Search results for: atomic-absorption spectrophotometry

Authors: D. Kekelidze, G. Tsotadze, G. Maisuradze, L. Akhalbedashvili, M. Chkhaidze

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Statement of Problem: The problem of solid wastes -dangerous sources of environmental pollution,is the urgent issue for Georgia as there are no waste-treatment and waste- incineration plants. Urban peripheral and rural areas, frequently along small rivers, are occupied by landfills without any permission. The study of the pollution of some environmental objects in the adjacent territories of solid waste landfill in Tbilisi carried out in 2020-2021, within the framework of project: “Ecological monitoring of the landfills surrounding areas and population health risk assessment”. Research objects: This research had goal to assess the ecological state of environmental objects (soil cover and surface water) in the territories, adjacent of solid waste landfill, on the base of changes heavy metals' (HM) concentration with distance from landfill. An open sanitary landfill for solid domestic waste in Tbilisi locates at suburb Lilo surrounded with densely populated villages. Content of following HM was determined in soil and river water samples: Pb, Cd, Cu, Zn, Ni, Co, Mn. Methodology: The HM content in samples was measured, using flame atomic absorption spectrophotometry (spectrophotometer of firm Perkin-Elmer AAnalyst 200) in accordance with ISO 11466 and GOST Р 53218-2008. Results and discussion: Data obtained confirmed migration of HM mainly in terms of the distance from the polygon that can be explained by their areal emissions and storage in open state, they could also get into the soil cover under the influence of wind and precipitation. Concentration of Pb, Cd, Cu, Zn always increases with approaching to landfill. High concentrations of Pb, Cd are characteristic of the soil covers of the adjacent territories around the landfill at a distance of 250, 500 meters.They create a dangerous zone, since they can later migrate into plants, enter in rivers and lakes. The higher concentrations, compared to the maximum permissible concentrations (MPC) for surface waters of Georgia, are observed for Pb, Cd. One of the reasons for the low concentration of HM in river water may be high turbidity – as is known, suspended particles are good natural sorbents that causes low concentration of dissolved forms. Concentration of Cu, Ni, Mn increases in winter, since in this season the rivers are switched to groundwater feeding. Conclusion: Soil covers of the areas adjacent to the landfill in Lilo are contaminated with HM. High concentrations in soils are characteristic of lead and cadmium. Elevated concentrations in comparison with the MPC for surface waters adopted in Georgia are also observed for Pb, Cd at checkpoints along and below (1000 m) of the landfill downstream. Data obtained confirm migration of HM to the adjacent territories of the landfill and to the Lochini River. Since the migration and toxicity of metals depends also on the presence of their mobile forms in water bodies, samples of bottom sediments should be taken too. Bottom sediments reflect a long-term picture of pollution, they accumulate HM and represent a constant source of secondary pollution of water bodies. The study of the physicochemical forms of metals is one of the priority areas for further research.

Keywords: landfill, pollution, heavy metals, migration

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Authors: Zuzana Tatarkova, Ivana Pilchova, Michal Cibulka, Martin Kolisek, Peter Racay, Peter Kaplan

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Introduction: Normal functioning of mitochondria is crucial for cardiac performance. Mitochondria undergo mitophagy and biogenesis, and mitochondrial proteins are subject to extensive post-translational modifications. The state of mitochondrial homeostasis reflects overall cellular fitness and longevity. Perturbed mitochondria produce less ATP, release greater amounts of reactive molecules, and are more prone to apoptosis. Therefore mitochondrial turnover is an integral aspect of quality control in which dysfunctional mitochondria are selectively eliminated through mitophagy. Currently, the progressive deterioration of physiological functions is seen as accumulation of modified/damaged proteins with limiting regenerative ability and disturbance of such affected protein-protein communication throughout aging in myocardial cells. Methodologies: For our study was used immunohistochemistry, biochemical methods: spectrophotometry, western blotting, immunodetection as well as more sophisticated 2D electrophoresis and mass spectrometry for evaluation protein-protein interactions and specific post-translational modification. Results and Discussion: Mitochondrial stress response to reactive species was evaluated as electron transport chain (ETC) complexes, redox-active molecules, and their possible communication. Protein-protein interactions revealed a strong linkage between age and ETC protein subunits. Redox state was strongly affected in senescent mitochondria with shift in favor of more pro-oxidizing condition within cardiomyocytes. Acute myocardial ischemia and ischemia-reperfusion (IR) injury affected ETC complexes I, II and IV with no change in complex III. Ischemia induced decrease in total antioxidant capacity, MnSOD, GSH and catalase activity with recovery in some extent during reperfusion. While MnSOD protein content was higher in IR group, activity returned to 95% of control. Nitric oxide is one of the biological molecules that can out compete MnSOD for superoxide and produce peroxynitrite. This process is faster than dismutation and led to the 10-fold higher production of nitrotyrosine after IR injury in adult with higher protection in senescent ones. 2D protein profiling revealed 140 mitochondrial proteins, 12 of them with significant changes after IR injury and 36 individual nitrotyrosine-modified proteins further identified by mass spectrometry. Linking these two groups, 5 proteins were altered after IR as well as nitrated, but only one showed massive nitration per lowering content of protein after IR injury in adult. Conclusions: Senescent cells have greater proportion of protein content, which might be modulated by several post-translational modifications. If these protein modifications are connected to functional consequences and protein-protein interactions are revealed, link may lead to the solution. Assume all together, dysfunctional proteostasis can play a causative role and restoration of protein homeostasis machinery is protective against aging and possibly age-related disorders. This work was supported by the project VEGA 1/0018/18 and by project 'Competence Center for Research and Development in the field of Diagnostics and Therapy of Oncological diseases', ITMS: 26220220153, co-financed from EU sources.

