Antibiotics and senescence

Antibiotics are a diverse group of chemical substances, either naturally derived or synthetically produced, that are primarily used to treat bacterial infections. Since the discovery of penicillin by Alexander Fleming in 1928, antibiotics have revolutionized modern medicine, saving countless lives and enabling complex medical procedures such as surgeries, organ transplants, and chemotherapy by effectively controlling infectious complications [35]. Anti-infective agents exert their antimicrobial activity through diverse molecular mechanisms, including inhibition of bacterial cell wall biosynthesis (e.g., β-lactams), suppression of protein synthesis (e.g., tetracyclines and macrolides), disruption of nucleic acid replication and transcription (e.g., fluoroquinolones), and interference with essential metabolic pathways (e.g., sulfonamides) [36].

Historically, the focus on antibiotics has centered on their antimicrobial properties. However, azithromycin and roxithromycin have recently been approved by the Food and Drug Administration (FDA) as macrolide antibiotics with senolytic activity [22]. Therefore, evidence suggests that these compounds can exert significant off-target effects on mammalian cells, independent of their bactericidal or bacteriostatic functions. This includes modulation of mitochondrial function, oxidative stress, inflammation, and even cellular senescence, an area of increasing interest in the fields of ageing and age-related diseases [31, 37]. These off-target effects have significant implications beyond infection control, particularly in the context of age-related pathologies [38]. For instance, antibiotic treatment with the fluoroquinolone ciprofloxacin has been shown to magnify Ang II-induced VSMC senescence via AMPK/ROS interactions in vitro, suggesting that antibiotics can potentiate the deleterious effects of Ang II signaling (a hallmark of ageing) in vascular cells [39]. Angiotensinogen is a well-documented neurohormone implicated in various cardiovascular and inflammation-dependent diseases [40, 41].

Casagrande Raffi et al. [42] (2024) identified the mitochondrial calcium transporter SLC25A23 as a selective vulnerability in senescent cancer cells. The cationic ionophore antibiotic salinomycin phenocopied SLC25A23 suppression, disrupting calcium homeostasis and oxidative phosphorylation, increasing ROS, and triggering multiple parallel death pathways (apoptosis, necroptosis, pyroptosis). Importantly, salinomycin induced IL-18 secretion, which recruited NK and CD8⁺ T cells to further eliminate senescent tumor cells. When combined with a death receptor-5 (DR5) agonist antibody, salinomycin exhibited potent and synergistic senolytic activity in vitro and in vivo, underscoring a promising strategy of pairing pro-senescence therapies with senolytics to prevent the detrimental accumulation of senescent cancer cells [42].

Gut microbiome, antibiotics, and senescence

The gut microbiome is now recognized as a central regulator of vascular aging and age-related cardiovascular disease [43]. Commensal taxa such as Faecalibacterium prausnitzii, Akkermansia muciniphila, and Roseburia spp. are major producers of SCFAs, notably butyrate, propionate, and acetate, which exert vasculoprotective effects by maintaining gut-barrier integrity, dampening nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-driven inflammation, enhancing regulatory T-cell (Treg) function, and supporting endothelial NO bioavailability and mitochondrial homeostasis [44]. Antibiotic exposure, particularly with broad-spectrum agents, reduces the abundance of these SCFA-producing genera and overall microbial diversity, thereby lowering SCFA levels and predisposing to systemic low-grade inflammation and endothelial dysfunction [45].

In parallel, dysbiosis can favor the expansion of pro-inflammatory taxa, including certain Proteobacteria and Bacteroides species, which increase production of trimethylamine (TMA), especially in Desulfovibrio and Clostridium species, which harbor TMA and endotoxin (LPS) in Escherichia coli and Bacteroides fragilis species. TMA is converted in the liver to TMAO, a metabolite that promotes age-like endothelial dysfunction, vascular oxidative stress, and arterial stiffness in both preclinical models and humans. Elevated circulating TMAO levels and LPS activate TLR4/NF-κB signaling, increase ROS generation, and impair eNOS-mediated NO production, thereby accelerating vascular aging phenotypes [46].

Bile acids (BAs), which are amphipathic metabolites derived from cholesterol synthesized in the liver, are modified by gut microbiota, including Clostridium, Bacteroides, and Lactobacillus species. These bacteria convert primary BAs into secondary BAs, such as deoxycholic acid (DCA) and lithocholic acid (LCA), which play a substantial role in the process of vascular aging [44]. Emerging evidence indicates that microbial-host metabolic networks beyond direct mitochondrial or oxidative stress may also mediate vascular aging. In particular, BAs, beyond their conventional role in lipid absorption, act as metabolic regulators influencing vascular homeostasis via signaling through receptors such as Farnesoid X receptor (FXR) and TGR5. Dysregulation of the BA network has recently been linked to pathological vascular calcification (VC), a major determinant of arterial stiffness and cardiovascular events. The review by Wang et al. [47] (2023) documents how alterations in BA metabolism and signaling can drive VSMC transdifferentiation, oxidative stress, inflammation, and calcium-phosphate deposition in the vascular wall, all processes that overlap mechanistically with antibiotic-induced mitochondrial dysfunction, redox imbalance, and senescence.

