Anti-Inflammatory Activity of Orally Administered Monostroma nitidum Rhamnan Sulfate against Lipopolysaccharide-Induced Damage to Mouse Organs and Vascular Endothelium.

We previously reported that rhamnan sulfate (RS) purified from Monostroma nitidum significantly suppressed lipopolysaccharide (LPS)-induced inflammation in cultured human vascular endothelial cells. Here, we analyzed the effect of orally administered RS on LPS-induced damage to mouse organs and vascular endothelium. RS (1 mg) was orally administered daily to BALB/c mice, 50 µg of LPS was intraperitoneally administered on day 8, and Evans blue was injected into the tail vein 6 h later. After 30 min, LPS-treated mice showed pulmonary Evans blue leakage and elevated plasma levels of liver damage markers, whereas this reaction was suppressed in LPS + RS-treated mice. Immunohistochemical and Western blot analysis of mouse organs 24 h after LPS treatment showed significant neutrophil infiltration into the lung, liver, and jejunum tissues of LPS-treated mice and high expression levels of inflammation-related factors in these tissues. Expression levels of these factors were significantly suppressed in LPS + RS-treated mice. Analysis of lung glycocalyx showed a significant reduction in glycocalyx in LPS-treated mice but not in LPS + RS-treated mice. Levels of syndecan-4, one of the glycocalyx components, decreased in LPS-treated mice and increased in LPS + RS-treated mice. The current results suggest that orally administered RS protects organs and vascular endothelium from LPS-induced inflammation and maintains blood circulation.

Anti-Influenza A Virus Activity of Rhamnan Sulfate from Green Algae Monostroma nitidum in Mice with Normal and Compromised Immunity.

Influenza viruses cause a significant public health burden each year despite the availability of anti-influenza drugs and vaccines. Therefore, new anti-influenza virus agents are needed. Rhamnan sulfate (RS) is a sulfated polysaccharide derived from the green alga Monostroma nitidum. Here, we aimed to demonstrate the antiviral activity of RS, especially against influenza A virus (IFV) infection, in vitro and in vivo. RS showed inhibitory effects on viral proliferation of enveloped viruses in vitro. Evaluation of the anti-IFV activity of RS in vitro showed that it inhibited both virus adsorption and entry steps. The oral administration of RS in IFV-infected immunocompetent and immunocompromised mice suppressed viral proliferation in both mouse types. The oral administration of RS also had stimulatory effects on neutralizing antibody production. Fluorescent analysis showed that RS colocalized with M cells in Peyer's patches, suggesting that RS bound to the M cells and may be incorporated into the Peyer's patches, which are essential to intestinal immunity. In summary, RS inhibits influenza virus infection and promotes antibody production, suggesting that RS is a potential candidate for the treatment of influenza virus infections.

Alkylating agents from sugars. Alkyl hexopyranoside derivatives as carrier systems for chlorambucil.

Chlorambucil derivatives involving alkyl 2-aminodeoxy sugars have been synthesized in good yield by coupling the chlorambucil moiety to positions C-2 or C-3 of the sugar, directly or via a spacer. The starting material was easily available from 2-acetamido-2-deoxy-D-glucose. The final compounds were tested for cytotoxicity, and some of those that presented the best results were studied for inhibition of cell proliferation.

Pretreatment with 3-O-methyl-D-glucose or 2-deoxy-D-glucose attenuates the post-mortem rise in rat brain lactate.

The present investigation examined the effects of pretreatment with 3-O-methyl-D-glucose (3OMG) or 2-deoxy-D-glucose (2DOG) on post-mortem rise in rat brain lactate to evaluate their potential use for minimizing ischemia-induced rise in brain lactate. The results showed that iv administration of either glucose analogue (2 g/kg) at 2.5 min prior to sacrifice significantly attenuated (to 0.61 of control levels) post-mortem brain lactate rise. Pretreating rats with 2-deoxy-D-glucose (2 g/kg) 15 min prior to sacrifice resulted in a greater inhibition (to 0.52 of control) of the post-mortem lactate rise. The effects of these two analogues (3OMG and 2DOG) can be accounted for by their inhibition of brain glucose transport and inhibition of brain glucose metabolism by 2DOG. The present results suggest that intervention with either of these glucose analogues under the proper experimental procedures may minimize the cytopathological consequences of ischemia related to the rise in brain lactate.

Pharmacologic inhibition of immediate hypersensitivity in the guinea pig conjunctiva.

The release of histamine and other mediators from an immediate hypersensitivity reaction is energy dependent and cyclic AMP dependent. Drugs which inhibit the active secretion of mediators, or which may change cyclic AMP are effective in inhibiting mediator release. We used a model of Type I (immediate) hypersensitivity in the conjunctiva of guinea pigs sensitized to normal rabbit serum to test the efficacy of 2-deoxy-D-glucose or a combination of isoproterenol and diethylcarbamazine in inhibiting conjunctival hypersensitivity. After topical challenge with rabbit serum, edema was evaluated in five areas of the guinea pig conjunctiva. Controls were compared to conjunctiva pretreated with 2-deoxy-D-glucose or isoproterenol and diethylcarbamazine. Pretreatment with 2-deoxy-D-glucose or a combination of isoproterenol and diethylcarbamazine was found to inhibit the immediate hypersensitivity reaction.

