Sun Protection Factor Research Articles

Enhanced Sun Protection Factor Of Octocrylene With Green Tea And Bhringraj Extracts

: The overexposure of human skin to ultraviolet radiation (UVR) can trigger photodamage, UV burn, pigmentation, erythema, and enhance the chance of dermal carcinoma. UVR causes DNA damage, leading to dermal cancer. Daily sunscreen application protects the skin from the adverse effects of sun rays, particularly UVB (290-320 nm) and UVA (320-400 nm). The ozone layer filters UVC (200-290 nm) radiation upon entry into the Earth's atmosphere. UVB causes sunburn, photo damage, and induces mutagenic changes in nucleic acids. UVA increases ROS (Reactive Oxygen Species) accumulation. ROS is responsible for cell repair, leading to carcinogenesis and photodamage. Herbal extracts containing polyphenols and flavonoids act as natural sunscreens that filter UVB light and possess antioxidant characteristics to modulate UV-induced Reactive Oxygen Species production. To achieve higher UV protection in sun care products, it is essential to incorporate herbal extracts with enhanced UVR protection. An approach for preparing sun care products with higher Sun Protection Factor (SPF) involves oil-in-water formulation with combinations of herbal extracts and octocrylene. The developed sunscreen composition containing different concentrations of herbal extracts was evaluated for their physicochemical properties and stability. In vitro SPF was studied for Camellia Sinensis (Green tea) Leaf Extract and Eclipta prostrata (bhringraj) leaf extract individually and in combination with octocrylene. The results of the in vitro SPF study revealed that Camellia Sinensis (Green tea) Leaf Extract with octocrylene exhibits a better Sun Protection Factor than Eclipta prostrata (bhringraj) leaf extract with octocrylene. The Sun Protection Factor (SPF) enhancement value of sunscreen compositions was compared to both sunscreen macroemulsion and nanoemulsion.

Thermosensitive ZnO-PMMA/PEG microgels: A smart sunscreen with adapting SPF to ambient temperature fluctuations

Increasing awareness of the importance of ultraviolet protection has led to the development and utilization of sunscreen products. The sun protection factor (SPF) value of traditional sunscreens is fixed and cannot be flexibly adapted to changing environmental requirements. Herein, we fabricate a series of thermosensitive ZnO-poly (methyl methacrylate)/nonlinear poly(ethylene glycol) (PMMA/PEG) core-shell microgel with different monomer ratios. The PMMA core particle is designed to immobilize ZnO nanoparticles for achieving high loading capacity, and the hydrophilic nonlinear PEG gel shell possesses good biocompatibility and provides adjustable SPF value in response to different environmental conditions. The prepared microgels are monodisperse spherical with a well-defined core-shell morphology. The shell thickness of the microgels can be easily controlled by changing the feeding ratios of shell precursors. The optimized ZnO-PMMA/PEG microgels display significant sun protection properties at a concentration of 10 wt% (SPF 45 ± 5.9, 20 °C) and enhanced UV resistance performance as the temperature increases (SPF 53.1 ± 1.1, 37 °C). Both cell and mouse experiments confirmed the limited skin penetration potential of the microgels and their good compatibility with biological systems. This developed ZnO-PMMA/PEG microgels exhibit promising application potential in intelligent sunscreen technology.

Physical Quality Evaluation and Determination of SPF (Sun Protection Factor) Value of Forest Coconut Oil Lotion (Pandanus julianettii Martelli) from Papua

Forest coconut fruit contains double-bonded fat or omega 3-6, tocopherol, or vitamin E. Vitamin E and some compounds such as flavonoids, tannins, and anthraquinone have potential as sunscreens. This study aims to evaluate the physical quality and determine the SPF value in forest coconut oil lotion analyzed in vitro. Physical quality evaluation includes organoleptic tests, homogeneity, spreadability, adhesion, pH, and the determination of SPF values by the UV-Vis spectrophotometry method. The results showed that each formula, namely FI (2%), FII (4%), and FIII (6%), was physically stable. The lotion preparation in each formula, namely FI (2%), FII (4%), and FIII (6%), has SPF values of 1.95, 1.57, and 1.19, respectively.

Photochemically Inert Broad-Spectrum Sunscreen by Metal-Phenolic Network Coatings of Titanium Oxide Nanoparticles.