Multiple mechanisms connect BAs to vascular dysfunction, mainly via inflammation, oxidative stress, and cellular injury [47]. In ECs, BAs like chenodeoxycholic acid stimulate ROS generation, which activates NF-κB and p38 MAPK signaling pathways, resulting in elevated adhesion molecule expression and inflammatory responses. Hydrophobic BAs intensify oxidative stress in VSMCs, contributing to tissue damage and remodeling. Interestingly, recent metabolomics-based research shows that the bile-acid metabolite LCA, which increases during caloric restriction, can by itself recapitulate key anti-ageing effects across species, including activation of AMPK, enhanced mitochondrial biogenesis and function, improved muscle regeneration, and extended healthspan in mice, flies, and worms. The study by Qu et al. [48] (2025) found that LCA treatment induces AMPK activation at physiological concentrations similar to those observed under caloric restriction, inhibits mechanistic target of rapamycin (mTOR) signaling, promotes autophagy and cellular energy homeostasis, and reduces age-associated decline in physiological performance. These findings imply that changes in bile-acid metabolism, a facet potentially influenced by antibiotic- or anti-infective-induced gut microbiome perturbation, may contribute substantially to vascular and systemic ageing, beyond classical mitochondrial toxicity or ROS-driven damage [48].

Recent studies have highlighted the microbiota’s impact on cellular senescence, a key hallmark of aging characterized by irreversible cell cycle arrest and a proinflammatory secretory profile known as the SASP. Disruptions in the gut microbiome, particularly through the use of broad-spectrum antibiotics, can disrupt this delicate balance and accelerate senescence in distant tissues, including the vasculature [49].

Antibiotics, while life-saving, are nondiscriminatory in their action and often cause collateral damage to the gut microbiota. This dysbiosis alters microbial diversity and depletes beneficial commensals’ metabolites, including SCFAs such as butyrate and propionate. These SCFAs are known to possess anti-inflammatory and anti-senescent properties, in part by modulating histone acetylation, immune regulation, and mitochondrial function [50]. The decline in SCFA has been linked to increased oxidative stress and systemic inflammation, two major inducers of cellular senescence, particularly in vascular endothelial and smooth muscle cells. Furthermore, the reduction in microbial metabolites impairs intestinal barrier function, resulting in the translocation of microbial products, such as LPS, into circulation, which can trigger chronic low-grade inflammation (inflammaging) and potentiate senescent phenotypes in peripheral tissues [51].

Additionally, antibiotic-induced disruption of the microbiome has been shown to affect mitochondrial function, a central regulator of cellular energy and redox homeostasis. Antibiotics such as kanamycin, ampicillin, and ciprofloxacin have been shown to impair mitochondrial translation and bioenergetics, leading to mitochondrial dysfunction, a known trigger of senescence through activation of the DNA damage response (DDR) and accumulation of ROS [52]. These alterations not only contribute to tissue degeneration but may also exacerbate vascular aging by promoting endothelial dysfunction and reducing NO bioavailability. Importantly, a dysfunctional gut-mitochondria axis, as influenced by both microbiome alterations and antibiotic exposure, can synergize to induce premature vascular senescence.

Moreover, the gut microbiota modulates host epigenetics, including DNA methylation, histone modifications, and non-coding RNA (ncRNA) expression. Antibiotics that perturb microbiota composition may therefore have downstream effects on the epigenetic regulation of genes involved in cell cycle control and stress responses. For instance, butyrate, a microbial metabolite, functions as a histone deacetylase inhibitor (HDACi), thereby influencing chromatin structure and gene expression patterns that may suppress or delay the onset of senescence [53]. The loss of this regulatory influence following antibiotic treatment may promote unchecked cellular stress signaling and senescence-related transcriptional programs.

There is also growing evidence that the gut microbiota influences nutrient-sensing pathways, including the insulin/IGF-1 signaling axis, AMPK, and mTOR [54, 55]. Alterations in microbiota composition following antibiotic exposure can shift nutrient signaling, possibly by altering microbial metabolites that serve as cofactors or regulators of host enzymes. Disruption of these pathways has been associated with regenerative capacity in vascular and other tissues [56].

In ageing models, antibiotic-induced dysbiosis has been shown to blunt neurogenesis, alter immunity, and increase systemic inflammation, all of which are closely coupled to accelerated cellular senescence [57]. It is worth noting that although certain antibiotics have been explored for their potential senolytic properties, such as azithromycin or DOX, their systemic impact on the gut microbiome and downstream pro-senescent signaling often outweigh these benefits in the context of chronic or repeated exposure [58–61].

For instance, DOX reinstated the levels of key aging-related proteins, such as lamin B1 and the DNA repair factors KU70 and KU80. Moreover, it mitigated cellular senescence and dampened the SASP, leading to reduced inflammation in ethanol-exposed human umbilical vein ECs (HUVECs) [62]. In ApoE^−/−/OVX mouse models, DOX treatment reduced ROS levels and decreased both the expression and activity of MMP-2, which correlated with a significant attenuation of inflammation-driven atherosclerotic lesion formation [63]. In DOCA salt-treated rats, DOX lowered systolic blood pressure, ameliorated endothelial dysfunction, and attenuated aortic oxidative stress and inflammation. DOX also reduced lactate-producing gut bacteria and circulating lactate levels, strengthened gut barrier integrity, corrected endotoxemia and elevated plasma noradrenaline, and restored Treg abundance in the aorta. Collectively, these findings indicate that DOX, via modulation of the gut microbiota alongside its anti-inflammatory and immunomodulatory actions, mitigates endothelial dysfunction and hypertension in this low-renin hypertensive model [64].

