Damage To Biomolecules Research Articles

Phytochemical composition and neuroprotective potential of Mirabilis jalapa: a review

Four-o’clock plant, scientifically named as Mirabilis jalapa, has gained significant attention for both its ornamental beauty and its medicinal properties, widely utilized as folk remedies. It is a plant grown in the warm climate as a species and showed different pharmacological effects in various therapeutic sectors such as neuroprotective and anxiolytic. Using PubMed, Web of Science Semantic Scholar and Google Scholar and the search terms Mirabilis jalapa phytochemicals; neuroprotection; anxiolytic effect; traditional medicine; flavonoids; alkaloids and neurological disorders literature supporting the medicinal role of Mirabilis jalapa were sourced. The members of Mirabilis jalapa contain flavonoids, alkaloids, triterpenes leaves and saponin through which it provides possibility for the neuroprotection feature. According to research, extracts of the plant can help prevent oxidative stress, a major factor in illnesses including Alzheimer’s and Parkinson’s. Animal studies reveal that components from M. jalapa interfere with Aluminum cytotoxicity by increasing antioxidant enzyme levels, as well as decreasing oxidative damage biomolecules. In addition, the flavonoid constituent has anxiolytic effects because its extract interferes with GABAergic transmission, whereas its effectiveness is comparable to diazepam. Furthermore, the plant has exhibited anticonvulsant effect possibly due to interaction with Ca channel and Glu transmission. Thus, these studies show directions in which the plant works, indicating that it may possess valuable means to treating neurological disorders. However, further clinical trials are needed to understand the exact effects of the plant in human organisms. Mirabilis jalapa therefore, is Discovered to be of great potential as a natural antioxidant and neuroprotective compound as well as anxiolytic remedies.

Determination of Antioxidant Activity and Biochemical Content of Homalothecium philippeanum (Spruce) Schimp.

Living organisms produce reactive oxygen species (ROS) during the oxygen processing. ROS damage biomolecules and causes oxidative stress. Antioxidants prevent cellular damage against these harmful effects of ROS by neutralizing free radicals. Medicinal plants provide a rich source of antioxidants to reduce oxidative stress and play an important role in the treatment of diseases. Bioactive compounds, especially polyphenols and flavonoids, protect cells against oxidative damage by neutralizing free radicals. Bryophytes, especially mosses, are one of the plant groups that attract attention in this area. Mosses show biologically active properties with secondary metabolites such as terpenes and flavonoids they contain. In this study, extraction of Homalothecium philippeanum moss with ethanol, methanol, and n-hexane solvents was carried out and the biochemical content analysis of the extracts was investigated. 1,2-Benzenedicarboxylic acid, bis(2-methylpropyl) ester was detected as the major component in the ethanol and methanol extracts of the H. philippeanum. Biologically active alkanes such as Tetradecane and Hexadecane were found in the n-hexane extract. The antioxidant activity of moss ethanol extract was investigated using the DPPH method and the EC50 value was determined as 7.084 mg/ml.

A reflexion on the oxidative stress and animal welfare: a review.

A wide range of studies have documented the role of oxidative stress in the development of chronic pathological disorders and even in the aging itself. However, its significance to modern animal health and welfare remains neglected. Oxidative stress in biological systems refers to a disturbance in the balance between pro-oxidants and antioxidants in favour of the former, leading to potential damage of biomolecules. In farm animals, oxidative stress may be involved in several pathological conditions, including those that are relevant for animal production and the general welfare of the individuals, resulting in some cases in irreversible losses. The oxidative stress concept and how it may result in disease or be prevented are complex questions with no simple answers and therefore, call professionals for deep reflection, to maintain a high standard of animal welfare and production. The aim of this review was to gather relevant information on the characteristics of pro-oxidants and antioxidant as well as their significance in animal production systems.

