Pharmacokinetic Profile of 1-Methylnicotinamide Nitrate in Rats

Urinary Exosomal Metabolites: Overlooked Clue for Predicting Cardiovascular Risk

Over the last decade, increasing research has focused on urinary exosomes (UEs) in biological fluids and their relationship with physiological and pathological processes. UEs are membranous vesicles with a size of 40-100 nm, containing a number of bioactive molecules such as proteins, lipids, mRNAs, and miRNAs. These vesicles are an inexpensive non-invasive source that can be used in clinical settings to differentiate healthy patients from diseased patients, thereby serving as potential biomarkers for the early identification of disease. Recent studies have reported the isolation of small molecules called exosomal metabolites from individuals' urine with different diseases. These metabolites could utilize for a variety of purposes, such as the discovery of biomarkers, investigation of mechanisms related to disease development, and importantly prediction of cardiovascular diseases (CVDs) risk factors, including thrombosis, inflammation, oxidative stress, hyperlipidemia as well as homocysteine. It has been indicated that alteration in urinary metabolites of N1-methylnicotinamide, 4-aminohippuric acid, and citric acid can be valuable in predicting cardiovascular risk factors, providing a novel approach to evaluating the pathological status of CVDs. Since the UEs metabolome has been clearly and precisely so far unexplored in CVDs, the present study has specifically addressed the role of the mentioned metabolites in the prediction of CVDs risk factors.

1-MNA Ameliorates High Fat Diet-Induced Heart Injury by Upregulating Nrf2 Expression and Inhibiting NF-κB in vivo and in vitro

High levels of free fatty acids (FFA) are closely associated with obesity and the development of cardiovascular diseases. Recently, nicotinamide adenine dinucleotide (NAD) metabolism has emerged as a potential target for several modern diseases including diabetes. Herein, we explored the underlying mechanisms of NAD metabolism associated with the risk of cardiovascular disease. Our study found that nicotinamide N-methyltransferase (NNMT) mRNA levels were significantly increased in the hearts of FFA-bound-albumin-overloaded mice and in H9C2 cells treated with palmitic acid (PA). We studied the mechanisms underlining the anti-inflammatory and anti-oxidant activities of 1-methylnicotinamide (1-MNA), a metabolite of NNMT. We found a significantly higher level of reactive oxygen species, inflammation, apoptosis, and cell hypertrophy in PA-treated H9C2 cells and this effect was inhibited by 1-MNA treatment. in vivo, 1-MNA improved inflammation, apoptosis, and fibrosis damage in mice and this inhibition was associated with inhibited NF-κB activity. In conclusion, our study revealed that 1-MNA may prevent high fatty diet and PA-induced heart injury by regulating Nrf2 and NF-κB pathways.

Synergistic effects of polymyxin and ionic liquids on lipid vesicle membrane stability and aggregation

Ionic liquids (ILs) have been investigated for potential antibacterial and antibiotic applications due to their ability to destabilize and permeabilize the lipid bilayers in cell membranes. Bacterial assays have shown that combining ILs with antibiotics can provide a synergistic enhancement of their antibacterial activities. We have characterized the mechanism by which the conventional ILs 1-butyl-3-methylimidazolium chloride (BMICl) and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIBF₄) enhance the lipid membrane permeabilization of the well-known antibiotic polymyxin B (PMB). We studied the sizes and membrane permeabilities of multilamellar and unilamellar lipid bilayer vesicles in the presence of ILs alone in aqueous solution, PMB alone, and ILs combined together with PMB. Light scattering-based experiments show that vesicle sizes dramatically increase when ILs are combined with PMB, which suggests that the materials combine to synergistically enhance lipid membrane disruption leading to vesicle aggregation. Lipid bilayer leakage experiments using tris (2,2'-bipyridyl) ruthenium (II) (Ru(bpy)₃²⁺) trapped in lipid vesicles, in which the trapped Ru(bpy)₃²⁺ fluorescence lifetime increases when it leaks out of the vesicle, show that combining BMIBF₄ and PMB together permeabilize the membrane significantly more than with PMB or the IL alone. This demonstrates that ILs can assist in antibiotic permeabilization of lipid bilayers which could explain the increased antibiotic activities in the presence of ILs in solution.