Tag Archives: vitamin B3
Scientific advancement on the way to molecular vitaminology at the Department of Vitamins and Coenzymes of the Palladin Institute of Biochemistry
M. Veliky, I. Shymanskyi, T. Kuchmerovska*, Yu. Parkhomenko
Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine,
Department of Vitamins and Coenzymes, Kyiv;
*e-mail: tkuchmerovska@gmail.com
Received: 05 May 2025; Revised: 08 July 2025;
Accepted: 30 October 2025; Available on-line: 2025
Modern advances in molecular vitaminology are characterized by a marked expansion in understanding the molecular mechanisms underlying the actions of vitamins and their biologically active derivatives as highly effective compounds that ensure controlled interactions between cellular regulatory systems and metabolic processes. The molecular mechanisms of the pleiotropic effects of the hormonally active form of vitamin D3, calcitriol (1α,25(OH)2D3), are realized in target tissues through vitamin D3 receptors (VDR), which are present in virtually all cells. Our studies have focused on VDR-mediated effects, including modulation of the transcriptional activity of NF-κB, NFAT, HIF-1 and PPAR, as well as involvement of regulatory pathways such as HIF-1α/VEGF and RANK/NF-κB. We have also examined signaling through glucocorticoid and mineralocorticoid receptors, which play a key role in the antioxidant, anti-inflammatory, and anti-apoptotic effects of vitamin D3 under normal conditions and in pathology (osteoporosis, neurodegenerative disorders associated with glucocorticoid-induced neurotoxicity and type 2 diabetes mellitus). The mechanisms of the neurotropic effects of vitamin B3 (nicotinamide) and a derivative of nicotinic and amino butyric acid, nicotinoil-GABA (N-GABA), have also been studied. It has been demonstrated that nicotinamide (NAm) inhibits the development of diabetic neuropathy by reducing the activity and level of the PARP-1 enzyme, suppressing its fragmentation and preventing DNA damage in the brain tissue, and normalizing the nuclear levels of SIRT1 and SIRT2 proteins in neurons. One of the effective methodological approaches in our studies has been the investigation of thiamine-binding proteins in the brain and the effects of thiamine deficiency on the expression and state of neurospecific proteins. Based on our findings, we have formulated a working hypothesis regarding the molecular mechanisms of vitamin B1 involvement in the functioning of the cholinergic component of the nervous system. This hypothesis suggests that, in addition to the pool of thiamine diphosphate (ThDP) that binds to ThDP-dependent enzymes, nerve cells contain a rapidly exchangeable pool of thiamine derivatives that are involved in acetylcholine metabolism. The research achievements of our Department demonstrate the therapeutic potential of vitamins D3, B3, B1, and their biologically active derivatives in preventing the development of neurodegenerative complications under various pathological conditions and provide a scientific basis for the development of novel vitamin supplements.
Effect of nicotinamide on amino acids content in bone collagen depending on biological availability of vitamins in diabetic rats
M. M. Guzyk1, Iu. T. Sergiichuk1,2, K. O. Dyakun1,2,
L. V. Yanitska3, T. M. Kuchmerovska1
1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: kuch@biochem.kiev.ua;
2Taras Shevchenko Kyiv National University, Ukraine;
3O. O. Bogomolets National Medical University, Kyiv
Connective tissue is highly susceptible to imbalances induced by diabetes. Diabetes-related osteopenia, decreased bone strength etc. may be associated with altered metabolism of various collagens. Although it is assumed that alterations in collagen amino acids (AA) may strongly affect protein properties and physiological functions, however, very limited evidences are present at the moment regarding AA composition of bone type I collagen and its relevance to abnormal availability of vitamins which are necessary for collagen synthesis in diabetes. We have tested whether nicotinamide (NAm) can influence type I collagen formation and AA composition as well as vitamins availability in diabetes. After 4 weeks of STZ-induced diabetes (60 mg/kg) male Wistar rats were injected for 2 weeks with/without NAm (200 mg/kg b. w.). Acid extraction of type I collagen from the bones was performed with following stepwise salting out. The content of type I collagen after its acid extraction from the bones was estimated by the amounts of hydroxyproline. Amino acids were assayed by cation exchange chromatography. Diabetes-associated changes in AA composition of type I collagen mainly affect those amino acids which are known to be involved in helix formation and cross-linking of the molecules. Diabetes was found to significantly reduce bone collagen contents of o-Pro, Gly, Ala, o-Lys and Pro, whereas Lys, His, Arg, Glu, Thr, Leu, Phe contents were elevated (P < 0.05). NAm treatment was able to partially normalise AA contents. In diabetes, blood serum and hepatic vitamin C and B3 contents were shown to be significantly lowered, whereas α-tocopherol was slightly increased compared with control (P < 0.05). Restoration of circulatory and liver vitamin C and B3 was observed. The data demonstrate the close relationship between the diabetes-associated decrease in type I collagen deposition, altered amino acids metabolism and impaired availability of vitamins, which are necessary for collagen synthesis. Thus, NAm might be a useful agent for treatment of bone failures related to diabetes.