Surface chemical and electronic properties of functionalized Fe3O4 nanoparticles influencing their cytotoxicity

Physico-chemical, electronic and magnetic properties of bare Fe3O4 nanoparticles (NPs) and functionalized NPs (f-NPs) with doxorubicin, tannic acid, curcumin, polyethylene glycol and their mixtures were determined using DLS, XRD, XPS and AES. The cytotoxicity of bare and f-NPs for various cell lines such as normal HEK-293 and cancer HeLa, MDA-MB-231, and MCF-7 was studied by MTT (3–(4,5–Dimethylthiazol–2–yl)–2,5–Diphenyltetrazolium Bromide) assay. Bare and f-NPs exhibited different cytotoxicity dependent on molecules bonding at the surface. Cytotoxicity increases with decreasing hydrodynamic diameter and increasing Zeta potential, increasing content of lattice and adsorbed O2−, carboxyl groups and C vacancies, NH4+ groups, decreasing overlayer thickness, electron charge transfer to oxygen and more nucleophilic character of electron rich surface oxygen. The strongest correlation was observed for hydrodynamic diameter, Fe surface content, overlayer thickness, Zeta-potential, Auger parameters indicating that surface processes and electron charge transfer leading to nucleophilic oxygen contribute mostly to cytotoxicity. Nucleophilic biomolecules may form a variety of covalent modifications with electrophilic adducts and hydrogen bonds with nucleophiles and the suspected predominant mechanism of biomolecule damage can be attributed to electron rich nucleophilic oxygen leading to a very selective C–H bonds cleavage resulting in oxidation of organic chains of biomolecule.

Uptake, Translocation, Toxicity, and Impact of Nanoparticles on Plant Physiological Processes.

The application of nanotechnology in agriculture has increased rapidly. However, the fate and effects of various nanoparticles on the soil, plants, and humans are not fully understood. Reports indicate that nanoparticles exhibit positive and negative impacts on biota due to their size, surface property, concentration within the system, and species or cell type under test. In plants, nanoparticles are translocated either by apoplast or symplast pathway or both. Also, it is not clear whether the nanoparticles entering the plant system remain as nanoparticles or are biotransformed into ionic forms or other organic compounds. Controversial results on the toxicity effects of nanomaterials on the plant system are available. In general, the nanomaterial toxicity was exerted by producing reactive oxygen species, leading to damage or denaturation of various biomolecules. The intensity of cyto- and geno-toxicity depends on the physical and chemical properties of nanoparticles. Based on the literature survey, it is observed that the effects of nanoparticles on the growth, photosynthesis, and primary and secondary metabolism of plants are both positive and negative; the response of these processes to the nanoparticle was associated with the type of nanoparticle, the concentration within the tissue, crop species, and stage of growth. Future studies should focus on addressing the key knowledge gaps in understanding the responses of plants to nanoparticles at all levels through global transcriptome, proteome, and metabolome assays and evaluating nanoparticles under field conditions at realistic exposure concentrations to determine the level of entry of nanoparticles into the food chain and assess the impact of nanoparticles on the ecosystem.

A lysosome-targeted fluorescent probe for thiol detection in drug analysis and multiple biological systems.

Biothiols, characterized by their unique sulfhydryl (-SH) groups, possess excellent antioxidant properties, effectively neutralizing the damage to cellular structures caused by reactive oxygen species (ROS) in living organisms. Additionally, lysosomes play a crucial role in decomposing damaged biomolecules through the action of their internal enzymes, regulating the cellular redox state, and mitigating oxidative stress. To facilitate rapid monitoring of intracellular biothiols, particularly within lysosomes, we constructed a lysosome-targeted biothiol fluorescent probe, PHL-DNP, in this study. PHL-DNP exhibited excellent photophysical properties in an aqueous test system, including strong fluorescence enhancement response, excellent selectivity, and low detection limits (Cys 16.5nM, Hcy 16.8nM, GSH 21.3nM, Cap 26.6nM). These attributes enabled easy and efficient qualification of Cys on test strips and accurate determination of the effective content of captopril tablets. Notably, PHL-DNP demonstrated low cytotoxicity and precise lysosomal targeting. Through bioimaging, PHL-DNP not only monitored changes in biothiol levels under oxidative stress but also assessed biothiols in complex biological systems such as live HeLa cells, zebrafish, tumor tissue sections, and radish roots. This provides a promising tool for quantitative analysis of biothiols, disease marker detection, and drug testing.

