Objectives: 

Oral administration of bovine lactoferrin (LF) reduces deleterious effects of X-ray irradiation as well as the adverse side effects of anti-cancer drugs. Cytokines are involved in reproduction, growth and development, normal homeostatic regulation, response to damage repair, and host resistance. Therefore, this study aimed to investigate the effect of oral administration of LF on circulating cytokine levels in mice exposed to X-rays.

Materials: 

Male 3H/He mice aged 6 weeks were used for this experiment. Mice were divided into two groups: control and LF-administered groups. Control mice fed a commercial diet. LF-treated mice fed a commercial diet containing bovine LF (oral administration at 200 mg/kg body weight/day). After dietary treatment for 3 weeks, total-body irradiation of mice was performed with lethal dose (LD)50/30 (a radiation dose at which 50 percent lethality occurs at 30-day : Exp.1) or LD25/30 (Exp.2) values of 6.8 and 5.0 Gy, respectively. Blood samples were collected at day 5 in Exp. 1 and at days 5, 10 and 30 in Exp.2. Levels of plasma cytokines, tumor necrosis factor (TNF-alfa), interleukin (IL)-1alfa, IL-1beta, IL-2, IL-4, IL-6, IL-10, IL-12 and IL-18, were examined using an enzyme-linked immunosorbent assay.

Results: 

In Exp. 1, the survival rate at day 30 was 62% in the control and 85 percent in LF-administered group. In Exp. 2, control and LF-administered groups showed 80 percent and 100 percent survival rates, respectively. Oral administration of LF induced lowered plasma TNF-alfa and IL-6, and elevated IL-2, IL-4 and IL-10. X-ray irradiation induced increased IL-6, and decreased IL-1beta, IL-4 and IL-10. Pre-administration of LF elevated plasma IL-1beta, IL-12 and IL-18 in mice exposed to X-rays, though no significant effects were seen on plasma TNF-alfa, IL-1alfa, IL-2, IL-4, IL-6 and IL-10 levels.

Conclusions: 

These findings strongly suggest that LF reduces deleterious effects of X-ray irradiation on mouse by modulating the immune and inflammatory cytokine responses.