OBJECTIVETo investigate the treatment and mechanism of compound carraghenates suppository to rat acute rectal mucous injury.

METHODSThe model of rat acute rectal mucous injury was established by 3% acetic acid. Two hundred and forty rats were divided equally into control and experimental group. The rats of experimental group were administrated with 20 mg carraghenates suppository via rectum twice a day, but rats of control group were not administrated with carraghenates suppository. Thirty rats in both groups were executed at different time points. The pathologic changes were observed and the rectal mucous injury was scored. Immunohistochemical staining was used to evaluate the effect of carraghenates suppository on expression of VEGF, iNOS, IL-8, MMP9, HIF-1 alpha and PCNA in the two groups.

RESULTSThe scores of rectal mucous injury was lower, the pathologic changes such as hyperaemia, edema, destroy of glands were less severe, and tissue repair time was shorter in experimental group compared with those in the control group at 24 h, 78 h and 120 h after administration of carraghenates suppository. No obvious cicatrisation was observed in experimental group. Expression of VEGF and MMP9 was significantly lower in experimental group compared with those in the control group at 24 h after administration. Expression of VEGF, iNOS, IL-8, MMP9, HIF-1alpha and PCNA were statistically decreased in experimental group than those in the control group at 72 h, 120 h after administration. MVD in experimental group was statistically decreased than that in the control group.

CONCLUSIONThe compound carraghenates suppository can reduce the rectal mucous injury from 3% acetic acid, and accelerate the wound healing without obvious cicatrisation. The compound carraghenates suppository can reduce the expression of MMP9, VEGF, IL-8, PCNA, iNOS and HIF-1 alpha, which may play a role in its protective mechanism.