In vitro Assessment of Solar Filters for Erythropoietic Protoporphyria in the Action Spectrum of Protoporphyrin IX

Introduction: Subjects with erythropoietic protoporphyria rely on broad-spectrum sunscreens with high sun protection factor, which is not informative on efficacy in the absorption spectrum of protoporphyrin IX, spanning visible radiation and peaking around 408 nm. Photoactivation of protoporphyrin IX is responsible for painful skin photosensitivity in erythropoietic protoporphyria.The authors assessed the protective efficacy of six sunscreens in vitro in the absorption spectrum of protoporphyrin IX.Method: Transmittance measurements were performed in the 300–850 nm wavelengths on samples of six photoprotective products applied to polymethyl methacrylate plates. Porphyrin protection factor was calculated in the 300–700 nm region to provide a measurement for the efficacy of each product based on the action spectrum of protoporphyrin IX.Results: Product A showed the highest porphyrin protection factor among tested products with a median value of 4.22. Product A is a sunscreen containing organic filters, titanium dioxide and synthetic iron oxides, pigmentary grade active ingredients that absorb visible radiation. Other products showed inefficient protection in the visible, with transmittance between 75 and 95% at 500 nm. The low porphyrin protection factor of inorganic filter product B was attributed to particle micronization, as declared by the manufacturer.Conclusion: Adding porphyrin protection factor to sunscreen labeling could help patients with erythropoietic protoporphyria and other photosensitivity disorders identify products tailored on their specific needs. The development of sunscreens providing protection from visible radiation and excellent cosmetical tolerability could improve the lifestyle of patients with erythropoietic protoporphyria.

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Congenital Erythropoietic Protoporphyria

Blood ◽

10.1182/blood.v22.5.532.532 ◽

1963 ◽

Vol 22 (5) ◽

pp. 532-544 ◽

Cited By ~ 11

Author(s):

F. STANLEY PORTER

Keyword(s):

Bone Marrow ◽

Inborn Error ◽

Protoporphyrin Ix ◽

Human Bone ◽

Inborn Error Of Metabolism ◽

Human Bone Marrow ◽

Erythropoietic Protoporphyria ◽

In Vitro Synthesis ◽

Basic Defect

Abstract Investigations into the pathophysiology of erythropoietic protoporphyria suggest that the basic defect is an inborn error of metabolism resulting in the overproduction of protoporphyrin IX by the bone marrow not in response to a failure of heme synthesis. A method is described for evaluating the in vitro synthesis of protoporphyrin and heme by human bone marrow.

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Pigment Migration and Adaptation in the Eye of the Squid, Loligo pealei

The Journal of General Physiology ◽

10.1085/jgp.63.1.22 ◽

1974 ◽

Vol 63 (1) ◽

pp. 22-36 ◽

Cited By ~ 35

Author(s):

N. W. Daw ◽

A. L. Pearlman

Keyword(s):

Absorption Spectrum ◽

Time Course ◽

Action Spectrum ◽

Indirect Evidence ◽

Screening Pigment ◽

Pigment Migration ◽

Optic Nerve Response ◽

Loligo Pealei ◽

Outward Migration

The migration of the screening pigment was investigated in the retina of the intact squid. The action spectrum of pigment migration corresponds to the action spectrum of the visual pigment, rhodopsin, rather than to the absorption spectrum of the screening pigment. The total number of quanta required for a fixed criterion of pigment migration is the same, when the quanta are delivered over any period of time from 6 s to an hour or more. When less than 3–10% of the rhodopsin is isomerized, the screening pigment migrates out to the tips of the receptors with a time-course of 5–15 min, and back again over the same period of time. When rather more than 10% is isomerized, the outward migration takes 5–15 min, but the screening pigment does not migrate inwards, even after several hours in the dark. Indirect evidence suggests that the band of screening pigment, when it reaches the tips of the receptors, is approximately equivalent to a filter of 0.6 log units. The spectral sensitivity of the optic nerve response was measured, and was found to be broader than the absorption spectrum of squid rhodopsin in vitro; the broadness could be explained by self-screening, assuming a density of rhodopsin of 0.6 log units at 500 nm.

