Radka Tafradjiiska-Hadjiolova

Prof. Dr. Radka Tafradjiiska-Hadjiolova


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

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

Representative Publications

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Verified
Journal Article
Open access
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Georgeta BochevaGeorgeta Bocheva
Georgeta Bocheva
Dimitar BakalovDimitar Bakalov
Dimitar Bakalov
PIPetar Iliev
Petar Iliev
RTRadka Tafradjiiska-Hadjiolova
Radka Tafradjiiska-Hadjiolova
While primarily produced in the pineal gland, melatonin’s influence goes beyond its well-known role in regulating sleep, nighttime metabolism, and circadian rhythms, in the field of chronobiology. A plethora of new data demonstrates melatonin to be a very powerful molecule, being a potent ROS/RNS scavenger with anti-inflammatory, immunoregulatory, and oncostatic properties. Melatonin and its metabolites exert multiple beneficial effects in cutaneous and systemic aging. This review is focused on the neuroprotective role of melatonin during aging. Melatonin has an anti-aging capacity, retarding the rate of healthy brain aging and the development of age-related neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, multiple sclerosis, amyotrophic lateral sclerosis, etc. Melatonin, as well as its metabolites, N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) and N1-acetyl-5-methoxykynuramine (AMK), can reduce oxidative brain damage by shielding mitochondria from dysfunction during the aging process. Melatonin could also be implicated in the treatment of neurodegenerative conditions, by modifying their characteristic low-grade neuroinflammation. It can either prevent the initiation of inflammatory responses or attenuate the ongoing inflammation. Drawing on the current knowledge, this review discusses the potential benefits of melatonin supplementation in preventing and managing cognitive impairment and neurodegenerative diseases.

23 May 2025 in Nutrients
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Journal Article
Open access
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TKTanya Kadiyska
Tanya Kadiyska
DVDimitar Vassilev
Dimitar Vassilev
ITIvan Tourtourikov
Ivan Tourtourikov
SCStanislava Ciurinskiene
Stanislava Ciurinskiene
DMDilyana Madzharova
Dilyana Madzharova
VMVanyo Mitev
Vanyo Mitev
Background/Objectives: Autism spectrum disorder (ASD) has a wide-ranging impact on individuals’ quality of life and development, and there is a critical need for greater awareness, early intervention, and comprehensive support strategies to effectively address the unique needs of those affected by ASD. Recent studies highlight the gut microbiome’s potential role in modulating ASD symptoms via the gut–brain axis, but specific microbial biomarkers remain unclear. This study aims to investigate differences in gut microbiota composition between ASD patients and neurotypical controls in a novel approach, specifically assessing ratios of Firmicutes/Bacteroidetes (F/B), Actinobacteria/Proteobacteria (A/P), and Prevotella/Bacteroides (P/B) as potential biomarkers. Methods: We analyzed gut microbiome samples from 302 Bulgarian children and adolescents diagnosed with ASD (aged 2–19 years). Microbial ratios (F/B, A/P, and P/B) were calculated and compared against previously reported reference meta-analytic means from European neurotypical populations. The statistical significance of deviations was assessed using parametric (t-tests), non-parametric (Wilcoxon signed-rank tests), and proportion-based (binomial tests) methods. Effect sizes were quantified using Cohen’s d. Significant differences between ASD cases and neurotypical reference values were observed across several age groups. Results: Notably, children with ASD demonstrated significantly lower F/B and A/P ratios, with the youngest cohort (0–4 years) exhibiting the greatest differences. Deviations in the P/B ratio varied across age groups, with a significant elevation in the oldest group (≥10 years). Collectively, ASD cases consistently exhibited microbiota profiles indicative of dysbiosis. Conclusions: Our findings support gut microbiome dysbiosis as a potential biomarker for ASD, highlighting significantly altered bacterial ratios compared to neurotypical controls. These microbiome shifts could reflect early-life disruptions influencing neurodevelopment. Future studies should adopt longitudinal and mechanistic approaches to elucidate causal relationships and evaluate therapeutic microbiome modulation strategies.

18 January 2022 in Applied Sciences
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Journal Article
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Evgenia BenovaEvgenia Benova
Evgenia Benova
PMPlamena Marinova
Plamena Marinova
RTRadka Tafradjiiska-Hadjiolova
Radka Tafradjiiska-Hadjiolova
ZSZafer Ahmed Sabit
Zafer Ahmed Sabit
Dimitar BakalovDimitar Bakalov
Dimitar Bakalov
Todor Ganchev BogdanovTodor Ganchev Bogdanov
Todor Ganchev Bogdanov
Cold atmospheric plasma (CAP) applications in various fields, such as biology, medicine and agriculture, have significantly grown during recent years. Many new types of plasma sources operating at atmospheric pressure in open air were developed. In order to use such plasmas for the treatment of biological systems, plasma properties should fulfil strong requirements. One of the most important is the prevention from heating damage. That is why in many cases, the post-discharge region is used for treatment, but the short living particles in the active discharge zone and reactions with them are missed in that case. We use the active region of surface-wave-sustained argon plasma for biological systems treatment. The previous investigations showed good bactericidal, virucidal, seeds germination and decontamination effects at a short treatment time, but the discharge conditions for bio-medical applications need specific adjustment. A detailed theoretical and experimental investigation of the plasma characteristics and their possible optimization in order to meet the requirements for bio-medical applications are presented in this paper. The length of the plasma torch, the temperature at the treatment sample position and the microwave radiation there are estimated and optimized by the appropriate choice of discharge tube size, argon flow rate and microwave power.

