Search Results (54)

Monitoring ultraviolet (UV) radiation dose distribution is crucial in many fields, like medicine and materials science, but traditional point-of-care methods limit the ability to fully assess the spatial extent of the irradiated surface. This paper presents the characterisation of a two-dimensional (2D) dosimetry system based on Pluronic F-127 hydrogel matrix doped with 2,3,5-triphenyltetrazolium chloride (TTC) with respect to exposition to UVA radiation. The hydrogel matrix (25% w/w) provides both high transparency and mechanical stability, while TTC (0.1% w/w) functions as a colour precursor that undergoes irreversible reduction to form water-insoluble red formazan upon UVA exposure. The insolubility of TTC formazan ensures that the resulting colour changes remain spatially stable within the dosimeter. The study included sample preparation in flat PMMA containers and analysis of the effect of radiation field uniformity in a UVP CL-1000 exposure chamber. It was supported by application of Kodak X-Omat 100 NIF UV Film dosimetry. The actual dose distribution in the chamber was shown to be significantly heterogeneous (CV coefficient of variation of approximately 18%), which emphasises the need for 2D dosimeters for precise validation of irradiation devices. The use of flatbed scanning and dedicated image analysis software allowed obtaining precise 2D dose distribution maps. The dosimeter was characterised in the dose range of 0–5000 mJ/cm², showing a reproducible response (R² = 0.9967). A resolution test was conducted to assess the precision of geometric representation. In the final stage of the study, the suitability of the developed dosimetry system was verified under conditions simulating heterogeneous UV radiation dose distribution using patterns printed with Computer-to-Film (CtF) technology. The results showed that optical effects in printed films significantly affect UV transmission, limiting accurate dose recording for black coverage above approximately 40–50%. The results obtained confirm that the TTC-Pluronic F-127 system is an effective, simple and low-cost tool for 2D monitoring of UVA radiation, with potential applications in cosmetology, dermatology, and material ageing tests. Full article

Background: Metabolic syndrome (MetS) is a cluster of pathologies (obesity, dyslipidemia, insulin resistance, hypertension) that affects over one quarter of old adults. MetS is a condition that markedly increases the susceptibility of various organs to dysfunctionality and is associated with the development of oxidative stress. The existing guidelines point out that exercise is highly advantageous for patients with MetS. However, there is a need for specific guidance and clinical evidence. Objective: This study aimed to investigate the effects of a moderate aerobic exercise program on older women without and with MetS. Methods: A total of 120 women aged 60–70 years old were recruited and divided into two groups: healthy old women (HOW, N = 60) and old women with MetS (OW-MetS, N = 60). Anthropometric values, biochemical parameters and markers of oxidative damage were evaluated before and after moderate aerobic exercise. Exercise was performed five days per week for three months (64 sessions). Each exercise session consisted of 40 min and included the following: (a) five minutes of warm-up exercise; (b) ten minutes of flexibility exercise with resistance using own weight and coordination; (c) twenty minutes of moderate-intensity aerobic exercise (heart rate max between 60% and 70%); and (d) five minutes to cool down/stretching with respiratory techniques. Results: A significant decrease in anthropometric variables was generated by the exercise program [waist circumference 4.35 cm (p < 0.05) in OW-MetS, body fat −1.55, −1.39% (p < 0.05) and muscle mass 0.8, 1.1% (p < 0.05) in HOW and OW-MetS, respectively]. The exercise program resulted in beneficial changes in all biochemical parameters in both groups. Importantly, HOMA values showed a significant decline of −0.85 and −6.17 in HOW and OW-MetS, respectively. Furthermore, oxidative stress was present in the OW-MetS group, which was reduced by the exercise program, resulting in a decrease in protein damage [formazan 45% and 42% in HOW and OW-MetS respectively] and an increase in antioxidant defenses (thiol groups 36%, 99% and GPx 55%, 20% in HOW and OW-MetS, respectively). Conclusions: The data of this study show that moderate aerobic exercise may be potentially useful in treating and preventing MetS in older patients. Full article