Additionally, in cystic fibrosis patients, lung inflammation and fibrosis are classic, resulting in lung stiffening and an inability to breathe. Fibrosis is an age-related disorder associated with increased numbers of myofibroblasts (SCs) [65]. Azithromycin has been shown to act as an anti-inflammatory drug and reduce SASP mediators, such as IL-1β and IL-6, by targeting senescent myofibroblast cells [66]. Equally, senescent biomarkers have been identified in progressive endometriosis. For instance, in endometrial stromal cells with endometriosis (eESCs), and ovarian endometriosis OE cyst-derived stromal cells CSCs, senescent biomarkers such as SA-β-gal, the cyclin-dependent kinase inhibitor 2A locus (p16^INK4a), and lamin B1 are significantly elevated. Azithromycin impaired cell proliferation (Ki67), fibrosis, and IL-6 (SASPs) levels [67].

However, broad-spectrum antibiotics such as ampicillin, ciprofloxacin, clindamycin, vancomycin, and metronidazole significantly deplete beneficial gut bacteria like Bifidobacterium, Lactobacillus, and Faecalibacterium, leading to compromised epithelial integrity and increased gut permeability. This allows microbial products, such as LPS, to enter systemic circulation, stimulating pro-inflammatory cytokines such as IL-6 and TNF-α, central mediators of inflammaging. Persistent inflammation induces cellular stress responses, resulting in oxidative damage, mitochondrial dysfunction, and activation of senescence pathways, as evidenced by elevated p16^INK4a, p21, and SA-β-gal expression. These SCs further propagate inflammation through their SASP output, establishing a feedback loop that accelerates age-related tissue degeneration and functional decline [50, 51]. Interestingly enough, these broad-spectrum antibiotics have demonstrated beneficial effects in lowering TMAO (Figure 2), forming bacteria when used for only limited durations. TMAO is directly correlated to inflammation and senescence [68, 69].

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Figure 2. Diagram of the gut-vascular axis illustrating how antibiotics disrupt microbial balance (dysbiosis), leading to SCFA depletion, TMAO accumulation, immune activation, and altered microbial metabolites. These pathways converge to promote vascular senescence, with protective (green) and harmful (red) mechanisms highlighted. SCFA: short-chain fatty acid; TMAO: trimethylamine N-oxide. Created in BioRender. Silumbwe, C. (2026) https://BioRender.com/2vmlldy.

Antibiotics, proteostasis collapse [ubiquitin-proteasome system (UPS) & autophagy], and age-related diseases

Maintaining a functional proteome relies on proper protein folding, quality control, and clearance systems, principally the UPS and autophagy-lysosome pathways. Ageing causes deterioration in both systems, leading to the accumulation of misfolded or aggregated proteins. This proteostatic failure is a recognized hallmark of aging and is implicated in disorders ranging from neurological, metabolic, and cardiovascular diseases [2, 80–83]. Conceptual and experimental studies further suggest that certain antibiotics can perturb proteostasis and inter organelle stress signaling, linking anti-infective exposure to senescence-related pathways. Taken together, these data justify discussing epigenetic and proteostasis mechanisms as biologically plausible axes through which anti-infective agents might influence vascular aging, while acknowledging that direct vascular evidence remains limited and largely hypothesis-generating [84].

In a rat model of chemically induced liver fibrosis, treatment with the antimalarial agent dihydroartemisinin (DHA) led to a marked accumulation of senescent activated hepatic stellate cells (HSCs) along fibrotic scars: more than 80% of p16-positive cells co-expressed p53, while fewer than 9% remained Ki-67 positive, indicating effective cell-cycle arrest and senescence rather than proliferation (Zhang et al. [85], 2017). Concurrently, DHA treatment significantly reduced collagen deposition and histological fibrosis scores in a dose-dependent manner compared with untreated fibrotic controls (p < 0.05). In vitro, DHA shifted HSCs toward G₂/M cell-cycle arrest and increased SA-β-gal positivity, alongside upregulation of senescence regulators (p53, p16, p21, HMGA1), confirming senescence induction by DHA. Mechanistically, this senescence induction required activation of autophagy and accumulation of transcription factor GATA6; knockdown of GATA6 abolished the effect, demonstrating a causal link. These findings suggest that DHA can suppress fibrogenic cell activation via induction of senescence, thereby limiting extracellular matrix (ECM) accumulation, a process conceptually analogous to ECM remodeling and fibrosis in vascular aging. Thus, anti-infective agents such as DHA may, under specific conditions, modulate cell homeostasis and tissue remodelling in a way that could impact vascular aging trajectories [85].

In a landmark proteomics study, antibiotic exposure (aminoglycosides) induced frequent clustered translation errors, up to four consecutive amino-acid misincorporations per peptide, with downstream error probability reaching 0.25–0.40 under drug-bound ribosome conditions, and an overall error-cluster frequency up to 10,000-fold above stochastic expectation. The resulting error-laden proteins triggered proteotoxic stress, protein aggregation, heat-shock response activation, and impaired cell viability, even at sub-lethal drug concentrations. Given that proteostasis failure, protein misfolding, and aggregation are established drivers of endothelial senescence, mitochondrial dysfunction, and vascular remodeling, this evidence provides a plausible mechanistic link between aminoglycoside exposure and accelerated vascular ageing, albeit currently restricted to bacterial models [86–88].

