[Immunomodulatory effects of Opuntia dillenii polysaccharides on specific immune function of mice].

OBJECTIVE: To investigate specific immune modulation of Opuntia dillenii polysaccharides (ODPs) on mice (body fluid and cells). METHODS: An immunosuppressed murine model was induced by intraperitoneal injection of cyclophosphamide (Cy, ip). The intraserous hemolysin IgM, IgG levels, the proliferation of spenocytes and the proportion of T lymphocyte subsets in peripheral blood were determined after the mice treated by ODPs. Proliferative effects of ODP-I, the main component purified from ODPs, on the lymphocytes in vitro were also studied. RESULTS: ODPs could significantly increase intraserous IgM and IgG levels, significantly enhance the proliferation of T and B lymphocytes and restore them to normal level. ODPs significantly reduced the percentage of CD4+ T lymphocytes subset, therefore significantly reduced the proportion of CD4+ and CD8+ T lymphocytes of peripheral blood from immunosuppressive mice and restored it to normal level. ODP-I significantly enhanced the natural proliferation of splenic lymphocyte and assisted the proliferation of T and B lymphocytes which induced by mitogen ConA or LPS. CONCLUSION: ODPs can enhance the specific immune function of immunosuppressed mice and the proliferation of lymphocytes in vitro.

Penicixanthene E, a new xanthene isolated from a mangrove-derived fungus Penicillium sp.

One new xanthene derivative, named penicixanthene E (1), together with one known compound 2, was isolated from the EtOAc extract of the endophytic fungus Penicillium sp. GXIMD 03101, which was identified from the mangrove Acanthus ilicifolius L. collected in the South China Sea. The structure of 1 was elucidated by 1D and 2D NMR spectral interpretation and HREISMS data. The absolute configurations of C-9 and C-11 in 1 were proposed based on electronic circular dichroism (ECD), but the configuration at C-3 in 1 was unassigned. Compound 1 represents a xanthene derivative that was first reported, in which carbon-carbon double bond has been reduced. The cytotoxic activities of all compounds were evaluated, the result showed that compound 1 has weak activity against pancreatic cancer SW1990.

Two new benzophenones isolated from a mangrove-derived fungus Penicillium sp.

One new benzophenone derivative, named penibenzophenone C (1), and a new benzophenone natural product, neamed penibenzophenone D (2), together with two known compounds (3, 4) were isolated from the EtOAc extract of the endophytic fungus Penicillium sp. isolated from the mangrove Acanthus ilicifolius L. collected in the South China Sea. The structures of 1-4 were elucidated by extensive NMR spectral interpretation and MS data. The new compounds 1 and 2 showed moderate antibacterial activities against methicillin-resistant Staphylococcus aureus with the MIC values of 3.12 and 6.25 µg ml-1, respectively.

Hypolipidaemic effects and mechanisms of the main component of Opuntia dillenii Haw. polysaccharides in high-fat emulsion-induced hyperlipidaemic rats.

The antihyperlipidaemic effects of ODP-Ia, one of the main components of Opuntia dillenii Haw. polysaccharides, were studied. Gavage administration of ODP-Ia was observed to significantly decrease serum lipid levels and to increase serum high-density lipoprotein cholesterol level in hyperlipidaemic rats. Similar suppressive patterns were also seen in hepatic total cholesterol and triglyceride levels. Moreover, the ODP-Ia administration significantly increased serum lecithin:cholesterol acyltransferase activity, increased the production of serum NO, inhibited hepatic HMG-CoA reductase activity, augmented serum and hepatic superoxide dismutase activities and decreased the serum and hepatic malondialdehyde contents in hyperlipidaemic rats. In addition, a histopathological examination revealed that ODP-Ia administration significantly suppressed inflammatory cell infiltration and the expression of VCAM-1. Together, these results indicate that ODP-Ia is a potential natural product for the treatment of hyperlipidaemia-related diseases by improving antioxidant levels, modulating the activities of enzymes involved in cholesterol metabolism, promoting the production of NO and suppressing the expression of VCAM-1, thereby suppressing lipid accumulation and inflammatory cell infiltration.