(1) Background: The oral cavity is a complex ecological environment that integrates elements of both the digestive and respiratory systems, contributing to its extensive microbial diversity. Despite its effectiveness, chlorhexidine is associated with undesirable effects, such as mucosal irritation and tooth staining, which have prompted research into natural alternatives. This study aimed to compare the antimicrobial activity of mouthwashes containing tea tree oil (TTO) alone and in combination with cannabidiol (CBD) and spilanthol with that of a chlorhexidine digluconate-based mouthwash (CHX) against selected oral bacterial and fungal strains. (2) Methods: To assess the antimicrobial effects of the tested mouthwashes on reference microbial strains, the agar diffusion method was applied in accordance with the guidelines of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). In addition, the microdilution method using 96-well microtiter plates was employed to determine the minimum inhibitory concentration (MIC) of the tested substances. Microbial viability was further evaluated using the WST-based colorimetric Microbial Viability Assay Kit, in which the intensity of the produced WST-formazan dye is directly proportional to the number of viable cells. (3) Results: In the disc diffusion assay, inhibition zones measured after 24 h varied among the tested microorganisms, with the largest zones observed for CHX against Candida parapsilosis (19.63 mm) and Streptococcus pyogenes (16.7 mm). In the microdilution assay against Candida albicans, the MIC₅₀ was achieved for preparations A and B at the highest tested concentrations (column 1), whereas for chlorhexidine (CHX), it was reached at lower concentrations (column 9). (4) Conclusions: ① All tested mouthwashes containing tea tree oil (TTO), either as a single active ingredient or in combination with cannabidiol (CBD) and spilanthol, demonstrated limited bacteriostatic and antifungal activity under the experimental conditions of this study. ② The chlorhexidine digluconate-based mouthwash exhibited significantly higher antibacterial and antifungal activity against all tested microbial strains compared to both the TTO-only mouthwashes and the formulation containing TTO combined with CBD and spilanthol. Full article

Background: Albendazole, mebendazole, and ivermectin are effective against adult Trichinella spiralis but show limited efficacy against encapsulated muscle stage larvae. This limitation highlights the need for improved experimental approaches to evaluate anthelmintic activity at this stage and to identify alternative therapeutic candidates. Methods: Seven antiparasitic drugs, albendazole (ABZ), miltefosine (MLT), ivermectin (IVM), tribendimidine (TBD), praziquantel (PZQ), artesunate (ART), and mefloquine (MEQ), were evaluated for in vitro activity against T. spiralis muscle larvae. Larval viability was quantified using a tetrazolium salt XTT assay to determine IC₅₀ values and compare with microscopic assessments. Based on in vitro activity, TBD was selected for in vivo evaluation in a mouse model, where efficacy was assessed by muscle larval burden and histopathological changes. Results: TBD, MEQ, IVM, and ABZ exhibited measurable in vitro efficacies against T. spiralis larvae, with TBD showing the lowest IC₅₀ value at 135.2 μM. XTT formazan absorbance correlated strongly with larval number and incubation time. In vivo, TBD treatment significantly reduced larval burdens in diaphragm and gastrocnemius muscles and was associated with reduced collagen capsule thickness, inflammation, and fibrosis compared with ABZ-treated controls. Conclusions: This study validated an assay for quantitative evaluation of T. spiralis muscle larvae and demonstrates robust in vitro and in vivo activity of TBD against this stage. Full article

