Design and synthesis of gallocyanine inhibitors of DKK1/LRP6 interactions for treatment of Alzheimer's disease

Based on NCI8642, a series of gallocyanine derivatives was synthesized with modifications of the substituent groups in position 1, 2 and 4 of the phenoxazinone scaffold. The effectiveness of gallocyanines to inhibit DKK1/LRP6 interactions and Tau phosphorylation induced by prostaglandin J2 and DKK1 was elucidated by both experimental data and molecular docking simulations. Bis-alkylated with flexible alkyl ester groups on C1 and bis-benzyl gallocyanines provided the most active inhibitors, while amino derivatives on C2 of NCI8642 that have alkoxy or benzyloxy substituents on C4, were less active. Furthermore, it is shown that treating of SHSY5Y cells with NCI8642 derivatives activates Wnt signaling and increases the levels of pGSK3β kinase and β-catenin.

Effect of Some Biologically Interesting Substituted Tetrahydro-1,4- Oxazines on Drug Metabolising Enzymes and on Inflammation

The effect on hepatic drug metabolising enzymes was evaluated for three representative structures and that were selected from a series of substituted oxazine derivatives designed to possess particular pharmacological properties such as analgesic, antioxidant and hypolipidemic activity. In addition, since xenobiotic metabolism, reactive oxygen and nitrogen species, atherosclerosis and inflammation are interrelated and mutually affected, the effects of and on acute inflammation in vivo and lipoxygenase activity in vitro were also investigated. It was found that treatment of rats with caused induction of cytochrome P450, enhancement of the metabolism of aminopyrine in vitro and of zoxazolamine and hexobarbital in vivo. Compound appeared to induce particularly erythromycin N-demethylation, while, a nitric ester, reduced the catalytically active cytochrome P450, although it increased the metabolism of specific cytochrome P450 substrates, i.e. 4-nitrophenol and erythromycin. Compounds and with strong hypolipidemic and antioxidant properties, reduced acute inflammatory response in two inflammation models and inhibited lipoxygenase activity in vitro. These results are helpful in optimising the biological profile as well as the potential applications of substituted oxazines.

Antifungal activities of posaconazole and granulocyte-macrophage colony-stimulating factor ex vivo and in mice with disseminated infection due to Scedosporium prolificans

Invasive infection due to Scedosporium prolificans is characterized by drug resistance and a high rate of mortality. The effects of posaconazole (POS), an investigational antifungal triazole, murine granulocyte-macrophage colony-stimulating factor (GM-CSF), and their combination against S. prolificans were evaluated ex vivo and in a newly developed murine model of disseminated infection due to this organism. When POS was combined with polymorphonuclear leukocytes from untreated or GM-CSF-treated mice (P < 0.01) ex vivo, it had increased activity in terms of the percentage of hyphal damage. Immunocompetent BALB/c mice were infected with 4 x 10(4) conidia of S. prolificans via the lateral tail vein. At 24 h postinfection the mice were treated with GM-CSF (5 microg/kg of body weight/day subcutaneously), POS (50 mg/kg/day by gavage), both agents, or saline only. Half of the brain, lung, liver, and kidney from each animal were cultured; and the other half of each organ was processed for histopathology. The mean survival times were 7.0 +/- 0.3 days for the controls, 7.4 +/- 0.4 days for POS-treated mice, 8.0 +/- 0.3 days for GM-CSF-treated mice (P = 0.08 compared with the results for the controls), and 7.3 +/- 0.3 days for POS-GM-CSF-treated mice. Fungal burdens (determined as the numbers of CFU per gram of tissue) were found in descending orders of magnitude in the kidneys, brains, livers, and lungs. The burdens were significantly reduced in the brains of GM-CSF-treated mice (P < 0.05) and the livers of POS-treated mice (P < 0.05). The numbers of lesions in the organs closely corresponded to the fungal burdens. GM-CSF tended to prolong survival (P = 0.08 compared with the results for the controls). While the combination of POS and GM-CSF showed enhanced activity ex vivo, it did not increase the activities of the two agents against this highly refractory filamentous fungus in mice.

Adjuvant regulation of cytokine profile and antibody isotype of immune responses to Mycoplasma agalactiae in mice

Traditionally, adjuvants have been administered with antigens to enhance immunity. We studied the effect of several adjuvants such as Freund's complete adjuvant (FCA), Freund's incomplete adjuvant (FIA), lipopolysaccharide (LPS), homopolymers of polyinosinic-polycytidylic acid (poly I:C) and polyadenylic-polyuridylic acid (poly A:U), lithium chloride (LiCl), saponin Quil A and calcium phosphate gel (CaHPO(4)) on the immune response of mice to formalin-inactivated Mycoplasma agalactiae. The specific antibody or cytokine producing splenocytes were detected by ELISAspot and immunocytochemistry, respectively. Depending on the adjuvant given, the number of M. agalactiae-specific antibody producing cells was increased 2.5-6-fold. IgG was the major class of M. agalactiae-specific antibodies followed by IgM, IgA and IgE. Among IgG isotypes, FCA, FIA, Quil A and CaHPO(4) induced an IgG1 response with substantial increase of the IgG2a, IgG2b and IgG3 isotypes while poly I:C shifted the response toward an IgG2a/IgG3 production. Finally, poly A:U induced an IgG2b response while LPS and LiCl augmented the IgG3/IgG1/IgG2a secretion. FCA augmented IL-4, IL-5 and IL-10 production suggesting a strong Th2 response, while IFN-gamma and IL-12 remained low; poly I:C enhanced IFN-gamma, IL-12 and TNF-alpha eliciting a Th1 response; poly A:U resulted in a IL-10, IL-5, IL-6 and IL-12 secretion; and LPS enhanced the IL-10, IL-6 and TNF-alpha production. Our data show that adjuvants augment M. agalactiae-specific antibody production and lead to B cell isotype-switching via the appropriate cytokine milieu. Certain adjuvants, such as poly I:C, therefore, appear as promising immune enhancers for vaccination against M. agalactiae infections.

