DNA damage in the elderly is associated with 5-MTHF levels: a pro-oxidant activity

Diazepam nanocapsules as an alternative for sleep induction: Development study and toxicity assessment

Diazepam (DZP) is a sedative medication prescribed to treat anxiety and as a sleep inducer, although its residual effects are unfavorable to patients. Nanotechnology represents a tool to improve the pharmacological characteristics of drugs, reducing their side effects. This study aimed to develop and characterize DZP nanocapsules and to evaluate their toxicity in alternative models and the hypnotic-sedative effect in mice. Nanocapsules were prepared by the nanoprecipitation method and properly characterized. Long-term and accelerated stability studies were performed. The in vitro release profile was determined by diffusion in Franz cells. The safety of the formulation was evaluated in the Caenorhabditis elegans (C. elegans) and the oral acute toxicity in mice. Pharmacological evaluation was performed using thiopental-induced sleeping time. DZP was successfully incorporated into Poly-(ɛ-caprolactone) (PCL) nanocapsules, with high entrapment efficiency. The nanocapsule did not affect the development or survival of C. elegans, different from the free drug, which affected the nematode development at the higher tested dose. No signs of toxicity, nor body mass or feed consumption changes were observed during the 14 days evaluated. Finally, this innovative formulation carrying DZP can produce a hypnotic-effect at a reduced dose compared to the free drug, with no toxicity in alternative models.

Highly sensitive analytical method for the accurate determination of 5-methyltetrahydrofolic acid monoglutamate in various volumes of human plasma using isotope dilution ultra-high performance liquid chromatography-mass spectrometry

One predominant and bioactive folate vitamer circulating in the blood is 5-methyltetrahydrofolate (5-Me-THF). In this study, a method for the accurate determination of 5-Me-THF in human plasma samples of various volumes was established using isotope dilution ultra-high performance liquid chromatography-mass spectrometry (ID-UPLC-MS). For this purpose, 500 μL of homogeneous human plasma was initially employed, and the 5-Me-THF and the ¹³C₅-5-Me-THF standard solutions prepared using 1% ascorbic acid in water gave the calibration solution and spiking sample. The desired amount of ¹³C₅-5-Me-THF standard solution was spiked into the sample followed by sample pretreatment. The method was validated for its repeatability, reproducibility, recovery, and limits of detection and quantification. Subsequently, it was applied to smaller volumes of human plasma samples (i.e., 50 and 10 μL), the results of which corresponded well with those obtained using 500 μL. The feasibility of the method was further confirmed using 10 μL of a standard reference material, SRM 3949, which is a human serum sample containing three different levels of 5-Me-THF. The established ID-UPLC-MS method was successfully applied to various volumes of human plasma or serum ranging from 500 to 10 μL, which exhibited particularly good sensitivity in addition to reliable results for the quantification of 5-Me-THF. Our method therefore expands on the ability to obtain accurate quantitative results for 5-Me-THF using small volumes of blood.

Genome-Protecting Compounds as Potential Geroprotectors

Throughout life, organisms are exposed to various exogenous and endogenous factors that cause DNA damages and somatic mutations provoking genomic instability. At a young age, compensatory mechanisms of genome protection are activated to prevent phenotypic and functional changes. However, the increasing stress and age-related deterioration in the functioning of these mechanisms result in damage accumulation, overcoming the functional threshold. This leads to aging and the development of age-related diseases. There are several ways to counteract these changes: 1) prevention of DNA damage through stimulation of antioxidant and detoxification systems, as well as transition metal chelation; 2) regulation of DNA methylation, chromatin structure, non-coding RNA activity and prevention of nuclear architecture alterations; 3) improving DNA damage response and repair; 4) selective removal of damaged non-functional and senescent cells. In the article, we have reviewed data about the effects of various trace elements, vitamins, polyphenols, terpenes, and other phytochemicals, as well as a number of synthetic pharmacological substances in these ways. Most of the compounds demonstrate the geroprotective potential and increase the lifespan in model organisms. However, their genome-protecting effects are non-selective and often are conditioned by hormesis. Consequently, the development of selective drugs targeting genome protection is an advanced direction.