Keywords: aging heart, mitochondria, proteomics, redox state

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Authors: Elvin P. Chizenga, Heidi Abrahamse

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Cancer cell resistance to therapy is the main cause of treatment failures and the poor prognosis of cancer convalescence. The progression of cervical cancer to other parts of the genitourinary system and the reported recurrence rates are overwhelming. Current treatments, including surgery, chemo and radiation have been inefficient in eradicating the tumor cells. These treatments are also associated with poor prognosis and reduced quality of life, including fertility loss. This has inspired the need for the development of new treatment modalities to eradicate cervical cancer successfully. Photodynamic Therapy (PDT) is a modern treatment modality that induces cell death by photochemical interactions of light and a photosensitizer, which in the presence of molecular oxygen, yields a set of chemical reactions that generate Reactive Oxygen Species (ROS) and other free radical species causing cell damage. Enhancing PDT using modified drug delivery can increase the concentration of the photosensitizer in the tumor cells, and this has the potential to maximize its therapeutic efficacy. In cervical cancer, all infected cells constitutively express genes of the E6 and E7 HPV viral oncoproteins, resulting in high concentrations of E6 and E7 in the cytoplasm. This provides an opportunity for active targeting of cervical cancer cells using immune-mediated drug delivery to maximize therapeutic efficacy. The use of nanoparticles in PDT has also proven effective in enhancing therapeutic efficacy. Gold nanoparticles (AuNps) in particular, are explored for their use in biomedicine due to their biocompatibility, low toxicity, and enhancement of drug uptake by tumor cells. In this present study, a biomolecule comprising of AuNPs, anti-E6 monoclonal antibodies, and Aluminium Phthalocyanine photosensitizer was synthesized for use in targeted PDT of cervical cancer. The AuNp-Anti-E6-Sulfonated Aluminium Phthalocyanine mix (AlPcSmix) photosensitizing biomolecule was synthesized by coupling AuNps and anti-E6 monoclonal antibodies to the AlPcSmix via Polyethylene Glycol (PEG) chemical links. The final product was characterized using Transmission Electron Microscope (TEM), Zeta Potential, Uv-Vis Spectrophotometry, Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction (XRD), to confirm its chemical structure and functionality. To observe its therapeutic role in treating cervical cancer, cervical cancer cells, HeLa cells were seeded in 3.4 cm² diameter culture dishes at a concentration of 5x10⁵ cells/ml, in vitro. The cells were treated with varying concentrations of the photosensitizing biomolecule and irradiated using a 673.2 nm wavelength of laser light. Post irradiation cellular responses were performed to observe changes in morphology, viability, proliferation, cytotoxicity, and cell death pathways induced. Dose-Dependent response of the cells to treatment was demonstrated as significant morphologic changes, increased cytotoxicity, and decreased cell viability and proliferation This study presented a synthetic biomolecule for targeted PDT of cervical cancer. The study suggested that PDT using this AuNp- Anti-E6- AlPcSmix photosensitizing biomolecule is a very effective treatment method for the eradication of cervical cancer cells, in vitro. Further studies in vivo need to be conducted to support the use of this biomolecule in treating cervical cancer in clinical settings.

