Photoprotective Potential Research Articles

Photoprotective properties of four structure propolis from Heterotrigona itama stingless beehive: Fractionation, bioactivity analysis, and chemical profiling

Heterotrigona itama stingless bee propolis extract is known for its diverse bioactive compounds, making it a potential natural shield against UV radiation. This research assesses the photoprotective potential of crude ethanol extract from H. itama propolis collected from four structures (involucrum, pillar, pot, and entrance) of five bee hives (H1-H5), totalling 20 samples. Initially, the samples underwent testing for SPF value and UV absorption spectra. The crude ethanol extract (E) from the involucrum (H4) with the highest SPF value and broadest spectrum was selected for fractionation using hexane and water. Subsequently, the extract (E) and its hexane (H) and water (W) fractions were subjected to SPF analysis, UVA/UVB absorption assessment, determination of total phenolic and flavonoid content, free radical scavenging capacity, anti-collagenase effects, and cytotoxicity assessment. Additionally, LC-MS/MS analysis was performed to identify chemical constituents in the active fraction (W). The extract E demonstrated an SPF of 8.23 ± 0.09 and UV absorption. Notably, its fraction W exhibited the highest SPF (16.55 ± 0.24) at 100 μg/mL, surpassing the H fraction (SPF 5.7 ± 0.45). Phenolic content was highest in the H fraction (388.95 ± 4.54 mg/g GAE DW), followed by the W fraction (286.76 ± 6.48 mg/g GAE DW) and crude E (91.83 ± 4.12 mg/g GAE DW) from the involucrum. Regarding flavonoids, the fraction W led with 79.82 ± 6.21 mg/g QE DW, followed by the H fraction (45.56 ± 0.05 mg/g QE DW) and E (34.57 ± 1.11 mg/g QE DW). The extract E also exhibited modest DPPH scavenging (EC50 = 120 μg/mL), while the H fraction demonstrated stronger activity (EC50 = 4.37 μg/mL), and the W fraction displayed moderate effects (EC50 = 17.55 μg/mL). Notably, the W fraction showed remarkable anti-collagenase activity, outperforming the positive control, EG. HaCaT cell cytotoxicity revealed that the extract E was cytotoxic, whereas the H and W fractions showed no toxicity. LC-MS/MS analysis identified bioactive flavonoids (e.g., pratensein, quercetin) in the W fraction. These findings highlight the superior photoprotective properties of the water fraction from the involucrum of H. itama stingless bee propolis extract, suggesting its potential as a natural and effective ingredient for sunscreen and skincare formulations.

Photoprotective efficacy of Sunset Yellow via inhibition of type-I and type-II pathway under exposure of sunlight.

Exposure to phototoxicants and photosensitizers can result in the generation of reactive oxygen species (ROS), leading to oxidative stress, DNA damage, and various skin-related issues such as aging, allergies, and cancer. While several photo-protectants offer defense against ultraviolet radiation (UV-R), their effectiveness is often limited by photo-instability. Sunset Yellow (SY), an FDA-approved food dye, possesses significant UV-R and visible light absorption properties. However, its photoprotective potential has remained unexplored. Our investigation reveals that SY exhibits remarkable photostability for up to 8 h under both UV-R and sunlight. Notably, SY demonstrates the ability to quench ROS, including singlet oxygen (1O2), superoxide radicals ( ), and hydroxyl radicals (·OH) induced by rose bengal, riboflavin and levofloxacin, respectively. Moreover, SY proves effective in protecting against the apoptotic and necrotic cell death induced by the phototoxicant chlorpromazine (CPZ) in HaCaT cells. Further, it was observed that SY imparts photoprotection by inhibiting intracellular ROS generation and calcium release. Genotoxicity evaluation provides additional evidence supporting SY's photoprotective effects against CPZ-induced DNA damage. In conclusion, these findings underscore the potential of SY as a promising photoprotective agent against the toxic hazards induced by phototoxicants, suggesting its prospective application in the formulation of broad-spectrum sunscreens.

