Effects of hyaluronic acid and chondroitin sulfate on acute radiation proctitis in rats.

Background: This study was designed to investigate the prophylactic and therapeutic effects of hyaluronic acid and chondroitin sulfate combination (HA/CS) on a model of acute radiation proctitis.

Methods: Rats were divided into five groups: SHAM; irradiation (IR) + saline (1 mL for 5th and 10th day); IR + HA/CS (1 mL for 5th and 10th day). A single fraction of 17.5 Gy was delivered to each rat. HA/CS was administered rectally each day after irradiation. Each rat was observed daily for signs of proctitis. Irradiated rats were euthanized on days 5 and 10. The mucosal changes were evaluated macroscopically and pathologically.

Results: According to the clinical findings, five rats in the irradiation + saline group showed grade 3-4 symptoms on the 10th day. No significant difference in the macroscopic finding scores on the 5th day was observed between the irradiation + saline and irradiation + HA/CS groups. In the pathological examination, radiation-induced mucosal damage was the most prominent finding 10 days after irradiation in saline-treated rats. On the 10th day, the irradiation + HA/CS group showed mild inflammation and slight crypt changes, which corresponded to grade 1-2 pathological findings.

Conclusion: We think that HA/CS used in radiation cystitis can be beneficial for radiation proctitis.