Abstract: In this study, the immunomodulatory effects of MSMI (melanin from Sepiella maindroni ink) on hypoimmune mice induced by Hydrocortisone(HYD) was investigated . ICR mice were selected as animal mode, which were randomly divided into six groups, including control groups, hypoimmune mice, positive control groups(Levamisole Hydrochloride), and MSMI treated groups of low, medium and high dosage. Except for the control group, all the other groups were treated with Hydrocortisone by subcutaneous injection. After a trial period of 10 days, the liver and spleen indexes and phagocytic capacity of macrophages were analyzed, and which were found to be significantly enhanced in the treated groups(P<0.01，P<0.01),(P<0.05,P<0.01) as compared to that in the control group. Antioxidant enzyme activities were also measured and they significantly increased compared to the hypoimmune mice group. However, lipid peroxidation assayed as melondialdehyde (MDA) reduced significantly in the treated groups compared to that in the control. It is suggested that MSMI can promote immune function of immune-depressed mice.

Key words: Sepiella Maindroni Ink, Melanin, macrophages, immune-depressed mice