Studies on immunomodulatory functions of lactoferrin under inflammatory stress in vitro and in vivo

• Main Authors: Wei-Siang Liao, 廖韋翔
• Other Authors: Jin-Yuarn Lin
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/37793461264005005458

碩士 === 國立中興大學 === 食品暨應用生物科技學系 === 96 === Lactoferrin is an iron-binding glycoprotein which exists in milk as well as other exocrine secretion in mammals. In recent years the study has indicated that lactoferrin might have multiple physiological functions such as antimicrobial, anti-tumor and immunomodulatory activities.To evaluate the effects of immounmodulatory, bovine and recombinant lactoferrin were first chosen to subject to different in vitro experimental models in this study. In an in vivo test, bovine lactoferrin was further investigated its immunomodulatory effects on lipopolysaccharide (LPS)-induced (i.p.) inflammation of mouse model. The results showed that bovine lactoferrin significantly inhibited splenocyte proliferation at concentrations of 31.3 and 125 μg/mL. However, the inhibitory function of lactoferrin was irrelevant to its iron absorption capacity. Recombinant human lactoferrin slightly increased cell viability of peritoneal cells at higher concentrations (1000 and 1250 μg/ml), suggesting that recombinant human lactoferrin might activate peritoneal cells. However, both bovine and recombinant human lactoferrin did not significantly affect the cell viability of inflamed splenocytes and peritoneal cells. Recombinant human lactoferrin (250 μg/ml) demonstrated a significant increased effect on inflammatory mediators (IL-1β、IL-6、IL-10、TNF-α) under different experimental models, but bovine lactoferrin did not. The results from in vivo study showed that bovine lactoferrin administration for 4 weeks decreased serum Ig A, Ig M and Ig G levels, but increased Ig E level at high dose feeding group. The results suggest that feeding with high concentrations (2.55 mg/ mouse) of lactoferrin for long term may induce allergic tendencies in vivo. Bovine lactoferrin administration did not significantly affect peritoneal cells and splenocytes from LPS-induced inflammation mice. In conclusion, bovine lactoferrin administration showed no significant improvement effects on LPS-induced systemic inflammation.