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51,915 result(s) for "sunscreens"
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A Comparative Study of Cerium Phosphates for Sunscreens
Crystalline cerium(III) phosphate (CePO[sub.4]), cerium(IV) phosphates, and nanocrystalline ceria are considered to be promising components of sunscreen cosmetics. This paper reports on a study in which, for the first time, a quantitative comparative analysis was performed of the UV-shielding properties of CePO[sub.4], Ce(PO[sub.4])(HPO[sub.4])[sub.0.5](H[sub.2]O)[sub.0.5], and CePO[sub.4]/CeO[sub.2] composites. Both the sun protection factor and protection factor against UV-A radiation of the materials were determined. Ce(PO[sub.4])(HPO[sub.4])[sub.0.5](H[sub.2]O)[sub.0.5] was shown to have a sun protection factor of 2.9, which is comparable with that of nanocrystalline ceria and three times higher than the sun protection factor of CePO[sub.4]. Composites containing both cerium dioxide and CePO[sub.4] demonstrated higher sun protection factors (up to 1.8) than individual CePO[sub.4]. When compared with the TiO[sub.2] Aeroxide P25 reference sample, cerium(III) and cerium(IV) phosphates demonstrated negligible photocatalytic activity. A cytotoxicity analysis performed using two mammalian cell lines, hMSc and NCTC L929, showed that CePO[sub.4], Ce(PO[sub.4])(HPO[sub.4])[sub.0.5](H[sub.2]O)[sub.0.5], and nanocrystalline ceria were all non-toxic. The results of this comparative study indicate that cerium(IV) phosphate Ce(PO[sub.4])(HPO[sub.4])[sub.0.5](H[sub.2]O)[sub.0.5] is more advantageous for use in sunscreens than either cerium(III) phosphate or CePO[sub.4]/CeO[sub.2] composites, due to its improved UV-shielding properties and low photocatalytic activity.
Influence of Five Drying Methods on Active Compound Contents and Bioactivities of Fresh Flowers from ISyringa pubescens/I Turcz
The flower of Syringa pubescens Turcz. is used in Chinese folk medicine and also as a flower tea for healthcare. The effects of five drying methods on the active compound contents, the antioxidant abilities, anti-inflammatory properties and enzyme inhibitory activities were evaluated. The plant materials were treated using shade-drying, microwave-drying, sun-drying, infrared-drying and oven-drying. The seven active compounds were simultaneously determined using an HPLC method. Furthermore, the chemical profile was assessed using scanning electron microscopy, ultraviolet spectroscopy and infrared spectroscopy. The antioxidant capacities and protective effects on L02 cells induced with hydrogen peroxide were measured. The anti-inflammatory effects on lipopolysaccharide-induced RAW264.7 cells were investigated. The enzyme inhibitory activities were determined against α-amylase, α-glucosidase cholinesterases and tyrosinase. The results indicated that drying methods had significant influences on the active compound contents and biological properties. Compared with other samples, the OD samples possessed low IC[sub.50] values with 0.118 ± 0.004 mg/mL for DPPH radical, 1.538 ± 0.0972 for hydroxyl radical and 0.886 ± 0.199 mg/mL for superoxide radical, while the SHD samples had stronger reducing power compared with other samples. The SHD samples could be effective against H[sub.2]O[sub.2]-induced injury on L02 cells by the promoting of T-AOC, GSH-PX, SOD and CAT activities and the reducing of MDA content compared with other samples. Furthermore, SPF samples, especially the SHD sample, could evidently ameliorate inflammation through the inhibition of IL-6, IL-1β and TNF-α expression. All the studied SPF samples exhibited evidently inhibitory effects on the four enzymes. The IC[sub.50] values of inhibitory activity on α-glucosidase and α-amylase from SHD sample were 2.516 ± 0.024 and 0.734 ± 0.034 mg/mL, respectively. SD samples had potential inhibitory effects on cholinesterases and tyrosinase with IC[sub.50] values of 3.443 ± 0.060 and 1.732 ± 0.058 mg/mL. In consideration of active compound contents and biological activities, it was recommended that SHD and SD be applied for drying SPF at an industrial scale.
