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Photochemistry and Photobiology Jul 2024The thermodynamic characteristics, antioxidant potential, and photoprotective benefits of full-spectrum cannabidiol (FS-CBD) against UVB-induced cellular death were...
The thermodynamic characteristics, antioxidant potential, and photoprotective benefits of full-spectrum cannabidiol (FS-CBD) against UVB-induced cellular death were examined in this study. In silico analysis of CBD showed antioxidant capacity via proton donation and UV absorption at 209.09, 254.73, and 276.95 nm, according to the HAT and SPLET methodologies. FS-CBD protected against UVB-induced bacterial death for 30 min. FS-CBD protected against UVB-induced cell death by 42% (1.5 μg/mL) and 35% (3.5 μg/mL) in an in vitro keratinocyte cell model. An in vivo acute irradiated CD-1 mouse model (UVB-irradiated for 5 min) presented very low photoprotection when FS-CBD was applied cutaneously, as determined by histological analyses. In vivo skin samples showed that FS-CBD regulated inflammatory responses by inhibiting the inflammatory markers TGF-β1 and NLRP3. The docking analysis showed that the CBD molecule had a high affinity for TGF-β1 and NLRP3, indicating that protection against inflammation might be mediated by blocking these proinflammatory molecules. This result was corroborated by the docking interactions between CBD and TGF-β1 and NLRP3, which resulted in a high affinity and inhibition of both proteins The present work suggested a FS-CBD moderate photoprotective agent against UVB light-induced skin damage and that this effect is partially mediated by its anti-inflammatory activity.
PubMed: 38958000
DOI: 10.1111/php.13993 -
Nature Communications Jul 2024Diatoms often outnumber other eukaryotic algae in the oceans, especially in coastal environments characterized by frequent fluctuations in light intensity. The...
Diatoms often outnumber other eukaryotic algae in the oceans, especially in coastal environments characterized by frequent fluctuations in light intensity. The identities and operational mechanisms of regulatory factors governing diatom acclimation to high light stress remain largely elusive. Here, we identified the AUREO1c protein from the coastal diatom Phaeodactylum tricornutum as a crucial regulator of non-photochemical quenching (NPQ), a photoprotective mechanism that dissipates excess energy as heat. AUREO1c detects light stress using a light-oxygen-voltage (LOV) domain and directly activates the expression of target genes, including LI818 genes that encode NPQ effector proteins, via its bZIP DNA-binding domain. In comparison to a kinase-mediated pathway reported in the freshwater green alga Chlamydomonas reinhardtii, the AUREO1c pathway exhibits a faster response and enables accumulation of LI818 transcript and protein levels to comparable degrees between continuous high-light and fluctuating-light treatments. We propose that the AUREO1c-LI818 pathway contributes to the resilience of diatoms under dynamic light conditions.
Topics: Diatoms; Light; Acclimatization; Chlamydomonas reinhardtii; Algal Proteins; Gene Expression Regulation
PubMed: 38956103
DOI: 10.1038/s41467-024-49991-7 -
Journal of Drugs in Dermatology : JDD Jul 2024Visual casts and discoloration are common barriers to sunscreen use in melanin-rich populations. However, photoprotective measures are essential for individuals with all...
BACKGROUND
Visual casts and discoloration are common barriers to sunscreen use in melanin-rich populations. However, photoprotective measures are essential for individuals with all skin types, including darker skin.
METHODS
Single-center, 7-day, open-label study of healthy adult females with Fitzpatrick Skin Types (FST) IV to VI and sensitive skin treated with once-daily daily facial moisturizer sun protection factor 35 (DFM SPF35). Subjects completed a cosmetic acceptability questionnaire at days 1 and 7. Photography using VISIA CR was performed at day 7. Adverse events were monitored throughout the study.
RESULTS
Thirty-two (32) subjects participated; 31.3% had FST IV, 53.1% V, and 15.6% VI skin. DFM SPF35 was viewed as cosmetically elegant. At day 1, 96.7% of subjects agreed product was easy to apply; 90.0% reported soft skin after product use; 86.7% said it had a lightweight, non-greasy feel and hydrated the skin. At day 7, 93.7% reported no visible white residue on their skin and said the product applied easily/absorbed well. The majority (90.6%) would continue using and would recommend the product; and 87.5% reported the product blended seamlessly into their skin, which agreed with clinical photography. Responses were consistent among subjects with normal, oily, or combination skin. No adverse events were reported.