Machine learning-assisted SERS approach enables the biochemical discrimination in Bcl-2 and Mcl-1 expressing yeast cells treated with ketoconazole and fluconazole antifungals

Antifungal medications are important due to their potential application in cancer treatment either on their own or with traditional treatments. The mechanisms that prevent the effects of these medications and restrict their usage in cancer treatment are not completely understood. The evaluation and discrimination of the possible protective effects of the anti-apoptotic members of the Bcl-2 family of proteins, critical regulators of mitochondrial apoptosis, against antifungal drug-induced cell death has still scientific uncertainties that must be considered. Novel, simple, and reliable strategies are highly demanded to identify the biochemical signature of this phenomenon. However, the complex nature of cells poses challenges for the analysis of cellular biochemical changes or classification. In this study, for the first time, we investigated the probable protective activities of Bcl-2 and Mcl-1 proteins against cell damage induced by ketoconazole (KET) and fluconazole (FLU) antifungal drugs in a yeast model through surface-enhanced Raman spectroscopy (SERS) approach. The proposed SERS platform created robust Raman spectra with a high signal-to-noise ratio. The analysis of SERS spectral data via advanced unsupervised and supervised machine learning methods enabled unquestionable differentiation (100 %) in samples and biomolecular identification. Various SERS bands related to lipids and proteins observed in the analyses suggest that the expression of these anti-apoptotic proteins reduces oxidative biomolecule damage induced by the antifungals. Also, cell viability assay, Annexin V-FITC/PI double staining, and total oxidant and antioxidant status analyses were performed to support Raman measurements. We strongly believe that the proposed approach paves the way for the evaluation of various biochemical structures/changes in various cells.

Potential use of antioxidants for the treatment of chronic inflammatory diseases.

The excessive production of various reactive oxidant species over endogenous antioxidant defense mechanisms leads to the development of a state of oxidative stress, with serious biological consequences. The consequences of oxidative stress depend on the balance between the generation of reactive oxidant species and the antioxidant defense and include oxidative damage of biomolecules, disruption of signal transduction, mutation, and cell apoptosis. Accumulating evidence suggests that oxidative stress is involved in the physiopathology of various debilitating illnesses associated with chronic inflammation, including cardiovascular diseases, diabetes, cancer, or neurodegenerative processes, that need continuous pharmacological treatment. Oxidative stress and chronic inflammation are tightly linked pathophysiological processes, one of which can be simply promoted by another. Although, many antioxidant trials have been unsuccessful (some of the trials showed either no effect or even harmful effects) in human patients as a preventive or curative measure, targeting oxidative stress remains an interesting therapeutic approach for the development of new agents to design novel anti-inflammatory drugs with a reliable safety profile. In this regard, several natural antioxidant compounds were explored as potential therapeutic options for the treatment of chronic inflammatory diseases. Several metalloenzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, are among the essential enzymes that maintain the low nanomolar physiological concentrations of superoxide (O2•-) and hydrogen peroxide (H2O2), the major redox signaling molecules, and thus play important roles in the alteration of the redox homeostasis. These enzymes have become a striking source of motivation to design catalytic drugs to enhance the action of these enzymes under pathological conditions related to chronic inflammation. This review is focused on several major representatives of natural and synthetic antioxidants as potential drug candidates for the treatment of chronic inflammatory diseases.

