-product of lipid peroxidation (MDA), reduced glutathione (GSH) and xanthine oxidase (XO) and the effect of caffeic acid (3,4-dihydroxycinnamic acid) phenethyl ester (CAPE) on these metabolite levels after adnexal torsion-detorsion model in rats. Method: Forty adult female albino rats were divided into five groups: basal control (n = 8), sham operation (n = 8), torsion-detorsion plus saline (n = 8), torsion-detorsion plus CAPE (n = 8). and only torsion (n = 8). Rats in the sham operation group underwent a surgical procedure similar to the other groups but the adnexa was not torsioned. Rats in the torsion group were killed after 360degrees clockwise adnexal torsion for 3 It and ovaries were harvested. CAPE was injected intraperitoneally 30 min before detorsion in the CAPE/cletorsion group and saline was administered in the saline/detorsion group. After 3 h of adnexal detorsion, the rats in both groups were killed and adnexa were surgically removed. Results: MDA levels and XO activities in torsion-detorsion plus saline group increased significantly when compared to basal control, torsion and sham operation groups (P < 0.001). In the CAPE group, MDA levels and XO activities were lower than those of torsion-detorsion plus saline group, and differences between the two groups were statistically significant (P < 0.001). GSH levels in torsion-detorsion plus saline group were decreased significantly when compared to basal control and sham operation groups (P < 0.001). GSH levels in the CAPE group were higher than those of torsion-detorsion plus saline group, and differences between the two groups were statistically significant (P < 0.004). Morphologically, polymorphonuclear leukocytic infiltration and vascular dilatation were obvious in the ischernia-reperfusion damaged ovary, a change partially reversed by CAPE. Conclusions: These results suggest that administration of CAPE has beneficial effects in the prevention of ischemia-reperfusion injury of the ovaries. (C) 2004 Elsevier Ireland Ltd. All rights reserved.