The interaction between organic and inorganic nutrients, bacterial communities, and soil fertility has been well documented over time. Conventional agricultural systems heavily utilize both inorganic and organic fertilizers, each exerting distinct effects on soil microbial dynamics and plant growth. The objective of our experiments was to identify the most effective fertilization strategy for improving the biological quality of a microbiologically impoverished and low-productivity soil. To this end, four fertilization strategies were evaluated: (i) organic fertilizers characterized by a high content of organic carbon (Fertil 4-5-7—variant 1); (ii) organic fertilizers with 12% organic nitrogen from proteins (Bio Ostara N—variant 2) (iii) combined inorganic–organic fertilizers (P35 Bio—variant 3) and (iv) mineral (inorganic) fertilizers (BioAktiv—variant V4). This study aimed to assess the short-term effects of fertilizers with varying chemical compositions on the density of cultivable heterotrophic bacteria and their associated dehydrogenase (DH) activity in a petrocalcic chernozem soil containing pedogenic carbonates. Soil sampling was conducted according to a randomized block design, comprising four replicates per treatment (control plus four fertilizer types). The enumeration of cultivable bacteria was performed using Nutrient Agar and A2R Agar media, whereas dehydrogenase activity (DHA) was quantified based on the reduction of 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) to 1,3,5-triphenyl-tetrazolium formazan (TPF) by bacterial dehydrogenase enzymes. Marked differences were observed in both parameters between the plots amended with inorganic fertilizers and those treated with organic fertilizers, as well as among the organic fertilizer treatments of varying composition. The most pronounced increases in both bacterial density and dehydrogenase activity (DHA) were recorded in the plots receiving the fertilizer with a high organic nitrogen content. In this treatment, the maximum bacterial population density reached 6.25 log₁₀ CFU g⁻¹ dry soil after approximately two months (May), followed by a significant decline starting in July. In contrast, DHA exhibited a more rapid response, reaching its peak in April (42.75 µg TPF g⁻¹ soil), indicating an earlier DHA activation of microbial metabolism. This temporal lag between the two parameters suggests that enzymatic activity responded more swiftly to the nutrient inputs than did microbial biomass proliferation. For the other two organic fertilizer variants, bacterial population dynamics were broadly similar, with peak densities recorded in June, ranging from 5.98 log₁₀ CFU g⁻¹ soil (V3) to 6.03 log₁₀ CFU g⁻¹ soil (V1). A comparable trend was observed in DHA: in V3, maximum DHA was attained in June (30 µg TPF g⁻¹ soil), after which it remained relatively stable, whereas in V1, it peaked in June (24.05 µg TPF g⁻¹ soil) and subsequently declined slightly toward the end of the experimental period. Overall, the temporal dynamics of bacterial density and DHA demonstrated a strong dependence on the quality and biodegradability of the organic matter supplied by each fertilizer. Both parameters were consistently lower under inorganic fertilization compared with organic treatments, suggesting that the observed increases in microbial density and activity were primarily mediated by the enhanced availability of organic substrates. The relationship between the density of culturable heterotrophic bacteria and dehydrogenase (DH) activity was strongly positive (r = 0.79), indicating a close functional linkage between bacterial density and oxidative enzyme activity. This connection suggests that the culturable fraction of the heterotrophic microbial community plays a key role in the early stages of organic matter mineralization derived from the applied fertilizers, particularly in the decomposition of easily degradable substrates. Full article

Biofilms are involved in both acute and chronic respiratory infections. While cigarette smoke extract (CSE) has been shown to increase biofilm formation by certain respiratory pathogens, the impact of emerging heated tobacco products (HTPs) remains unclear. We compared the effects of CSE with two HTP aerosol extracts on biofilm biomass and metabolic activity of common respiratory pathogens. Reference strains of Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae, and non-typeable Haemophilus influenzae (NTHi), known respiratory pathogens, were grown as 24 h biofilms in 96-well plates (48 h for S. aureus and P. aeruginosa). These were exposed to CSE and HTP extracts from iQOS™ (Terea™ Turquoise, ILUMA™ device) and glo™ (neo™ Azure, HyperPro™ device), prepared in liquid culture media. Biofilm density was quantified by the crystal violet assay. Metabolic activity (planktonic and biofilm) was assessed by MTT reduction to formazan. At 24 h, CSE markedly reduced H. influenzae biomass versus iQOS™, glo™, and control, while K. pneumoniae, S. aureus, and P. aeruginosa showed no significant biomass differences. At 48 h, CSE significantly increased biomass in P. aeruginosa and S. aureus versus other exposures. Biofilm MTT assay measured metabolic activity increased in CSE exposure for K. pneumoniae versus iQOS™ and control, and for S. aureus versus control. Overall, HTP extracts showed limited, inconsistent effects compared with CSE, indicating combustion-derived constituents more strongly promote biofilm maturation in this model. Full article