10 December 2023 in Processes
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Journal Article
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Todor Ganchev BogdanovTodor Ganchev Bogdanov
Todor Ganchev Bogdanov
PMPlamena Marinova
Plamena Marinova
Lubomir TraikovLubomir Traikov
Lubomir Traikov
Pavlina Andreeva-GatevaPavlina Andreeva-Gateva
Pavlina Andreeva-Gateva
TSTheophil Sedloev
Theophil Sedloev
THTodor Hikov
Todor Hikov
Impaired wound healing in diabetic individuals presents a significant clinical challenge, and this study explores the impact of low-temperature microwave plasma in an argon atmosphere, a type of cold atmospheric plasma (CAP), on wound regeneration in diabetic rats. The findings reveal that this CAP treatment accelerates wound regeneration in diabetic rats, promoting faster wound closure, reducing inflammation, and enhancing critical regenerative processes such as angiogenesis, collagen synthesis, and extracellular matrix remodeling. Additionally, CAP exhibits anti-inflammatory effects by modulating the immune response towards a pro-regenerative state. These results underscore the potential of CAP in diabetic wound care, offering a promising approach to address delayed wound healing in diabetic patients and potentially improving the quality of life for those with chronic diabetic wounds.

4 March 2026 in Metabolites
Verified
Journal Article
Open access
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VSVictor Slavov
Victor Slavov
Lubomir TraikovLubomir Traikov
Lubomir Traikov
SCStanislava Ciurinskiene
Stanislava Ciurinskiene
RTRadka Tafradjiiska-Hadjiolova
Radka Tafradjiiska-Hadjiolova
TKTanya Kadiyska
Tanya Kadiyska
Background/Objectives: Autism spectrum disorder (ASD) is biologically heterogeneous, and immune-linked variation may be associated with differences in tryptophan–kynurenine pathway (KP) metabolism. Here, we report a targeted urinary profile of KP metabolites, NAD (nicotinamide adenine dinucleotide), and neopterin in a Bulgarian pediatric ASD cohort to describe within-cohort patterns and associations. Methods: Second-morning, acid-stabilized spot urine was collected from 73 children with ASD in Bulgaria (3–13 years; 57 males; 16 females). No contemporaneous neurotypical control group was enrolled; therefore, laboratory-provided reference limits are reported only as contextual benchmarks and are not interpreted as ASD-specific abnormalities. Tryptophan (TRP), kynurenine (KYN), kynurenic acid (KYNA), 3-hydroxykynurenine (3-HK), quinolinic acid (QUIN), NAD, and neopterin were quantified and derived indices were computed (KYN/TRP × 1000; QUIN/KYNA). Non-parametric statistics, Benjamini–Hochberg false discovery rate (FDR) correction, and Spearman correlation analyses were applied. Results: Neopterin was strongly associated with QUIN and KYN in creatinine-normalized data (QUIN: ρ = 0.59, q36 = 2.64 × 10−7; KYN: ρ = 0.54, q36 = 3.69 × 10−6); these associations persisted when reconstructed as absolute concentrations (e.g., QUIN_abs: ρ = 0.68, q36 = 2.69 × 10−10) and after partial Spearman correlation controlling for spot creatinine (partial ρ = 0.46, q = 2.52 × 10−4). One NAD value was <LOQ and was imputed as ½LOQ; sensitivity analyses did not materially change inference. Conclusions: In this ASD-only cross-sectional dataset, urinary neopterin levels co-varied with urinary KYN and QUIN and with KP indices. Clinical interpretation and causal inference require controlled and longitudinal studies with richer covariate capture.

17 July 2024 in Processes
Verified
Journal Article
Open access
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Todor Ganchev BogdanovTodor Ganchev Bogdanov
Todor Ganchev Bogdanov
MSMaria Simeonova
Maria Simeonova
Lubomir TraikovLubomir Traikov
Lubomir Traikov
THTodor Hikov
Todor Hikov
APAndrey Petrov
Andrey Petrov
RMRene Mileva
Rene Mileva
Our study explores the potential of a novel microwave plasma source for enhancing wound healing in BALB-C mouse models. Chronic wounds, particularly in diabetic individuals, present significant challenges due to impaired regenerative capacity. Cold Atmospheric Plasma (CAP) has emerged as a promising approach, offering diverse therapeutic benefits. However, its specific efficacy in the context of diabetic wounds remains underexplored. We developed and characterized a microwave plasma source optimized for wound treatment, inducing acute wounds and treating them with CAP in a controlled experimental setup. The treated group exhibited accelerated wound closure compared to controls, suggesting CAP’s potential to enhance the healing process. Our findings underscore CAP’s multifaceted impact on the wound healing cascade, highlighting its ability to promote angiogenesis, modulate inflammatory responses, and exhibit antimicrobial properties. These results position CAP as a promising intervention in acute wound management, paving the way for further exploration of its therapeutic potential in clinical settings.