Oral treatment of rats with bovine lactoferrin inhibits carrageenan-induced inflammation; correlation with decreased cytokine production.

The aim of this study was to investigate an effect of oral treatment of rats with bovine lactoferrin (BLF) on carrageenan-induced inflammation. Rats were given 5 oral doses of BLF (10 mg each) on alternate days and 24 h after the last dose a carrageenan inflammation was induced in the hind foot. Control rats were given 0.9% natrium chloride (NaCl) or bovine serum albumin (BSA). The magnitude of the reaction was measured after 2 h (optimal response) and expressed as an increase of the foot pad thickness in milimeters. The evaluation of BLF effects on carrageenan reaction was supplemented by determination of the ability of spleen cell cultures to produce interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) upon lipopolysaccharide (LPS) induction using bioassays. The results revealed an inhibition of the carrageenan-induced inflammation in BLF-treated rats by 50 and 40% as compared to NaCl and BSA control groups, respectively. The inhibition was also associated with a substantial decrease in the ability of splenocytes to produce IL-6 in BLF-treated rats (94 and 83% as compared to NaCl- and BSA-treated groups). The LPS-induced TNF-alpha production was also decreased, although to a lesser degree (48 and 35%, respectively). The decreased ability of spleen cells to produce inflammatory cytokines in BLF-treated rats indicates that hyporeactivity of the immune system cells may be the basis for the inhibition of carrageenan-induced inflammation.