Topical isoflavones provide effective photoprotection to skin. Photodermatol Photoimmunol Photomed
Isoflavones, one main group of phytoestrogens, have antioxidative and photoprotective effects in cellular and mouse studies. The aim of this study is to obtain a more comprehensive understanding of the isoflavone-mediated photoprotection with the pig skin model, a more human-resembling model.
The pig skin was treated with five well-known isoflavone compounds (genistein, equol, daidzein, biochanin A, and formononetin) and one antioxidant combination solution of 15% vitamin C and 1% vitamin E and 0.5% ferulic acid (CEF) daily for 4 days. Skin was irradiated with solar-simulated UV irradiation, 1 to 5 minimal erythema dose (MED) at 1-MED intervals. Evaluation was carried out 24 h later by colorimeter-measured erythema and sunburn cell numbers.
Topical application of 0.5% solutions of three individual phytoestrogens - genistein, daidzein, biochanin A - are better than similar solutions of equol or formononetin in protecting pig skin from solar-simulated ultraviolet (SSUV)-induced photodamage, as measured by sunburn cell formation and/or erythema. However, the protection was less than that provided by a topical combination antioxidant standard containing 15% L-ascorbic acid, 1%alpha-tocopherol, and 0.5% ferulic acid.
Isoflavones provide effective photoprotection and are good candidate ingredients for protection against ultraviolet (UV) photodamage.
Available from: Barbara Iovine
- "Our results are consistent with recent studies on the effects exerted by genistein and other isoflavones in combined formulations. Recently, it has been demonstrated that the topical application of solutions containing 0.5% of four individual isoflavones (genistein, daidzein, biochanin A and formononetin) photo-protects pig skin from either UV-induced sunburn cell formation and/or erythema The authors to investigate the mechanism of action, examine ethanolic solutions of isoflavones for their UV absorption and use the erythema response and sunburn cell numbers in pig skin to evaluate the photo-protective effect of isoflavone . In addition, the isoflavone aglycone forms have poor solubility in water and oil; thus, a special galenic mixture is necessary to introduce these isoflavone preparations into cosmetic formulations. "
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ABSTRACT: Isoflavones exist in nature predominantly as glucosides such as daidzin or genistin and are rarely found in their corresponding aglycone forms daidzein and genistein. The metabolism and absorption of isoflavones ingested with food is well documented, but little is known about their use as topical photo-protective agents. The aim of this study was to investigate in a comparative analysis the photo-protective effects of isoflavones in both their aglycone and glucoside forms. In human skin fibroblasts irradiated with 60 mJ/cm2 ultraviolet B (UVB), we measured the expression levels of COX-2 and Gadd45, which are involved in inflammation and DNA repair, respectively. We also determined the cellular response to UVB-induced DNA damage using the comet assay. Our findings suggest that both the isoflavone glucosides at a specific concentration and combination with an aglycone mixture exerted an anti-inflammatory and photo-protective effect that prevented 41% and 71% of UVB-induced DNA damage, respectively. The advantages of using either isoflavone glucosides or an aglycone mixture in applications in the field of dermatology will depend on their properties and their different potential uses.
- "Isoflavones (genistein, equol, daidzein, biochanin A, and formononetin) were formulated as 0.5% individual isoflavone solutions, and the photoprotection with the pig skin model was compared with one antioxidant combination solution of 15% vitamin C and 1% vitamin E and 0.5% ferulic acid. The results show that the protection was less than that provided by the topical antioxidant combination, but nevertheless the isoflavones provide effective photoprotection and are good candidate ingredients for protection against UV photodamage. "
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ABSTRACT: Reactive oxygen species (ROS) and free radicals have been implicated in a number of diseases and disorders, and the skin, for its localization, is exposed to a large number of environmental threats. Free radical scavengers and antioxidants have thus been proposed as protective or therapeutic agents against ROS-mediated injuries. Oral treatment with several antioxidants has been reported to provide skin protection against deleterious effects of ultraviolet radiation. Topical delivery of antioxidants has increasingly gained interest and development, especially by offering better targeting to the upper skin layer. However, the topical delivery of antioxidants for dermal action is a challenging research field since the molecules are, in general, susceptible to degradation. The search for a new delivery system that, simultaneously, preserves the antioxidant stability and enhances its deposition on the skin, opened a new chapter in drug delivery design. Nanocarriers have been successful in enhancing the clinical efficiency of several drugs. More recent approaches in modulating through the skin delivery led to the development of specialized nanoparticulated systems. The first part of this article presents a review of the potential of antioxidants as pharmacological agents in ROS related diseases, with a special focus on oxidative stress implicated skin pathologies: ROS formation and natural protection against ROS toxicity, ROS-mediated skin damage and skin protection by antioxidants. In the second part of this work, we present reported formulation strategies for dermal delivery of antioxidants focusing on the nanoparticulated systems developed in recent years.
Available from: Giuseppe Monfrecola
- "Similarly, topical application of genistein before UVB radiation dose-dependently reduced c-fos and c-jun expression in the mouse skin . More recently, topical genistein treatment of mouse skin was found to protect against UVBinduced oxidative DNA damage , and to exert antioxidant and anticarcinogenic effects in the skin of hairless mice . The other isoflavone, daidzein, is just as effective as genistein in protecting cells against oxidative DNA damage . "
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ABSTRACT: The anti-inflammatory effects and antioxidant activities of individual isoflavones are well established although little is known about the photoprotective effect of their combination. The aim of this study was to investigate the photoprotective effects of different concentrations of genistein and daidzein individually or combined. We measured the expression levels of the cyclo-oxygenase-2 (COX-2) and growth arrest and DNA-damage inducible (Gadd45) genes, which are involved in inflammation and DNA repair, respectively, in BJ-5ta human skin fibroblasts irradiated with 60 mJ/cm(2) UVB. We also determined the cellular response to UVB-induced DNA damage by Comet assay. We report that genistein and daidzein when administered combined, and at a specific concentration and ratio, exerted a synergistic photoprotective effect that was greater than the effect obtained with each isoflavone alone. The results reported herein suggest that low concentrations of genistein and daidzein combined may be good candidate ingredients for protective agents against UV-induced photodamage.
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