nicotinamide (Papulex)

NAD+ precursor treatment prevents cardiomyopathy but disrupts erythroid maturation in mitochondrial progeria.

Khan Nahid A NA, Ahlqvist Kati K, Pradhan Swagat S, Landoni Juan J et al.

Nicotinamide adenine dinucleotide (NAD+) plays a central role in energy metabolism, and its decline is linked to various degenerative diseases. While NAD+ restoration holds therapeutic promise, its long term, tissue-specific consequences remain poorly understood. We investigated effects of nicotinamide riboside (NR) supplementation for "mutator" mice manifesting mitochondrial progeria. Our results reveal strikingly divergent outcomes: in proliferative bone marrow, NR-treated mutators show reductive stress with accumulation of NADH/NADPH, altered amino acid, nucleotide, folate levels, and impaired heme biosynthesis. In blood, erythrocyte maturation defects are aggravated, exacerbating anemia. Conversely, in postmitotic cardiac tissue, NR enhanced contractility, reduces stress response markers and normalized metabolic profile. These findings indicate that while beneficial for heart, chronic NAD+ boosting can compromise erythrocyte maturation in the context of mitochondrial disease. The data emphasize importance of evaluating systemic effects of NAD+ boosting therapies beyond the primary affected tissues and development of tissue-specific metabolic interventions for degenerative diseases.

Therapeutic potential of an ethnoveterinary formulation against Staphylococcus aureus-induced mastitis via modulating TLR-2/NOX-2 pathway.

Ratheesh M M, Jose Svenia P SP, Sheethal S S, Sandya S S et al.

Mastitis is a major inflammatory disorder of the mammary gland that causes substantial economic losses in the dairy industry, with Staphylococcus aureus (S. aureus) being one of the predominant causative pathogens. The current treatment options are limited by antimicrobial resistance and drug residues. Therefore, alternative therapeutic strategies are needed. The present study aimed to evaluate the anti-inflammatory and antioxidant effects of an ethnoveterinary oil (EO) formulation in an experimental model of S. aureus-induced mastitis. The EO formulation was prepared according to a standardized traditional ethnoveterinary composition. Mastitis was induced in healthy lactating primiparous Wistar rats by intramammary infusion of S. aureus (2 × 108 CFU/mL), and the twenty-four female Wistar rats were divided into four groups of 6: normal control (NC), mastitis control (MT), standard drug-treated (MT + DEX), and MT + EO-treated groups. The chemical composition of EO was characterized by GC-MS analysis, which identified 21 bioactive compounds, predominantly erucic acid, along with phenolic compounds, fatty acid derivatives, terpenoids, and steroidal constituents known for their anti-inflammatory potential. Biochemical analyses revealed that EO significantly restored endogenous antioxidant enzyme activities and reduced lipid peroxidation in mammary tissues. Furthermore, EO significantly decreased myeloperoxidase (MPO) levels and N-acetyl-β-D-glucosaminidase activity, indicating reduced neutrophil infiltration and protection against epithelial cell damage. The levels of Pro-inflammatory cytokines were markedly elevated in mastitis control group whereas EO treatment significantly suppressed their production. In addition, EO downregulated the gene expression of Toll like receptor-2 (TLR-2) and Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX-2), suggesting modulation of key inflammatory and oxidative stress-related pathways. Histopathological and special staining analyses further confirmed the preservation of mammary gland architecture and attenuation of inflammatory infiltration following EO treatment. Collectively, these findings demonstrate that EO exerts potent anti-mastitic effects through the combined modulation of oxidative stress and inflammatory responses and may serve as a promising natural therapeutic alternative for the management of S. aureus associated mastitis in Wistar rat model.

Corrigendum to "An enzyme kinetic model for quantitative interpretation of the role of nicotinamide nucleotide transhydrogenase (NNT) in cell physiology" [Free Rad. Biol. Med. 254 (2026) 660-675].

Gan Zhuohui Z, van der Stelt Inge I, Grefte Sander S, Diez Maria Suarez MS et al.

Adipose FGF21 signalling mediates the anti-senescence effects of protein restriction.

Yang Xiaohan X, Wu Yanni Y, Yang Yi Y, Huang Long L et al.

Dietary protein restriction (PR) is a well-recognized nutritional intervention that enhances metabolic health and extends lifespan. However, the mechanisms behind this phenomenon are not well understood. Here, using genetic loss-of-function models for fibroblast growth factor 21 (Fgf21) and its obligate co-receptor β-Klotho (Klb), we demonstrate that FGF21-KLB signalling in adipocytes is indispensable for the anti-senescence effects of PR. Specifically, adipocyte FGF21 signalling preserves mitochondrial integrity, maintains an anti-inflammatory milieu and sustains nicotinamide adenine dinucleotide (NAD+) homeostasis under PR. Mechanistically, FGF21 enhances adipocyte NAD+ abundance through activation of AMP-activated protein kinase to maintain mitochondrial integrity. Additionally, high-protein feeding induces adipocyte senescence and metabolic dysfunction could be mitigated by exogenous FGF21 supplementation. Together, these findings establish adipose FGF21 signalling as a pivotal endocrine axis that couples dietary protein availability to adipocyte NAD+ metabolism and identify it as a promising target for the prevention and treatment of age-related metabolic disorders. KEY POINTS: Dietary protein restriction improves metabolic health and extends lifespan, but the mechanisms responsible for these benefits are not fully understood. Fibroblast growth factor 21 (FGF21) is a hormone strongly induced by low-protein diets and has emerged as an important regulator of metabolic adaptation. We show that FGF21 signalling specifically in adipose tissue is essential for the anti-senescence effects of dietary protein restriction. FGF21 preserves mitochondrial integrity by maintaining nicotinamide adenine dinucleotide metabolism through AMP-activated protein kinase activation. Targeting the FGF21-adipose tissue pathway may provide new strategies to prevent or treat age-related metabolic dysfunction.