The immunosuppressive effect of sinomenine on lymphocytes stimulated by allogeneic islets

Abstract

Objective To investigate the immunosuppressive effect of sinomenine (SIN) on the lymphocytes stimulated by allogeneic islets and the influence on activity and function of islets. Methods Isolated islets from Wistar rats as the stimulus and lymphocytes from spleen of Lewis rats as the reactive cells were cocultured in vitro, and then divided into 4 groups: SIN group with SIN, islets and lymphocytes cocultured; Tac (tacrolimus) group with Tac, islets and lymphocytes cocultured; negative control group with islets and lymphocytes cocultured; blank control group with lymphocyte cultured alone.The concentration of interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-10 and insulin in the supernatant were detected by enzyme-linked immunosorbent assay, the proliferation of lymphocytes was measured by methyl thiazolyl tetrazolium assay, and the activity of islet cells was tested by acridine orange and propidium iodide staining. Results On the 3th days after cocultured, the proliferation rates of lymphocytes in the SIN group and Tac group were (33.9±2.8)% and (33.2±3.0)% respectively, both lower than that in the negative control group (P all 0.05). The concentration of IFN-γ and IL-2 in the SIN group were (67±6) and (322±21) pg/mL respectively, both lower than those in the negative control group and higher than those in the blank control group (P all 0.05). The supernatant concentration of IL-10 in the SIN group was (76±4) pg/mL, and higher than those in the other 3 groups (P all <0.05). The insulin stimulation index and activity of islets in the SIN group were (1.73±0.24) and (82.5±4.7)% respectively, both superior to those in the Tac group and the negative control group (P all <0.05). Conclusions SIN not only had immunosuppressive effect on lymphocytes stimulated by allogeneic islets, but also could alleviate the immune injury to the islets. What′s more, it could maintain the activity and insulin secretion function of islet cells better compared with Tac. Key words: Sinomenine; Islets; Immunosuppressive; Lymphocytes