Effects of evening primrose oil and 5-fluorouracil on the healing of colonic anastomoses in rats

Aim: This study was designed to evaluate the efficacy of evening primrose oil (EPO) on colonic anastomosis. Methods: Sixty rats with colonic anastomosis were randomly divided into six groups. EPO and 5Fluorouracil (5-FU) were administered at doses of 5 g/kg/day and 20 mg/kg/day, respectively. Group 1 served as sham control. The rats in Group 2 (EPO) received EPO (14 days preoperatively), in Group 3 (Extended EPO) received EPO (14 days preoperatively and 7 days postoperatively), in Group 4 (5FU) received intraperitoneally 5-FU (5 days preoperatively), in Group 5 (5-FU+EPO) received EPO (14 days preoperatively), and 5-FU (5 days preoperatively), in Group 6 (5-FU+ extended EPO) received EPO (14 days preoperatively and 7 days postoperatively) and 5-FU (5 days preoperatively). Histopathological examination, bursting pressure, and hydroxyproline content were used for evaluation. Results: Significant differences were found between the Groups 1, 2, and 3 and Groups 4, 5, and 6 in bursting pressures. Polymorphonuclear leukocyte (PMNL) and lymphocyte infiltration was significantly less in group 3, compared to the control and group 2. The least PMNL infiltration was in group 6 compared to groups 4 and 5. The hydroxyproline level was different in group 3 compared to the control and group 2. Furthermore, groups 5 and 6 were different compared to group 4. Conclusion: EPO had favorable effects on colonic anastomosis even in groups where 5-FU was used.