Background/Objectives: Ascorbic acid (AA)is a micronutrient with concentration-dependent anticancer properties, acting either as a reactive oxygen species (ROS) scavenger or inducer. Methods: Conventional redox-based assays such as MTS/MTT often overestimate cell proliferation due to AA’s interaction with tetrazolium salts, leading to increased formazan production. To overcome this limitation, we employed the Propidium Iodide Triton X-100 (PI/TX-100) assay to evaluate AA’s cytotoxic effects across a diverse panel of cancer and normal cell lines, including prostate (22Rv1, C4-2B, DU-145, LNCaP), breast (MCF-7, MDA-MB-231, MDA-MB-453), lung (A549), liver (HepG2, SK-HEP-1, Huh7), and kidney (Vero) cells. Results: AA significantly suppressed cancer cell viability compared to normal cells (RWPE1 and Vero), with the strongest effects observed in hormone receptor-positive lines. The relative sensitivity to AA followed distinct patterns within each cancer type. Mechanistically, AA-induced cell death involved ROS generation, lipid peroxidation, cell cycle arrest, ferroptosis, apoptosis, and downregulation of pyruvate dehydrogenase kinase 1 (PDHK1). Conclusions: These findings further support the potential of AA as a selective anticancer agent and highlight the importance of assay choice in evaluating its therapeutic efficacy. Full article

Turmeric oleoresin (TO), a natural pigment derived from Curcuma longa rhizomes, is valued for its health benefits, which are primarily attributed to its rich curcuminoid content (curcumin, demethoxycurcumin, and bisdemethoxycurcumin). Despite these benefits, curcuminoids are known to be light-sensitive and possess photosensitizing properties. This study investigated the impact of common light sources, fluorescent light and white LED (both at 10 W/m²), on the chemical stability, antioxidant activity, cytotoxicity, and photosensitizing properties of TO. Exposure to both light sources significantly reduced TO’s color and fluorescence intensity, with white LED causing greater instability. HPLC analysis confirmed a decrease in individual curcuminoid levels, with curcumin degrading most rapidly under both conditions. The DPPH radical scavenging activity of irradiated TO decreased compared to fresh or dark-stored turmeric, whereas its ABTS radical scavenging activity increased upon light exposure. Photosensitizing potency, measured by formazan decolorization and lipid peroxide formation, declined as TO decomposed under light. Conversely, the cytotoxicity of TO against B16F10 melanoma cells was significantly enhanced under light exposure, though this effect was diminished significantly after 24 h of pre-irradiation. These findings underscore the instability of turmeric pigment under common lighting conditions, which should be a crucial consideration when processing, storing, and distributing turmeric-containing products. Full article

The two-dimensional (2D) measurement of radiation dose distribution on non-planar surfaces requires the use of a flexible dosimeter. This work concerns the use of a unique cotton textile-based dosimeter to characterize the dose distribution of a ⁶⁰Co source used in the research and sterilization of products. Alternatively, for high-dose-rate experiments, an electron beam accelerator has been used. The dosimeter was prepared by the padding-squeezing-drying of a cotton textile made of cellulose, where a 10% solution of nitrotetrazolium blue chloride (NBT) was used for the padding process. NBT served as a radiation-sensitive compound, which transformed into a purple-brown NBT formazan upon exposure to ionizing radiation. The NBT dosimeter is scanned after irradiation using a flatbed scanner, and the data is processed using dedicated software packages, which together constitute a 2D dose distribution measurement system. The green channel of the RGB color model contributes the most to the color change of the dosimeter. The calibration relation obtained for the green channel showed that the dosimeter responds to doses of 0.8–45 kGy. Conversions of the green channel signal were performed using the calibration relation to analyze the 2D dose at a large distance and close to a ⁶⁰Co source shielded by a solid metal and a cylindrical metal structure with holes. Additionally, the dose distribution was assessed using a dosimeter placed on metal implant models undergoing radiation serialization. This work demonstrates the potential of such a dosimeter for characterizing high-dose-rate ⁶⁰Co sources and measuring the dose distribution on non-planar surfaces. Full article