Keywords: anti-E6 monoclonal antibody, cervical cancer, gold nanoparticles, photodynamic therapy

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Authors: Rusudan Chagelishvili, Nino Sulava, Tamar Beridze, Nana Rezesidze, Nikoloz Tatuashvili

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The South Caucasus is one of the most important centers of prehistoric metallurgy, known for its Colchian bronze culture. Modern Lechkhumi – historical Mountainous Colchis where the existence of prehistoric metallurgy is confirmed by the discovery of many artifacts is a part of this area. Studies focused on prehistoric smelting sites, related artefacts, and ore deposits have been conducted during last ten years in Lechkhumi. More than 20 prehistoric smelting sites and artefacts associated with metallurgical activities (ore roasting furnaces, slags, crucible, and tuyères fragments) have been identified so far. Within the framework of integrated studies was established that these sites were operating in 13-9 centuries B.C. and used for copper smelting. Palynological studies of slags revealed that chestnut (Castanea sativa) and hornbeam (Carpinus sp.) wood were used as smelting fuel. Geological exploration-analytical studies revealed that copper ore mining, processing, and smelting sites were distributed close to each other. Despite recent complex data, the signs of prehistoric mines (trenches) haven’t been found in this part of the study area so far. Since 2018 the archaeological-geological exploration has been focused on the southern part of Lechkhumi and covered the areas of villages Okureshi and Opitara. Several copper smelting sites (Okureshi 1 and 2, Opitara 1), as well as a Colchian Bronze culture settlement, have been identified here. Three mine workings have been found in the narrow gorge of the river Rtkhmelebisgele in the vicinities of the village Opitara. In order to establish a link between the Opitara-Okureshi archaeometallurgical sites, Late Bronze Age settlements, and mines, various scientific analytical methods -mineralized rock and slags petrography and atomic absorption spectrophotometry (AAS) analysis have been applied. The careful examination of Opitara mine workings revealed that there is a striking difference between the mine #1 on the right bank of the river and mines #2 and #3 on the left bank. The first one has all characteristic features of the Soviet period mine working (e. g. high portal with angular ribs and roof showing signs of blasting). In contrast, mines #2 and #3, which are located very close to each other, have round-shaped portals/entrances, low roofs, and fairly smooth ribs and are filled with thick layers of river sediments and collapsed weathered rock mass. A thorough review of the publications related to prehistoric mine workings revealed some striking similarities between mines #2 and #3 with their worldwide analogues. Apparently, the ore extraction from these mines was conducted by fire-setting applying primitive tools. It was also established that mines are cut in Jurassic mineralized volcanic rocks. Ore minerals (chalcopyrite, pyrite, galena) are related to calcite and quartz veins. The results obtained through the petrochemical and petrography studies of mineralized rock samples from Opitara mines and prehistoric slags are in complete correlation with each other, establishing the direct link between copper mining and smelting within the study area. Acknowledgment: This work was supported by the Shota Rustaveli National Science Foundation of Georgia (grant # FR-19-13022).

Keywords: archaeometallurgy, Mountainous Colchis, mining, ore minerals

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Authors: Nendouvhada Livhuwani Portia, Nicole Sibuyi, Kwazikwakhe Gabuza, Adewale Fadaka

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Metabolic dysfunction-associated liver disease (MASLD) is a chronic condition characterized by excessive fat accumulation in the liver, distinct from conditions caused by alcohol, viral hepatitis, or medications. MASLD is often linked with metabolic syndrome, including obesity, diabetes, hyperlipidemia, and hypertriglyceridemia. This disease can progress to metabolic dysfunction-associated steatohepatitis (MASH), marked by liver inflammation and scarring, potentially leading to cirrhosis. However, only 43-44% of patients with steatosis develop MASH, and 7-30% of those with MASH progress to cirrhosis. The exact mechanisms underlying MASLD and its progression remain unclear, and there are currently no specific therapeutic strategies for MASLD/MASH. While anti-obesity and anti-diabetic medications can reduce progression, they do not fully treat or reverse the disease. As an alternative, green-synthesized metal nanoparticles (MNPs) are emerging as potential treatments for liver diseases due to their anti-diabetic, anti-inflammatory, and anti-obesity properties with minimal side effects. MNPs like gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) have been shown to improve metabolic processes by lowering blood glucose, body fat, and inflammation. The study aimed to explore the effects of green-synthesized MNPs on gene expression in an in vitro model of MASH using C3A/HepG2 liver cells. The MASH model was created by exposing these cells to free fatty acids (FFAs) followed by lipopolysaccharide (LPS) to induce inflammation. Cell viability was assessed with the Water-Soluble Tetrazolium (WST)-1 assay, and lipid accumulation was measured using the Oil Red O (ORO) assay. Additionally, mitochondrial membrane potential was assessed by the tetramethyl rhodamine, methyl ester (TMRE) assay, and inflammation was measured with an Enzyme-Linked Immunosorbent Assay (ELISA). The study synthesized AuNPs from Carpobrotus edulis fruit (CeF) and avocado seed (AvoSE) and AgNPs from Salvia africana-lutea (SAL) using optimized conditions. The MNPs were characterized by UV-Vis spectrophotometry and Dynamic Light Scattering (DLS). The nanoparticles were tested at various concentrations for their impact on the C3A/HepG2-induced MASH model. Among the MNPs tested, AvoSE-AuNPs showed the most promise. They reduced cell proliferation and intracellular lipid content more effectively than CeFE-AuNPs and SAL-AgNPs. Molecular analysis using real-time polymerase chain reaction revealed that AvoSE-AuNPs could potentially reverse MASH effects by reducing the expression of key pro-inflammatory and metabolic genes, including tumor necrosis factor-alpha (TNF-α), Fas cell surface death receptor (FAS), Peroxisome proliferator-activated receptor (PPAR)-α, PPAR-γ, and Sterol regulatory element-binding protein (SREBPF)-1. Further research is needed to confirm the molecular mechanisms behind the effects of these MNPs and to identify the specific phytochemicals responsible for their synthesis and bioactivities.