CONCLUSIONS
DFM SPF35 blended well into the skin and was perceived favorably among subjects with SOC after 1 and 7 days of use. Subjects felt it had good cosmetic acceptability without unacceptable white residues or a greasy feeling. Dermatologists need to be versed in products that can be used on a variety of skin types.J Drugs Dermatol. 2024;23(7):515-518. doi:10.36849/JDD.8223.
Topics: Humans; Female; Sunscreening Agents; Adult; Sun Protection Factor; Photography; Middle Aged; Skin Pigmentation; Young Adult; Skin; Administration, Cutaneous; Surveys and Questionnaires; Skin Cream
PubMed: 38954626
DOI: 10.36849/JDD.8223 -
Journal of Drugs in Dermatology : JDD Jul 2024To understand the prevalence and types of publications addressing darker skin types within the existing evidence base for sunscreen use. Evidence Review: PubMed... (Review)
Review
BACKGROUND
To understand the prevalence and types of publications addressing darker skin types within the existing evidence base for sunscreen use. Evidence Review: PubMed was searched from 1988, the time point at which the first skin of color (SOC) article was identified, through December 2022 using PubMed's Medical Subject Headings terms and keyword searches in title and abstract, with and without terms for SOC and ethnicity. Identified articles were reviewed for relevance, de-duplicated, and categorized; results are summarized.
FINDINGS
Of the 5927 articles on sunscreen overall, only 314 (5.3%) articles addressed SOC, with the majority published since 2007 and representing only 4% to 7% of total publications annually except in 2022 when the proportion of SOC articles was 23.5%. Of the articles on SOC, many reported sunscreen knowledge and patient behaviors (29%), but very few reported clinical trials (5%). The 3 conditions most often discussed were melasma, post-inflammatory hyperpigmentation, and dyschromia. South Asian ethnicities (India, Pakistan, Bangladesh) had the highest representation within the literature, followed by Hispanics.
CONCLUSIONS AND RELEVANCE
Although it was assumed there would be fewer papers discussing the use of sunscreen in darker skin types, the scale of the disparity revealed by this study is stark. The increase in a number of articles in 2022 suggests an increasing focus on SOC, but further discussion of the issues presented here will help the SOC community address gaps in the evidence base and better inform discussions on sunscreen and photoprotection between clinicians and patients.J Drugs Dermatol. 2024;23(7):575-577. doi:10.36849/JDD.8250.
Topics: Humans; Sunscreening Agents; Skin Pigmentation; Health Knowledge, Attitudes, Practice; Ultraviolet Rays
PubMed: 38954618
DOI: 10.36849/JDD.8250 -
Histochemistry and Cell Biology Jul 2024Skin represents the main barrier against the external environment, but also plays a role in human relations, as one of the prime determinants of beauty, resulting in a...
Skin represents the main barrier against the external environment, but also plays a role in human relations, as one of the prime determinants of beauty, resulting in a high consumer demand for skincare-related pharmaceutical products. Given the importance of skin aging in both medical and social spheres, the present research aims to characterize microscopic changes in human skin composition due to intrinsic aging (as opposed to aging influenced by external factors) via histological analysis of a photoprotected body region. Samples from 25 autopsies were taken from the periumbilical area and classified into four age groups: group 1 (0-12 years), group 2 (13-25 years), group 3 (26-54 years), and group 4 (≥ 55 years). Different traditional histological (hematoxylin-eosin, Masson's trichrome, orcein, toluidine, Alcian blue, and Feulgen reaction) and immunohistochemical (CK20, CD1a, Ki67, and CD31) stains were performed. A total of 1879 images photographed with a Leica DM3000 optical microscope were morphometrically analyzed using Image ProPlus 7.0 for further statistical analysis with GraphPad 9.0. Our results showed a reduction in epidermis thickness, interdigitation and mitotic indexes, while melanocyte count was raised. Papillary but not reticular dermis showed increased thickness with aging. Specifically, in the papillary layer mast cells and glycosaminoglycans were expanded, whereas the reticular dermis displayed a diminution in glycosaminoglycans and elastic fibers. Moreover, total cellularity and vascularization of both dermises were diminished with aging. This morphometric analysis of photoprotected areas reveals that intrinsic aging significantly influences human skin composition. This study paves the way for further research into the molecular basis underpinning these alterations, and into potential antiaging strategies.
PubMed: 38954026
DOI: 10.1007/s00418-024-02305-w -
Frontiers in Physiology 2024Several fluorescent proteins (FPs) and chromoproteins (CPs) are present in anthozoans and play possible roles in photoprotection. Coral tissues in massive corals often...