Total phenolic content and in vitro photoprotective activity of ethanolic extract of torch ginger (Etlingera elatior)

Background: Previous research highlighted the photoprotective potential of various extracts from torch ginger leaves, but the efficacy of ethanolic extracts, particularly from leaves and other plant parts, remained unexplored.
 Objective: This study aimed to assess the total phenolic content and SPF value of ethanolic extracts from torch ginger leaves, flowers, and stems, comparing these with a known photoprotective agent, oxybenzone.
 Method: Ethanolic extraction was performed on approximately 200 grams of each plant part. The total phenolic content was determined using the Folin-Ciocalteu method, while SPF values were measured spectrophotometrically between 290 and 320 nm. Statistical analysis involved Kruskal-Wallis tests followed by post-hoc Fisher's LSD.
 Results: The leaf extract exhibited the highest phenolic content (483.788 ± 2.57 mg GAE/g) and SPF value at 1000 ppm, surpassing that of flowers, stems, and the positive control, oxybenzone. The correlation between phenolic content and SPF value across plant parts was statistically significant.
 Conclusion: The ethanolic extract of torch ginger leaves shows superior photoprotective potential, indicated by its high phenolic content and SPF value, suggesting its promising application in natural sunscreen formulations up to the permissible active substance limit of 6% set by BPOM.

Myconoside and Calceolarioside E Restrain UV-Induced Skin Photoaging by Activating NRF2-Mediated Defense Mechanisms.

Chronic and excessive ultraviolet (UVA/UVB) irradiation exposure is known as a major contributor to premature skin aging, which leads to excessive reactive oxygen species generation, disturbed extracellular matrix homeostasis, DNA damage, and chronic inflammation. Sunscreen products are the major preventive option against UVR-induced photodamage, mostly counteracting the acute skin effects and only mildly counteracting accelerated aging. Therefore, novel anti-photoaging and photopreventive compounds are a subject of increased scientific interest. Our previous investigations revealed that the endemic plant Haberlea rhodopensis Friv. (HRE) activates the antioxidant defense through an NRF2-mediated mechanism in neutrophiles. In the present study, we aimed to investigate the photoprotective potential of HRE and two of its specialized compounds-the phenylethanoid glycosides myconoside (MYC) and calceolarioside E (CAL)-in UVA/UVB-stimulated human keratinocytes in an in vitro model of photoaging. The obtained data demonstrated that the application of HRE, MYC, and CAL significantly reduced intracellular ROS formation in UVR-exposed HaCaT cells. The NRF2/PGC-1α and TGF-1β/Smad/Wnt signaling pathways were pointed out as having a critical role in the observed CAL- and MYC-induced photoprotective effect. Collectively, CAL is worth further evaluation as a potent natural NRF2 activator and a promising photoprotective agent that leads to the prevention of UVA/UVB-induced premature skin aging.

Formulation and optimization of phytosomes of ethanolic extract of Viola tricolor flowers using design of experiment (DOE) to evaluate in vitro photoprotective potential as sunscreen cream

Viola tricolor L. has many uses in treatment of various skin disorders, which attributed to their antioxidant-flavonoid compounds. The aim of this study was evaluation of photoprotection, cytotoxicity and phototoxicity of the ethanolic extract of Viola tricolor flowers (EE-Viola). At concentration of 0.2 mg/mL of EE-Viola, the sun protection factor (SPF) value was 15.3 ± 0.7. By evaluation of the survival of mouse fibroblast cells (3T3) in the presence and absence of UV light using MTT-based colorimetric assay, the calculated IC50 was found to be 30.79 µg/mL and 34.89 µg/mL, respectively. The phytosomes of EE-Viola (Phy&EE-Viola) were then prepared using thin-layer hydration technique and optimized by experimental design method. The optimum particle size (487.6 nm) and encapsulation efficiency (95.2%) of the prepared phytosomes obtained when ratio of extract amount to lecithin amount (3 to 1), experiment temperature of 50 °C, and bath sonication were used. The optimum prepared phytosome was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and differential scanning calorimetry. In the next step, Phy&EE-Viola was formulated in a cream base and its photoprotective potential was evaluated. Finally, the Phy&EE-Viola cream was evaluated for its pH, spread-ability, occlusivity, in vitro SPF determination, release and stability studies. The SPF value of the cream containing 4% of Phy&EE-Viola was equal to 14.0 ± 0.7. The results clearly indicated that the cream formulations exhibited a good stability at applied temperatures and good release profile. Therefore, the obtained cream of Phy&EE-Viola might be introduced as candidate as for sun protection which merit further investigations.