Titanium dioxide (TiO2) nanoparticles are extensively used as a sunscreen filter due to their long-active ultraviolet (UV)-blocking performance. However, their practical use is being challenged by high photochemical activities and limited absorption spectrum. Current solutions include the coating of TiO2 with synthetic polymers and formulating a sunscreen product with additional organic UV filters. Unfortunately, these approaches are no longer considered effective because of recent environmental and public health issues. Herein, TiO2-metal-phenolic network hybrid nanoparticles (TiO2-MPN NPs) are developed as the sole active ingredient for sunscreen products through photochemical suppression and absorption spectrum widening. The MPNs are generated by the complexation of tannic acid with multivalent metal ions, forming a robust coating shell. The TiO2-MPN hybridization extends the absorption region to the high-energy-visible (HEV) light range via a new ligand-to-metal charge transfer photoexcitation pathway, boosting both the sun protection factor and ultraviolet-A protection factor about 4-fold. The TiO2-MPN NPs suppressed the photoinduced reactive oxygen species by 99.9% for 6 h under simulated solar irradiation. Accordingly, they substantially alleviated UV- and HEV-induced cytotoxicity of fibroblasts. This work outlines a new tactic for the eco-friendly and biocompatible design of sunscreen agents by selectively inhibiting the photocatalytic activities of semiconductor nanoparticles while broadening their optical spectrum.

UV-Protection Activities of Labu Siam (Sechium edule) Extract Based on Sun Protection Factor (SPF)

Exposure to sunlight has a negative effect on the skin. Sunscreens are used to protect the skin from the harmful effects caused by UV radiation. The ability of a sunscreen to protect the skin by delaying erythema is expressed by the value of the Sun Protection Factor (SPF). The purpose of this study was to analyze the UV protection activity of chayote (Sechium edule) based on the Sun Protection Factor (SPF) value, which was measured using UV-Vis spectrophotometry and calculated using the Mansyur equation. Based on the results of the study, it can be concluded that the SPF value of chayote (Sechium edule) extract has UV protection activity. At concentrations of 1%, 2%, and 3% there is activity as UV protection with SPF values of 7.487; 11.817; and 16,889. From the results obtained, it can be seen that the higher the concentration, the greater the SPF value obtained.UV-Protection Activities of Labu Siam (Sechium edule) Extract Based on Sun Protection Factor (SPF)

Phytochemical profiles and evaluation of the biological potential of ethyl acetate and n-butanol fractions of the aerial parts of Cistus albidus L.

The phytochemical profiles of the ethyl acetate (EAFCA) and n-butanol (BFCA) fractions of the aerial parts of Cistus albidus L., were characterised by a developed LC-ESI-MS/MS method, using 53 fingerprint phytochemicals, revealing the presence of 26 and 22 compounds, respectively with quinic acid, gallic acid, protocatechuic acid, catechin, gentisic acid, tannic acid, ellagic acid, quercitrin, astragalin as the major compounds of the EAFCA, in very higher amounts than in the BFCA. The antioxidant activity was evaluated using six methods (DPPH•, ABTS•+, GOR•, CUPRAC, FRAP and Phenanthroline). In agreement with its highest polyphenolic content (430.12 ± 1.02 µg GAE/mg of extract) and largest amounts of identified polyphenolics, the EAFCA exhibited a higher antioxidant activity than the BFCA. Additionally, the EAFCA showed the highest acetylcholinesterase (AChE) inhibition (IC50 of 25.1 ± 2.58 µg/mL). Moreover, both EAFCA and BFCA demonstrated high photoprotective activity, with sun protection factor (SPF) values of 36.49 and 36.52, respectively.

BSA Adsorption on Titanium Dioxide Nanoparticle Surfaces for Controlling Their Cellular Uptake in Skin Cells.

