Şefika Nur Demir

Ms. Şefika Nur Demir

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 January 2025 in Mutation Research - Genetic Toxicology and Environmental Mutagenesis
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Journal Article
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Ahmet Ali BerberAhmet Ali Berber
Ahmet Ali Berber
ŞDŞefika Nur Demir
Şefika Nur Demir
NKNihan Akıncı Kenanoğlu
Nihan Akıncı Kenanoğlu
HAHüseyin Aksoy
Hüseyin Aksoy

15 June 2026 in Toxics
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Journal Article
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Ahmet Ali BerberAhmet Ali Berber
Ahmet Ali Berber
CACansu Akbulut
Cansu Akbulut
ŞDŞefika Nur Demir
Şefika Nur Demir
MKMuammer Kurnaz
Muammer Kurnaz
Microplastic (MP) contamination has become a defining feature of twenty-first century environmental change, yet the toxicological and ecological consequences for amphibians and reptiles—two vertebrate classes already facing severe extinction pressures—remain fragmented across taxa, regions, and methodological traditions. Here, we synthesize field and experimental evidence from five continents to provide a taxonomically balanced, mechanistically grounded, and geographically explicit assessment of MP exposure, bioaccumulation, and toxicity in herpetofauna, drawing on a structured literature search in Web of Science, Scopus, and PubMed (January 2015—March 2026). Field detection rates of MPs in amphibian larvae range from 26% in conservatively screened Central European populations to 73–80% in anuran tadpoles from high-anthropogenic-pressure Anatolian catchments, with fibrous polyethylene terephthalate (PET), polyethylene (PE), and polypropylene (PP) particles dominating the detected burden. Mechanistic evidence converges on oxidative stress cascades, hypothalamic–pituitary–thyroid axis disruption, gut and cutaneous microbiome dysbiosis, and compromised antiviral and antifungal immunity, with the latter potentially amplifying vulnerability to Batrachochytrium dendrobatidis and to ranavirus. Among reptiles, sea turtles display near-universal MP ingestion with documented maternal transfer to eggs; freshwater turtles, terrestrial squamates, and crocodilians remain critically understudied. Three structural asymmetries constrain current ecotoxicological risk characterization: taxonomic bias toward anurans and sea turtles, geographic bias toward the Global North, and experimental bias toward acute, supra-environmental laboratory exposures using pristine, single-polymer particles that fail to capture the chemical complexity of weathered field mixtures. We argue that MP burden may warrant consideration as a candidate stressor criterion within IUCN Red List assessments and within environmental risk assessment frameworks for freshwater and terrestrial biodiversity once a robust quantitative relationship between MP burden and demographic decline or population-level fitness has been established, and propose six hypothesis-driven research priorities: methodological standardization, reptile toxicokinetics, transgenerational epigenetics, MP–pathogen microbiome interactions and their translation into population viability models, temperature × MP interaction under climate warming, and population-genetic consequences of contemporary MP-driven selection, as the most tractable avenues for ecotoxicological progress and for the development of herpetofauna-specific risk characterization frameworks.

25 August 2023 in Sakarya University Journal of Science
Verified
Journal Article
Closed access
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Ahmet Ali BerberAhmet Ali Berber
Ahmet Ali Berber
ŞDŞefika Nur Demir
Şefika Nur Demir
NKNihan Akıncı Kenanoğlu
Nihan Akıncı Kenanoğlu
The extensive use of herbicidal products in agriculture and forestry has raised concerns over potential adverse effects on human health and the environment. Chloroacetanilide herbicides are a group of synthetic chemicals used to control weeds in agriculture and forestry. However, so[me of their members have been characterized as possible carcinogens. The genotoxicity and carcinogenicity of two chloroacetanilide herbicides, delachlor and xylachlor, are discussed. This article proposes to use tools to predict their potential toxicities based on their chemical structure. Four software tools, Vega Hub, Toxtree, Lazar, and TEST, are used to predict the potential genotoxic and carcinogenic effects of the herbicides. Vega Hub uses QSAR models, Toxtree uses a decision tree approach, Lazar uses data mining algorithms, and TEST uses QSAR methods to estimate toxicity. The canonical Simplified Molecular Input Line Entry Specification (SMILES) systems of delachlor and xylachlor are entered into each software tool to create a prediction. The study found that delachlor and xylachlor is a class 3 highly toxic compounds with potential mutagenic and carcinogenic effects based on Toxtree and Vega Hub. Meanwhile, Lazar and TEST predicted that delachlor and xylachlor are unlikely to be mutagenic. This study to determine the toxicity of the herbicides delachlor and xylachlor has shown that the possible effects of these herbicides on health and the environment need to be further investigated. The results provide valuable insights into chloroacetanilide herbicide toxicity and help develop safer, more environmentally friendly alternatives.