In vitro photoprotective potential of aryl-sandwiched (thio)semicarbazones against UVA mediated cellular and DNA damage

The most prevalent solar ultraviolet radiation is ultraviolet-A (UVA) radiation. It is the inducer of reactive oxygen species (ROS), a potent mediator of inflammation and photocarcinogenesis. Regular application of sunscreens containing UVA filters is an effective preventive measure in mitigating the risk associated with the formation of dermal carcinoma. Therefore, the development of new photoprotective agents is of great need. The current work examined the in vitro photoprotection of the aryl-linked (thio)semicarbazone derivatives against UVA-mediated DNA damage, inflammation, reactive nitrogen species (RNS), and ROS. Except for the inflammatory cytokine assay, which was carried out on the human monocytic leukemia (THP-1) cell line, all tests were conducted on the human dermal fibroblast (BJ) cell line. In comparison to benzophenone (reference compound), the compound (2Z, 2′Z)-2,2′-(1,3-Phenylenebis (methanylylidene)) bis (hydrazine-1-carbothioamide) (DD-21) demonstrated considerable protection against UVA-induced damage. Compared to the UVA-irradiated control, DD-21 significantly decreased the levels of nitric oxide (NO) and ROS (p < 0.001). In the presence of DD-21, the release of UVA-induced pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), was also significantly reduced (p < 0.05). Moreover, it was observed that DD-21 protected the cells from UVA-mediated DNA strand breaks and also inhibited the formation of cyclobutane pyrimidine dimers (CPDs) upon comparison to the UVA-exposed control cells (p < 0.001). In conclusion, the findings of this study revealed that DD-21 exhibits remarkable photoprotective properties, thus demonstrating its potential as a candidate UVA filter.

Identification and characterization of major bioactive compounds from Andrographis paniculata (Burm. f.) extracts showed multi-biomedical applications

The Andrographis paniculata recognized as most valuable medicinal plant in folk medicine. Hence, this research was designed to evaluate antibacterial potential of petroleum ether (PE) and methanol (ME) extracts of A. paniculata against skin infection causing bacterial pathogens such as Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae, Enterobacter aerogenes, Proteus vulgaris, and Propionibacterium acnes. Also assessed the antidiabetic (α-glucosidase and α-amylase inhibition assay), antioxidant, and photoprotective potential of PE and ME extract analyses. The major bioactive compounds were identified and characterized through UV, FTIR, 1H-NMR and 13C-NMR spectra analyses. The ME extract contain more number of phytochemicals (alkaloids, flavonoids, saponins, terpenoids, glycoside, protein, and phytosterol) than PE extract. The antibacterial activity result also revealed that the ME (as dose dependent) extract showed better activity at 250 mg mL−1 as in the following order: P. acnes (6–29 mm) > K. pneumoniae (3–28 mm) > S. aureus (3–27 mm) > P. vulgaris (3–26 mm) > S. pyogenes (2–25 mm) > E. aerogenes (1–23 mm). PE: E. aerogenes (3–20 mm) > P. vulgaris (2–19 mm) > P. acnes (3–18 mm) > K. pneumoniae (3–17 mm) > S. aureus (2–16 mm) > S. pyogenes (0–11 mm). The MIC value of ME extract was found as 100–150 mg mL−1 and it was better than PE extract. Similarly, the ME also possesses dose based α-glucosidase inhibition activity as up to 85% at 250 mg mL−1 concentration. The fluorescence spectra analysis method also stated that the ME extract possess photoprotective bioactive agent. The ME fractions (F01 and F02) obtained from TLC and column chromatogram were identified as 3-O-β-d-glucosyl-14- deoxyandrographiside and 14-deoxyandrographolide respectively through UV, FTIR, 1H-NMR and 13C-NMR spectra analyses. Such compounds may be responsible for significant antibacterial activity against pathogenic bacteria causing skin infections, excellent antidiabetic activity, as well as photoprotective potential.

