Protective Effects of Collagen Peptides on the Dexamethasone-Induced Immunosuppression in Mice

Abstract

Collagen peptides are collagen derived products by enzymatic proteolysis, which is widely distributed in mammalian connective tissues. They have exhibited various bioactivities, including antioxidant activity, antihypertensive activity, improvement of joint pain, etc. However, the immunomodulatory effects of collagen peptides in the condition of immune suppression have not been elucidated. The objective of this study was to investigate the effects of collagen peptides on immune function in immunosuppressed mice. The immunosuppression was induced by intraperitoneal injection of dexamethasone for three days and at same time, collagen peptides (0, 300, 600, 900 mg/kg body weight) were given by gavage for seven days. On the day 8, the mice were sacrificed by decapitation. The body weight and the weights of thymus and spleen were recorded. Thymus and spleen indexes were calculated. The proliferation and interleukin-2 production of splenic T lymphocytes and ratio of CD4+/CD8+T lymphocytes in the peripheral blood were examined. Compared with the control mice, the body weight, thymus and spleen indexes, the proliferations and interleukin-2 production in T lymphocytes and the ratios of CD4+/CD8+T cells were significantly decreased in dexamethasone induced immunosuppressed mice. However, in collagen peptides treated mice, the thymus indexes, proliferation index, secretion of interleukin-2 and the ratio of CD4+/CD8+ were significantly increased compared with the mice in experimental model group. These results indicate that collagen peptides could play a protect role in glucocorticoid-induced immunosuppression.