Bioenergetics of iron snow fueling life on Europa

The main sources of redox gradients supporting high-productivity life in the Europan and other icy ocean world oceans were proposed to be photolytically derived oxidants, such as reactive oxygen species (ROS) from the icy shell, and reductants (Fe(II), S(-II), CH4, H2) from bottom waters reacting with a (ultra)mafic seafloor. Important roadblocks to maintaining life, however, are that the degree of ocean mixing to combine redox species is unknown, and ROS damage biomolecules. Here, we envisage a unique solution using an acid mine drainage (AMD)-filled pit lakes analog system for the Europan ocean, which previous models predicted to be acidic. We hypothesize that surface-generated ROS oxidize dissolved Fe(II) resulting in Fe(III) (hydr)oxide precipitates, that settle to the seafloor as "iron snow." The iron snow provides a respiratory substrate for anaerobic microorganisms ("breathing iron"), and limits harmful ROS exposure since they are now neutralized at the ice-water interface. Based on this scenario, we calculated Gibbs energies and maximal biomass productivities of various anaerobic metabolisms for a range of pH, temperatures, and H2 fluxes. Productivity by iron reducers was greater for most environmental conditions considered, whereas sulfate reducers and methanogens were more favored at high pH. Participation of Fe in the metabolic redox processes is largely neglected in most models of Europan biogeochemistry. Our model overcomes important conceptual roadblocks to life in icy ocean worlds and broadens the potential metabolic diversity, thus increasing total primary productivity, the diversity and volume of habitable environmental niches and, ultimately, the probability of biosignature detection.

Antioxidant Polymers with Phenolic Pendants for the Mitigation of Cellular Oxidative Stress.

Overproduction of reactive oxygen species (ROS) in cells is a major health concern as it may lead to various diseases through oxidative damage of biomolecules. Commonly used traditional small molecular antioxidants (polyphenols, carotenoids, vitamins, etc.) have inadequate efficacy in lowering excessive levels of ROS due to their poor aqueous solubility and bioavailability. In response to the widespread occurrence of antioxidant polyphenols in various biorenewable resources, we aimed to develop water-soluble antioxidant polymers with side chain phenolic pendants. Four different types of copolymers (P1-P4) containing phenyl rings with different numbers of hydroxy (-OH) substituents (0: phenylalanine, 1: tyrosyl, 2: catechol, or 3: gallol) were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization with a desired molar mass (8500-10000 g/mol) and a narrow dispersity (Đ ≤ 1.3). After successful characterizations of P1-P4, their in vitro antioxidant properties were analyzed by different methods, including 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+), 4,4'-diamino-3,3',5,5'-tetramethylbiphenyl (TMB), and β-carotene (βC) assays. Our results revealed that the gallol pendant polymers can effectively scavenge ROS. Furthermore, electron paramagnetic resonance (EPR) spectroscopy with DPPH• also confirmed the radical quenching ability of the synthesized polymers. The gallol pendant polymers, at a well-tolerated concentration, could effectively penetrate the macrophage cells and restore the H2O2-induced ROS to the basal level. Overall, the present approach demonstrates the efficacy of water-soluble antioxidant polymers with gallol pendants toward the mitigation of cellular oxidative stress.

A novel thienothiophene-based “dual-responsive” probe for rapid, selective and sensitive detection of hypochlorite

BackgroundHypochlorite/hypochlorous acid (ClO−/HOCl) is a biologically crucial reactive oxygen species (ROS), produced in living organisms and has a critical role as an antimicrobial agent in the natural defense system. However, when ClO− is produced excessively, it can lead to the oxidative damage of biomolecules, resulting in organ damage and various diseases. Therefore, it is imperative to have a straightforward, quick and reliable method for over watching the minimum amount of ClO− in different environments. ResultsHerein, a new probe TTM, containing thienothiophene and malononitrile units, was developed for exceptionally selective and sensitive hypochlorite (ClO−) detection. TTM demonstrated a rapid “turn-on” fluorescence response (<30 s), naked-eye detection (colorimetric), voltammetric read-out with anodic scan, low detection limit (LOD = 0.58 μM and 1.43 μM for optical and electrochemical methods, respectively) and applicability in detecting ClO− in real water samples and living cells. Significance and noveltyThis study represents one of the rare examples of a small thienothiophene-based molecule for both optical and electrochemical detections of ClO− in an aqueous medium.

Sensing chemical-induced genotoxicity and oxidative stress via yeast-based reporter assays using NanoLuc luciferase.