Development, in vitro and ex vivo evaluation of bioadhesive colloidal systems for curcumin skin delivery aiming the antioxidant and photoprotective activities

This work aimed to develop bioadhesive colloidal systems containing curcumin (CUR) for antioxidant and photoprotective applications. Gels and emulgels were prepared and characterized as rheology, texture profile analysis, softness, bioadhesive properties using porcine skin, skin permeability and antioxidant activity. Moreover, the formulations were investigated for their photoprotective potential using UVB-irradiated L929 fibroblasts, analyzing cellular viability with or without UVB irradiation, determination of reactive oxygen species (ROS), DNA damage, and cellular migration. The presence of CUR in the systems did not influence their mechanical textural properties and the rheological behavior (p > 0.05), displaying shear thinning characteristics, hysteresis area and rheopexy. The formulations exhibited important antioxidant activity, by scavenging radicals DPPH•, ABTS•+, superoxide anion, and reducing ferric ions. Gel-containing CUR (GEL CUR) exhibited a less cytotoxic effect in L929 fibroblasts than free CUR, besides increasing cell viability in UVB exposure. The treatment with GEL CUR in UVB-irradiated cells attenuated oxidative stress, displaying the ability to scavenge ROS generation (31.3 %), decrease DNA damage (≈30 %), and promote cellular repopulation at wound-scratch assay (8 % after 48h), which was statistically superior in comparison to the control and showing relevant activity. These colloidal systems showed suitable properties for topical application, with good antioxidant activity, permeation ability and potential application for the prevention of UVB-induced skin photodamage.

Artemia salina Leach in photoprotection: A new model to evaluate the potential of nanoparticles for topical application

Using animals in research has generated heated debates around the world and in the scientific community. This fact, as well as the need to prove the safety and efficacy of pharmaceutical products, has led to a growing interest in the search for alternative methods. Given this scenario, developing new alternative methods has become vital, also including an economic perspective. Invertebrate models can be easily applied in research assays owing to their advantages, such as effortless handling, low cost, small size, and simple anatomy. Therefore, this study aimed to evaluate the use of the invertebrate microcrustacean Artemia salina Leach for phototoxicity and photoprotection assays. As a product model, solid lipid nanoparticles of the flavonoid rutin (SLNR) were produced, which shows several activities, focusing on antioxidant action. SLNR were obtained by the hot melt microemulsion technique using a high-shear homogenizer. These were characterized and evaluated for the average particle size (185 ± 12.19 nm), polydispersity index (0.140 ± 0.11), zeta potential (−34.04 ± 1.43 mV), and encapsulation efficiency (98.82 ± 0.37 %), representing satisfactory values for topical applications. Regarding the physicochemical characterization by thermal analysis, infrared spectroscopy by Fourier transform and X-ray diffraction results showed a decrease in the crystallinity of rutin. In the assay with Artemia salina, the lethal doses were determined against UVA radiation (LD50 = 133.2 ± 0.82 J/cm2) and UVB (LD50 = 0.45 ± 0.056 J/cm2). In the phototoxicity assay, the SLNR showed photochemopreventive action, mainly against UVA radiation. In photoprotection studies, formulations containing SLNR exhibited greater photoprotection against UVB radiation (86.60 % ± 7.64 viability) than UVA (58.00 % ± 10.95 viability). In conclusion, the method using Artemia salina L. proved to be a very effective and promising tool to evaluate the phototoxic and photoprotective potential of nanostructured systems.

