Effects of Diacetyl Flavoring Exposure in Mice Metabolism.

Diacetyl is a flavoring that imparts a buttery flavor to foods, but the use or exposure to diacetyl has been related to some diseases. We investigated the effect of oral intake of diacetyl in male and female C57/Bl mice. We performed a target metabolomics assay using ultraperformance liquid chromatography paired with triple quadrupole mass spectrometry (UPLC-MS/MS) for the determination and quantification of plasmatic metabolites. We observed alterations in metabolites present in the urea and tricarboxylic acid (TCA) cycles. Peroxynitrite plasmatic levels were evaluated by a colorimetric method, final activity of superoxide dismutase (SOD) was evaluated by an enzymatic method, and mouse behavior was evaluated. Majority of the assay showed differences between control and treatment groups, as well as between genders. This may indicate the involvement of sex hormones in the regulation of a normal metabolic profile, and the implication of sex differences in metabolite disease response.

Increased chemical acetylation of peptides and proteins in rats after daily ingestion of diacetyl analyzed by Nano-LC-MS/MS.

BACKGROUND: Acetylation alters several protein properties including molecular weight, stability, enzymatic activity, protein-protein interactions, and other biological functions. Our previous findings demonstrating that diacetyl/peroxynitrite can acetylate L-lysine, L-histidine, and albumin in vitro led us to investigate whether diacetyl-treated rats suffer protein acetylation as well. METHODS: Wistar rats were administered diacetyl daily for four weeks, after which they were sacrificed, and their lung proteins were extracted to be analysed by Nano-LC-MS/MS (Q-TOF). A C18 reversed-phase column and gradient elution with formic acid/acetonitrile solutions from 2 to 50% over 150 min were used to separate the proteins. Protein detection was performed using a microTOF-Q II (QTOF) equipped with captive source and an electrospray-ionization source. The data from mass spectrometry were processed using a Compass 1.7 and analyzed using Protein Scape, software that uses Mascot algorithms to perform protein searches. RESULTS: A set of 3,162 acetylated peptides derived from 351 acetylated proteins in the diacetyl-treated group was identified. Among them, 23 targeted proteins were significantly more acetylated in the diacetyl-treated group than in the PBS control. Protein acetylation of the group treated with 540 mg/kg/day of diacetyl was corroborated by Western blotting analysis. CONCLUSIONS: These data support our hypothesis that diacetyl exposure in animals may lead to the generation of acetyl radicals, compounds that attach to proteins, affecting their functions and triggering adverse health problems.

1-[(2,3-Dihydro-1-benzofuran-2-yl) methyl]piperazines as novel anti-inflammatory compounds: Synthesis and evaluation on H3 R/H4 R.

The histamine receptors (HRs) are members of G-protein-coupled receptor superfamily and traditional targets of huge therapeutic interests. Recently, H3 R and H4 R have been explored as targets for drug discovery, including in the search for dual-acting H3 R/H4 R ligands. The H4 R, the most recent histamine receptor, is a promising target for novel anti-inflammatory agents in several conditions such as asthma and other chronic inflammatory diseases. Due to similarity with previously reported ligands of HRs, a set of 1-[(2,3-dihydro-1-benzofuran-2-yl)methyl]piperazines were synthesized and evaluated in competitive binding assays as H3 R/H4 R ligands herein. The results showed the compounds presented affinity (Ki ) for H3 R/H4 R in micromolar range, and they are more selective to H3 R. All the compounds showed no important cytotoxicity to mammalian cells. The phenyl-substituted compound LINS01005 has shown the higher affinity of the set for H4 R, but no considerable selectivity toward this receptor over H3 R. LINS01005 showed interesting anti-inflammatory activity in murine asthma model, reducing the eosinophil counts in bronchoalveolar lavage fluid, as well as the COX-2 expression. The presented compounds are valuable prototypes for further improvements to achieve better anti-inflammatory agents.

1-[(2,3-Dihydro-1-benzofuran-2-yl) methyl]piperazines as novel anti-inflammatory compounds: synthesis and evaluation on H3R/H4R

The histamine receptors (HRs) are members of G-protein-coupled receptor superfamily and traditional targets of huge therapeutic interests. Recently, H3R and H4R have been explored as targets for drug discovery, including in the search for dual-acting H3R/H4R ligands. The H4R, the most recent histamine receptor, is a promising target for novel anti-inflammatory agents in several conditions such as asthma and other chronic inflammatory diseases. Due to similarity with previously reported ligands of HRs, a set of 1-[(2,3-dihydro-1-benzofuran-2-yl)methyl]piperazines were synthesized and evaluated in competitive binding assays as H3R/H4R ligands herein. The results showed the compounds presented affinity (K-i) for H3R/H4R in micromolar range, and they are more selective to H3R. All the compounds showed no important cytotoxicity to mammalian cells. The phenyl-substituted compound LINS01005 has shown the higher affinity of the set for H4R, but no considerable selectivity toward this receptor over H3R. LINS01005 showed interesting anti-inflammatory activity in murine asthma model, reducing the eosinophil counts in bronchoalveolar lavage fluid, as well as the COX-2 expression. The presented compounds are valuable prototypes for further improvements to achieve better anti-inflammatory agents.