Mutagens and oxidative agents damage biomolecules, such as DNA; therefore, detecting genotoxic and oxidative chemicals is crucial for maintaining human health. To address this, we have developed several types of yeast-based reporter assays designed to detect DNA damage and oxidative stress. This study aimed to develop a novel yeast-based assay using a codon-optimized stable or unstable NanoLuc luciferase (yNluc and yNluCP) gene linked to a DNA damage- or oxidative stress-responsive promoter, enabling convenient sensing genotoxicity or oxidative stress, respectively. End-point luciferase assays using yeasts with a chromosomally integrated RNR3 promoter (PRNR3)-driven yNluc gene exhibited high levels of chemiluminescence via NanoLuc luciferase and higher fold induction by hydroxyurea than a multi-copy plasmid-based assay. Additionally, the integrated reporter system detected genotoxicity caused by four different types of chemicals. Oxidants (hydrogen peroxide, tert-butyl hydroperoxide, and menadione) were successfully detected through transient expressions of luciferase activity in real-time luciferase assay using yeasts with a chromosomally integrated TRX2 promoter (PTRX2)-linked yNlucCP gene. However, the luciferase activity was gradually induced in yeasts with a multi-copy reporter plasmid, and their expression profiles were notably distinct from those observed in chromosomally integrated yeasts. The responses of yNlucCP gene against three oxidative chemicals, but not diamide and zinc oxide suspension, were observed using chromosomally integrated reporter yeasts. Given that yeast cells with chromosomally integrated PRNR3-linked yNluc and PTRX2-linked yNlucCP genes express strong chemiluminescence signals and are easily maintained and handled without restrictive nutrient medium, these yeast strains with NanoLuc reporters may prove useful for screening potential genotoxic and oxidative chemicals.

The relationship between BCG immunotherapy and oxidative stress parameters in patients with nonmuscle invasive bladder cancer

IntroductionEnvironmental chemicals have been associated with the regulation of oxidative stress markers, which have the potential for the development of bladder cancer. However, limited studies on the function of oxidative stress parameters and nonmuscle invasive bladder cancer (NMIBC) in therapy response are available. Here we studied the oxidative stress parameters in response to BCG immunotherapy in NMIBC patients. Material and MethodsA total of 120 patients with NMIBC and treatment with BCG were enrolled and categorized into 2 groups on BCG response, 50 patients were BCG-responsive (BCG-R) and 70 were BCG-nonresponsive (BCG-N). BCG-R have no evidence of tumor recurrence or advancement after 1 year of BCG immunotherapy, but BCG-N has a recurrence of tumor after 3 to 6 months cycles of BCG instillation, as determined by cystoscopy. In all groups, we measured the levels of oxidative stress markers- malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and catalase (CAT). ResultsThe levels of oxidative stress markers viz. MDA, NO, and SOD in the BCG-N group were significantly higher (P < 0.001) than in the BCG-R group. Furthermore, the data demonstrated a significant correlation between oxidative stress marker and NMIBC T1 high grade and tumor size >2.5 cm. However, no statistically significant difference was found between studied groups with CAT. ConclusionThe findings suggest that the carcinogenesis of NMIBC is associated with oxidative damage of biomolecules and indicates the involvement of oxidative stress markers in the development and recurrence of NMIBC.; Therefore, it is critical to ensure the management for T1 high grade and tumor size of >2.5 cm for antioxidant protection.

Use of oxidative stress biomarkers in the study of exposure to pesticides

The extensive use of chemical compounds in agriculture has been related to the occupational exposure of farmers, in addition to environmental degradation and contamination. Such factors can potentiate the imbalance between oxidant and antioxidant compounds, thus allowing the excessive production of reactive oxygen species, which can damage biomolecules and lead to various diseases, including Alzheimer's and cancer. To correlate the toxic effects with exposure to pesticides, oxidative stress biomarkers have become a viable alternative, as they are more stable, specific, and sensitive molecules, with greater measurement capacity, being able to express normal and pathological biological processes or pharmacological responses to therapeutic interventions. Thus, this work aimed to evaluate the application of the use of oxidative stress biomarkers in the study of exposure to pesticides. After reviewing the literature in online databases (PubMed, Science Direct, Web of Science, and Google Scholar), it was possible to conclude that different parameters have been used as fundamental tools during all stages of risk assessment after exposure to pesticides.