Nanoparticles (NPs) are continuously being developed for many applications including imaging, biomedicine, and everyday products. It is difficult to avoid contact with NPs such as titanium dioxide (TiO2) NPs, which are widely used in sunscreens. However, the safety of TiO2 NPs for skin contact and inhalation remains controversial. If NPs cannot penetrate the skin, they will be unable to circulate in the bloodstream, accumulate in the body, or cause side effects, ensuring their safety. Therefore, this study aimed to modify TiO2 NP surfaces to inhibit their uptake in skin cells. Inspired by protein corona studies, bovine serum albumin (BSA) was chosen to functionalize TiO2 NP surfaces via physical adsorption. The maximum BSA adsorption occurred at pH 5.0. The physicochemical properties (size, ζ-potential, morphology, ultraviolet (UV) absorption efficiency, and sun protection factor (SPF)) of TiO2-BSA NPs were comparable to those of TiO2 NPs, indicating that these properties did not affect cellular uptake. In the safety evaluation, TiO2 NPs and TiO2-BSA NPs exhibited high biocompatibility with skin cells and no phototoxicity after UVA and UVB irradiation. In the efficacy evaluation, both NPs possessed the same photoprotection abilities, reducing membrane damage and DNA breakage after UVA irradiation. Compared with TiO2 NPs, TiO2-BSA NPs showed substantially reduced skin penetration in Franz diffusion cells (91%) and human immortalized keratinocyte (HaCaT) cells (89%). A qualitative cellular uptake study using transmission electron microscopy and confocal laser scanning microscopy confirmed that TiO2 NPs were more abundant than TiO2-BSA NPs inside the HaCaT cells. These findings indicate that TiO2 surface functionalization with BSA inhibits cellular uptake in skin cells while maintaining safety and UV protection efficacy, which might be extended to other NP-based sunscreens.

Pulp or Peel? Comparative Analysis of the Phytochemical Content and Selected Cosmetic-Related Properties of Annona cherimola L., Diospyros kaki Thumb., Cydonia oblonga Mill. and Fortunella margarita Swingle Pulp and Peel Extracts.

Fruit peels might be a valuable source of active ingredients for cosmetics, leading to more sustainable usage of plant by-products. The aim of the study was to evaluate the phytochemical content and selected biological properties of hydroglycolic extracts from peels and pulps of Annona cherimola, Diospyros kaki, Cydonia oblonga, and Fortunella margarita as potential cosmetic ingredients. Peel and pulp extracts were compared for their antiradical activity (using DPPH and ABTS radical scavenging assays), skin-lightening potential (tyrosinase inhibitory assay), sun protection factor (SPF), and cytotoxicity toward human fibroblast, keratinocyte, and melanoma cell lines. The total content of polyphenols and/or flavonoids was significantly higher in peel than in pulp extracts, and the composition of particular active compounds was also markedly different. The HPLC-MS fingerprinting revealed the presence of catechin, epicatechin and rutoside in the peel of D. kaki, whereas kaempferol glucoside and procyanidin A were present only in the pulp. In A. cherimola, catechin, epicatechin and rutoside were identified only in the peel of the fruit, whereas procyanidins were traced only in the pulp extracts. Quercetin and luteolinidin were found to be characteristic compounds of F. margarita peel extract. Naringenin and hesperidin were found only in the pulp of F. margarita. The most significant compositional variety between the peel and pulp extracts was observed for C. oblonga: Peel extracts contained a higher number of active components (e.g., vicenin-2, kaempferol rutinoside, or kaempferol galactoside) than pulp extract. The radical scavenging potential of peel extracts was higher than of the pulp extracts. D. kaki and F. margarita peel and pulp extracts inhibited mushroom and murine tyrosinases at comparable levels. The C. oblonga pulp extract was a more potent mushroom tyrosinase inhibitor than the peel extract. Peel extract of A. cherimola inhibited mushroom tyrosinase but activated the murine enzyme. F. margarita pulp and peel extracts showed the highest in vitro SPF. A. cherimola, D. kaki, and F. margarita extracts were not cytotoxic for fibroblasts and keratinocytes up to a concentration of 2% (v/v) and the peel extracts were cytotoxic for A375 melanoma cells. To summarize, peel extracts from all analyzed fruit showed comparable or better cosmetic-related properties than pulp extracts and might be considered multifunctional active ingredients of skin lightening, anti-aging, and protective cosmetics.

The Preparation of Curcumin-Loaded Pickering Emulsion Using Gelatin-Chitosan Colloidal Particles as Emulsifier for Possible Application as a Bio-Inspired Cosmetic Formulation.

