Multifloral white honey outclasses manuka honey in methylglyoxal content: assessment of free and encapsulated methylglyoxal and anti-microbial peptides in liposomal formulation against toxigenic potential of Bacillus subtilis Subsp spizizenii strain.

The therapeutic virtues of honey no longer need to be proven. Honey, which is rich in nutrients, is an excellent nutritional food because of its many properties; however, honey has been diverted from this primary function and used in clinical research. Evidence has shown that honey still possesses unknown properties and some of these aspects have never been addressed. In this work, two bioactive compounds found in honey (methylglyoxal and antimicrobial peptides) were evaluated for their anti-Bacillus subtilis activity with particular attention to their dilution factor. Although this bacterial strain does not possess an indigenous virulence factor gene, it becomes virulent by transferring plasmids with B. thuringiensis or expression of toxins from Bordetella pertussis. As is known, methylglyoxal is a toxic electrophile present in many eukaryotic and prokaryotic cells, which is generated by enzymatic and non-enzymatic reactions. Its overexpression successfully kills bacteria by inducing membrane disruption. Also, AMPs show potent inhibitory action against Gram-positive bacteria. Because of the lack of information concerning the main ingredients of honey, the microencapsulation process was used. Both methylglyoxal (MGO) and peptide-loaded liposomes were synthesized, characterized and compared to their free forms. The liposomal formulations contained a mixture of eggPC, cholesterol, and octadecylamine and their particle sizes were measured and their encapsulation efficacy calculated. The results revealed that Algerian multifloral white honey contained higher levels of MGO compared to manuka honey, which prevented bacterial growth and free MGO was relatively less effective. In fact, MGO killed BS in the loaded form with the same bacteriostatic and bactericidal index. However, the action of AMPs was different. Indeed, the investigation into the reactivity of MGO in the solvent indicated that regardless of the level of water added, honey is active at a fixed dilution. This data introduces the notion of dilution and abolishes the concept of concentration. Moreover, the synergistic antibacterial effect of the compounds in honey was diminished by the matrix effect. The degree of liposome-bacteria-fusion and the delay effect observed could be explain by both the composition and nature of the lipids used. Finally, this study reinforces the idea that under certain conditions, the metalloproteinases in honey produce AMPs.

Development of analytical methods GC-MS vs LC-UV for the serum monitoring of an inflammatory glycotoxin (methylglyoxal): A new biomarker of bovine hepatobiliary distomatosis.

Two analytical methods; high performance liquid chromatography and gas chromatography were used to determine the content of 2-methylquinoxaline, a methylglyoxal-derived agent in sera from cattle with fascioliasis. Methylglyoxal is a highly mutagenic and cytotoxic reactive dicarbonyl compound formed by non-enzymatic fragmentation of triose phosphate GAP and DHAP during glycolysis which regularly contributes to repositioning the energetic balance between physiological and pathological situations. The aim of this study was to propose the MGO as a new biomarker in the bovine fasciolosis. Strongly infected animals showed a correlation between the relatively high levels of Fasciola hepatica anti-f2 antibody and methylglyoxal compared to unharmed animals. Also, an acute hyperglycemia was recorded and closely related to hepatic parenchyma hyperplasia, inflammation, bile ducts obstruction and scléro-fibrous foci formation.Unlike HPLC, which has shown analytical flaws and irregularities, GC-MS remains an excellent diagnostic tool for detecting and quantifying methylglyoxal in biological fluids. The developed method has been validated under FDA guidelines. A full scan-range was set from m/z 39 to 144/999 and the molecular weight of the 2-methylquinoxaline was identified according to NIST Database and ES. Methylglyoxal was the only analyte successfully quantified in a relatively short run time. It was linear over a concentration range of 0.057-5.7  µg.ml-1with mean recoveries and RSD of 118% and 3.63% respectively. The intra and inter-day assays were satisfying and not exceed 3.00%. Results reflect the degree of precision of our method and indicate that MGO was an important contributor to understand the hepatic failure independently of other serum markers.