Refinement of the rKLi8.3-Based Serodiagnostic ELISA Allows Detection of Canine Leishmaniosis in Dogs with Low Antibody Titers.

The diagnosis of canine leishmaniasis (CanL) still represents a challenge due to the variable clinical manifestations and the large number of asymptomatic dogs. Serological tests are most commonly used to detect infected animals, revealing anti-Leishmania antibodies, mainly of the IgG isotype. Recently, a new diagnostic antigen, rKLi8.3, containing 8.3 kinesin tandem repeats (TR) from a Leishmania infantum strain from Sudan, has been shown to provide excellent specificity and sensitivity for the detection of Leishmania-infected humans and dogs. However, asymptomatic animals with very low antibody titers are often difficult to detect by serodiagnosis. Thus, we wondered whether the addition of an anti-IgG-enhancing step in the protein A/G-based rKLi8.3-ELISA will improve the diagnostic performance without decreasing the specificity. For this, parasitologically confirmed CanL cases with low or high clinical scores, uninfected healthy controls and dogs with other infections were tested by rKLi8.3-ELISA as well as two different immunochromatographic rapid tests, rKLi8.3-lateral flow test (LFT) and Dual Path Platform (DPP®) based on the rK28 antigen. Our results show that the diagnostic accuracies of the rKLi8.3-ELISA and LFT were similar to that of DPP, missing several asymptomatic animals. However, the addition of a secondary, amplifying anti-dog IgG antibody in the protein A/G-based rKLi8.3-ELISA enabled the detection of nearly all asymptomatic dogs without compromising its specificity.

Combining UFLC-QTOF-MS analysis with biological evaluation of Centrosema coriaceum (Fabaceae) leaves.

Centrosema coriaceum Benth belongs to Fabaceae family and have few studies of biological activity and chemical composition. Thus, the aims of this work were to determine chemical profile of the ethanolic extract of C. coriaceum leaves (CCE) by UFLC-QTOF-MS and to evaluate its in vitro biological potential. CCE showed MIC value of 1000 µg/mL against Candida glabrata (fungistatic effect) and high affinity in cell envelope by increasing cell permeability in nucleotide leakage, sorbitol and ergosterol assays. CCE showed antioxidant activity in all assays performed. For the anti-inflammatory and cytotoxicity activities, CCE, at all tested concentrations, significantly inhibited the production of nitric oxide and did not decrease J774A.1 cell viability below 70%. Finally, rutin, kaempferol-3O-rutinoside, caffeic acid, and sucrose were identified in CCE by UFLC-QTOF-MS. These results suggest, for the first time, that C. coriaceum has interesting antifungal, antioxidant, and anti-inflammatory activities.

Synthesis of genistein coupled with sugar derivatives and their inhibitory effect on nitric oxide production in macrophages.

The isoflavone genistein 1 and some derivatives modulate IL-12, TNF-α and NO production by macrophages and lung cancer cell lines, and improve the clinical signs of experimental autoimmune encephalomyelitis (EAE). Seven genistein derivatives connected at C-6 position of a sugar, such as d-glucose and d-galactose, were synthesized. The ability to modulate macrophage response was evaluated, showing variable inhibition capacity of NO and TNF-α production in J774.A1 and RAW 264.7. Five of the seven compounds were non-cytotoxic; compound 8 was more effective to inhibit NO and TNF-α production, without affecting cell viability.

Lipophilic amino alcohols reduces carrageenan-induced paw edema and anti-OVA DTH in BALB/c mice.

The inflammation process is a coordinated response of the organism related to immune response with release of pro-inflammatory substances, as nitric oxide, TNF-α and IL-1ß. In this work, a series of lipophilic amino alcohols were evaluated on RAW264.7 and primary macrophages for the modulation of nitric oxide and TNF-α. The most potent compounds were submitted to the treatment of BALB/c mice and evaluation of the carrageenan-induced paw edema and TNF-α and IL1-ß release in the paws and anti-OVA delayed type hypersensitivity reaction. RAW264.7 and primary macrophages were incubated in the presence of amino alcohols at different concentrations (1, 0.5, 0.05 and 0.005 µg mL(-1)). All tested compounds were not cytotoxic, however the inhibition of NO and TNF-α were observed only in RAW264.7 cultures. The NO production were reduced in 100% for all compounds, but only the compounds 4a and 4b expressively reduced the TNF-α release (67% and 92% respectively). On the carrageenan-induced paw edema, the compound 4b treatment showed reduction of edema, TNF-α and IL-1ß as efficient as dexamethasone treatment. Meanwhile, the compound 4a treatment showed only slight reduction of paw edema. In the anti-OVA DTH reaction, both compounds showed reduction in the paw edema as effective as dexamethasone. In function of the observed results in vitro and in the acute and anti-OVA inflammation of mice paw edema compound 4b showed promissory anti-inflammatory properties.

Synthesis of 1,4-anthracene-9,10-dione derivatives and their regulation of nitric oxide, IL-1ß and TNF-α in activated RAW264.7 cells.

Mitoxantrone is an anthracenedione antineoplastic and immunosuppressive agent approved for multiple sclerosis treatment. Novel mono- and disubstituted anthraquinone derivatives, analogues of mitoxantrone, were synthesized through the addition of lipophilic amino alcohols and evaluated for their effect on IL-1ß, TNF-α and nitric oxide production by LPS/IFN-γ-stimulated RAW264.7 cells. The disubstituted 1,4-anthracene-9,10-dione 10 showed significant inhibition of nitric oxide, TNF-α and IL-1ß production at the concentration of 5 µg/mL, with a much lower cytotoxicity than mitoxantrone. The monosubstituted 3, 4, 11, 12 and 13 also displayed a moderate to good inhibitory capacity on IL-1ß production. However, the methylated compounds 11, 12 and 13 failed to inhibit the TNF-α production, and compound 13 was the only one to decrease the production of nitric oxide. None of these derivatives was toxic at the tested concentrations. Compounds 10 and 13 had better inhibitory capacity of the inflammatory mediators analyzed, with reliable viability of the cells.