Immunomodulatory activity of 3beta,6beta-dihydroxyolean-12-en-27-oic acid in tumor-bearing mice.

3beta,6beta-dihydroxyolean-12-en-27-oic acid (1) is a pentacyclic triterpenoid isolated from the rhizomes of Astilbe chinensis. To evaluate the in vivo antitumor potential and to elucidate its immunological mechanisms, effect of 1 on the growth of mouse-transplantable tumors, and the immune response in naive and tumor-bearing mice were investigated. The mice inoculated with mouse tumor cell lines were orally treated with 1 at the doses of 40, 60, and 80 mg/kg for 10 days. The effects of 1 on the growth of mouse-transplantable S180 sarcoma and H22 hepatoma, splenocyte proliferation, cytotoxic T lymphocyte (CTL) activity, natural killer (NK) cell activity, and production of interleukin-2 (IL-2) from splenocytes in S180-bearing mice were measured. Furthermore, the effect of 1 on 2,4-dinitrofluorobenzene (DNFB)-induced delayed-type hypersensitivity (DTH) reactions and the sheep red blood cell (SRBC)-induced antibody response in naive mice were also studied. Compound 1 could not only significantly inhibit the growth of mouse transplantable S180 sarcoma and H22 hepatoma, increase splenocytes proliferation, CTL and NK cell activity, and the level of IL-2 secreted by splenocytes in tumor-bearing mice, but also remarkably promote the DTH reaction and enhance anti-SRBC antibody titers in naive mice. These results suggested that 1 could improve both cellular and humoral immune response, and could act as antitumor agent with immunomodulatory activity.

Manganese superoxide dismutase expressed in silkworm larvae, Bombyx mori L enhances the NK activity and splenocyte proliferation against Sarcoma 180 tumor cells in vivo.

Natural killer cell (NK) is known as a major immune system in body through mediating cell death via several possible pathways, and one of three subpopulations of lymphocytes functioning as scavenger of tumor, virus infected cells etc. Our present results found that the SOD-contained silkworm larvae powder caused an enhancement of the effect on NK cell cytotoxicity, which implied this material modulated the immune system in mice in vivo. The NK cell activities of S180 tumor modeled mice treated with silkworm powder including SOD were enhanced significantly ranging from 30% to 48%, respectively, compare to a distilled water feeding control and silkworm powder without SOD. Meanwhile, the ConA-stimulated splenocyte proliferation of all three treated groups was higher than that of the control both in T cells or B cells. The average tumor weight of S180 modeled mice treated with doses of SOD-contained silkworm powder was lighter than that of water control showing the tumor inhibition rates (IR) reached to 22.51% to 37%, respectively. In conclusion, these findings demonstrate that administration of silkworm larvae powder containing SOD results in activation of NK cells and immune T-cell and B-cell, suggesting the silkworm larvae powder containing SOD play a positive role in tumor inhibition.

Silkworm powder containing manganese superoxide dismutase regulated the immunity and inhibited the growth of Hepatoma 22 cell in mice.

The effects of SOD contained silkworm powder on immune regulation and inhibition against Hepatoma 22 tumor cells in vivo were investigated. The activity of natural killer cell (NK) and the ConA-stimulated spleen proliferation were measured. The results found that the SOD-contained silkworm powder caused an enhancement on NK cell activity, which implied this material modulated the immune system in mice in vivo. The NK cell activities of Hepatoma 22 tumor modeled mice treated with silkworm powder including SOD were increased significantly compared to a modeled control and silkworm powder without SOD, reaching 36.18%. In addition, the ConA-stimulated spleen proliferation of SOD treated mice was higher than that of the controls. The treatment of SOD contained silkworm powder presented 40.3% of average inhibition rate to Hepatoma 22 tumor, showing stronger inhibition against tumor. There were no significant difference in body weight between modeled control and SOD silkworm powder feeding in Hepatoma 22 tumor modeled mice, suggesting the SOD silkworm powder is safety as an inhabitant to tumor. In conclusion, these findings demonstrate that administration of silkworm powder containing SOD results in activation of NK cells and immunity, suggesting the silkworm powder containing SOD plays a positive role in tumor inhibition.