[The preventive and therapeutic effects of low molecular weight heparin on DSS-induced colitis in mice]

To evaluate the preventive and therapeutic effects of low molecular weight heparin (LMWH) on dextran sulphate sodium (DSS)-induced colitis in mice.

Twenty normal mice were randomized into two groups: 10 mice of the prevention group received DSS per os and LMWH by sub-cutaneous injection for 7 days; 10 mice as controls received DSS per os and sub-cutaneous normal saline for 7 days. Another 20 mice with DSS-induced colitis were randomized into two groups: the treatment group received sub-cutaneous injection of LMWH and the control group received subcutaneous injection of normal saline for 7 days. The preventive and therapeutic effects of LMWH were assessed by disease activity index (DAI), histologic score and MSB fibrin staining to identify microvascular thrombus.

The DAI, rectal and transverse histological scores of the prevention group compared with those of the control group were 2.40 vs 2.52 (P > 0.05), 1.65 vs 1.85 (P > 0.05), 1.55 vs 1.72 (P > 0.05), respectively. Microvascular thrombi in the prevention group decrease significantly as compared with the control; microvascular thrombi were positive in 6 of 10 controls, but only one was positive in the prevention group, P = 0.029. The DAI, rectal and transverse histological scores in the treatment group compared with those of the control were 0.42 vs 0.44 (P > 0.05), 1.36 vs 1.75(P < 0.05), 1.30 vs 1.65(P < 0.05), respectively. Microvascular thrombi were positive in 3 of 10 controls, and one microvascular thromous was positive in the treatment group, P = 0.291.

LMWH could effectively prevent microvascular thrombosis and inhibit colonic and rectal inflammation in the mice with DSS-induced colitis. These animal experimental results suggested that LMWH might also be used effectively in ulcerative colitis.