Screening of novel bovine-elastin-derived peptides with elastase inhibition and photoprotective potential: a combined in silico and in vitro study.

The demand for food-based anti-photoaging products is surging because of the rising recognition of health and beauty, as well as enhanced comprehension of the detrimental impact of ultraviolet (UV) radiation. This study aimed to investigate the potential of bioactive peptides derived from bovine elastin, specifically focusing on identifying novel elastase inhibitory peptides and assessing their photoprotective properties using bioinformatics techniques. A total of 48 bioactive peptides were screened in bovine elastin hydrolysate (EH) utilizing Peptide Ranker analysis. Three novel elastase inhibitory peptides, GAGQPFPI, FFPGAG and FPGIG (in descending order of activity), exhibited potent inhibitory effects on elastase in vitro, surpassing the inhibitory effect of EH by a factor of 1-2 and reaching significantly lower concentrations (8-15 times lower) than EH. The cumulative inhibitory effect of GAGQPFPI, FFPGAG, and FPGIG reached 91.5%. Further analysis revealed that FFPGAG and FPGIG exhibited mixed inhibition, whereas GAGQPFPI displayed non-competitive inhibition. Molecular simulations showed that these peptides interacted effectively with the elastase active site through hydrogen bonding and hydrophobic interactions. Furthermore, GAGQPFPI, FFPGAG, and FPGIG demonstrated high stability in gastrointestinal digestion, demonstrated transcellular permeability across Caco-2 cell monolayers, and exhibited remarkable photoprotective properties against UVB-irradiated HaCaT cells. GAGQPFPI showed the most promising potential as a functional food with photoprotective effects against UVB damage and inhibitory properties against elastase. © 2023 Society of Chemical Industry.

Seasonal Differences in Leaf Photoprotective Potential between Adults and Juveniles of Two Mediterranean Perennials with Distinct Growth Forms: A Comparative Field Study.

The photosynthetic differences between adult and juvenile Mediterranean plants were previously studied under field conditions, yet the corresponding differentiation of their photoprotective efficiency has not been sufficiently investigated. The present study aims to examine possible differences in the photoprotective potential between adults and juveniles of two native Mediterranean plants with distinct growth forms. Thus, the seasonal variations in individual carotenoids, electron transport rate (ETR), and non-photochemical quenching (NPQ) were monitored in fully exposed mature leaves from adults and juveniles of the winter deciduous tree Cercis siliquastrum L. and the evergreen sclerophyllous shrub Nerium oleander L. All plants were grown under apparently similar field conditions. In both species, juveniles displayed substantially lower ETR and increased NPQ values than adults in spring, with the differences intensifying during summer drought and diminishing in autumn. Concomitantly, juveniles showed significantly higher chlorophyll-based total carotenoids in spring and summer mainly due to the higher investment in xanthophyll cycle components (VAZ), in combination with an increased mid-day de-epoxidation state (DEPS) and partial retention of zeaxanthin in the dark. In N. oleander, although ETR was lower in juveniles during winter, NPQ was extremely low in both ages. In conclusion, juveniles exhibit enhanced photoprotection potential, especially in the summer, due to their reduced photochemical capacity. The photosynthetic superiority of adults during the favorable spring period may be attributed to the needs of the co-existing reproductive effort.

Evaluation of Photoprotective of Gyrinops versteegii (Gilg.) Domke Leaves Extract with Different Solvents and Its Spatial Distribution