In the field of preparing cosmetic formulations, recent advances recommend the usage of excipients derived from biocompatible materials. In this context, the present study aimed to prepare and characterize the curcumin-loaded Pickering emulsion for possible applications in cosmetic formulation. The coconut oil which is often the component of skin care formulations is used as the oily phase. Curcumin, which is well known for absorbing solar radiation, is expected to work synergistically with coconut oil towards improving the sun protection factor (SPF) of the formulation. Additionally, curcumin can also protect the intracellular components through its well-known antioxidant mechanisms. The Pickering emulsion of coconut oil into water was prepared using the composite colloidal particles derived from β-carboxymethyl chitosan (CMC) and Gelatin-A (GA) as the emulsifying agent. The reaction conditions in terms of the weight ratios of CMC and GA, the pH of the reaction medium, the oil volume fraction, and the homogenization speed were optimized to obtain the most stable Pickering emulsion. The obtained systems were physico-chemically characterized by dynamic light scattering, zeta potential, optical microscopy, and rheometric measurements. The final CMC-GA-stabilized emulsion demonstrated an oil droplet size of 100 µm and a SPFspectrophotometric (290-320 nm) value of 8.5 at a curcumin loading of 4 mg/mL. Additionally, the final formulation facilitated the uptake of curcumin into fibroblast (WI26) cells under in vitro conditions. Together, the investigation demonstrates a bio-inspired approach to prepare a curcumin-loaded green Pickering emulsion using biocompatible pharmaceutical grade excipients, which may find utility in cosmetic applications.

Fabrication of CeO2/CaO nanocomposite as ultraviolet screening agent and its application in sunscreen

In order to improve CeO2 ultraviolet absorption performance and transparency, this paper puts forward that different proportions of calcium oxide are doped during the formation of CeO2. Doping calcium ions with larger ion size and lower valence leads to the formation of oxygen defects by inhibiting the precipitation of oxygen from cerium oxide and keeps the fluorite structure of cerium oxide stable. The effects of CaO doping on the crystal structure, morphology, and optical characteristics of CeO2 were analyzed by XRD, SEM, TEM, TGA, XPS, UV–vis spectrophotometry. The pH of sunscreen, spread ability and some physical as well as chemical evaluations were carried out, while to study its UV protection performance the sunscreen SPF test was performed. The UV–vis results revealed that CeO2/20%CaO showed highly efficient UV absorption capacity. After adding calcium oxide, the catalytic activity of the material is reduced, due to which the generation of free radicals is demoted, and the harm to human body is decreased. After the addition of 3 wt% nanomaterials into sunscreen, the sun protection factor（SPF ）values of pure cerium oxide and CeO2/20%CaO are 1.95 and 2.81, and their sun protection coefficient is increased by 69.39%. Therefore, it is an ideal candidate as a component of ultraviolet screening agent in sunscreens and provides a new idea for the research direction of cerium oxide in anti-ultraviolet applications.

Molecularly engineered lignin to polyphenol via organocatalysis as an active sunscreen ingredient

Phenolation is one of the effective strategies to synthesize lignin-based polyphenols, improve lignin's properties, and extend its value-added applications in biological, medicinal and cosmetic fields. Herein, by taking the structural feature advantage of lignin, an effective and green strategy was developed to molecularly engineer lignin into a robust lignin-3-(2-hydroxyphenyl)propionate ester (LPPE) derivative via a transesterification reaction between 3,4-dihydrocoumarin (DHC) and the aliphatic hydroxyls in lignin under organocatalysis. The strategy is optimized and the novel derivative was systematically characterized by 1H, 13C and 31P nuclear magnetic resonance (NMR) and Fourier transform infrared (FT-IR) spectroscopy. The findings indicated that the successful introduction of 3-(2-hydroxyphenyl)propionate groups using a OH groups/DHC/organic base molar ratio of 1꞉1꞉0.3 at 120 °C for 6 h increased the content of phenolic hydroxyl groups from 1.793 1 to 3.017 9 mmol/g, and the LPPE exhibited excellent ultraviolet-absorbing and antioxidant performance with up to 90 % free radical scavenging activity within 20 min using 5 mg/mL of LPPE. In addition, good biocompatibility and a high Sun protection factor (SPF) value of 40.9 were achieved at 5 % (w) dosage of LPPE in the cream, indicating its significant application potential in sunscreen.

