Abstract:

Purpose: In order to infer the influence of casein glycomacropeptide (CGMP) on the cytokine network in rats treated
with dimethyl hydrazine, we studied the changes in cytokines in peripheral blood and colon of rats challenged with intraperitoneal
injection of dimethyl hydrazine, followed by intragastric administration of different doses of CGMP. Methods: A total of 60 Wistar
rats were randomly divided into five groups: normal, model, low dose CGMP, moderate dose CGMP and high dose CGMP groups.
The rats from all other groups except for the normal group were injected weekly with dimethyl hydrazine at 30 mg/kg bw. At
the same time, the rats in the low-, moderate- and high dose-CGMP groups were orally administered daily with CGMP at 10, 50
and 100 mg/(kg·d), respectively. Fifteen weeks later, the rats were killed and colon and serum samples were taken. The number
of colon aberrant crypt foci was counted, and the levels of cytokines in colon and peripheral blood were detected by using the
Luminex assay. Results: 1) no significant difference in body weight in rats among CGMP-treated and control groups was seen
whereas CGMP significantly reduced the levels of endotoxin and reactive oxygen species in a dose-dependent manner; 2) CGMP
significantly inhibited the formation of aberrant crypt foci (ACF) in a dose-dependent manner; 3) CGMP significantly inhibited
imbalance of Th1/Th2 cytokines in rats treated with dimethyl hydrazine in a dose-dependent manner. Conclusions: CGMP could
improve colon damage in rats treated with dimethyl hydrazine by effectively inhibiting the formation of ACF in a dose-dependent
manner, downregulating the levels of Th2 cytokines such as IL-4, and promoting the secretion of Th1 cytokines such as IL-2 to
improve the imbalance of the cytokine network.

Key words: casein glycomacropeptide (CGMP), cytokine network, aberrant crypt foci(ACF)