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).
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.
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.