Effect of Ag and Ni-Doped Cerium Oxide Nanoparticles on the Formation of ROS and Evaluation as an Alternative Physical Sunscreen Material.

CeO2 nanoparticles (nanoceria) were proposed as an alternative physical sunscreen agent with antioxidant properties and comparable UV absorption performance. Green synthesis of nanoceria with Ag and Ni dopants resulted in doped nanoceria with lower catalytic activity and biologically-safe characteristics. The doped nanoceria was characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), Rancimat Instrument, and UV-Vis Spectrophotometer for SPF (Sun Protection Factor) determination. XRD and TEM analysis showed that nanoceria had been successfully formed in nanoscale-sized with a change in crystallite size due to the crystal defect phenomenon caused by dopant addition. While the Rancimat test and band gap energy analysis were conducted to evaluate the oxidative stability and reactive oxygen species formation, it was confirmed that dopant addition could decrease catalytic activity of material, resulting in Ni-doped Ce with a longer incubation time (11.81 h) than Ag-doped Ce (10.58 h) and non-doped Ce (10.30 h). In-vitro SPF value was measured using the thin layer technique of sunscreen prototype with Virgin Coconut Oil (VCO)-based emulsion, which yielded 10.862 and 5.728 SPF values for 10% Ag-doped Ce and 10% Ni-doped Ce, respectively. The dopant addition of nanoceria could reduce catalytic activity and give a decent in vitro UV-shielding performance test; thus, Ag and Ni-doped nanoceria could be seen as promising candidates for alternative physical sunscreen agents.

Exploring the potential of Cytisus purgans as a source of bioactive molecules: In vitro pharmacological evaluation

IntroductionCytisus purgans is an uncommon species found in Algeria (Aures, Mahdids and Lella Khadidja). In the current study, we present, to the best of our knowledge, the first detailed chemical profile of its extracts and collect various pieces of evidence that underscore their therapeutic potential. MethodsThe ethyl acetate extract (EAE) of C. purgans was purified using different chromatographic methods. The bioactive compounds obtained were analysed by NMR and mass spectroscopy to identify their structures. The therapeutic potential of the extracts was investigated using several in vitro assays. Results and discussionThe developed spectral analysis techniques enabled the structural elucidation of seven compounds. The analysis identified four isoflavones, including daidzein, genistein, isoprunetin and biochanin A. Additionally, one flavone, chrysin and one flavonol, quercetin, were positively identified. Notably, the phytosterol daucosterol was also isolated and characterised. The studied extracts were found to be rich in polyphenols and flavonoids. The EAE had the highest polyphenolic (163.85 ± 3.82 mg GAE/g dry extract) and flavonoid content (180.84 ± 3.68 mg QE/g dry extract). The extracts showed potent anti-oxidant activity, as demonstrated by DPPH 50 % inhibitory concentration (EAE: IC50 = 26.66 µg/mL, BuE: IC50 = 30.91 µg/mL), ferric reducing anti-oxidant power IC50 (EAE: IC50 = 6.37 ± 0.27 µg/mL, BuE: IC50 = 13.02 ± 0.1 µg/mL) and total anti-oxidant capacity values (EAE 106.57 ± 5.81 AAE/g dry extract, BuE 105.46 ± 8.64 AAE/g dry extract). This anti-oxidant activity contributed significantly to effective sun protection (EAE sun protection factor (SPF) = 87.84, BuE SPF = 31.67). Additionally, the extracts inhibited acetylcholinesterase (EAE IC50 = 24.40 ± 2.84 µg/mL, BuE IC50 = 68.07 ± 02.26 µg/mL) and butyrylcholinesterase enzymes (EAE IC50 = 36.39 ± 0.75 µg/mL, BuE IC50 = 66.19 ± 01.25 µg/mL) the most and significantly inhibited urease (EAE IC50 = 77.82 ± 4.59 µg/mL, BuE IC50 = 127.05 ± 2.87 µg/mL). ConclusionConsidering the findings, C. purgans emerges as a promising reservoir of bioactive compounds that have the potential to contribute to the development of treatments for specific diseases. The identification of these compounds and their therapeutic potential provides valuable insights into their potential use in drug development.

