Effect of type II collagen extract on immunosuppression induced by methotrexate in rats.

This study investigated the effect of type II collagen extract on SD rats with deteriorated immunity caused by methotrexate. The test samples were dosed once a day for 28 days by gastric gavage at dosage 250 mg/kg and 500 mg/kg after methotrexate treatment, and the changes on body weight, total blood leukocyte numbers, the percentages of B-cells, CD4+ T-cells and CD8+ T-cells in the blood and spleen were observed. The changes on body weight, the total blood leukocyte numbers, the total lymphocyte numbers in the spleen, the ratio of CD4+ and CD8+ T-cells in the blood and spleen were increased significantly in type II collagen extract groups as compared with the control group. According to the above results, type II collagen extract has an effect of increasing immune responses on rats with deteriorated immunity caused by methotrexate.