Keywords: gold nanoparticles, green nanotechnology, metal nanoparticles, obesity

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Authors: Aisha Musaazi Sebunya Nakitto, Anika E. Wagner, Yusuf B. Byaruhanga, John H. Muyonga

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The prevalence and burden of diabetes are rapidly increasing globally, stemming from changes in lifestyle and dietary habits. Although several drugs are available to treat type 2 diabetes mellitus (T2DM), many are accompanied by several side effects and are often costly. Solanum anguivi Lam. fruits (SALF) are bitter berries that commonly grow in the wild and are traditionally cultivated by many globally as a remedy for T2DM. This effect is likely attributable to the presence of bioactive compounds such as phenolics, flavonoids, saponins, alkaloids, and vitamin C in SALF. In this study, we investigated the morphological characteristics of different SALF accessions and the effect of ripeness stages and thermal treatments on the bioactive compounds contents (BCC) and antioxidant activity (AA) of SALF accessions. Using the fruit fly Drosophila melanogaster (D. melanogaster) model, we explored the potential impact of dietary SALF in preventing and treating T2DM phenotypes. Morphological characterization was conducted based on descriptors of Solanum species. The BCC and AA of SALF at different ripeness stages (unripe, yellow, orange, and red) and after thermal treatments were determined using spectrophotometry, HPLC, and gravimetry. Male and female fruit flies were fed a high-sugar diet (HSD) to induce a T2DM-like phenotype, while control flies were fed on SY10 medium for up to 24 days. Experimental flies were exposed to HSD supplemented with 5 or 10 mg/ml SALF. The therapeutic and prevention effect of SALF in T2DM-like phenotype was investigated on weight, climbing activity, glucose and triglyceride contents, survival, and gene expression of PPARγ co-activator 1α fly homolog Srl and Drosophila insulin-like peptides. Methods in fly studies included Gustatory assay, Climbing assay, Glucose GOD-PAP assay, Triglyceride GPO-PAP assay, Roti-Quant®, and Real Time-PCR analysis. The ripeness stage significantly influenced SALF BCC and AA, and this was dependent on the accession. The unripe stage had the highest AA and total phenolics and flavonoids; the orange stage was rich in saponins, while the red stage had the highest alkaloid contents. Boiling and steaming increased the total phenolics and AA up to 4-fold and 3-fold, respectively. Drying at low temperatures resulted in higher phenolics and AA than the control. In the therapeutic model, the HSD-fed female flies exhibited elevated glucose levels, which exhibited a dose-dependent reduction upon exposure to a SALF-supplemented diet. Female flies fed on a SALF+ HSD exhibited a significant increase in survival compared to HSD-fed and control diet-fed flies. SALF supplementation did not alter the weights, fitness, and triglyceride levels of female flies in comparison with HSD-only-fed flies. The mRNA levels of Srl decreased in HSD-fed flies compared to the control-fed, with no effect observed in females exposed to HSD+SALF. Similarly, in the preventative model, the SALF diet resulted in higher survival of supplemented flies compared to controls. Consumption of boiled unripe SALF may result in the highest health benefits due to the high phenolic contents and antioxidant activity observed. Dietary intake of SALF significantly lowered glucose levels and increased survival of the D. melanogaster model. Additional studies in higher organisms are needed to explore the preventative and therapeutic potential of SALF in T2DM.

Keywords: antioxidant activity, bioactive compounds, bitter berries, Drosophila melanogaster, Solanum anguivi, type 2 diabetes mellitus, survival

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