Orally ingested lactoferrin and glycine display in vivo synergistic anti-inflammatory activity

There is a growing awareness of the interaction of food constituents with the immune system. The present studies aim to evaluate immunomodulatory effects of two of these nutritional components, i.e. glycine and lactoferrin. Mice orally supplemented with glycine, lactoferrin or a combination, were injected intradermally in the ear, with zymosan. Ear swelling (as a measure for inflammation) and the number of TNF-α producing spleen cells were analysed. In a collagen induced arthritis (CIA) model mice were orally supplemented with a combination of glycine and lactoferrin starting after the second collagen booster. Arthritis development was scored and the pro-inflammatory cytokine levels in the serum were detected. Glycine and lactoferrin were able to decrease the zymosan induced inflammatory response locally (decreased ear swelling) as well as systemically (reduced number of TNF-α producing spleen cells). Glycine effects (20, 50 and 100 mg/mouse/day) were concentration dependent whereas for lactoferrin only the lowest doses (0.1 and 1 mg/mouse/day) inhibited the inflammatory response significantly. Surprisingly higher doses of lactoferrin (5 and 25 mg/mouse/day) failed to influence the inflammatory reaction. A combination of both nutrients (lactoferrin 0.1 mg/mouse/day in combination with glycine 20 or 50 mg/mouse/day) inhibited the zymosan induced ear swelling synergistically. In the CIA model the combination of glycine and lactoferrin (lactoferrin 0.1 mg/mouse/day with glycine 20 mg/mouse/day) was able to inhibit arthritis development and decrease the level of pro-inflammatory cytokines in the serum. The present data indicate that the glycine-lactoferrin concept might offer in the near future a powerful nutritional way in modulating chronic inflammatory diseases.