INTRODUCTION
Several fluorescent proteins (FPs) and chromoproteins (CPs) are present in anthozoans and play possible roles in photoprotection. Coral tissues in massive corals often display discoloration accompanied by inflammation. Incidences of the pink pigmentation response (PPR) in massive , described as inflammatory pink lesions of different shapes and sizes, has recently increased worldwide. FPs are reported to be present in PPR lesions, wherein a red fluorescent protein (RFP) appears to play a role in reducing reactive oxygen species. However, to date, the biochemical characterization and possible roles of the pigments involved are poorly understood. The present study aimed to identify and characterize the proteins responsible for pink discoloration in massive colonies displaying PPRs, as well as to assess the differential distribution of pigments and the antioxidant properties of pigmented areas.
METHOD
CPs were extracted from PPR lesions using gel-filtration chromatography and identified via genetic analysis using liquid chromatography-tandem mass spectrometry. The coexistence of CPs and RFP in coral tissues was assessed using microscopic observation. Photosynthetic antivity and hydrogen peroxide-scavenging activitiy were measured to assess coral stress conditions.
RESULTS
The present study revealed that the same CP (plut2.m8.16902.m1) isolated from massive was present in both the pink spot and patch morphologies of the PPR. CPs were also found to coexist with RFP in coral tissues that manifested a PPR, with a differential distribution (coenosarc or tip of polyps' tentacles). High hydrogen peroxide-scavenging rates were found in tissues affected by PPR.
DISCUSSION AND CONCLUSION
The coexistence of CPs and RFP suggests their possible differential role in coral immunity. CPs, which are specifically expressed in PPR lesions, may serve as an antioxidant in the affected coral tissue. Overall, this study provides new knowledge to our understanding of the role of CPs in coral immunity.
PubMed: 38952870
DOI: 10.3389/fphys.2024.1339907 -
Frontiers in Plant Science 2024subsp. Scop. (sea rocket) is a succulent halophyte with significant potential as a nutritious food source, being rich in essential nutrients such as vitamins,...
subsp. Scop. (sea rocket) is a succulent halophyte with significant potential as a nutritious food source, being rich in essential nutrients such as vitamins, minerals, and antioxidants. This annual species exhibits two distinct leaf morphotypes: entire lamina (EL) and pinnatifid lamina (PL). Our understanding of their ecophysiological and nutritional profiles is still limited. The present study investigated the wild EL and PL sea rocket plants from southern Italy during their vegetative stage. The bio-morphological traits (leaf mass area-LMA, dry matter and chlorophyll concentrations), main inorganic ions, key antioxidants (carotenoids, anthocyanins, phenols, flavonoids, glucosinolates, vitamin C as ascorbic and dehydroascorbic acid), and antioxidant activity (by FRAP, DPPH, ABTS assays) were analyzed. Additionally, photosynthetic gas exchange and chlorophyll fluorescence were measured. PL plants showed thicker leaves (higher LMA) and greater accumulation of photo-protective pigments (carotenoids and anthocyanins), despite similar chlorophyll levels. The PL plants also demonstrated higher photosynthetic activity, transpiration rates, and stomatal conductance, with reduced non-photochemical quenching. The EL morphotype had higher cation (K, Mg, Ca, Na) and vitamin C (135.3 mg 100 g FW) concentrations, while no significant disparities were observed between the morphotypes in phenolic concentration (208.5 mg g.a.e. 100 g FW), flavonoids (71.5 mg q.e. 100 g FW), or glucosinolates (61 mg g FW). Interestingly, while the EL type had higher vitamin C, the PL morphotype showed superior antioxidant activity (FRAP, DPPH) and seems to be better adapted to water/nutrient scarcity typical of southern Italy. Both morphotypes offer potential as high-nutritional foods, however, future research should investigate the genotype-specific production of antioxidant compounds in EL and PL plants in response to environmental stresses, including salinity for potential exploitation as a new crop.
PubMed: 38947950
DOI: 10.3389/fpls.2024.1397852 -
Plant, Cell & Environment Jul 2024The acclimation of the green algae Chlamydomoas reinhardtii to high light (HL) has been studied predominantly under continuous illumination of the cells. Here, we...
The acclimation of the green algae Chlamydomoas reinhardtii to high light (HL) has been studied predominantly under continuous illumination of the cells. Here, we investigated the impact of fluctuating HL in alternation with either low light (LL) or darkness on photosynthetic performance and on photoprotective responses. Compared to intervening LL phases, dark phases led to (1) more pronounced reduction of the photosystem II quantum efficiency, (2) reduced degradation of the PsbS protein, (3) lower energy dissipation capacity and (4) an increased pool size of the xanthophyll cycle pigments. These characteristics indicate increased photo-oxidative stress when HL periods are interrupted by dark phases instead of LL phases. This overall trend was similar when comparing long (8 h) and short (30 min) HL phases being interrupted by long (16 h) and short (60 min) phases of dark or low light, respectively. Only the degradation of PsbS was clearly more efficient during long (16 h) LL phases when compared to short (60 min) LL phases.