&lt;p&gt;&lt;em&gt;&lt;span lang="EN-US"&gt;Gyrinops versteegii &lt;/span&gt;&lt;/em&gt;&lt;span lang="EN-US"&gt;(Gilg.) Domke is one of the Thymelaeaceous family species with high economic value. The leaf synthesizes secondary metabolites (SMs) supporting herbal medicine, including a class of SMs that serve as sunscreen. However, the SMs are not equally distributed in the plant, depending on the organs, tissues or cell type. This research aimed to determine the spatial distribution of secondary metabolites in the leaves, especially in the epidermis and mesophyll tissues. The epidermis tissues were separated from the mesophyll using the &lt;em&gt;carborundum abrasion &lt;/em&gt;(CA) technique, followed by the extraction of SMs using three different polarity solvents, namely methanol, hexane and chloroform. The photoprotective potential was evaluated using the SPF value with the spectrophotometry approach. Subsequently, the phytochemical analysis was done for the total tannin, flavonoid, and phenols content. The results showed that the highest SPF value was observed in the methanol epidermis extract with SPF value of 8.61, followed by methanol mesophyll extract (4.52), chloroform epidermis extract (3.97), chloroform mesophyll extract (2.52) and hexane epidermis extract (0.60) and hexane mesophyll extract (0.16). Total phenolic content (flavonoid, tannin and phenol) in epidermis extract with methanol solvent was higher (12.347 ± 0.652 mg GAE/g DW), followed by extract with chloroform and hexane solvents. The total phenolic content (flavonoid, tannin and phenol) of mesophyll extract with methanol solvent showed the highest content, followed by chloroform mesophyll and hexane extracts. The results of the histochemical analysis showed that photoprotective compounds accumulate in the epidermis and mesophyll tissue of the leaf of &lt;em&gt;G. versteegii&lt;/em&gt;.&lt;/span&gt;&lt;/p&gt;

Basking in the sun: how mosses photosynthesise and survive in Antarctica.

The Antarctic environment is extremely cold, windy and dry. Ozone depletion has resulted in increasing ultraviolet-B radiation, and increasing greenhouse gases and decreasing stratospheric ozone have altered Antarctica's climate. How do mosses thrive photosynthetically in this harsh environment? Antarctic mosses take advantage of microclimates where the combination of protection from wind, sufficient melt water, nutrients from seabirds and optimal sunlight provides both photosynthetic energy and sufficient warmth for efficient metabolism. The amount of sunlight presents a challenge: more light creates warmer canopies which are optimal for photosynthetic enzymes but can contain excess light energy that could damage the photochemical apparatus. Antarctic mosses thus exhibit strong photoprotective potential in the form of xanthophyll cycle pigments. Conversion to zeaxanthin is high when conditions are most extreme, especially when water content is low. Antarctic mosses also produce UV screening compounds which are maintained in cell walls in some species and appear to protect from DNA damage under elevated UV-B radiation. These plants thus survive in one of the harshest places on Earth by taking advantage of the best real estate to optimise their metabolism. But survival is precarious and it remains to be seen if these strategies will still work as the Antarctic climate changes.

Peels of the fruits of Campomanesia guazumifolia (cambess) O. berg and Campomanesia sessiliflora (O. Berg) mattos: Residues with cosmetic and food potentials

Extracts from leaves of the genus Campomanesia (Myrtaceae) have been used to develop products. Simultaneously, the peels of fruits of this genus still have few studies in the literature, being treated as residue. In this context, the present study aimed to analyze the chemical composition and antioxidant, antimicrobial, and photoprotective potential of ethanolic extracts from the fruits peels of the species Campomanesia sessiliflora (O.Berg) Mattos (CS) and Campomanesia guazumifolia (Cambess.) O. Berg (CG). For this, phytochemical screening and quantification of secondary metabolites by spectroscopic and chromatographic analysis and photosynthetic pigments were performed. Antioxidant potential and sun protection factors were also determined by spectrophotometry. The broth microdilution technique determined the antimicrobial activity. The contents of anthocyanins, alkaloids, phenolic compounds, and tannins are higher in GC, and the contents of flavonoids do not differ statistically. Caffeine was identified in the CG (5.54 ± 0.03 mg g−1), and gallic acid (4.68 ± 0.03 mg g−1) in the CS. The CG extract has higher levels of chlorophyll, but only the CS has carotenoids. The photoprotective potentials of CS (6.35 ± 0.52) and CG (5.56 ± 0.59) did not differ significantly. However, the antioxidant potential of CG (34.68 ± 1.97 μg mL−1) is higher than that of CS (68.85 ± 2.73 μg mL−1). The two extracts have antimicrobial activity, with CG obtaining greater activity. The two extracts have the potential for the formulation of cosmetics and foods.

