Effect of milk hydrolysates on inflammation markers and drug-induced transcriptional alterations in cell-based models

Nonsteroidal anti-inflammatory drugs (NSAID) are associated with gastrointestinal inflammation and subsequent damage to the intestinal tissue. Earlier studies in our laboratory have found that specific casein hydrolysates (CH) might be useful in the treatment of gastrointestinal wounds. The underlying mechanisms that support inflammation and wound healing are not completely understood, but transcriptional alterations may be used as markers for inflammation and wound healing. The bioactivity of 3 CH prepared by treatment of commercial casein with pepsin (60 min) followed by corolase (0, 10, or 60 min) were investigated in intestinal epithelial cells treated with the NSAID indomethacin. The bioactivity was evaluated as transcriptional alterations of transforming growth factor-β1 (TGF-β1), cyclooxygenase-2 (COX-2), peroxisome proliferator-activated receptor-γ (PPAR-γ) and nuclear factor κB (NFκB) by real-time PCR. Furthermore, the effect of CH on lipopolysaccharide-induced inflammation was evaluated in macrophages by measuring PG E(2) levels. Casein hydrolysates treated with corolase for 10 or 60 min after pepsin treatment downregulated transcription of TGF-β1 and NFκB (P < 0.05) compared with the hydrolysate treated with pepsin only. Hydrolysate prepared by corolase treatment for 60 min after pepsin hydrolysis downregulated transcription of COX-2 (P < 0.05) compared with hydrolysate treated with corolase for only 10 min whereas transcription of PPAR-γ was not affected (P > 0.05). Additionally, the hydrolysate prepared by pepsin treatment only (0 min corolase) had a pro-inflammatory effect on macrophages via PG E(2) stimulation (P < 0.05). In conclusion, CH produced by a combination of pepsin and corolase treatments downregulated the transcription levels of TGF-β1, COX-2, and NFκB.