Physical, chemical and biological characteristics of clays from Durban (South Africa) for applications in cosmetics

AbstractClay soils are rock‐decomposed materials comprised of both clay‐ and non‐clay‐like minerals. Clays' physiochemical and mineralogical composition determines their applicability use in cosmetics. Because of their high bioburden, they must be effectively characterized before being incorporated into cosmetics. The scope of the current study was to characterize two different samples of red and white clays for their physical, chemical and biological properties; mined from Durban, South Africa. Characterization was performed using techniques like X‐ray fluorescence, X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope, hydrogen potential, soil colour, oil absorption, swelling capacity, texture, bulk density, plastic and apparent viscosity, sun protection factor and microbiological analysis.

Characterization and Anti-Ultraviolet Radiation Activity of Proanthocyanidin-Rich Extracts from Cinnamomum camphora by Ultrasonic-Assisted Method.

The ultrasonic-assisted extraction (UAE) method was employed to separate Cinnamomum camphora proanthocyanidin-rich extracts (PCEs). This extraction process was optimized by the Box-Behnken design, and the optimal conditions, on a laboratory scale, were as follows: an ethanol concentration of 75%, a liquid-to-solid ratio of 24 mL/g, an ultrasonic time of 39 min, and an ultrasonic power of 540 W. Under the obtained conditions, the PCE yield extracted by UAE was higher than that from heat reflux extraction and soaking extraction. An ultra-performance liquid chromatography-tandem mass spectrometry analysis was employed to characterize the phloroglucinolysis products of the C. camphora PCEs, by which epigallocatechin, catechin, epicatechin, and (-)-epigallocatechin-3-O-gallate were identified as the terminal units; epigallocatechin, epicatechin, and (-)-epigallocatechin-3-O-gallate were recognized as extension units. The C. camphora PCEs possessed higher anti-ultraviolet activity in vitro compared with the commercially available sunscreen additive of benzophenone with respect to their ethanol solutions (sun protection factor of 27.01 ± 0.68 versus 1.96 ± 0.07 at a concentration of 0.09 mg/mL) and sunscreens (sun protection factor of 17.36 ± 0.62 versus 14.55 ± 0.47 at a concentration of 20%). These results demonstrate that C. camphora PCEs possess an excellent ultraviolet-protection ability and are promising green sunscreen additives that can replace commercial additives.

Fractionation of lignin using eco-friendly organic cosolvent and preparation of light-colored lignin micro-nanoparticles for sustainable natural sunscreens

The inherent challenges posed by lignin, such as its high heterogeneity, complex structure and dark color, have impeded its widespread high-value utilization. In the present study, a green cosolvent system comprising ethanol (EtOH) and dimethyl carbonate (DMC) was employed for the fractional separation of alkali lignin. Through careful manipulation of the solvent ratio, interactions between the solvents and lignin were effectively regulated, leading to the reduction of lignin heterogeneity and the isolation of lignin fractions with distinct properties. Notably, a high yield of up to 35.65% of lignin with desirable characteristics, including a light color, low molecular weight, and high hydroxyl groups content, was achieved. Furthermore, this specific lignin fraction exhibited enhanced UV absorption and antioxidative properties, rendering it highly suitable for potential applications in sun protection products. When incorporated as micro-nano particles, it exhibited great compatibility with hand creams and elevated their sun protection factor (SPF). This innovative approach not only presents a green and straightforward lignin fractionation process but also highlights the untapped potential of lignin in the realm of sun protection applications.

Investigating the Optimal Duration of the Sun Exposure for Adequate Cutaneous Synthesis of Vitamin D3 in Baghdad City: Depending on Fitzpatrick Skin Classification for Different Skin Types

     Vitamin D3 deficiency is regarded as a public health issue in Iraq, particularly during the winter. Sun exposure is the main source of vitamin D3, where the surface ultraviolet (UV) radiation plays an important role in human health. The amount of time that must be spent in the sun each day was determined for the amount of exposed skin, for all skin types, with and without sunscreen under clear sky conditions in the city of Baghdad (Long 44.375, Lat 33.375). UV index data was obtained by TEMIS satellite during the year 2021. From data analysis, we found that most days during the year were within the high level of ultraviolet radiation values ​​in the city of Baghdad, and most of them were during the summer, where the person needed less time of exposure to sunlight to obtain vitamin D3 in the case of exposing the face and hands or the whole body. As a result, it can be concluded that the amount of UV radiation is affected by several factors: depending on latitude, day of the year, time of day and the season, body area exposed to the radiation, and use of sun protection factor. These factors influence the time of sun exposure required to initiate cutaneous vitamin D3 synthesis.