Aloe Vera for Protects Skin Tissues from The Damaging Impacts of Ultraviolet Radiation

When Overexposure to sun UV radiation leads to skin damage and increases the risk of skin cancer; thus, it is a factor in aging, which accelerate skin aging and increases the risk of skin cancer. To determine the Photoprotective potential was evaluated by biomechanical measurements of tissue and histopathological examination of the skin. Showed The skin group irradiated with exposed for 4 h to UV (UV lamps, wavelength 365 nm, power 6 W) without Aloe vera showed significant biomechanical measurements of tissues and histopathological change and showed skin necrosis of dermal collagen. The Treatment with Aloe vera protected skin tissues against UV exposure for 4 h to UV light (UV lamps, wavelength 365 nm, power 6 W damage by biomechanical measurements of tissues restoring histopathological changes. The extracted Aloe vera is shown.

Photosynthetic pigments and photoprotective metabolites of Colombian pacific marine macroalgae in response to contrasting ultraviolet-index periods

Tropical macroalgae have developed specific defense mechanisms, synthesizing photoprotective molecules to cope with solar radiations, especially ultraviolet radiation, which hits them intensely. Despite the vast Colombian marine biodiversity, not all the country's coastlines have received the same attention, like the Pacific coast. In this study, we assessed photosynthetic pigments (chlorophylls and carotenoids) and photoprotective compounds (mycosporine-like amino acids - MAAs) in seaweeds from the Colombian Pacific coast. We collected seven species of seaweeds, namely Boodleopsis verticillata, Bostrychia calliptera, B. radicans, B. cf. scorpioides; Catenella impudica, Cladophora graminea and Rhizoclonium riparium, easily found in supralittoral and mangrove ecosystems, at low tide, in contrasting periods of high and low UV index over the year of 2021. The sampling area encompassed a latitudinal gradient (3° S to 6° S) along the Colombian Pacific coast, changing the pattern of the chlorophyll-a and total carotenoid content in different species collected in contrasting UV-index periods. MAAs were quantified using standards (shinorine, porphyra-334, and palythine). This study corroborates the hypothesis that tropical species produce higher concentrations of MAAs in response to UV radiation, with significant differences in the high UV-index period. The highest MAA content (5.68 mg.g−1 DW) was reported in Bostrychia calliptera during the high UV-index period. Ceramiales and Cladophorales species represented a photoprotective potential with at least six different MAAs. Shinorine, palythine and porphyra-334 were quantified; and mycosporine-methylamine-serine and aplysiapalythine C were putatively identified by LC-MS/MS dereplication, this, therefore representing a pioneer study on the chemical composition of Colombian Pacific marine macroalgae.

How Does Pseudo-Jahn-Teller Effect Induce the Photoprotective Potential of Curcumin?

In this paper, the molecular and electronic structure of curcumin is studied. High-symmetric gas-phase tautomers and their deprotonated forms in various symmetry groups are identified. The stability of lower-symmetry structures was explained by using the Pseudo-Jahn-Teller (PJT) effect. This effect leads to stable structures of different symmetries for the neutral enol and keto forms. The presented analysis demonstrated the potential significance of the PJT effect, which may modulate the setting of electronic and vibrational (vibronic) energy levels upon photodynamic processes. The PJT effect may rationalize the photoprotection action and activity of naturally occurring symmetric dyes.

Development and evaluation of sunscreen cream containing solid lipid nanoparticles of Spinacia oleraceae.

