Therapeutic effect of recombinant human interleukin-11 and curcumin on jejunal damage in mice after neutron irradiation

Objective: To explore the therapeutic effect of recombinant human interleukin (rhIL-11) and curcumin on jejunal damage in mice after neutron irradiation. Methods: 140 male BALB/c mice were randomly divided into 4 groups: 20 mice in healthy control group, 60 mice in mere irradiation group, 30 mice in IL-11 treatment group and 30 mice in curcumin treatment group. The mere irradiation group mice were wholly exposed to 3 Gy neutron irradiation. The treatment groups mice were imtraperitoneally injected with rhIL-11 at the dosage of 500 μg·kg-1·d-1 and ourcumin of 200 mg·kg-1·/-1 through enterocoelia once a day for a d after irradiation. The mortality of the mice were observed. The mice in the control and mere irradiation groups were killed 6 h, 1, 3, and 6 d post-irradiation, respectively, and the mice of the 2 treatment groups were killed 3 and 6 d post-irradiation, respectively and the samples of jujunum were colleted. HE staining, argyrophilic of nucleolar organizer staining, Feulgen staining, and image analysis were used to observe the pathology and levels of argyrophilic proteins and DNA. Results: The mice in the mere irradiation group all died at 5 d post-irradiation, while 2 mice in the IL-11 treatment group and 3 in the curcumin group survived. Large area necrosis and exfoliation were found in the intestinal epithelial mucosa of the mere irradiated group mice since 6 h to 3 d after irradiation. Crypt cell regeneration was seen occasionally found 3 days later and much more 5 days later. Crypt cell regeneration was obviously found in the intestinal epithelial mucosa and lots of new villi were observed 5 d after irradiation in both treatment groups, however, the amounts of crypt cells and new villi of the curcumin treatment group were less than those of the IL-11 treatment group. The contents of AgNOR and DNA in the intestinal epithelial cells 5 days after irradiation of the 2 treatment groups were all significantly higher than those of the mere irradiation group (F=0.015-0.035, all P<0.05) but without significant differences between them. Conclusions: Jejunal damage in mice could be induced after 3 Gy neutron irradiation. rhIL-11 and curcumin might reduce the damage and promote the regeneration and repair of the intestinal epithelium. (authors)