Kalghatgi et al. [52] demonstrated that fluoroquinolones, aminoglycosides, and β-lactams trigger mitochondrial dysfunction in mammalian cells, causing profound reductions in basal and maximal respiration and a surge in mitochondrial ROS and H₂O₂ production. This oxidative stress environment is a potent inducer of protein misfolding, oxidation of cysteine and methionine residues, protein carbonylation, and aggregation of damaged polypeptides, classical markers of proteostasis failure. In their study, bactericidal antibiotics increased oxidized DNA (8-OHdG), protein carbonyls, and lipid peroxidation by 2–4-fold (p < 0.01) in human epithelial cells, while mice exposed for 2–16 weeks showed systemic increases in ROS, protein nitration, and upregulation of antioxidant genes such as Sod2 and Gpx1 (≥ 2-fold, p < 0.05). Chronic oxidative stress and accumulation of misfolded or oxidized proteins are recognized triggers of the unfolded protein response (UPR), ER stress activation (PERK-eIF2α, ATF4, CHOP pathways), and impaired autophagy, all of which are well-established drivers of cellular senescence and aging phenotypes. Within vascular tissues specifically, proteostasis decline promotes endothelial dysfunction, reduced nitric-oxide bioavailability, heightened inflammatory signaling, and ECM remodeling, contributing to arterial stiffening and vascular aging. Thus, although the study did not directly examine vascular cells, its finding that bactericidal antibiotics induce widespread oxidative damage and protein-level injury provides a mechanistic foundation for the hypothesis that anti-infective agents may accelerate vascular aging via proteostasis collapse, particularly when mitochondrial injury, ROS generation, and impaired protein quality control converge in long-lived vascular endothelial or smooth-muscle cells. Fluoroquinolones, aminoglycosides, and β-lactams have been shown to induce mitochondrial dysfunction and increased ROS in mammalian cells. This oxidative damage affects proteins, lipids, and DNA, creating additional substrates for UPS removal and eventually saturating its capacity [52]. This could alternatively activate AMPK. However, sustained dysfunction may lead to metabolic inflexibility, chronic mTOR complex 1 (mTORC1) activation, organelle accumulation, and impaired autophagy, similar to observations in nutrient-starved cells [89]. This consequently leads to senescence and the expression of pro-inflammatory signals, typically observed in inflammation-dependent disorders [60, 89].

Some antibiotics, particularly macrolides such as azithromycin and erythromycin, can interfere with autophagic flux. They increase lysosomal pH or disrupt autophagosome-lysosome fusion, leading to the accumulation of undegraded proteins and damaged organelles [88]. In cystic fibrotic patients, where azithromycin has demonstrated significant clinical outcomes, experimental data from Renna et al. [90], 2011 showed that it inhibited autophagosome-lysosome fusion in human epithelial and macrophage models, increasing LC3-II accumulation by 2.5–4.0-fold, elevating p62/SQSTM1 and ubiquitinated protein aggregates by 2–3.5-fold, and reducing lysosomal acidification by 40–60% (p < 0.001). These defects reflect a profound blockade of autophagic flux, leading to impaired clearance of misfolded proteins and damaged mitochondria. Classically, persistent autophagy inhibition triggers ER stress, UPR activation (PERK-eIF2α-ATF4/CHOP), and redox imbalance, canonical pathways that drive proteostasis collapse, mitochondrial dysfunction, senescence, and chronic inflammation. This was further associated with an increased non mycobacteria tuberculosis (NMT) infection susceptibility [90].

Mitochondrial damage triggers a dysfunctional mitophagy response, leading to inefficient clearance of damaged mitochondria. This failure leads to persistent ROS and DNA damage, further promoting inflammation and senescence [33]. Interestingly, long-term administration of the autophagy inhibitor chloroquine (50 mg/kg) to middle-aged mice paradoxically extended both median lifespan (786 vs. 689 days; 11.8% increase, p = 0.0002) and maximum lifespan (11.4%) despite evidence of impaired autophagic flux, proteasome inhibition, and altered glycogen metabolism according to Doeppner et al. [91], 2022. Treated animals displayed 30–40% accumulation of autophagosomes (↑ LC3B-II), a 25–35% reduction in proteasome activity, and decreased hepatic glycogenolysis, together indicating a profound shift in nutrient and proteostasis pathways. In the context of vascular ageing, these findings suggest that partial inhibition of canonical pro-longevity pathways (autophagy, proteasome activity) may still yield lifespan benefits by inducing compensatory metabolic reprogramming and stress adaptation, possibly via altered AMPK-mTOR and NAD⁺/sirtuin nutrient-sensing axes. Such paradoxical benefits highlight the complexity of targeting autophagy and proteostasis in vascular endothelium, where low-grade stressors may mimic hormesis, enhancing resilience to oxidative stress and delaying senescence [91].

Antibiotics, genomic instability, and epigenetics

Currently, no published study directly demonstrates that infections or anti-infectious agents can cause epigenetic modifications. However, both anti-infectious agents and infections may alter the expression profiles of microRNAs (miRNAs) and long ncRNAs (lncRNAs), which, in turn, regulate key epigenetic enzymes such as DNA methyltransferases (DNMT) and histone-modifying proteins [92, 93]. Crimi et al. [94] (2020) review offers important, necessary clinical evidence that bacterial infections, often managed with antimicrobial therapy, can induce substantial and persistent epigenetic remodeling in human tissues. Across multiple patient-derived samples, they documented alterations in DNA methylation patterns, histone acetylation and deacetylation states, and differential expression of ncRNAs, all of which regulate inflammatory signaling, immune activation, and tissue remodeling. These host-directed epigenetic changes, observed in epithelial and immune cells exposed to multidrug-resistant organisms, demonstrate that infection and its treatment can reprogram chromatin architecture in vivo [94].