More research is needed to understand the benefits of environmentally safe and human-friendly herbal-based sunscreen agents against ultraviolet (UV) radiation. Because of the toxicity of synthetic chemicals in photoprotective agents, researchers were increasingly focusing on herbal photoprotective formulations. The photoprotective agent's skin retention can be considerably improved by forming solid lipid nanoparticles (SLN). The study's objective is to evaluate the photoprotective potential of sunscreen cream containing spinach (Spinacia oleracea)-loaded SLN. A solvent emulsification technique was used to develop the spinach-loaded SLN. The various characterization techniques of the developed SLN were performed. Out of all the formulations, the optimized one was fitted into cream and estimated for its photoprotective action. The images obtained from scanning electron microscopy (SEM) revealed the morphological characteristics of the prepared SLN. The sunscreen cream's viscosity, spreadability, extrudability, and release rate were within acceptable limits. The formulation's in vitro and in vivo sun protection factor (SPF) was reported to be 15.9 and 14.75, respectively. The results indicated that the prepared formulation possesses good photoprotective action. The accelerated stability tests were carried out with no noticeable changes in the parameters. Our work demonstrated the possibility of using spinach-loaded SLN as a photoprotective agent in cosmetic formulations.

Cerium Oxide Nanoparticles Conjugated with Tannic Acid Prevent UVB-Induced Oxidative Stress in Fibroblasts: Evidence of a Promising Anti-Photodamage Agent.

Exposure to ultraviolet radiation induces photodamage towards cellular macromolecules that can progress to photoaging and photocarcinogenesis. The topical administration of compounds that maintain the redox balance in cells presents an alternative approach to combat skin oxidative damage. Cerium oxide nanoparticles (CNPs) can act as antioxidants due to their enzyme-like activity. In addition, a recent study from our group has demonstrated the photoprotective potential of tannic acid (TA). Therefore, this work aimed to synthesize CNPs associated with TA (CNP-TA) and investigate its photoprotective activity in L929 fibroblasts exposed to UVB radiation. CNP conjugation with TA was confirmed by UV-Vis spectra and X-ray photoelectron spectroscopy. Bare CNPs and CNP-TA exhibited particle sizes of ~5 and ~10 nm, superoxide dismutase activity of 3724 and 2021 unit/mg, and a zeta potential of 23 and -19 mV, respectively. CNP-TA showed lower cytotoxicity than free TA and the capacity to reduce the oxidative stress caused by UVB; supported by the scavenging of reactive oxygen species, the prevention of endogenous antioxidant system depletion, and the reduction in oxidative damage in lipids and DNA. Additionally, CNP-TA improved cell proliferation and decreased TGF-β, metalloproteinase-1, and cyclooxygenase-2. Based on these results, CNP-TA shows therapeutic potential for protection against photodamage, decreasing molecular markers of photoaging and UVB-induced inflammation.

Quantification and in vitro photo-protective studies of phenolic compounds from Baccharis papillosa Rusby

Context: The ethanolic extract of the leaves from Baccharis papillosa, a plant used in Bolivian folk medicine, presents high UVB/UVA absorption spectrum, and therefore, it could have photo-protective potential. Aims: To isolate, identify and quantify the compounds of an enriched extract in phenolic compounds obtained from the ethanolic extract of Baccharis papillosa in different seasons and geographical altitudes, and evaluate its photo-protective potential. Methods: The enriched extract in phenolic compounds was submitted to phytochemical analysis for compound isolation. The enriched extract and isolated compounds were identified by NMR, and monitored by HPLC and spectroscopic methods. The enriched extract with photo-protective potential was analyzed to determine its Spectroscopic Sun Protection Factor (SSPF), its Broad Spectrum Index (BSI) and its photo-protective activity on Escherichia coli bacteria. Results: Six flavonoids and two cinnamic acid derivatives were isolated and identified. Four of them are reported in B. papillosa for the first time in this study. The highest concentration of total flavonoids was observed in spring and at the highest altitude. The major compound, drupanin, was the main responsible of the high UVB (290-320 nm) absorption spectrum. The high presence of flavonoids in the extract explains the absorption spectrum in the UVA (320-400 nm) region. Conclusions: The phenolic compounds enriched extract has photo-protective properties comparable to standard commercial synthetic sunscreens and presents an attractive BSI.