Influence of environmental conditions on exocrine pancreatic response to intravenous injection of ethanol or 2-deoxyglucose in the dog.

When dogs have free access to the outside, an intravenous injection of ethanol depresses secretin-stimulated exocrine pancreatic secretion by a vagally mediated mechanism. This was shown in two separate series of six and seven dogs each. When dogs were kept in air-conditioned windowless kennels, the response to a meal was unchanged but the response to ethanol was reversed to stimulation. In four dogs, ethanol 1 g/kg was given during a secretin infusion. Three months after changing from open to closed kennels the inhibition (-86% for protein output) was still present, but after 6 months ethanol produced a stimulation (+62%) of pancreatic secretion. This increase was abolished, but not reversed, by keeping the animals outside during the day for four weeks, whereas after three months there was a partial restoration of the inhibitory effect (-39%). In contrast, changing from an open to a closed kennel changed the initial response to 2-deoxy-D-glucose (2-DG), 100 mg/kg, from stimulation to inhibition. These results suggest that environmental conditions affect the cranial regulation of pancreatic secretion.

Tonotopic bands produced by tones commenced long after 2-deoxyglucose injection.

Presentation of two different tones at two different time periods each under two different types (14C or 3H) of 2-deoxyglucose (2-DG) produced two bands of labelling in the inferior colliculus (IC) of a guinea pig. Filtering tests revealed that both bands were produced by only one of the labels (14C). Four guinea pigs were given one injection of 2-DG and then stimulated with two tones, each presented at different time periods. Two bands of labelling were produced in IC, with one band being produced by tones given 55-90 min after injection. The implications of this long lasting effect of 2-DG are discussed for the general 2-DG model and for sequential double labelling experiments.

Bimodal effect of 2-deoxy-D-glucose on feeding.

Perfusion of 2-deoxy-D-glucose (2-DG) into the IIIrd ventricle (i.c.v.) or intraperitoneal (i.p.) injections produced changes in feeding and other overt behavior, as well as indicative changes in electroencephalograms (EEG). Applications of 2-DG, either i.p. or i.c.v., induced hyperphagia within 4 hr which was then followed by hypophagia for at least 96 hr. EEGs evinced low frequency patterns during the lethargy and ataxia symptoms which were present after i.p. injection. After i.c.v. injections, the low frequency EEG during the lethargy and ataxia were not evident. Present results in connection with prior reports indicate that 2-DG has a long term bimodal effect on feeding which may be mediated through central neurons. Hypophagia after peripheral application of 2-DG appeared to be caused at least as much by concomitant traumatism as by effects on neural control of feeding.

2-Deoxy-D-glucose-induced hypothermia: thermoregulatory pathways in rat.

2-Deoxy-D-glucose (2-DG) elicits significant and prolonged hypothermia in a variety of animals when administered either peripherally or centrally. From our current studies it would appear that, in high concentrations (250 mg/kg or more, ip), 2-DG can act directly on peripheral tissues in the rat by competitively interfering with glucose metabolism and consequently with normal heat producing mechanisms. When a low concentration of 2-DG (20 micrograms) is injected centrally, the ensuing glucopenia results in vagal stimulation and subsequent diminution of peripheral heat production. Vagal involvement is concluded from studies with atropine, which demonstrated total inhibition of the usual 2-DG depression of body temperature by administration to the ventral premammillary nucleus (PMV), a site that is normally extremely sensitive to this analog of glucose. Additionally, from studies with PMV-lesioned rats, it was concluded that an intact nucleus is necessary for thermoregulation in a normal, a hot, or a cold environment.

Intraperitoneal administration and other modifications of the 2-deoxy-D-glucose technique.

Experiments were conducted to determine the optimal conditions necessary for implementing modifications of the 2-deoxyglucose (2-DDG) technique. Substitution of tritium-labeled 2-DDG with subsequent microdissection of selected brain regions and liquid scintillation counting produced results that were highly correlated with both [14C]radioautograms and glucose utilization values as obtained by Sokoloff et al. The route of administration of isotope was also varied. Whole brain uptake at maximal levels of incorporation was the same for both intravenously and intraperitoneally injected animals. Radioautograms from i.p. and i.v. injected animals were indistinguishable. Densitometric analyses of the i.p. radioautograms were highly correlated with glucose utilization values. Thus, relative indices of functional activity may be obtained when experimental circumstances preclude arteriovenous cannulations and restraint. The use of naive, unrestrained animals, therefore, makes the 2-DDG technique applicable to a broader range of studies.