Abscisic acid ameliorates d-galactose -induced aging in mice by modulating AMPK-SIRT1-p53 pathway and intestinal flora

The role and mechanism of quercetin in improving late-onset hypogonadism through network analysis and experimental validation

The rising incidence of late-onset hypogonadism (LOH) profoundly diminishes the quality of life in men due to declining testosterone levels. Quercetin is an important active metabolite in various traditional botanical drugs that enhance male fertility, yet its mechanisms of action remain unclear. This study delves into the therapeutic potential and underlying mechanisms of quercetin in LOH management, proposing novel treatment strategies. An aging murine model was created and treated with quercetin starting at 12 weeks of age. Sperm parameters were evaluated, and serum and testicular testosterone and inflammatory cytokines were quantified via ELISA. Histological analyses of testicular tissue were performed. Network analysis and molecular docking studies predicted quercetin's therapeutic pathways in LOH. Key proteins involved in testosterone synthesis and testicular aging were verified using western blotting and immunofluorescence. Aged TM3 cells were treated with quercetin to corroborate the effects on testicular Leydig cells. In the murine model, the quercetin treatment group showed an increase in sperm average path velocity (VAP) by 1.21 ± 0.087-fold (p < 0.01), an increase in straight-line velocity (VCL) by 1.12 ± 0.18-fold (p < 0.01), a rise in serum testosterone levels by 0.27 ± 0.48-fold (p < 0.05), and an increase in testosterone levels in testicular tissue by 0.30 ± 0.20-fold (p < 0.05), while IL-1β levels decreased to 0.61 ± 0.13-fold (p < 0.01) compared to the aging group. Network analysis suggested quercetin's efficacy in LOH may be mediated through the AR and PI3K/AKT pathways. In quercetin-treated aged mice, a reduction in γH2AX and an increase in Ki67 expression were observed in testicular tissue, alongside upregulated expression of key testosterone synthesis proteins-steroidogenic acute regulatory (STAR) and scavenger receptor class B type 1 (SRB1), accompanied with enhanced AR expression and AKT1 phosphorylation. Similar results were confirmed in testicular Leydig cells. Compared to the group treated with bleomycin alone, the bleomycin plus quercetin treatment group showed a reduced positive area in β-gal staining, downregulation of the senescence-associated marker γH2AX, increased expression of the key testosterone synthesis protein SRB1, and elevated levels of expression of quercetin's potential target AR as well as phosphorylation of AKT1. Quercetin ameliorates the aging of testicular Leydig cells and promotes testosterone synthesis through modulation of the AR/PI3K/AKT signaling pathway, presenting a promising therapeutic approach for LOH.

Methylated urolithin A, mitigates cognitive impairment by inhibiting NLRP3 inflammasome and ameliorating mitochondrial dysfunction in aging mice

Effective therapeutic interventions for elderly patients are lacking, despite advances in pharmacotherapy. Methylated urolithin A (mUro A), a modified ellagitannin (ET)-derived metabolite, exhibits anti-inflammatory, antioxidative, and anti-apoptotic effects. Current research has primarily investigated the neuroprotective effects of mUroA in aging mice and explored the underlying mechanisms. Our study used an in vivo aging model induced by d-galactose (D-gal) to show that mUro A notably improved learning and memory, prevented synaptic impairments by enhancing synaptic protein expression and increasing EPSCs, and reduced oxidative damage in aging mice. mUro A alleviated the activation of the NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome, leading to reduced glial cell activity and neuroinflammation in both accelerated aging and naturally senescent mouse models. Moreover, mUroA enhanced the activity of TCA cycle enzymes (PDH, CS, and OGDH), decreased 8-OHdG levels, and raised ATP and NAD+ levels within the mitochondria. At the molecular level, mUro A decreased phosphorylated p53 levels and increased the expression of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), thus enhancing mitochondrial function. In conclusion, mUro A alleviates cognitive impairment in aging mice by suppressing neuroinflammation through NLRP3 inflammasome inhibition and restoring mitochondrial function via the p53-PGC-1α pathway. This suggests its potential therapeutic agent for brain aging and aging-related diseases.

Function and Mechanism of Abscisic Acid on Microglia-Induced Neuroinflammation in Parkinson's Disease

Parkinson's disease (PD), as a neurologically implemented disease with complex etiological factors, has a complex and variable pathogenesis. Accompanying further research, neuroinflammation has been found to be one of the possible factors in its pathogenesis. Microglia, as intrinsic immune cells in the brain, play an important role in maintaining microenvironmental homeostasis in the brain. However, over-activation of neurotoxic microglia in PD promotes neuroinflammation, which further increases dopaminergic (DA) neuronal damage and exacerbates the disease process. Therefore, targeting and regulating the functional state of microglia is expected to be a potential avenue for PD treatment. In addition, plant extracts have shown great potential in the treatment of neurodegenerative disorders due to their abundant resources, mild effects, and the presence of multiple active ingredients. However, it is worth noting that some natural products have certain toxic side effects, so it is necessary to pay attention to distinguish medicinal ingredients and usage and dosage when using to avoid aggravating the progression of diseases. In this review, the roles of microglia with different functional states in PD and the related pathways inducing microglia to transform into neuroprotective states are described. At the same time, it is discussed that abscisic acid (ABA) may regulate the polarization of microglia by targeting them, promote their transformation into neuroprotective state, reduce the neuroinflammatory response in PD, and provide a new idea for the treatment of PD and the selection of drugs.