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International Journal of Molecular... May 2023The widespread role of titanium (IV) oxide (TiO) in many industries makes this substance of broad scientific interest. TiO can act as both a photoprotector and... (Review)
Review
The widespread role of titanium (IV) oxide (TiO) in many industries makes this substance of broad scientific interest. TiO can act as both a photoprotector and photocatalyst, and the potential for its role in both applications increases when present in nanometer-sized crystals. Its sunlight-scattering properties are used extensively in sunscreens. Furthermore, attempts have been made to incorporate TiO into dermal formulations of photolabile drugs. However, the propensity to generate reactive oxygen species (ROS) rendering this material potentially cytotoxic limits its role. Therefore, modifications of TiO nanoparticles (e.g., its polymorphic form, size, shape, and surface modifications) are used in an effort to reduce its photocatalytic effects. This review provides an overview of the potential risks arising from and opportunities presented by the use of TiO in skin care formulations.
Topics: Humans; Titanium; Oxides; Dermatitis, Phototoxic; Nanoparticles
PubMed: 37175865
DOI: 10.3390/ijms24098159 -
Frontiers in Plant Science 2020Plants experience low ambient temperature and low red to far-red ratios (L-R/FR) of light due to vegetative shading and longer twilight durations in cool seasons. Low...
Plants experience low ambient temperature and low red to far-red ratios (L-R/FR) of light due to vegetative shading and longer twilight durations in cool seasons. Low temperature induce photoinhibition through inactivation of the photosynthetic apparatus, however, the role of light quality on photoprotection during cold stress remains poorly understood. Here, we report that L-R/FR significantly prevents the overreduction of the entire intersystem electron transfer chain and the limitation of photosystem I (PSI) acceptor side, eventually alleviating the cold-induced photoinhibition. During cold stress, L-R/FR activated cyclic electron flow (CEF), enhanced protonation of PSII subunit S (PsbS) and de-epoxidation state of the xanthophyll cycle, and promoted energy-dependent quenching (qE) component of non-photochemical quenching (NPQ), enzyme activity of Foyer-Halliwell-Asada cycle and D1 proteins accumulation. However, L-R/FR -induced photoprotection pathways were compromised in tomato () and () co-silenced plants and () -silenced plants during cold stress. Our results demonstrate that both PGR5/PGRL1- and NDH-dependent CEF mediate L-R/FR -induced cold tolerance by enhancing the thermal dissipation and the repair of photodamaged PSII, thereby mitigating the overreduction of electron carriers and the accumulation of reactive oxygen species. The study indicates that there is an anterograde link between photoreception and photoprotection in tomato plants during cold stress.
PubMed: 32547581
DOI: 10.3389/fpls.2020.00669 -
The Journal of Clinical and Aesthetic... Aug 2019is widely available as an oral supplement and has been shown to exhibit photoprotective properties which might provide adjunctive benefit when used along with topically...
is widely available as an oral supplement and has been shown to exhibit photoprotective properties which might provide adjunctive benefit when used along with topically applied suncreens. However, data are lacking with the majority of formulations (including extracts) related to their quantitative and qualitative polyphenol content and specific photoprotective properties. This article reviews results from a study of six different extract formulations, comparing their polyphenol and excipient contents and specific photoprotective properties. Consistency was observed primarily with one specific brand of extract oral capsules, which is also supported by a large body of published evidence.
PubMed: 31531171
DOI: No ID Found -
Chemistry (Weinheim An Der Bergstrasse,... Jun 2020Photolabile protecting groups (PPGs) have been exploited in a wide range of chemical and biological applications, due to their ability to provide spatial and temporal...
Photolabile protecting groups (PPGs) have been exploited in a wide range of chemical and biological applications, due to their ability to provide spatial and temporal control over light-triggered activation. In this work, we explore the concept of a new photocage compound based on the commercial UVA/UVB filter oxybenzone (OB; 2-hydroxy-4-methoxybenzophenone) for photoprotection and controlled release of carbonyl groups. The point here is that oxybenzone not only acts as a mere PPG, but also provides, once released, UV photoprotection to the carbonyl derivative. This design points to a possible therapeutic approach to reduce the severe photoadverse effects of drugs containing a carbonyl chromophore.
PubMed: 32189405
DOI: 10.1002/chem.202000123 -
Toxicology Feb 2017Antarctica moss Sanionia uncinata (Hedw.) Loeske is exposed in situ to damaging levels of ultraviolet (UV) radiation. This moss has the ability to respond to UV...
