Patients with constipation have slow waves in their gastrointestinal smooth muscles and less faecal water contents, which are closely associated with down-regulation of the interstitial cells of Cajal (ICC) in the gastrointestinal muscles and the aquaporin protein AQP3 expressed in colon epithelial cells.
Compared with the constipation model group, the mulberry-treated groups showed decreased aquaporin gene expression (Aqp3, Aqp4, Aqp8 and Aqp9), decreased serum levels of inhibitory neurotransmitters (nitric oxide and vasoactive intestinal peptide) (P < 0.05), and increased serum levels of excitability neurotransmitters (acetyl choline, substance P, and motilin).
The results of this study suggest that NAR relieves Lop-induced constipation by increasing the levels of interstitial cells of Cajal markers (c-Kit and SCF), as well as AQP3.