Virucidal and Immunostimulating Activities of Monogalactosyl Diacylglyceride from Coccomyxa sp. KJ, a Green Microalga, against Murine Norovirus and Feline Calicivirus.

Human noroviruses are the most common pathogens causing acute gastroenteritis and may lead to more severe illnesses among immunosuppressed people, including elderly and organ transplant recipients. To date, there are no safe and effective vaccines or antiviral agents for norovirus infections. In the present study, we aimed to demonstrate the antiviral activity of monogalactosyl diacylglyceride (MGDG) isolated from a microalga, Coccomyxa sp. KJ, against murine norovirus (MNV) and feline calicivirus (FCV), the surrogates for human norovirus. MGDG showed virucidal activities against these viruses in a dose- and time-dependent manner-MGDG at 100 µg/mL reduced the infectivity of MNV and FCV to approximately 10% after 60 min incubation. In the animal experiments of MNV infection, intraoral administration of MGDG (1 mg/day) exerted a therapeutic effect by suppressing viral shedding in the feces and produced high neutralizing antibody titers in sera and feces. When MGDG was orally administered to immunocompromised mice treated with 5-fluorouracil, the compound exhibited earlier stopping of viral shedding and higher neutralizing antibody titers of sera than those in the control mice administered with distilled water. Thus, MGDG may offer a new therapeutic and prophylactic alternative against norovirus infections.

[Enhancing the immunogenic activity of influvac vaccine in the use of adjuvant TI complexes modified by echinochrome A].

The self-assembly of marine macrophyte glycolipids, holothurian saponin, and cholesterol gave rise to nanoscale morphological structures called tubular immunostimulating (TI) complexes. Whether the latter could be used on the basis of vaccine preparations containing the influenza virus subunit antigens was studied. There was an obvious increase in the immunogenicity of influenza virus hemagglutinin when the experimental animals were immunized with this antigen as part of TI complexes. It was shown that the adjuvant activity of the TI complex to influenza virus hemagglutinin could be enhanced by adding the known antioxidant echinochrome A from a sand-dollar (Echinarachnius parma) to the matrix of the TI complex.

Rose hip and its constituent galactolipids confer cartilage protection by modulating cytokine, and chemokine expression.

BACKGROUND: Clinical studies have shown that rose hip powder (RHP) alleviates osteoarthritis (OA). This might be due to anti-inflammatory and cartilage-protective properties of the complete RHP or specific constituents of RHP. Cellular systems (macrophages, peripheral blood leukocytes and chondrocytes), which respond to inflammatory and OA-inducing stimuli, are used as in vitro surrogates to evaluate the possible pain-relief and disease-modifying effects of RHP. METHODS: (1) Inflammatory processes were induced in RAW264.7 cells or human peripheral blood leukocytes (PBL) with LPS. Inflammatory mediators (nitric oxide (NO), prostaglandin E(2) (PGE(2)) and cytokines/chemokines) were determined by the Griess reaction, EIA and multiplex ELISA, respectively. Gene expression was quantified by RT-PCR. RHP or its constituent galactolipid, GLGPG (galactolipid (2S)-1, 2-di-O-[(9Z, 12Z, 15Z)-octadeca-9, 12, 15-trienoyl]-3-O-ß-D-galactopyranosyl glycerol), were added at various concentrations and the effects on biochemical and molecular parameters were evaluated. (2) SW1353 chondrosarcoma cells and primary human knee articular chondrocytes (NHAC-kn) were treated with interleukin (IL)-1ß to induce in vitro processes similar to those occurring during in vivo degradation of cartilage. Biomarkers related to OA (NO, PGE(2), cytokines, chemokines, metalloproteinases) were measured by multiplex ELISA and gene expression analysis in chondrocytes. We investigated the modulation of these events by RHP and GLGPG. RESULTS: In macrophages and PBL, RHP and GLGPG inhibited NO and PGE(2) production and reduced the secretion of cytokines (TNF-α, IFN-γ, IL-1ß, IL-6, IL-12) and chemokines (CCL5/RANTES, CXCL10/IP-10). In SW1353 cells and primary chondrocytes, RHP and GLGPG diminished catabolic gene expression and inflammatory protein secretion as shown by lower mRNA levels of matrix metalloproteinases (MMP-1, MMP-3, MMP-13), aggrecanase (ADAMTS-4), macrophage inflammatory protein (MIP-2, MIP-3α), CCL5/RANTES, CXCL10/IP-10, IL-8, IL-1α and IL-6. The effects of GLGPG were weaker than those of RHP, which presumably contains other chondro-protective substances besides GLGPG. CONCLUSIONS: RHP and GLGPG attenuate inflammatory responses in different cellular systems (macrophages, PBLs and chondrocytes). The effects on cytokine production and MMP expression indicate that RHP and its constituent GLGPG down-regulate catabolic processes associated with osteoarthritis (OA) or rheumatoid arthritis (RA). These data provide a molecular and biochemical basis for cartilage protection provided by RHP.

In vivo antitumor effect of liposomes with sialyl Lewis X including monogalactosyl diacylglycerol, a replicative DNA polymerase inhibitor, from spinach.

The glycoglycerolipid monogalactosyl diacylglycerol (MGDG) isolated from spinach selectively inhibits the activities of replicative DNA polymerase species and suppresses the growth of human cancer cell lines, while not affecting normal human cells. Liposomes, carrying surface-bound sialyl Lewis X (SLX) and containing MGDG (SLX-Lipo-MGDG) and the fluorescent dye Cy5.5, were administered intravenously to mice bearing HT-29 human colon adenocarcinoma tumors and liposome distribution observed using fluorescence imaging equipment in vivo. In an in vivo antitumor assay on nude mice bearing HT-29 solid tumors, SLX-Lipo-MGDG was shown to be a stronger and more promising suppressor of solid tumors than MGDG alone. These results suggest that spinach MGDG could be developed into an anticancer compound, SLX-Lipo-MGDG could serve as an effective clinical anticancer drug and that these liposomes may be useful tools as the basis for active targeting drug delivery systems.