Effects of beta-D-glucan on steroid-induced impairment of colonic anastomotic healing.

BACKGROUNDS/AIMS: Inflammation during the early phase of anastomotic wound healing is an essential cellular response and is suppressed by corticosteroids. The anti-inflammatory effect of corticosteroids is largely responsible for its impairment of wound healing in bowel anastomosis. Beta-D-glucan, a commonly used macrophage activator, has been shown to improve anastomotic wound healing under normal conditions. In the present study, we have investigated the effects of beta-D-glucan on anastomotic wound healing in rats treated with long-term corticosteroid. METHODOLOGY: 92 male Sprague-Dawley rats were randomized into four groups. 1 : control, 2: control + beta-D-glucan, 3 : steroid, 4 : steroid + beta-D-glucan. Methylprednisolone (5mg/kg) was injected IM daily for 14 days in groups 3 and 4. After 14 days, following anaesthesia and laparotomy, colonic anastomosis was performed 3 cm away from the peritoneal reflection of rectum. In groups 2 and 4, 100mg/kg beta-D-glucan was administered orally for 7 days before laparotomy. On postoperative day 3, relaparotomies were performed and bursting pressures, hydroxyproline levels and histopathological specimens were studied. RESULTS: The mean values of bursting pressures groups were 50.8 (95% CI 46.99-56.50), 58.2 (95% CI 54.49-61.90), 32.0 (95% CI 29.21-34.98), 45.9 (95% CI 43.09-48.80) respectively. The differences of the mean values of the groups between group 1 and 2 and also 3 were significant (p = 0.002, p < 0.001). The mean values of hydroxyproline of the groups were 3.8 (95% CI 3.56-4.06), 4.7 (95% CI 4.50-5.04), 2.9 (95% CI 2.73-3.20), 3.9 (95% CI 3.65-4.22) respectively. The differences of the values of the groups between control (group1) and group 2 and also group 3 were significant (p = 0.001, p < 0.001). In histopathological examination, increased macrophages and fibroblast population were observed in specimens from beta-D-glucan-treated animals. CONCLUSION: The results indicate that in rat model, oral administration of beta-D-glucan causes a significant improvement in the healing of anastomotic wound impaired by long-term corticosteroid administration.