Yu-Lu Wei1, Jia-Ying Xu2, Ru Zhang3, Zheng Zhang3, Lin Zhao2, Li-Qiang Qin4. 1. Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, 215123, China; State Key Laboratory of Radiation Medicine and Protection, Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institution, Soochow University, Suzhou, 215123, China. 2. State Key Laboratory of Radiation Medicine and Protection, Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institution, Soochow University, Suzhou, 215123, China. 3. Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, 215123, China. 4. Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, 215123, China. Electronic address: qinliqiang@suda.edu.cn.
Abstract
OBJECTIVE: Intestinal injury is common after radiotherapy. We aim to investigate the effects of lactoferrin (Lf) on X-ray-induced intestinal injury in Balb/C mice. METHODS: In assessing animal survival, a total of 40 animals were assigned randomly to 8Gy group, 2 mg Lf+8Gy group, 4 mg Lf+8Gy group, and 6 mg Lf+8Gy group. Mice were administered with Lf intraperitoneally and exposed to single whole-body X-ray irradiation. Lf administration lasted for 3 days. Survival rate was compared among groups. For the observation of intestinal injury, a total of 60 animals were divided randomly into control group, 5Gy group, 2 mg Lf+5Gy group, and 4 mg Lf+5Gy group. Lf was administered once a day. Five mice in each group were randomly sacrificed at days 1, 3, and 9 after irradiation. Fasting blood was used to determine serum levels of pro-inflammatory cytokines IL-6 and TNF-α, and anti-inflammatorycytokine IL-10. Intestinal tissues were collected to examine histological changes and determine the protein expression levels of NF-κB, IKKα and IKKβ. RESULTS: Mean survival time was 4.30 ± 1.34, 4.20 ± 0.71, 5.75 ± 2.44 and 6.70 ± 2.54 days in four groups, respectively, with significantly longer duration in 6 mg Lf+8Gy group than in the 8Gy group. Survival rate was significantly higher in 4 mg Lf+8Gy group and 6 mg Lf+8Gy group, compared with the 8Gy group. For intestinal histology, the radiation-induced injury was considerably improved in the 2 mg Lf+5Gy and 4 mg Lf+5Gy groups. Villus length and its ratio to crypt depth significantly increased in the two Lf intervention groups. Compared with 5Gy group, serum levels of IL-6 and TNF-α significantly decreased in the two Lf intervention groups at days 3 and 9. Furthermore, Lf significantly reduced the radiation-induced expression of IKKα/β and NF-κB at day 3 and/or day 9. CONCLUSION: Lf extended the survival time of radiated mice and improved intestinal injury by decreasing inflammatory cytokines and downregulating NF-κB expression.
OBJECTIVE:Intestinal injury is common after radiotherapy. We aim to investigate the effects of lactoferrin (Lf) on X-ray-induced intestinal injury in Balb/C mice. METHODS: In assessing animal survival, a total of 40 animals were assigned randomly to 8Gy group, 2 mg Lf+8Gy group, 4 mg Lf+8Gy group, and 6 mg Lf+8Gy group. Mice were administered with Lf intraperitoneally and exposed to single whole-body X-ray irradiation. Lf administration lasted for 3 days. Survival rate was compared among groups. For the observation of intestinal injury, a total of 60 animals were divided randomly into control group, 5Gy group, 2 mg Lf+5Gy group, and 4 mg Lf+5Gy group. Lf was administered once a day. Five mice in each group were randomly sacrificed at days 1, 3, and 9 after irradiation. Fasting blood was used to determine serum levels of pro-inflammatory cytokines IL-6 and TNF-α, and anti-inflammatorycytokine IL-10. Intestinal tissues were collected to examine histological changes and determine the protein expression levels of NF-κB, IKKα and IKKβ. RESULTS: Mean survival time was 4.30 ± 1.34, 4.20 ± 0.71, 5.75 ± 2.44 and 6.70 ± 2.54 days in four groups, respectively, with significantly longer duration in 6 mg Lf+8Gy group than in the 8Gy group. Survival rate was significantly higher in 4 mg Lf+8Gy group and 6 mg Lf+8Gy group, compared with the 8Gy group. For intestinal histology, the radiation-induced injury was considerably improved in the 2 mg Lf+5Gy and 4 mg Lf+5Gy groups. Villus length and its ratio to crypt depth significantly increased in the two Lf intervention groups. Compared with 5Gy group, serum levels of IL-6 and TNF-α significantly decreased in the two Lf intervention groups at days 3 and 9. Furthermore, Lf significantly reduced the radiation-induced expression of IKKα/β and NF-κB at day 3 and/or day 9. CONCLUSION: Lf extended the survival time of radiated mice and improved intestinal injury by decreasing inflammatory cytokines and downregulating NF-κB expression.