Obestatin Accelerates the Healing of Acetic Acid-Induced Colitis in Rats

Abstract

Obestatin, a 23-amino acid peptide derived from the proghrelin, has been shown to exhibit some protective and therapeutic effects in the gut. The aim of present study was to determine the effect of obestatin administration on the course of acetic acid-induced colitis in rats. Materials and Methods. Studies have been performed on male Wistar rats. Colitis was induced by a rectal enema with 3.5% acetic acid solution. Obestatin was administered intraperitoneally twice a day at a dose of 8 nmol/kg, starting 24 h after the induction of colitis. Seven or 14 days after the induction of colitis, the healing rate of the colon was evaluated. Results. Treatment with obestatin after induction of colitis accelerated the healing of colonic wall damage and this effect was associated with a decrease in the colitis-evoked increase in mucosal activity of myeloperoxidase and content of interleukin-1β. Moreover, obestatin administration significantly reversed the colitis-evoked decrease in mucosal blood flow and DNA synthesis. Conclusion. Administration of exogenous obestatin exhibits therapeutic effects in the course of acetic acid-induced colitis and this effect is related, at least in part, to the obestatin-evoked anti-inflammatory effect, an improvement of local blood flow, and an increase in cell proliferation in colonic mucosa.

Figure 1

Effect of saline or obestatin given intraperitoneally for 7 or 14 days on the area of colonic lesions in rats without or with acetic acid-induced colitis. Mean value ± SEM. N = 10 animals in each experimental group and each time of observation. ^a P < 0.05 compared to control at the same time of observation; ^b P < 0.05 compared to colitis plus saline at the same time of observation.

Figure 2

Effect of saline or obestatin given intraperitoneally for 7 or 14 days on the rate of DNA synthesis in colonic mucosa in rats without or with acetic acid-induced colitis. Mean value ± SEM. N = 10 animals in each experimental group and each time of observation. ^a P < 0.05 compared to control at the same time of observation; ^b P < 0.05 compared to colitis plus saline at the same time of observation.

Figure 3

Effect of saline or obestatin given intraperitoneally for 7 or 14 days on mucosal blood flow in the colon rats without or with acetic acid-induced colitis. Mean value ± SEM. N = 10 animals in each experimental group and each time of observation. ^a P < 0.05 compared to control at the same time of observation; ^b P < 0.05 compared to colitis plus saline at the same time of observation.

Figure 4

Effect of saline or obestatin given intraperitoneally for 7 or 14 days on interleukin-1β concentration in colonic mucosa in rats without or with acetic acid-induced colitis. Mean value ± SEM. N = 10 animals in each experimental group and each time of observation. ^a P < 0.05 compared to control at the same time of observation; ^b P < 0.05 compared to colitis plus saline at the same time of observation.

Figure 5

Effect of saline or obestatin given intraperitoneally for 7 or 14 days on myeloperoxidase activity in colonic mucosa in rats without or with acetic acid-induced colitis. Mean value ± SEM. N = 10 animals in each experimental group and each time of observation. ^a P < 0.05 compared to control at the same time of observation; ^b P < 0.05 compared to colitis plus saline at the same time of observation.