PubMed: 38946377
DOI: 10.1111/pce.15020 -
Physiologia Plantarum 2024Maximal sunlight intensity varies diurnally due to the earth's rotation. Whether this slow diurnal pattern influences the photoprotective capacity of plants throughout...
Maximal sunlight intensity varies diurnally due to the earth's rotation. Whether this slow diurnal pattern influences the photoprotective capacity of plants throughout the day is unknown. We investigated diurnal variation in NPQ, along with NPQ capacity, induction, and relaxation kinetics after transitions to high light, in tomato plants grown under diurnal parabolic (DP) or constant (DC) light intensity regimes. DP light intensity peaked at midday (470 μmol m s while DC stayed constant at 300 μmol m s at a similar 12-hour photoperiod and daily light integral. NPQs were higher in the morning and afternoon at lower light intensities in DP compared to DC, except shortly after dawn. NPQ capacity increased from midday to the end of the day, with higher values in DP than in DC. At high light Φ did not vary throughout the day, while Φ varied consistently with NPQ capacity. Reduced Φ suggested less susceptibility to photodamage at the end of the day. NPQ induction was faster at midday than at the start of the day and in DC than in DP, with overshoot occurring in the morning and midday but not at the end of the day. NPQ relaxation was faster in DP than in DC. The xanthophyll de-epoxidation state and reduced demand for photochemistry could not explain the observed diurnal variations in photoprotective capacity. In conclusion, this study showed diurnal variation in regulated photoprotective capacity at moderate growth light intensity, which was not explained by instantaneous light intensity or increasing photoinhibition over the day and was influenced by acclimation to constant light intensity.
Topics: Solanum lycopersicum; Circadian Rhythm; Light; Photosynthesis; Photoperiod; Xanthophylls; Sunlight; Chlorophyll; Photosystem II Protein Complex; Kinetics; Plant Leaves
PubMed: 38945685
DOI: 10.1111/ppl.14410 -
Clinical, Cosmetic and Investigational... 2024The topical application of antioxidants has been shown to augment the skin's innate antioxidant system and enhance photoprotection. A challenge of topical antioxidant...
PURPOSE
The topical application of antioxidants has been shown to augment the skin's innate antioxidant system and enhance photoprotection. A challenge of topical antioxidant formulation is stability and penetrability. The use of a targeted drug delivery system may improve the bioavailability and delivery of antioxidants. In this ex vivo study, we assessed the effects of the topical application of a liposome-encapsulated antioxidant complex versus a free antioxidant complex alone on skin photoaging parameters and penetrability in human skin explants.
PATIENTS AND METHODS
Human organotypic skin explant cultures (hOSEC) were irradiated to mimic photoaging. The encapsulated antioxidant complex and free antioxidant complex were applied topically onto the irradiated hOSEC daily for 7 days. The two control groups were healthy untreated hOSEC and irradiated hOSEC. Photoprotective efficacy was measured with pro-inflammatory cytokine (IL-6 and IL-8) and matrix metalloproteinase 9 (MMP-9) secretion. Cell viability and metabolic activity were measured via resazurin assay. Tissue damage was evaluated via lactate dehydrogenase (LDH) cytotoxicity assay. Skin penetration of the encapsulated antioxidant complex was assessed via fluorescent dye and confocal microscopy.
RESULTS
Compared to healthy skin, irradiated skin experienced increases in IL-6, IL-8 (p < 0.05), and MMP-9 (p < 0.05) secretion. After treatment with the encapsulated antioxidant complex, there was a 39.3% reduction in IL-6 secretion, 49.8% reduction in IL-8 (p < 0.05), and 38.5% reduction in MMP-9 (p < 0.05). After treatment with the free antioxidant complex, there were no significant differences in IL-6, IL-8, or MMP-9 secretion. Neither treatment group experienced significant LDH leakage or reductions in metabolic activity. Liposomes passed through the stratum corneum and into the epidermis.
CONCLUSION
The topical application of a liposome-encapsulated antioxidant complex containing ectoin, astaxanthin-rich microalgae extract, and THDA improves penetrability and restored IL-6, IL-8, and MMP-9 levels in irradiated human skin explants, which was not seen in the comparator free antioxidant complex group.
PubMed: 38933604
DOI: 10.2147/CCID.S461753