Effect of tamoxifen treatment on catalase (CAT) and superoxide dismutase (SOD) expression and localization in the hen oviduct

The imbalance between free reactive oxygen species (ROS) generation and removal (e.g., by antioxidative enzymes) leads to the damage of important biomolecules and cells. Earlier studies in hens showed that treatment with tamoxifen (TMX; estrogen receptor inhibitor) modulates oxidative stress and causes the reproductive system regression realized by cell apoptosis. The aim of the present study was, therefore, to examine the expression and immunolocalization of the key enzymatic antioxidants, i.e. catalase (CAT) and superoxide dismutase (SOD), in the chicken oviduct following TMX treatment. Laying hens were treated daily with TMX until a pause in egg-laying occurred and then euthanized on day 8 of the experiment. Quantitative real-time PCR and western blot analyses showed the presence of CAT and SOD transcripts and proteins, respectively, in all oviductal segments, i.e., the infundibulum, magnum, isthmus, shell gland and vagina. In control hens (laying), the mRNA expression of CAT was the highest in the shell gland, lower in the isthmus and the lowest in other oviductal parts, whereas protein expression was the highest in the magnum, lower in the isthmus and the lowest in other segments. The SOD transcript and protein abundances only were lower in the magnum than in other segments. Immunoreactive CAT and SOD products were localized in all layers of the oviductal wall, but the intensity of staining depended on the cell type. TMX treatment affected CAT and SOD expression and the effect of TMX depended on gene, protein, cell type and oviductal part. Generally, CAT expression was elevated, while SOD expression was decreased under TMX treatment. These results point to the importance of CAT and SOD in the maintenance of proper oviduct health and function. Changes in ROS scavenging enzymes after estrogen receptor blockage indicate the significance of estrogen in the regulation of oxidative status in the avian oviduct.

Design, Synthesis and Therapeutic investigation of Tryptamine derivatives as Potential Antioxidant and Amyloid inhibitor/disaggregator

Oxidative stress is one of the main causative factors for pathogenesis of numerous disorders including psychological and neurodegenerative diseases (Alzheimer’s disease and Parkinsonism). Amyloid aggregates induced oxidative stress is involved in disfunction and degeneration of brain cells in Alzheimer’s disease. Antioxidants are important natural or synthetic molecules having tendency to curb free radicals and discontinuing their chain reactions prior to the damage of essential biomolecules. Drugs possessing antioxidant activity are being extensively anticipated for developing novel therapeutic agents in numerous pathological conditions accompanying oxidative stress like AD. In this study twelve tryptamine derivatives were synthesized and investigated for antioxidant, fibril inhibition and disaggregation potential. In vitro antioxidant potential of the derivatives was examined by using DPPH (2,2‑diphenyl‑1‑picrylhydrazyl) assay and revealed that SR10, SR14, SR23 and SR42 displayed better antioxidant activity (IC50 in the range of 0.75±0.05µM-14.43±0.77µM) than the standard ascorbic acid (IC50 =15.83±0.88µM). In vitro amyloid fibril inhibition and disaggregation assay was carried out by using HEWL (Hen egg white lysozyme) presenting moderate to high inhibition/disaggregation activities. Molecular dockingassessment recognized themode of bindingswithin active site of human antioxidant enzyme peroxiredoxin (PDB ID: 3MNG). These tryptamine derivatives with potential antioxidant and inhibition/disaggregation activitieswill be beneficialto develop and designdrug molecules forneurodegenerative disorders.

Utilization of Acacia Leaves for Patients with Diabetes Mellitus, Cancer and Coronary Heart

Free radicals can cause cell damage and also damage biomolecules, such as DNA, proteins, and lipoproteins in the body which can trigger degenerative diseases, such as diabetes mellitus, cancer, coronary heart disease. Acacia plant has been widely recognized as an antioxidant agent that removes free radicals which can prove a useful therapeutic tactic in controlling diabetes, cancer and coronary heart disease. This research method uses qualitative methods. This study aims to determine the use of Acacia Leaves for people with Diabetes Mellitus, Cancer and Coronary Heart. The results of this study found that acacia leaves contain lots of antioxidants which can treat diabetes mellitus, cancer and heart disease. Acacia leaves are very good for consumption by people with diabetes, cancer, and coronary heart because they contain saponins, flavonoids, polyphenols, and antimicrobials which are efficacious for reducing cholesterol and blood sugar levels

Endogenous Photosensitizers in Human Skin.