Clinical and experimental evidence indicates that bacterial infections, often involving drug-resistant strains, can leave lasting epigenetic marks in host cells. For example, infection with Helicobacter pylori is associated with hypermethylation of key epithelial genes such as CDH1, WW domain-containing oxidoreductase (WWOX), and mutL homolog-1 (MLH1), while Listeria monocytogenes and Pseudomonas aeruginosa have been shown to induce histone hyperacetylation or deacetylation, respectively, in human endothelial or immune cells; these chromatin changes alter gene expression programs long-term. Moreover, circulating miRNAs (e.g., miR-361-5p, miR-889, miR-576-3p) are consistently upregulated in patients with chronic or drug-resistant bacterial infections. Such epigenetic reprogramming may create persistent changes in host cell phenotype, potentially contributing to tissue remodeling, chronic inflammation, impaired repair, and, over time, accelerated vascular aging [95–98]. Although evidence in vascular cells is still lacking, these findings provide a biologically plausible epigenetic axis by which repeated infections or anti-infective treatments might accelerate vascular aging. While this review does not investigate vascular or endothelial tissue specifically, the pathways affected, including chronic inflammation, oxidative stress responsiveness, resolution of injury, and immune memory, are central to the biology of endothelial senescence and vascular aging. Thus, the study provides mechanistic plausibility that anti-infective exposures may influence long-term vascular aging trajectories through epigenetic drift or maladaptive chromatin remodeling, even though direct vascular evidence has not yet been established [94].

Ciprofloxacin has been shown to directly modulate host epithelial gene expression via epigenetic mechanisms, independent of its antibacterial activity. In HT-29 human colon epithelial cells, butyrate treatment normally induces strong upregulation of endogenous antimicrobial peptides, LL-37 and β-defensin-3, but co-exposure to ciprofloxacin significantly suppressed this induction in a dose-dependent manner, reducing LL-37 mRNA expression by approximately 45–60% at 20–40 µg/mL (p < 0.01), and β-defensin-3 expression by 40–55% in the same range (p < 0.05). These transcriptional changes were accompanied by a corresponding reduction in LL-37 protein levels, confirmed by western blot analysis. Mechanistically, ciprofloxacin exposure induced dephosphorylation of histone H3 at Ser10, a known regulatory mark associated with transcriptional activation, indicating that the antibiotic suppresses host defense gene expression through epigenetic modification rather than cytotoxicity. Importantly, in vivo validation using a rabbit model showed that ciprofloxacin reduced butyrate-induced mucosal cathelicidin (CAP-18) expression by 50%, reinforcing the physiological relevance of these findings. Hence, the authors argue that the modulation of host gene expression, including key innate immunity peptides, by ciprofloxacin (and clindamycin) occurs via epigenetic mechanisms, likely mediated by histone modifications, rather than purely via microbiota killing or direct bacterial effects [99]. However, because the study was conducted in colon epithelial cells and focused solely on innate-immunity endpoints, showing only a single histone modification (H3-Ser10 dephosphorylation) without broader epigenetic or vascular markers, its relevance to vascular aging remains speculative.

Recent evidence further supports the concept that antibiotics can disrupt host chromatin regulation and epigenetic homeostasis in a manner relevant to aging biology. Ljubić et al. [100] (2025) demonstrated that exposure to widely used antibiotics, geneticin, hygromycin B, and rifampicin, induces robust transcriptional activation of normally silenced pericentromeric α-satellite DNA in human cell lines, with transcription increasing by 1.6–3.0-fold in A-1235 cells and up to 4.9-fold in HeLa cells in a dose-dependent manner (all p < 0.02). This derepression was accompanied by a significant loss of the heterochromatin mark H3K9me3 and a reciprocal gain of the active chromatin mark H3K18ac, revealing antibiotic-induced erosion of heterochromatin integrity. Because satellite DNA activation and heterochromatin relaxation are tightly linked to genomic instability, DNA double-strand breaks, R-loop formation, chromosomal missegregation, and activation of the DDR, these findings are mechanistically important: heterochromatin breakdown is a central hallmark of both cellular senescence and vascular aging. Vascular endothelial and smooth-muscle cells rely on stable heterochromatin to maintain genome integrity, mitochondrial homeostasis, and controlled inflammatory signaling; thus, persistent heterochromatin destabilization is known to accelerate endothelial senescence, increase SASP cytokine release, impair nitric-oxide signaling, and promote arterial stiffening. Although the study did not directly assess vascular cells, the demonstration that clinically relevant antibiotics can alter host chromatin architecture and activate normally silenced repetitive elements provides a biologically plausible pathway by which anti-infective agents might influence vascular-aging trajectories. If similar epigenetic de-repression occurs in endothelial or vascular smooth-muscle cells, it could potentiate genomic instability-driven mitochondrial dysfunction, increase oxidative burden, enhance NF-κB-mediated inflammation, and ultimately accelerate the transition toward a senescent vascular phenotype [100].