Antarctica moss Sanionia uncinata (Hedw.) Loeske is exposed in situ to damaging levels of ultraviolet (UV) radiation. This moss has the ability to respond to UV radiation exposure producing secondary metabolites such as flavonoids, and has been recommended as a potential source of photoprotective compounds and antioxidants. The aim of the present paper was to investigate the free-radical scavenging activity and mutagenic and photomutagenic properties of methanolic (ME), hydroethanolic (HE) and ethanolic (EE) extracts of S. uncinata. The phenolic contents were evaluated by high-performance liquid chromatography (HPLC) and spectrophotometry. The findings showed that ME and EE presented the highest phenolic contents and inhibited free radical-scavenging activity against 2,2'-diphenyl-1 picrylhydrazyl (DPPH) and the HPLC analysis indicated several classes of phenolic acids and flavonoids. The sun protection factors (SPF) were determined by an in vitro method and the results showed significant values. The SPF values of BZ-3 at 50μg/mL increased significantly in association with ME, HE and EE. The extracts did not induce mutagenicity in auxotrophic Salmonella typhimurium histidine and photomutagenicity was not detected in the TA102 and TA104 strains after exposure to UV-A at doses of up to 6.5J/cm for the TA102 strain and up to 0.24J/cm for the TA104 strain. In addition, with the exception of ME, all the extracts induced photoprotective effects in the presence of the TA104 strain at 0.04J/cm. The present results suggest that S. uncinata extracts did not induce photomutation and showed promise for photoprotection against the photobiological and ROS-inducing effects of the UV-A radiation.
Topics: Animals; Antarctic Regions; Bryophyta; Dose-Response Relationship, Drug; Free Radical Scavengers; Mutagenicity Tests; Mutagens; Plant Extracts; Rats; Salmonella typhimurium; Sunscreening Agents; Ultraviolet Rays
PubMed: 27234318
DOI: 10.1016/j.tox.2016.05.021 -
Current Research in Structural Biology 2024Orange carotenoid proteins (OCPs) are unique photoreceptors that are critical for cyanobacterial photoprotection. Upon exposure to blue-green light, OCPs are activated... (Review)
Review
Orange carotenoid proteins (OCPs) are unique photoreceptors that are critical for cyanobacterial photoprotection. Upon exposure to blue-green light, OCPs are activated from a stable orange form, OCP, to an active red form, OCP, which binds to phycobilisomes (PBSs) and performs photoprotective non-photochemical quenching (NPQ). OCPs can be divided into three main families: the most abundant and best studied OCP1, and two others, OCP2 and OCP3, which have different activation and quenching properties and are yet underexplored. Crystal structures have been acquired for the three OCP clades, providing a glimpse into the conformational underpinnings of their light-absorption and energy dissipation attributes. Recently, the structure of the PBS-OCP complex has been obtained allowing for an unprecedented insight into the photoprotective action of OCPs. Here, we review the latest findings in the field that have substantially improved our understanding of how cyanobacteria protect themselves from the toxic consequences of excess light absorption. Furthermore, current research is applying the structure of OCPs to bio-inspired optogenetic tools, to function as carotenoid delivery devices, as well as engineering the NPQ mechanism of cyanobacteria to enhance their photosynthetic biomass production.
PubMed: 38736459
DOI: 10.1016/j.crstbi.2024.100141 -
Plants (Basel, Switzerland) Oct 2023Polyphenols are a diverse class of natural compounds that are widely distributed in various fruits, vegetables, and herbs. They possess antioxidant and anti-inflammatory... (Review)
Review
Polyphenols are a diverse class of natural compounds that are widely distributed in various fruits, vegetables, and herbs. They possess antioxidant and anti-inflammatory properties and bring benefits in the prevention and treatment of various diseases. Studies suggested that polyphenols may improve cardiovascular health and may have neuroprotective effects. The Mediterranean region is a vast area. Although the territory encompasses a wide variety of cultures and dietary patterns, there are some commonalities in terms of the plant-based foods and their polyphenol content. Such polyphenols have been studied for their potential photoprotective effects on the skin. We focused on nutraceutical effects of Mediterranean plants in skin photoprotection in atopic dermatitis, psoriasis, and chronic urticaria. Results highlight the importance of exploring natural compounds for therapeutic purposes. The wide variety of polyphenols found in different foods and plants allows for a diverse range of pharmacological effects. The Mediterranean diet, rich in polyphenol-containing foods, is associated with a lower incidence of various chronic diseases, including dermatological conditions. While more research is needed to fully understand the mechanisms of action and optimal dosing of polyphenols, there is initial evidence to support their potential use as adjunctive therapy for atopic dermatitis, psoriasis, and chronic urticaria.
PubMed: 37896042
DOI: 10.3390/plants12203579 -
Frontiers in Medicine 2023Exposure to solar radiation can cause a range of skin damage, including sunburn, erythema, skin carcinogenesis, the release of reactive oxygen species (ROS),...
INTRODUCTION
Exposure to solar radiation can cause a range of skin damage, including sunburn, erythema, skin carcinogenesis, the release of reactive oxygen species (ROS), inflammation, DNA damage, and photoaging. Other wavelengths beyond UVB, such as UVA, blue light, and infrared radiation, can also contribute to the harmful effects of solar radiation. Reconstructed full-thickness human skin has the potential to serve as effective predictive in vitro tools for evaluating the effects of solar radiation on the skin. The aim of this work was to evaluate the damaging effects of UVA, blue light, and infrared radiation in a full-thickness skin model in terms of viability, inflammation, photoaging, tissue damage, photocarcinogenesis.
