Nanoformulations of quercetin: a potential phytochemical for the treatment of uv radiation induced skin damages

Abstract The continuous prolonged exposures of sun light especially the ultra violet (UV) radiation present in it, cause not only the risk of skin cancer but also it may cause premature skin aging, photodermatoses and actinic keratoses. Flavonoids (including Flavane, Flavanone, Flavone, Flavonol, Isoflavone, Neoflavone etc.) having potent antioxidant activity, used as topical applications for protection against UV induced skin damages as well as for skin care. Most commonly used flavonoid is quercetin (Flavonol), which is present in fruits, vegetables, and herbs. We aim to review the research focused on development of different novel formulations to treat UV radiations induced skin diseases. In this review, several formulations of flavonoid quercetin were discussed and their outcomes were compiled and compared in context to solubility, stability and efficiency of application. On the basis this comparative analysis we have concluded that three formulations, namely glycerosomes, nanostructured lipid carriers and deformable liposomes hold good applications for future aspects for topical delivery of quercetin. These formulations showed enhanced stability, increased quercetin accumulation in different skin layers, facilitated drug permeation in skin and long-lasting drug release.

Dermatitis de contacto fotoalérgica y test de fotoparches: revisión de la literatura y aplicación de la técnica en clínica alemana de Santiago / Photoallergic contact dermatitis and test photopatches: literature review and application of the technique at clínica alemana de Santiago

Las fotodermatosis son un conjunto de patologías cutáneas originadas o agravadas por exposición a radiación ya sea solar o artificial. Se clasifican en cuatro categorías: 1. Idiopáticas o mediadas inmunológicamente 2. Dermatosis fotoagravadas, 3. Fotosensibilidad inducida por agentes y 4. Trastornos por reparación defectuosa del ADN. La fotosensibilidad inducida por agentes consiste en reacciones secundarias a la exposición de ciertos químicos, llamados fotosensibilizadores y a distintos tipos de radiación lumínica. Los fotosensibilizadores pueden ser de origen endógeno o exógeno, aquellos exógenos provienen desde el ambiente, fármacos u otros productos (tanto sistémicos como tópicos), los cuales sufren modificaciones estructurales al entrar en contacto con radiación, provocando como consecuencia, distintas manifestaciones cutáneas. En este artículo se revisarán principalmente las reacciones fototóxicas y fotoalérgicas (ambas, reacciones de fotosensibilidad inducidas por agentes exógenos) indagando en sus diferencias y el enfrentamiento clínico de cada una. También, se revisarán los exámenes que permiten estudiar los distintos diagnósticos diferenciales, especialmente el test de fotoparches, el cual está cobrando cada vez más importancia en la práctica clínica.

Photodermatoses are a group of skin diseases induced or aggravated by exposure to radiation, whether solar or artificial. They are classified into four general categories: 1. Idiopathic or immunologically mediated photodermatoses 2. Photoexacerbated dermatoses 3. Agent induced photosensitivity 4. DNA repair defects Photosensitivity induced by agents are secondary reactions to the exposure to some chemicals, called photosensitizers, and to different types of light radiation. Photosensitizers can be classified as exogenous or endogenous. Exogenous agents come from the environment, drugs or other products (both systemic and topical), which undergo structural changes when they come into contact with radiation, causing different skin manifestations as consequence. Differences between phototoxic and photoallergic reactions (both photosensitivity reactions induced by exogenous agents), the clinical approach of each one of them, and available tests that are used to make a diagnosis, especially, photo patch test will be reviewed in this article

Porfiria cutánea tarda: revisión de la literatura a propósito de un caso / Porphyria cutanea tarda: a case report and literature review

La porfiria cutánea tarda (PCT) es el tipo más frecuente de porfiria, conjunto de enfermedades metabólicas, sistémicas, caracterizadas por una alteración en la síntesis del grupo hemo. La PCT se considera parte de las fotodermatosis, y puede subdividirse en variedad familiar o esporádica. El principal factor precipitante es el consumo excesivo de alcohol, y se manifiesta clínicamente como fragilidad cutánea con formación de vesículas en zonas fotoexpuestas, principalmente dorso de manos y cara, con prurito ocasional en zonas afectadas. En algunos casos se puede ver hipertricosis facial e hiperpigmentación. No presenta síntomas sistémicos. La cuantificación de porfirinas en orina confirma el diagnóstico. Se puede tratar con medidas generales, sangrías y/o antimaláricos en dosis bajas, con buena respuesta. Puede recurrir después de meses o años, por lo que requiere control de por vida. Se presenta el reporte de un caso con características clínicas clásicas y revisión bibliográfica actualizada de esta entidad.

Porphyria cutanea tarda (PCT) is the most common type of porphyria, a group of systemic metabolic diseases, characterized by defects in the heme production. PCT is considered amongst the photodermatoses, and may be classified as familial or sporadic. The main precipitating factor is excessive alcohol consumption, and it presents clinically with skin fragility and vesicle formation on photoexposed areas, mainly the back of the hands and face. Some patients may show hypertrichosis, hyperpigmentation, and pruritus. There are no systemic symptoms associated with this condition. Quantification of porphyrins in urine confirms the diagnosis. Treatment options include general measures, blood letting, and/or low dose antimalarials, usually with good results. This disease may recur months or years after treatment, determining the need for lifelong follow-up. We present a case with a classical clinical presentation, along with an updated review of the literature.

Photosensitive spongiotic/lichenoid eruption of micropapules and plaques: A morphologically distinct entity.

Background: A distinct morphological pattern of photodermatosis has been observed with shiny skin colored to hypopigmented tiny papules, discrete or coalescing to form plaques. Aims: To study the clinico-pathological features of patients presenting with these lesions. Methods: A total of 72 patients were recruited. Clinical examination and skin biopsy was carried out to evaluate the morphological patterns and the histopathological features. Results: In all patients, tiny discrete to coalescent papules were observed on sun-exposed sites but usually sparing the face. The condition occurred more commonly in women. Three specific histopathological patterns were observed : 0 spongiotic (43.7%), lichenoid (22.5%), psoriasiform (18.7%) and also perivascular pattern in 5%. Conclusion: Photosensitive lichenoid eruption is a morphologically distinct photodermatoses that is commonly seen in Indian patients with pathological features showing mostly spongiotic changes and in some cases lichenoid changes.

Photodermatoses in India.

Photodermatoses are a group of disorders resulting from abnormal cutaneous reactions to solar radiation. They include idiopathic photosensitive disorders, drug or chemical induced photosensitivity reactions, DNA repair-deficiency photodermatoses and photoaggravated dermatoses. The pathophysiology differs in these disorders but photoprotection is the most integral part of their management. Photoprotection includes wearing photoprotective clothing, applying broad spectrum sunscreens and avoiding photosensitizing drugs and chemicals.