Equally, by modulating ncRNA activity, this could indirectly reshape chromatin structure and gene expression, thereby contributing to ageing and disease course. This ncRNA-epigenetic axis highlights a novel and underexplored pathway through which antibiotics might influence long-term cellular functions. For example, Miravirsen, an antisense oligonucleotide targeting miR-122, has shown antiviral efficacy against hepatitis C virus (HCV) [101, 102]; lncRNA 9708-1 enhances antifungal defense in murine models of vulvovaginal candidiasis by upregulating FAK and strengthening epithelial barriers [103]; and emerging antiviral miRNA therapies, such as miRNA mimics or inhibitors, are being investigated to block viral replication or boost immune responses, particularly in SARS-CoV-2 [104].

Crimi et al. [94] (2020) reported that hypermethylation of DNA at the E-cadherin (CDH1), upstream transcription factor-1/2 (USF1/2), WWOX, and MLH1 loci in gastric mucosa was associated with malignant transformation, suggesting their potential as early disease biomarkers. In addition, miR-361-5p, miR-889, and miR-576-3p were found to be upregulated in tuberculosis patients. Similarly, Listeria monocytogenes indirectly promoted histone H3 hyperacetylation, triggering inflammatory responses in human ECs. In contrast, Pseudomonas aeruginosa secreted the quorum-sensing molecule 2-aminoacetophenone (2-AA), which directly induced H3 deacetylation and facilitated bacterial persistence in human monocytes. Together, these findings underscore the substantial role of infectious pathogens in modulating epigenetic mechanisms, a key hallmark of ageing [94].

In a whole-genome sequencing study of HSPCs from HSCT donors and recipients, de Kanter et al. [105] identified a subset of transplant recipients in whom multiple HSPC clones exhibited several-fold higher age-adjusted mutation burdens and a distinctive single-base substitution signature (SBSA) dominated by C>A transversions. In vitro exposure of human CD34⁺ HSPCs to ganciclovir (5 µM) significantly increased γ-H2AX signal and single-base substitutions compared with untreated cells. It recapitulated the SBSA mutational profile, thereby causally linking this nucleoside-analog antiviral to enhanced mutagenesis. Machine-learning analysis further detected SBSA in therapy-related leukemias and solid tumors of transplant recipients, where it contributed a substantial fraction of total mutations, including cancer driver events. These data provide strong mechanistic evidence that prolonged antiviral therapy can impose a persistent mutational “scar” on human stem cells, reinforcing genomic instability as a potential route through which anti-infective exposure may accelerate biological and vascular ageing in vulnerable populations [105]. Other mechanisms through which anti-infectious agents may modulate epigenetic response may include the following.

Mitochondrial dysfunction leads to NAD⁺ depletion and subsequent sirtuin loss

Bactericidal antibiotics (ciprofloxacin, ampicillin, kanamycin) impair mitochondrial function and increase ROS production in mammalian cells, causing oxidative damage to DNA, lipids, and proteins [52]. Kalghatgi et al. [52] (2013) provided compelling mechanistic evidence that clinically relevant concentrations of bactericidal antibiotics, including ciprofloxacin, ampicillin, and kanamycin, induce significant mitochondrial dysfunction and oxidative damage in human epithelial and fibroblast cells. These agents caused sharp increases in intracellular ROS, mitochondrial superoxide, and H₂O₂ release (p < 0.01), accompanied by inhibition of electron transporter chain (ETC) complexes I (↓ 16–25%) and III (↓ 30–40%). Resulting oxidative injury was evident through elevated γ-H2AX foci, 8-OH-dG, protein carbonyls, and MDA. In vivo, antibiotic-treated mice exhibited parallel systemic oxidative stress, demonstrating physiological relevance. Importantly, antioxidant co-treatment (NAC) fully rescued mitochondrial and oxidative abnormalities without reducing antimicrobial efficacy [52]. Elevated ROS levels activate the DDR and deplete NAD⁺, a cofactor critical for SIRTUIN activities. Loss of sirtuin-mediated histone deacetylation (notably H4K16ac and H3K9ac) disrupts heterochromatin structure, impairs DNA repair pathways such as non-homologous end joining (NHEJ) and homologous recombination (HR), and exacerbates genomic instability and inflammation-induced senescence in vascular cells [106].

Gut microbiome disruption leads to SCFA depletion and subsequent epigenetic shifts

Krautkramer et al. [107] (2016) found that the gut microbiota profoundly influenced global histone post-translational modifications across multiple tissues. In germ-free mice, histone acetylation/methylation states differ markedly from those of conventionally colonized mice. However, supplementation with SCFAs, especially butyrate and propionate, restores histone modification patterns to those seen in colonized animals. Broad-spectrum antibiotics can reduce SCFA-producing bacteria by up to 70%, thus reducing SCFA availability [107]. Since SCFAs act as endogenous HDACi, their depletion skews chromatin toward hyper-repression of anti-inflammatory genes and expression of pro-inflammatory SASP gene programmes. In addition, altered microbiota affect the activity of DNMT and ten-eleven translocation (TET) enzymes, contributing to site-specific DNA methylation changes that favor senescence and vascular inflammation [107, 108]. The compounding effects of mitochondrial dysfunction and epigenetic dysregulation, characterized by NAD⁺ depletion, histone hyperacetylation, and DNA methylation changes, lead to genomic instability, including increased γ-H2AX foci, telomere shortening, activation of retrotransposons, and DNA repair deficiency. In both ECs and VSMCs, these insults induce a senescent phenotype characterized by elevated p16^INK4a/p21^CIP1 expression, SASP secretion, oxidative stress, and dysfunctional ECM production. Senescent VSMCs shift towards a synthetic, pro-inflammatory phenotype, promoting arterial stiffening and plaque progression. ECs exhibit reduced NO bioavailability, increased permeability, impaired angiogenesis, and elevated inflammatory gene expression, all of which are signatures of vascular aging [2, 81, 83].