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Ahmet Ali BerberAhmet Ali Berber
Ahmet Ali Berber
EYEsra Yıldız
Esra Yıldız
ŞDŞefika Nur Demir
Şefika Nur Demir
NKNihan Akıncı Kenanoğlu
Nihan Akıncı Kenanoğlu
NBNurcan Berber
Nurcan Berber
Global antibiotic consumption continues to rise across pediatric and adult populations, while the genotoxic consequences of host eukaryotic exposure remain less systematically characterized than the parallel problem of antimicrobial resistance. Several lines of evidence, from molecular cytogenetics, redox biology, and systems toxicology, now permit a more mechanistically resolved synthesis of antibiotic-induced genome stress than was previously possible, although a substantial fraction of this evidence is preclinical and warrants cautious clinical extrapolation. This narrative review evaluates the molecular mechanisms, cytogenetic biomarkers, and translational implications of antibiotic-induced genotoxicity, with a primary focus on six clinically prominent classes (fluoroquinolones, nitroimidazoles, aminoglycosides, macrolides, β-lactams, and tetracyclines) and a brief extension to glycopeptides and glycylcyclines. We organize the evidence around three convergent mechanistic axes rather than around individual drugs. Accumulating evidence supports three intersecting off-target axes: (i) eukaryotic topoisomerase II interference, principally documented for fluoroquinolones; (ii) mitochondrial dysfunction, reflecting the evolutionary kinship between the mitoribosome and bacterial ribosomes; and (iii) inflammation-coupled redox stress, often amplified by microbiome perturbation. These pathways converge on a common spectrum of DNA lesions—including double-strand breaks, oxidatively modified bases, replication-fork stalling, and chromosomal mis-segregation) detected by complementary assays (CBMN-Cyt, comet, γH2AX, and oxidative and mitochondrial biomarkers). Pediatric, pregnant, geriatric, and oncology populations may represent biologically distinct susceptibility strata, although direct human evidence for several of these inferences remains limited. Causal inference is constrained by infection as a confounder, frequent use of supratherapeutic in vitro concentrations, reliance on immortalized cell lines that may not recapitulate primary-cell repair capacity, inter-laboratory variability across cytogenetic assays, and a marked scarcity of pediatric and pregnancy biomonitoring data. Most existing positive signals derive from preclinical models; clinically validated long-term outcomes, particularly carcinogenic endpoints, remain inconsistently demonstrated for most antibiotic classes outside metronidazole. Antibiotic-induced genotoxicity appears to be a measurable and mechanistically tractable dimension of drug safety, though its clinical magnitude in real-world exposure scenarios requires further investigation. Integrating multi-omics, microphysiological systems, single-cell genotoxicology, and AI-assisted prediction may improve risk resolution, particularly in vulnerable populations. We argue that antimicrobial stewardship discussions should consider host genome integrity alongside resistance, while remaining mindful that the mechanistic case currently outpaces clinical-endpoint validation.

Verified
Journal Article
Open access
PDF file
Ahmet Ali BerberAhmet Ali Berber
Ahmet Ali Berber
CACansu Akbulut
Cansu Akbulut
EYEsra Yıldız
Esra Yıldız
Sinem ÖztürkSinem Öztürk
Sinem Öztürk
ŞDŞefika Nur Demir
Şefika Nur Demir
NBNurcan Berber
Nurcan Berber
This study evaluates the cytotoxic and genotoxic-like potential of an ipfencarbazone-based herbicide formulation (IPF-BH; commercial product Hokuto, containing 250 g/L of the triazolinone herbicide ipfencarbazone) in human peripheral lymphocytes in vitro across a concentration range of 62.5–1000 µg/mL. Cytotoxicity was monitored via the mitotic index (MI), while cytogenetic damage was assessed using the cytokinesis-block micronucleus (MN) assay and the alkaline comet assays. Comparisons were performed using one-way ANOVA, followed by Dunnett’s post hoc test, against the negative control. Results indicated a concentration-dependent cytotoxic effect, with a marked reduction in MI observed at all tested concentrations (p < 0.001). MN frequency was significantly elevated at concentrations ≥125 µg/mL, whereas the 62.5 µg/mL concentration did not induce significant micronuclei formation. The comet assay revealed increased DNA damage parameters (tail length, tail intensity (%), and tail moment) across the tested concentration range, albeit with a non-monotonic profile for tail length and tail intensity. These findings suggest that IPF-BH exposure is associated with marked cytotoxicity and a genotoxic response in this in vitro model at concentrations within the OECD 487-acceptable cytotoxicity window, together with cytotoxicity-associated genotoxic-like effects at strongly cytotoxic concentrations in human peripheral lymphocytes under in vitro conditions. Because IPF-BH is a commercial formulation, and no direct mechanistic endpoints (e.g., reactive oxygen species, mitochondrial transmembrane potential, lipid peroxidation, glutathione) were measured, and because the present design was performed without exogenous metabolic activation (no S9 supplementation), the observed effects cannot be unambiguously attributed to ipfencarbazone alone or to a defined mechanism of action; extrapolation to in vivo genotoxicity requires complementary +S9 and rodent in vivo follow-up studies.