Endogenous photosensitizers play a critical role in both beneficial and harmful light-induced transformations in biological systems. Understanding their mode of action is essential for advancing fields such as photomedicine, photoredox catalysis, environmental science, and the development of sun care products. This review offers a comprehensive analysis of endogenous photosensitizers in human skin, investigating the connections between their electronic excitation and the subsequent activation or damage of organic biomolecules. We gather the physicochemical and photochemical properties of key endogenous photosensitizers and examine the relationships between their chemical reactivity, location within the skin, and the primary biochemical events following solar radiation exposure, along with their influence on skin physiology and pathology. An important take-home message of this review is that photosensitization allows visible light and UV-A radiation to have large effects on skin. The analysis presented here unveils potential causes for the continuous increase in global skin cancer cases and emphasizes the limitations of current sun protection approaches.

Effect of Au@SiO2 core shell nanoparticles on HG-induced oxidative stress triggered apoptosis in keratinocytes

Growing evidences suggest that excess generation of highly reactive free oxygen/nitrogen radicals (ROS/RNS) are largely due to hyperglycemia causes oxidative stress. Further, excess accumulation of ROS/RNS in cellular compartments aggravates the development and progression of diabetes and its associated complications. Impaired wound healing in diabetic condition is a known vital complication all around the world. Thus, an antioxidant agent having the potential for hindering the oxidative/nitrosative stress triggered diabetic skin complication is required. The present investigation was carried out to understand the impact of silica coated gold nanoparticle (Au@SiO2 NPs) on high glucose (HG)-induced keratinocyte complications. We demonstrated that HG environment enhanced the ROS and RNS accumulations and reduced in cellular antioxidant capacities in keratinocte cells, however, Au@SiO2 NPs treatment restored the HG effect. Furthermore, excess production of ROS/RNS was associated with mitochondrial dysfunction, characterized by loss of mitochondrial membrane potential (ΔΨm), and increased in mitochondrial mass, which was restored by Au@SiO2 NPs treatment in keratinocyte cells. In addition, HG-induced excess production of ROS/RNA caused an increased in the biomolecules damage including lipid peroxidation (LPO), and protein carbonylation (PC), 8-oxoguanine DNA glycosylase-1 (OGG1) expression and increased 8-hydroxydeoxyguanosine (8-OHdG) accumulations in DNA, leading to activation of ERK1/2MAPK, AKT and tuberin pathway, inflammatory reaction, and finally apoptotic cell death. In conclusion, our findings showed that Au@SiO2 NPs treatment improved the HG-induced keratinocytes injury by suppressing the oxidative/nitrosative stress, elevating the antioxidant defence system, thereby inhibiting the inflammatory mediators and apoptosis, which may be a therapeutic cure for the diabetic keratinocyte problems.

Near-infrared-activated anticancer platinum(IV) complexes directly photooxidize biomolecules in an oxygen-independent manner.

Conventional light-driven cancer therapeutics require oxygen and visible light to indirectly damage biomolecules, limiting their efficacy in deep, hypoxic tumours. Here we report the use of near-infrared-activated small-molecule Pt(IV) photooxidants to directly oxidize intracellular biomolecules in an oxygen-independent manner, achieving controllable and effective elimination of cancer stem cells. These Pt(IV) complexes accumulate in the endoplasmic reticulum and show low toxicity in the dark. Upon irradiation, the resultant metal-enhanced photooxidation effect causes them to robustly photooxidize survival-related biomolecules, induce intense oxidative stress, disrupt intracellular pH (pHi) homeostasis and initiate nonclassical necrosis. In vivo experiments confirm that the lead photooxidant can effectively inhibit tumour growth, suppress metastasis and activate the immune system. Our study validates the concept of metal-enhanced photooxidation and the subsequent chemotherapeutic applications, supporting the development of such localized photooxidants to directly damage intracellular biomolecules and decrease pHi as a strategy for effective metal-based drugs.