Other anti-infective drugs and vascular ageing

Beyond the well-documented off-target effects of antibiotics, emerging evidence suggests that other anti-infectious agents, including antivirals, antiparasitics, and antifungals, may significantly influence vascular ageing processes. These agents, through mechanisms such as mitochondrial toxicity, oxidative stress generation, and disruption of angiogenic and nutrient-sensing pathways, have the potential to induce endothelial dysfunction, accelerate vascular senescence, and impair tissue repair dynamics [106, 109, 110].

In primary human coronary artery ECs (HCAECs), PI (ritonavir and lopinavir) accelerated premature senescence, increased ROS, increased cell cycle inhibitors (p16^INK4a, p21^CIP1), reduced proliferation, and triggered SASP-associated inflammation. Senescence markers were also elevated in peripheral blood mononuclear cells (PBMCs) from HIV patients receiving PI therapy [111–113].

Broad-spectrum antivirals (e.g., tenofovir, zidovudine, remdesivir), in cultured human aortic ECs (HAECs), caused mitochondrial membrane depolarization, elevated ROS, altered lysosomal content, reduced vWF expression, and signs of autophagy dysregulation and micronuclei formation, hallmarks of endothelial aging and dysfunction [112, 114–116]. In a study by Auclair et al. [117] to delineate which molecular pathways (especially SIRT1, USP18, inflammation, insulin signaling) are modulated by ART (dolutegravir, maraviroc, and ritonavir-boosted atazanavir) in HCAECs, and examine how ART influences vascular aging phenotypes, dolutegravir and maraviroc appeared to have protective or neutral effects (reducing inflammation, suppressing senescence) in coronary ECs; atazanavir/r, in contrast, promoted endothelial senescence and inflammation [117]. Other studies show that antiviral and ART stress converge on the miR-34a-SIRT1 axis to accelerate vascular aging [118–120]. In vitro, HIV-Tat protein (100 nM) or PI such as lopinavir/ritonavir (102 µM) significantly increased senescence in ECs, with SA-β-gal positivity increasing by 40% and SIRT1 protein decreasing by 40% (n = 6, p < 0.01); these effects were rescued by antagomiR-34a, confirming a causal role [118]. In vivo, mice exposed to NRTI (AZT, stavudine) displayed impaired acetylcholine-induced vasorelaxation, accompanied by increased vascular superoxide; scavenging with tiron restored endothelial responses, implicating ROS-mediated NO quenching as the proximate mechanism of dysfunction [121]. Human data reinforce these findings: ECs from HIV-positive patients receiving ART exhibited elevated miR-34a levels and reduced SIRT1 levels compared with uninfected controls (n = 6–9, p < 0.05), correlating with vascular stiffness and endothelial dysfunction [118]. More broadly, induction of miR-34a under chronic antiviral stress has been associated with both cardiovascular disorders (atherosclerosis, endothelial dysfunction) and neurological complications (cerebrovascular ageing, BBB impairment), highlighting its role as a stress-responsive hub in vascular senescence [122, 123]. Additionally, in HIV-1 infected patients on highly active ART (HAART), the prognosis has significantly improved, but was associated with significant side effects such as diabetes, atherosclerosis, and cardiovascular complications, and miR-34/SIRT1-dependent epigenetic modifications [124]. A surge in oxidative stress and, consequently, inflammation in human mononuclear cells, which are a type of white blood cell, was noted. This process is often linked to the development of inflammation-dependent disorders such as atherosclerosis and other cardiovascular diseases [125, 126].

In human microvascular ECs (HMEC-1 or HUVEC), itraconazole inhibited VEGFR2 glycosylation and signaling, blocked endothelial proliferation, and suppressed in vivo angiogenesis. Impaired angiogenic capacity contributes to vascular aging and repair deficits. However, these cellular effects have shown benefits in antitumor therapy [127–129]. Head et al. [127] demonstrated that the antifungal itraconazole directly targets VDAC1 in ECs, disrupting a critical mitochondrial gatekeeper of metabolic flux. By binding to VDAC1, itraconazole reduced mitochondrial membrane potential by 30–40% and suppressed oxygen consumption by 25–35%, while simultaneously increasing mitochondrial ROS nearly twofold and reducing endothelial proliferation by 40%. In the context of nutrient sensing and vascular aging, these effects mirror age-associated impairments in mitochondrial nutrient utilization and redox signaling: reduced adenosine triphosphate (ATP)-linked respiration compromises energy sensing via AMPK-mTOR pathways, while excess ROS disturbs the balance of NAD⁺/sirtuin signaling. Collectively, itraconazole’s off-target action on VDAC1 illustrates how pharmacological disruption of mitochondrial nutrient sensing accelerates hallmarks of vascular aging, including bioenergetic decline, oxidative stress, and impaired endothelial repair [127, 128].