New insights into greener skin healthcare protection: Lignin nanoparticles as additives to develop natural-based sunscreens with high UV protection

Despite lignin nanoparticles (LNPs) being extensively employed as assistant agents to improve the UV-blocking performance of sunscreens, there is a lack of information addressing how and to what extent the chemical and structural features of these particles relate to the improvements observed in the Sun Protection Factors (SPF) of the sunscreens. In this study, lignin oligomers were prepared by a solvothermal extraction process of five typical biomasses in a water–acetone co-solvent without noticeable degradation of the cellulose fraction. Afterward, LNPs were produced from the self-assembly of these lignin oligomers via the solvent-shifting methodology. When incorporated into the sunscreen, these had different morphologies, and exerted different UV-blocking capacities. The effects of the chemical structure and size distribution of the LNPs were systematically studied and compared to those of the original lignin oligomers. LNPs exhibited better UV-blocking ability than soluble lignin oligomers due to the more exposed chromophore on the surface. Besides, compact LNPs with conjugating CO and β-O-4 linkages, as well as the presence of the syringyl unit rich in the methoxyl group in the structures, were beneficial in boosting the UV resistance of the sunscreens. Even though smaller LNPs with higher surface area favored the UV shielding performance, LNPs with widely distributed sizes could further help decrease the UV transmittance. These findings provide an excellent basis for using lignin-derived materials as sunscreen additives and pave the way to developing new environmentally friendly materials for the cosmetic industry.

Assessing the safety and efficacy of DIY-homemade sunscreens with natural, aromatic and herbal ingredients

Sunscreen products are widely used during the summer months to protect against increased sunlight exposure. While there have been advancements in the effectiveness and safety of commercial sunscreens, there is a growing interest in "completely natural" and homemade skincare products, including sunscreens. These homemade alternatives often incorporating aromatic and medicinal herbal preparations, are being touted as safe alternatives on online social media platforms and alternative health websites. It is essential to recognize that scientific research has primarily focused on evaluating the effectiveness and safety of commercially available sunscreen products. Concerns have arisen regarding the potential risks associated with non-commercial sunscreens, particularly those labeled as "homemade" or "completely natural." Therefore, it is crucial to investigate whether these DIY sunscreen products, advertised as natural and additive-free, pose any health threats due to their inadequate sun protection properties. This study aims to examine the formulations of these proposed homemade sunscreen products, specifically evaluating their durability, protection against ultraviolet A and B (UVA and UVB) radiation, and average sun protection factor (SPF) values from a toxicological perspective. Emphasizing the importance of safety in sunscreen products is paramount, as the use of unsafe sunscreens can lead to serious health risks, including skin cancer, premature aging, and other skin disorders.

Exploration of photoprotective and antibiotic activity of wild Polypodiaceae ferns from Costa Rica

Skin disorders affect millions of people all over the world. There are limited options to treat dermal illnesses such as vitiligo, psoriasis, and atopic dermatitis (eczema). Central American ferns are a potential source of bioactive metabolites against those diseases. Currently, Polypodium leucotomos Poir. is the only one being commercially utilized for this purpose. In this work, we evaluated the concentration of the skin bioactive compounds: quinic and chlorogenic acid, in the extract of 20 wild ferns from Costa Rica. We also evaluated the antimicrobial capabilities of the crude extracts of wild ferns and the sun protection factor (SPF) of the extracts. We found 19 out of 20 have either an important concentration of the compounds mentioned above or antimicrobial properties. Also, most samples result in higher SPF than P. aureum’s rhizome. We also have studied the fern acclimatization, at different shading conditions, finding a significant influence of the culturing conditions on metabolite production. After acclimatization. So far, we demonstrate that various ferns included in this study are a potential source of treatments for skin conditions.