METHODS
Full thickness skin models were purchased from Henkel (Phenion FT; Düsseldorf, Germany), and irradiated with increasing doses of UVA, blue light, or infrared radiation. Different endpoints were analyzed on the tissues: Hematoxylin-eosin staining, inflammation mediators, photoaging-related dermal markers and oxidative stress marker GPX1, evaluated by real-time quantitative PCR, as well as photocarcinogenesis markers by Western Blot.
RESULTS AND DISCUSSION
The results showed differential responses in cytokine release for each light source. In terms of photoaging biomarkers, collagen, metalloproteinases 1 and 9, elastin, and decorin were modulated by UVA and blue light exposure, while not all these markers were affected by infrared radiation. Furthermore, exposure to UVA and blue light induced loss of fibroblasts and modulation of the photocarcinogenesis markers p53 and p21. In conclusion, the presented results suggest that the various wavelengths of solar light have distinct and differential damaging effects on the skin. Understanding the differential effects of UVA, blue light, and infrared radiation can serve as a valuable tool to investigate the efficacy of photoprotective agents in full thickness skin models.
PubMed: 38105899
DOI: 10.3389/fmed.2023.1267409 -
Antioxidants (Basel, Switzerland) Jul 2022The antioxidant system of the human body plays a crucial role in maintaining redox homeostasis and has an important protective function. Carotenoids have pronounced... (Review)
Review
The antioxidant system of the human body plays a crucial role in maintaining redox homeostasis and has an important protective function. Carotenoids have pronounced antioxidant properties in the neutralization of free radicals. In human skin, carotenoids have a high concentration in the stratum corneum (SC)-the horny outermost layer of the epidermis, where they accumulate within lipid lamellae. Resonance Raman spectroscopy and diffuse reflectance spectroscopy are optical methods that are used to non-invasively determine the carotenoid concentration in the human SC in vivo. It was shown by electron paramagnetic resonance spectroscopy that carotenoids support the entire antioxidant status of the human SC in vivo by neutralizing free radicals and thus, counteracting the development of oxidative stress. This review is devoted to assembling the kinetics of the carotenoids in the human SC in vivo using non-invasive optical and spectroscopic methods. Factors contributing to the changes of the carotenoid concentration in the human SC and their influence on the antioxidant status of the SC in vivo are summarized. The effect of chemotherapy on the carotenoid concentration of the SC in cancer patients is presented. A potential antioxidant-based pathomechanism of chemotherapy-induced hand-foot syndrome and a method to reduce its frequency and severity are discussed.
PubMed: 35892651
DOI: 10.3390/antiox11081451 -
British Journal of Health Psychology Feb 2020Social support influences adherence to treatment in chronic illness, but there is uncertainty about its facilitators and constraints. This study explored the forms,...
OBJECTIVES
Social support influences adherence to treatment in chronic illness, but there is uncertainty about its facilitators and constraints. This study explored the forms, processes, and responses associated with mobilization of informal support across three life contexts amongst patients with Xeroderma Pigmentosum (XP), a condition requiring rigorous photoprotection to reduce cancer risks.
DESIGN
Qualitative interview study.
METHODS
A total of 25 adults with XP participated in semi-structured interviews conducted face to face. An inductive thematic analysis was applied using a framework approach.
RESULTS
Practical support, involving both assistance with recommended photoprotection and adjusting daily activities to reduce exposure, was the key form of support provided by family and friends. However, responses to this support differed with two groups identified based on the relative priority given to photoprotection in daily life and processes of disclosure. For 'positive responders', support aligned with their own priorities to photoprotect, conveyed feelings of being cared-for and was facilitated by talking openly. In contrast, for 'negative responders' support conflicted with their priority of living 'normally' and their limited disclosure hindered receipt of helpful support in personal, clinic, and work interactions. Fears of workplace stigma also reduced disclosure amongst participants open in other contexts.
CONCLUSIONS
Practical support conveyed psychosocial support with positive effects on adherence. This suggests the traditional separation into practical and emotional support is overly simplistic, with measures potentially missing important aspects. Interactional processes contribute to the effects of support, which can be addressed by targeting disclosure, stigma, and other barriers at individual and organizational levels. Statement of contribution What is already known on this subject? Social support can be both a facilitator and a hindrance to treatment adherence. Practical support is identified as the most important form of support in the context of adherence. The processes of support underpinning its relationship to adherence are unclear. What does this study add? Variations in the provision and impacts of support are influenced by participants' disclosure and attitudes to photoprotection, with two key groups comprising 'positive responders' and 'negative responders'. The influence of emotional support on adherence may be underestimated through neglect of the ways in which practical support often conveys feelings of being valued and cared-for. Barriers to mobilizing effective adherence support extends across life spheres, with fears of stigma and discrimination in work settings highlighting the need to intervene at individual and organizational levels.
Topics: Adolescent; Adult; Family; Female; Friends; Humans; Interviews as Topic; Male; Middle Aged; Patient Compliance; Protective Clothing; Qualitative Research; Social Support; Sunscreening Agents; Xeroderma Pigmentosum; Young Adult
PubMed: 31756279
DOI: 10.1111/bjhp.12396