Furthermore, in a recent preclinical study, miconazole significantly reduced cellular senescence in colonic epithelial cells and improved colitis outcomes in a murine colitis model. Specifically, treatment reduced the proportion of SA-β-gal-positive cells and downregulated p16/p21 expression in DSS-injured colonic cells. In vivo, miconazole ameliorated weight loss, reduced bloody stools, and restored colonic mucosal integrity, concomitant with suppression of NF-κB inflammatory signaling and modulation of gut microbiota. These data suggest that miconazole might exert a senomorph-like effect under inflammatory stress [130]. In a vascular EC line (EA.hy926), amphotericin B (a polyene antifungal) induced membrane depolarization, decreased Ca²⁺ signaling, and reduced the cellular ATP/adenosine diphosphate (ADP) ratio by more than 30%, indicating mitochondrial dysfunction and impaired energy metabolism, both potential triggers for endothelial senescence and vascular dysfunction [131]. Interestingly, Ciclopirox (CPX), a topical antifungal agent and iron chelator, has been shown to induce senescence in HPV-positive cervical cancer lines, suppressing viral oncogenes and arresting proliferation even when mTOR signalling is impaired. With longer treatment, apoptosis follows. This suggests that specific antifungal agents may promote positive senescence and could be repurposed for cancer or aging interventions [132]. Repurposed from its antiparasitic use, thiabendazole has been shown to disrupt established blood vessels in animal models, acting as a vascular disrupting agent. It reversibly dismantles vascular structures and reduces angiogenesis in preclinical tumor models, suggesting potential effects on vascular homeostasis if applied chronically [133, 134]. A summary describing the implications of anti-infectious agents on vascular aging and a possible conceptual framework are shown in Figures 3 and 4, respectively. They address study heterogeneity by introducing a multilayered, pathway-centric framework that integrates diverse findings across mitochondrial dysfunction, microbiome signaling, proteostasis failure, and senescence/SASP, enabling mechanistic synthesis without overstating direct clinical causality (Figures 3 and 4).

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Figure 3. Flow chart showing the dual impact of anti-infectious agents on vascular ageing. Antibiotics disrupt the gut microbiota, leading to dysbiosis that, in turn, contributes to mitochondrial dysfunction, inflammation, oxidative stress, and epigenetic deregulation. Antivirals (e.g., tenofovir, efavirenz), antifungals (e.g., itraconazole), and antiparasitics (e.g., thiabendazole) directly converge on shared mechanisms. Together, these pathways accelerate vascular aging outcomes, including endothelial dysfunction and impaired vascular repair. Created in BioRender. Silumbwe, C. (2026) https://BioRender.com/cqjy6qr.

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Figure 4. Dual role of anti-infective drugs in vascular ageing. Protective agents such as tetracyclines (e.g., doxycycline) and macrolides (e.g., azithromycin) exert vasculoprotective actions by suppressing SASP, preserving mitochondrial function, and reducing inflammation. On the contrary, pro-ageing agents, including aminoglycosides (gentamicin), fluoroquinolones (ciprofloxacin), antivirals (protease inhibitors), antifungals (itraconazole), and antiparasitics (thiabendazole), promote mitochondrial toxicity, proteostasis disruption, angiogenesis inhibition, and dysbiosis, thereby accelerating vascular ageing. SASP: senescence-associated secretory phenotype. Created in BioRender. Silumbwe, C. (2026) https://BioRender.com/2k1v3di.

Vaccines as potential therapeutic strategies

Recent advances in geroscience highlight that immune-based interventions, including vaccines, can be strategically designed to target pathological aging pathways. Building on this, our synthesis suggests that anti-infective agents may serve as a conceptual blueprint for developing vascular-ageing-focused vaccines. Several features of anti-infectives make them ideal prototypes: many exhibit precise molecular targeting (e.g., bacterial ribosomes, viral proteases), predictable off-target liabilities (e.g., mitochondrial toxicity, gut dysbiosis), and well-characterized immunomodulatory effects. These same properties mirror the mechanisms now being pursued in next-generation geroprotective vaccines, such as antigen-specific immunization against IL-1β, ANGII/AT1R, oxidized LDL epitopes, tau, NGF, or TGF-β. Notably, vaccines are emerging as major therapeutic options for age-related diseases, including atherosclerosis, abdominal aortic aneurysm, hypertension, osteoarthritis, and T2DM, by inducing durable, antigen-specific immune modulation [148–151]. Situating anti-infective drugs within this broader immune-targeted framework underscores a critical translational insight. The adverse vascular effects observed with some anti-infective classes (e.g., fluoroquinolone-associated elastin degradation, aminoglycoside mitochondrial injury) illuminate the same biological pathways (proteostasis loss, mitochondrial dysfunction, ECM remodeling, inflammaging) that geroprotective vaccines aim to modulate. Therefore, understanding these mechanisms not only supports safer use of anti-infectives but also offers a novel conceptual foundation for identifying antigens, pathways, and biomarkers that could be leveraged in future vascular-aging vaccine design. This reframes anti-infective drugs not simply as risk modifiers but as mechanistic “experiments of nature” that reveal therapeutic targets for vaccine-based strategies against vascular aging (see Table 4).

Collectively, Tables 3, 5, 6, and 7 integrate mechanistic, animal, and human evidence to demonstrate that anti-infective agents exert class-specific, bidirectional effects on vascular aging, with protective actions linked to anti-inflammatory and senomorphic pathways, and adverse effects driven by mitochondrial dysfunction, proteostasis disruption, and microbiome-mediated inflammageing, within clearly defined levels of bias and translational relevance.