Investigating the use of titanium dioxide (TiO2) nanoparticles on the amount of protection against UV irradiation
In this study, three samples of commercial titanium dioxide nanoparticles (TiO 2 ) in different sizes were used to investigate their effect on the formulation of sunscreen creams. The aim was to evaluate their role in the performance of sunscreens (i.e. SPF, UVAPF, and critical wavelength). Then the particle size of these samples was determined by photon correlation spectroscopy methods. As a result, the size of primary particles was reduced by using milling and homogenization methods at different times. The results showed that the particle size of samples TA, TB, and TC in the ultrasonic homogenizer decreased from 966.4, 2745.8, and 2471.6 nm to 142.6, 254.8, and 262.8 nm, respectively. These particles were used in the pristine formulation. Then the functional characteristics of each formulation were determined by standard methods. TA had the best dispersion in cream compared to other samples due to its smaller size (i.e. 142.6 nm). For each formulation, two important parameters, including pH and TiO 2 dosage, were investigated in different states. The results showed that the formulations prepared with TA had the lowest viscosity compared to formulations containing TB and TC. SPSS 17 statistical software analysis of variance showed that the performance of SPF, UVAPF and λc in formulations containing TA had the highest levels. Also, the sample containing TAU with the lowest particle size values had the highest protection against UV rays (SPF). According to the photocatalytic functionality of TiO 2 , the photodegradation of methylene blue in the presence of each nanoparticle of TiO 2 was studied. The results showed that smaller nanoparticles (i.e. TA) had more photocatalytic activity under UV–Vis irradiation during 4 h (TA (22%) > TB (16%) > TC (15%)). The results showed that titanium dioxide can be used as a suitable filter against all types of UVA and UVB rays.
The Study of the Effectiveness of Ethyl methyl hydroxypyridin e Succinate in Acute Alcohol Intoxication
The effectiveness of ethylmethylhydroxypyridine succinate (EMHPS) in acute alcohol intoxication was tested in a study on SPF male outbred ICR mice. Ethanol (concentration 40%) was administered to animals once intraperitoneally at a dose of 4 g/kg. Control animals were injected with saline in an equivalent volume. In 15 min after the administration of alcohol, the animals were injected intravenously or intramuscularly with EMHPS at a dose of 50 or 100 mg/kg or with saline via the same route in an equivalent volume. Animal behavior was tested 3 and 24 h later after administration of the substances. After 3 and 24 h, mice in the pathological control groups developed semiptosis, the gait and the turning over reflex were impaired, the strength of the hind limbs decreased and the distance between the hind limbs increased when landing; in the open-field test, the latency of the first movement increased, and the number of rearing postures decreased. Intravenous and intramuscular administration of EMHPS in doses of 50 and 100 mg/kg had a pronounced antitoxic and neuroprotective effect in acute alcohol intoxication: all studied parameters did not differ significantly from the control. Key Words: ethylmethylhydroxypyridine succinate; Mexidol; acute alcohol intoxication; SPF outbred mice ICR
Sunscreens Cause Coral Bleaching by Promoting Viral Infections
Background: Coral bleaching (i.e., the release of coral symbiotic zooxanthellae) has negative impacts on biodiversity and functioning of reef ecosystems and their production of goods and services. This increasing world-wide phenomenon is associated with temperature anomalies, high irradiance, pollution, and bacterial diseases. Recently, it has been demonstrated that personal care products, including sunscreens, have an impact on aquatic organisms similar to that of other contaminants. Objectives: Our goal was to evaluate the potential impact of sunscreen ingredients on hard corals and their symbiotic algae. Methods: In situ and laboratory experiments were conducted in several tropical regions (the Atlantic, Indian, and Pacific Oceans, and the Red Sea) by supplementing coral branches with aliquots of sunscreens and common ultraviolet filters contained in sunscreen formula. Zooxanthellae were checked for viral infection by epifluorescence and transmission electron microscopy analyses. Results: Sunscreens cause the rapid and complete bleaching of hard corals, even at extremely low concentrations. The effect of sunscreens is due to organic ultraviolet filters, which are able to induce the lytic viral cycle in symbiotic zooxanthellae with latent infections. Conclusions: We conclude that sunscreens, by promoting viral infection, potentially play an important role in coral bleaching in areas prone to high levels of recreational use by humans.