Anti-inflammatory and immunomodulating properties of grape melanin. Inhibitory effects on paw edema and adjuvant induced disease

Natural or synthetic melanin (CAS 8049-97-6) is a high molecular weight heteropolymer, product of the enzyme tyrosinase, found to possess radical scavenging and antioxidant functions. It was of interest, therefore, to study in detail the possible anti-inflammatory and/or immunosuppressive properties of a melanin isolated from grapes. The inhibitory effect of melanin on carrageenin-induced edema, as well as on edemas produced by other phlogistics, was remarkable suggesting that melanin interferes with the prostaglandin as well as the leukotriene and/or complement system mediated inflammation. Grape melanin showed potent inhibitory effect on adjuvant induced disease (AID) in rat, suppressing significantly the primary inflammation and almost totally the secondary lesions of arthritis. Melanin under the present experimental conditions not only strongly inhibited the in vitro lipid peroxidation of rat liver microsomal membranes, but furthermore protected the in vivo hepatic peroxidation occurring in AID rats, demonstrating its antioxidant and cytoprotective properties. The serum proinflammatory cytokines IL-1, IL-6 and TNF-a and the serum globulin fraction were elevated in AID rats, parameters which were more or less normalised by melanin treatment in contrast to the reduced serum levels of IL-2 which were not affected. Similarly to other lipoxygenase inhibitors and hydroxyl radical scavenger NSAIDs, melanin treatment did not affect IL-1 neither increased the splenic mitogenic responses, unlike the classical cyclooxygenase inhibitory NSAIDs. The subpopulation Th1 (T4+ or T8+) of lymphocytes is mainly responsible for cellular immune responses and thus their possible inhibition by melanin could lead to suppression of the development of AID, a model for cell-mediated immunity. The effect of melanin on T-cells is exhibited by the reduced spleen mitogenic responses to a T-cell mitogen and the reduced serum levels of IL-2 of treated rats. In conclusion, grape melanin is an interesting anti-inflammatory and immunomodulating natural product which appears to have multiple cellular targets within the reticuloendothelial and immune system.

Anti-inflammatory properties of new adamantane derivatives. Design, synthesis, and biological evaluation

A series of adamantane-containing molecules consisting of two lipophilic centers which are linked by different bridges (oxime esters, oxime ethers, amides, and symmetric alcohols), were designed and synthesized as anti-inflammatory agents. Their anti-inflammatory activity was evaluated as their ability to inhibit phlogistic-induced mouse paw edema. Some of the tested compounds exhibited activity comparable to that of diclofenac, others had a weaker activity, while some oxime esters proved to enhance the inflammatory response. In all cases, activity was dose-dependent. The deacylated compound 10 was found to be the most active of the series, inhibiting inflammation due to Baker's yeast, the mechanism of which involves mainly the activation of lipoxygenase and/or complement systems, a property which is absent from most selective cyclooxygenase only inhibiting non-steroidal anti-inflammatory drugs (NSAIDs).

Regulation of cytokine gene expression by adjuvants in vivo

Antibody isotype affects biological activity of the antibodies and therefore should be considered in prevention of disease by vaccination. In previous reports, we demonstrated that adjuvants affect the antibody isotype switching process and favour the production of certain isotypes. The present study extends these findings and shows fundamental differences in the cytokine induction pattern according to the adjuvant used. Cytokine mRNA levels were determined by in situ RNA-RNA hybridization performed on splenocytes isolated from mice injected with different adjuvants. The results revealed that Freund's complete adjuvant (FCA), Freund's incomplete adjuvant (FIA), Al(OH)3 and QuilA administration results in a type-2 (humoral) response, increasing IL-4, IL-5 and IL-13 gene expression, while poly I:C exhibits a type-1 (cell-mediated) response, increasing the production of interferon-gamma (IFN-gamma), IL-2 and IL-6 mRNA. Finally, BeSO4 and poly A:U augment IL-5 and IL-6 mRNA production, while lipopolysaccharide (LPS) and LiCl augment IL-6 and tumour necrosis factor-alpha (TNF-alpha) mRNA production. Also, the adjuvants appear capable of overcoming the inherent IL-2/IFN-gamma and IL-4 dichotomy of C57B1/6 and BALB/c mice, respectively, in response to cellular antigens such as Leishmania and herpes simplex virus (HSV). The overall data suggest that adjuvants direct the isotype switching process via induction of certain cytokines, a finding that can be useful in selection of the most efficient isotype of protective antibodies for disease prevention by vaccination.