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SUN PROTECTION FACTOR DETERMINATION STUDIES OF SOME SUNSCREEN FORMULATIONS USED IN COSMETICS FOR THEIR SELECTION

Journal of Drug Delivery and Therapeutics ◽

10.22270/jddt.v8i5-s.1924 ◽

2018 ◽

Vol 8 (5-s) ◽

pp. 149-151 ◽

Cited By ~ 1

Author(s):

Masheer Ahmed Khan

Keyword(s):

Sun Protection ◽

Protection Factor ◽

Dynamic View ◽

Laboratory Measure ◽

In Vitro Assessment ◽

Sun Protection Factor ◽

Uv Dose ◽

Selection Of

The study involves determination of sun protection factor (SPF) values of some sunscreen formulations for their use in cosmetics. The Sun Protection Factor (SPF) is a very popular instrument in the marketing of sunscreens. Sun protection factor is a laboratory measure of the effectiveness of sunscreen, the higher the SPF, the more protection a sunscreen offers against the ultraviolet radiations causing sunburn. It is often not understood how sunscreens work and where the limitations of the SPF are. A lot of aspects of the SPF are confusing, e.g. the race for higher and higher numbers, the effect on SPF when less sunscreen is applied and if sunscreen should be used at all because they may block the Vitamin D synthesis. The study explains how sunscreens work, how the SPF is determined and where the limitations of the current methods exist. The dynamic view of 'UV radiation applied' and the 'UV dose transmitted' through the sunscreen onto the skin as well as onto a substrate in vitro help in the understanding and are also promising approaches in the in vitro assessment. The study is helpful in selection of some sunscreens formulations used in cosmetics with better safety and high SPF values. Keywords: Sun Protection Factor, SPF, Sunscreens

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In vitro assessment of immunomodulatory and anti-Campylobacter activities of probiotic lactobacilli

Scientific Reports ◽

10.1038/s41598-019-54494-3 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 4

Author(s):

Khaled Taha-Abdelaziz ◽

Jake Astill ◽

Raveendra R. Kulkarni ◽

Leah R. Read ◽

Afsaneh Najarian ◽

...

Keyword(s):

Broiler Chickens ◽

Protective Efficacy ◽

Intestinal Epithelial ◽

Inhibitory Effects ◽

Autoinducer 2 ◽

Human Intestinal Epithelial Cells ◽

In Vitro Assessment ◽

Ifn Γ ◽

Probiotic Lactobacilli

AbstractThe present study was undertaken to assess the antimicrobial activity of Lactobacillus spp. (L. salivarius, L. johnsonii, L. reuteri, L. crispatus, and L. gasseri) against Campylobacter jejuni as well as their immunomodulatory capabilities. The results demonstrated that lactobacilli exhibit differential antagonistic effects against C. jejuni and vary in their ability to elicit innate responses in chicken macrophages. All lactobacilli exerted inhibitory effects on C. jejuni growth, abrogated the production of the quorum sensing molecule autoinducer-2 (AI-2) by C. jejuni and inhibited the invasion of C. jejuni in human intestinal epithelial cells. Additionally, all lactobacilli, except L. reuteri, significantly reduced the expression of virulence-related genes in C. jejuni, including genes responsible for motility (flaA, flaB, and flhA), invasion (ciaB), and AI-2 production (luxS). All lactobacilli enhanced C. jejuni phagocytosis by macrophages and increased the expression of interferon (IFN)-γ, interleukin (IL)-1β, IL-12p40, IL-10, and chemokine (CXCLi2) in macrophages. Furthermore, L. salivarius, L. reuteri, L. crispatus, and a mixture of all lactobacilli significantly increased expression of the co-stimulatory molecules CD40, CD80, and CD86 in macrophages. In conclusion, these findings demonstrate that lactobacilli possess anti-Campylobacter and immunomodulatory activities. Further studies are needed to assess their protective efficacy against intestinal colonization by C. jejuni in broiler chickens.

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