Can you make sunscreen at home?
Influencer Nara Smith and her husband Lucky Blue Smith showed their audience how they make sunscreen at home. We tried to see if it’ll actually protect you from the sun.
In Vitro Antioxidant, Photoprotective, and Volatile Compound Profile of Supercritical COsub.2 Extracts from Dandelion Flowers
This study aimed to develop a sustainable approach for isolating bioactive lipophilic components from Taraxacum officinale flowers using supercritical carbon dioxide extraction (SFE-CO[sub.2]) and to assess the effect of adding 5% ethanol (EtOH) as a co-solvent on extraction yield, in vitro antioxidant capacity in CUPRAC and ABTS assays (TEAC[sub.CUPRAC] and TEAC[sub.ABTS]), total phenolic (TPC) and flavonoid (TFC) content, β-carotene concentration, and photoprotective potential, expressed as the sun protection factor (SPF). SFE-CO[sub.2] at 35 MPa and 40 °C resulted in 50% of the total yield within 15 min, with equilibrium reached after 120 min (final yield of 4.6 g/100 g flowers). Co-solvent addition increased yield by ~50% and shortened extraction time. The EtOH-modified extract exhibited markedly higher antioxidant activity, with a 2-fold increase in TEAC[sub.CUPRAC] (167 mg TE/g E), an 11-fold increase in TEAC[sub.ABTS] (194 mg TE/g E), and a 3-fold increase in TPC (91 mg GAE/g E), along with improved recovery of flavonoids and β-carotene. Volatile profiling revealed monoterpenoids, aldehydes, and esters as dominant groups, with carvone (14.0–16.5%) and dill ether (4.2–5.8%) as major contributors to aroma. The SFE-CO[sub.2] + 5% EtOH extract achieved the highest SPF value (49.5 at 1 mg/mL; SPF > 6 at >0.1 mg/mL), indicating strong photoprotective potential and potential suitability for natural antioxidant and cosmetic applications.
RP-18 TLC and Computational Descriptors of Skin Permeability of Sunscreens
The relationships between the reversed-phase thin layer chromatographic retention parameters obtained on octadecyl-modified silica (RP-18) sorbent for mobile phases containing water and one of six water-miscible organic modifiers (acetone, methanol, acetonitrile, tetrahydrofurane, N,N-dimethylformamide, 1,4-dioxane) and skin permeability coefficients were studied for a group of 21 cosmetic raw materials, mainly organic sunscreens and preservatives. The correlations between the skin permeability coefficients log K d calculated in silico using EpiSuite software and the RP-18 thin layer chromatographic retention parameters are mostly linear, especially for compounds of lower-to-medium lipophilicity. It was established that skin permeability coefficient models based on retention parameters collected for mobile phases containing acetone or dioxane (75% v/v), proposed for structurally unrelated cosmetic raw materials are also applicable to other actives, as shown using a test set of compounds whose in vivo log K d data are available. Skin permeability models developed in this study have the benefit of being based on easily obtained, chromatographic descriptors and their applicability extends beyond cosmetic chemistry.
Update on photoprotection
Photoprotection by sunscreens, clothing and glasses are important to protect the skin against the detrimental effects of sun exposure. In order to achieve complete protection, topical strategies must shield against the range of solar wavelengths ultraviolet A, ultraviolet B, infrared radiation that can damage the skin. To provide the necessary broad spectrum coverage, combinations of chemical and physical UV filters along with molecules that are capable of interfering with and/or preventing the deleterious effects of sunlight are discussed in this review.