The human gastrointestinal (GI) track host trillions of microorganisms that secrete molecules, including extracellular vesicles (EVs) and extracellular condensates (ECs) that may affect physiological and patho-physiological activities in the host. However, efficient protocols for the isolation of pure and functional GI-derived EVs|ECs is lacking. Here, we describe the use of high-resolution particle purification liquid chromatography (PPLC) gradient-bead-column integrated with polyvinylpolypyrrolidone (PVPP)-mediated extraction of impurities to isolate EVs from colonic content (ColEVs). PVPP facilitates the isolation of pure, non-toxic, and functionally active ColEVs that were internalized by cells and functionally activate HIV LTR promoter. ColEVs isolated without PVPP have a reductive effect on MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) without living cells, suggesting that ColEVs contain reductases capable of catalyzing the reduction of MTT to formazan. The assessment of the origin of ColEVs reveals that they are composed of both bacteria and host particles. This protocol requires ~12 h (5 h preprocessing, 7 h isolation) to complete and should be used to purify EVs from sources contaminated with microbial agents to improve rigor. This protocol provides a robust tool for researchers and clinicians investigating GI-derived EVs and the translational use of GI-derived EVs for diagnostic and therapeutic use. Additionally, GI-derived EVs may serve as a window into the pathogenesis of diseases. Full article

The photoreduction of plastoquinone, a para-benzoquinone, by chlorophyll initiates photosynthesis in chloroplasts. The direct photoreduction of biologically relevant quinones by dietary chlorophyll metabolites has been reported and may influence health outcomes. We examined red light-mediated photoreduction of ortho- and para-naphthoquinones including vitamin K₃ using the photosensitizers methylene blue and pheophorbide A, a chlorophyll metabolite. Naphthoquinone reduction was monitored by UV/Visible spectroscopy and required a photosensitizer, red light and a tertiary amine electron donor. Combinations of methylene blue and ethylenediaminetetraacetic acid or pheophorbide A and triethanolamine in 20% dimethylformamide were employed for all photoreduction experiments. Hydrogen peroxide was generated during the photochemical reactions by singlet oxygen-dependent oxidation of the reduced naphthoquinones. Hydrogen peroxide was quantified with horseradish peroxidase following irradiation; the reduced naphthoquinones acted as peroxidase co-substrates. Histidine, a singlet oxygen scavenger, enhanced the rate of photoreduction by limiting the re-oxidation process. Catalase slowed the rate of photoreduction by regenerating molecular oxygen from hydrogen peroxide so that it could be photoexcited to singlet oxygen. The rates and extent of naphthoquinone photoreduction were dependent on molecular oxygen exposure in different reaction formats including in a cuvette and a plate well. Reduction of the tetrazolium salt MTT to the formazan via electron transfer from the photoreduced quinones was also used to quantitate the extent of photoreduction. Full article

Histone deacetylase inhibitors (HDACi) show high antineoplastic potential in preclinical studies in various solid tumors, including gastric carcinoma; however, their use in clinical studies has not yet yielded convincing efficacies. Thus, further studies on cellular/molecular effects of HDACi are needed, for improving clinical efficacy and identifying suitable combination partners. Here, we investigated the role of oxidative stress in gastric cancer cells upon treatment with HDACi. A particular focus was laid on the role of the Nrf2 pathway, which can mediate resistance to cell-inhibitory effects of reactive oxidative species (ROS). Using fluorescence-based ROS sensors, oxidative stress was measured in human gastric cancer cell lines. Activation of the Nrf2 pathway was monitored in luciferase reporter assays as well as by mRNA and proteomic expression analyses of Nrf2 regulators and Nrf2-induced genes. Furthermore, the effects of ROS scavenger N-acetyl-L-cysteine (NAC) and Nrf2-knockdown on HDACi-dependent antiproliferative effects were investigated in colorimetric formazan-based and clonogenic survival assays. HDACi treatment led to increased oxidative stress levels and consequently, treatment with NAC reduced cytotoxicity of HDACi. In addition, vorinostat treatment stimulated expression of a luciferase reporter under the control of an antioxidative response element, indicating activation of the Nrf2 system. This Nrf2 activation was only partially reversible by treatment with NAC, suggesting ROS independent pathways to contribute to HDACi-promoted Nrf2 activation. In line with its cytoprotective role, Nrf2 knockdown led to a sensitization against HDACi. Accordingly, the expression of antioxidant and detoxifying Nrf2 target genes was upregulated upon HDACi treatment. In conclusion, oxidative stress induction upon HDAC inhibition contributes to the antitumor effects of HDAC inhibitors, and activation of Nrf2 represents a potentially important adaptive response of gastric cancer cells in this context. Full article

The exopolymer (ESPp) was obtained from Bacillus licheniformis IDN-EC, composed of a polyglutamic acid and polyglycerol phosphate chain O-substituted with αGal moieties (αGal/αGlcNH₂ 3:1 molar ratio) and with a 5000 Da molecular weight. The cytotoxicity activity of EPSp was determined by reducing the MTT (3-[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyltetrazolium bromide) to formazan on HeLa cells. This EPS did not show cytotoxicity against the tested cell line. The ESPp presented great advantages as an antioxidant with free radical scavenging activities (1,1-diphenyl-2-picryl-hydrazyl radical (DPPH),hydroxyl radical (OH), and superoxide anion (O₂₋)) (65 ± 1.2%, 98.7 ± 1.9%, and 97 ± 1.7%), respectively. Moreover, EPSp increased the enzyme activity for catalase (CAT) and glutathione peroxidase (GSH-Px) in HeLa cells (CAT, 2.6 ± 0.24 U/mL; and GSH-Px, 0.75 ± 0.3 U/L). The presence of ESPp showed a significant protective effect against H₂O₂ in the cell line studied, showing great viability (91.8 ± 2.8, 89.9 ± 2.9, and 93.5 ± 3.6%). The EPSp presented good emulsifying activity, only for vegetable oils, olive oil (50 ± 2.1%) and sesame (72 ± 3%). Sesame was effective compared to commercials products, Triton X-100 (52.38 ± 1.6%), Tween 20 (14.29 ± 1.1%), and sodium dodecyl sulphate (SDS) (52.63 ± 1.6%). Furthermore, the EPS produced at 0.6 M has potential for environmental applications, such as the removal of hazardous materials by emulsification whilst resulting in positive health effects such as antioxidant activity and non-toxicity. EPSp is presented as a good exopolysaccharide for various applications. Full article

Photosensitizers cause oxidative damages in various biological systems under light. In this study, the method for analyzing photosensitizing activity of various dietary and medicinal sources was developed using 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan (thiazolyl blue formazan; MTT-F) as a probe. Significant and quantitative decolorization of MTT-F was observed in the presence of photosensitizers used in this study under light but not under dark conditions. The decolorization of MTT-F occurred irradiation time-, light intensity-, and photosensitizer concentration-dependently. The decolorized MTT-F was reversibly reduced by living cells; the LC-MS/MS results indicated the formation of oxidized products with −1 m/z of base peak from MTT-F, suggesting that MTT-F decolorized by photosensitizers was its corresponding tetrazolium. The present results indicate that MTT-F is a reliable probe for the quantitative analysis of photosensitizing activities, and the MTT-F-based method can be an useful tool for screening and evaluating photosensitizing properties of various compounds used in many industrial purposes. Full article